summaryrefslogtreecommitdiffstats
path: root/src/qt3support/canvas/q3canvas.cpp
blob: 89e128976244fff2d0afa24c16b7cec848d661a6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (qt-info@nokia.com)
**
** This file is part of the Qt3Support module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at qt-sales@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/

#include "q3canvas.h"
#include "qapplication.h"
#include "qbitmap.h"
#include "qdesktopwidget.h"
#include "qimage.h"
#include "q3ptrdict.h"
#include "qpainter.h"
#include "q3polygonscanner.h"
#include "qtimer.h"
#include "q3tl.h"

#include <stdlib.h>

QT_BEGIN_NAMESPACE

using namespace Qt;

class Q3CanvasData {
public:
    Q3CanvasData() :
	itemDict(1013), animDict(503)
    {
    }

    Q3PtrList<Q3CanvasView> viewList;
    Q3PtrDict<void> itemDict;
    Q3PtrDict<void> animDict;
};

class Q3CanvasViewData {
public:
    Q3CanvasViewData() {}
#ifndef QT_NO_TRANSFORMATIONS
    QMatrix xform;
    QMatrix ixform;
#endif
    QRegion eraseRegion;
};

// clusterizer

class Q3CanvasClusterizer {
public:
    Q3CanvasClusterizer(int maxclusters);
    ~Q3CanvasClusterizer();

    void add(int x, int y); // 1x1 rectangle (point)
    void add(int x, int y, int w, int h);
    void add(const QRect& rect);

    void clear();
    int clusters() const { return count; }
    const QRect& operator[](int i) const;

private:
    QRect* cluster;
    int count;
    const int maxcl;
};

static
void include(QRect& r, const QRect& rect)
{
    if (rect.left()<r.left()) {
	    r.setLeft(rect.left());
    }
    if (rect.right()>r.right()) {
	    r.setRight(rect.right());
    }
    if (rect.top()<r.top()) {
	    r.setTop(rect.top());
    }
    if (rect.bottom()>r.bottom()) {
	    r.setBottom(rect.bottom());
    }
}

/*
A Q3CanvasClusterizer groups rectangles (QRects) into non-overlapping rectangles
by a merging heuristic.
*/
Q3CanvasClusterizer::Q3CanvasClusterizer(int maxclusters) :
    cluster(new QRect[maxclusters]),
    count(0),
    maxcl(maxclusters)
{ }

Q3CanvasClusterizer::~Q3CanvasClusterizer()
{
    delete [] cluster;
}

void Q3CanvasClusterizer::clear()
{
    count=0;
}

void Q3CanvasClusterizer::add(int x, int y)
{
    add(QRect(x,y,1,1));
}

void Q3CanvasClusterizer::add(int x, int y, int w, int h)
{
    add(QRect(x,y,w,h));
}

void Q3CanvasClusterizer::add(const QRect& rect)
{
    QRect biggerrect(rect.x()-1,rect.y()-1,rect.width()+2,rect.height()+2);

    //Q_ASSERT(rect.width()>0 && rect.height()>0);

    int cursor;

    for (cursor=0; cursor<count; cursor++) {
	if (cluster[cursor].contains(rect)) {
	    // Wholly contained already.
	    return;
	}
    }

    int lowestcost=9999999;
    int cheapest=-1;
    cursor = 0;
    while(cursor<count) {
	if (cluster[cursor].intersects(biggerrect)) {
	    QRect larger=cluster[cursor];
	    include(larger,rect);
	    int cost = larger.width()*larger.height() -
		       cluster[cursor].width()*cluster[cursor].height();

	    if (cost < lowestcost) {
		bool bad=false;
		for (int c=0; c<count && !bad; c++) {
		    bad=cluster[c].intersects(larger) && c!=cursor;
		}
		if (!bad) {
		    cheapest=cursor;
		    lowestcost=cost;
		}
	    }
	}
	cursor++;
    }

    if (cheapest>=0) {
	include(cluster[cheapest],rect);
	return;
    }

    if (count < maxcl) {
	cluster[count++]=rect;
	return;
    }

    // Do cheapest of:
    //     add to closest cluster
    //     do cheapest cluster merge, add to new cluster

    lowestcost=9999999;
    cheapest=-1;
    cursor=0;
    while(cursor<count) {
	QRect larger=cluster[cursor];
	include(larger,rect);
	int cost=larger.width()*larger.height()
		- cluster[cursor].width()*cluster[cursor].height();
	if (cost < lowestcost) {
	    bool bad=false;
	    for (int c=0; c<count && !bad; c++) {
		bad=cluster[c].intersects(larger) && c!=cursor;
	    }
	    if (!bad) {
		cheapest=cursor;
		lowestcost=cost;
	    }
	}
	cursor++;
    }

    // ###
    // could make an heuristic guess as to whether we need to bother
    // looking for a cheap merge.

    int cheapestmerge1 = -1;
    int cheapestmerge2 = -1;

    int merge1 = 0;
    while(merge1 < count) {
	int merge2=0;
	while(merge2 < count) {
	    if(merge1!=merge2) {
		QRect larger=cluster[merge1];
		include(larger,cluster[merge2]);
		int cost=larger.width()*larger.height()
		    - cluster[merge1].width()*cluster[merge1].height()
		    - cluster[merge2].width()*cluster[merge2].height();
		if (cost < lowestcost) {
		    bool bad=false;
		    for (int c=0; c<count && !bad; c++) {
			bad=cluster[c].intersects(larger) && c!=cursor;
		    }
		    if (!bad) {
			cheapestmerge1=merge1;
			cheapestmerge2=merge2;
			lowestcost=cost;
		    }
		}
	    }
	    merge2++;
	}
	merge1++;
    }

    if (cheapestmerge1>=0) {
	include(cluster[cheapestmerge1],cluster[cheapestmerge2]);
	cluster[cheapestmerge2]=cluster[count--];
    } else {
	// if (!cheapest) debugRectangles(rect);
	include(cluster[cheapest],rect);
    }

    // NB: clusters do not intersect (or intersection will
    //     overwrite). This is a result of the above algorithm,
    //     given the assumption that (x,y) are ordered topleft
    //     to bottomright.

    // ###
    //
    // add explicit x/y ordering to that comment, move it to the top
    // and rephrase it as pre-/post-conditions.
}

const QRect& Q3CanvasClusterizer::operator[](int i) const
{
    return cluster[i];
}

// end of clusterizer

// there's no more device coordinate clipping done, so introduce these
// clip setting compat functions

static void qt_setclipregion(QPainter *p, const QRegion &r)
{
    QMatrix matrix = p->worldMatrix();
    p->setWorldMatrix(QMatrix());
    p->setClipRegion(r);
    p->setWorldMatrix(matrix);
}

static void qt_setcliprect(QPainter *p, const QRect &r)
{
    qt_setclipregion(p, QRegion(r));
}


class Q_COMPAT_EXPORT Q3CanvasItemPtr {
public:
    Q3CanvasItemPtr() : ptr(0) { }
    Q3CanvasItemPtr(Q3CanvasItem* p) : ptr(p) { }

    bool operator<=(const Q3CanvasItemPtr& that) const
    {
	// Order same-z objects by identity.
	if (that.ptr->z()==ptr->z())
	    return that.ptr <= ptr;
	return that.ptr->z() <= ptr->z();
    }
    bool operator<(const Q3CanvasItemPtr& that) const
    {
	// Order same-z objects by identity.
	if (that.ptr->z()==ptr->z())
	    return that.ptr < ptr;
	return that.ptr->z() < ptr->z();
    }
    bool operator>(const Q3CanvasItemPtr& that) const
    {
	// Order same-z objects by identity.
	if (that.ptr->z()==ptr->z())
	    return that.ptr > ptr;
	return that.ptr->z() > ptr->z();
    }
    bool operator==(const Q3CanvasItemPtr& that) const
    {
	    return that.ptr == ptr;
    }
    operator Q3CanvasItem*() const { return ptr; }

private:
    Q3CanvasItem* ptr;
};


/*!
    \class Q3CanvasItemList
    \compat
    \brief The Q3CanvasItemList class is a list of Q3CanvasItems.

    Q3CanvasItemList is a Q3ValueList of pointers to \l{Q3CanvasItem}s.
    This class is used by some methods in Q3Canvas that need to return
    a list of canvas items.

    The \l Q3ValueList documentation describes how to use this list.

    \sa QtCanvas, {Porting to Graphics View}
*/

/*!
  \internal
*/
void Q3CanvasItemList::sort()
{
    qHeapSort(*((Q3ValueList<Q3CanvasItemPtr>*)this));
}

/*!
  \internal
*/
void Q3CanvasItemList::drawUnique(QPainter& painter)
{
    Q3CanvasItem* prev=0;
    for (Iterator it=fromLast(); it!=end(); --it) {
	Q3CanvasItem *g=*it;
	if (g!=prev) {
	    g->draw(painter);
	    prev=g;
	}
    }
}

/*!
    Returns the concatenation of this list and list \a l.
*/
Q3CanvasItemList Q3CanvasItemList::operator+(const Q3CanvasItemList &l) const
{
    Q3CanvasItemList l2(*this);
    for(const_iterator it = l.begin(); it != l.end(); ++it)
       l2.append(*it);
    return l2;
}

class Q3CanvasChunk {
public:
    Q3CanvasChunk() : changed(true) { }
    // Other code assumes lists are not deleted. Assignment is also
    // done on ChunkRecs. So don't add that sort of thing here.

    void sort()
    {
	list.sort();
    }

    const Q3CanvasItemList* listPtr() const
    {
	return &list;
    }

    void add(Q3CanvasItem* item)
    {
	list.prepend(item);
	changed = true;
    }

    void remove(Q3CanvasItem* item)
    {
	list.remove(item);
	changed = true;
    }

    void change()
    {
	changed = true;
    }

    bool hasChanged() const
    {
	return changed;
    }

    bool takeChange()
    {
	bool y = changed;
	changed = false;
	return y;
    }

private:
    Q3CanvasItemList list;
    bool changed;
};


static int gcd(int a, int b)
{
    int r;
    while ((r = a%b)) {
	a=b;
	b=r;
    }
    return b;
}

static int scm(int a, int b)
{
    int g = gcd(a,b);
    return a/g*b;
}



/*!
    \class Q3Canvas
    \compat
    \brief The Q3Canvas class provides a 2D area that can contain Q3CanvasItem objects.

    The Q3Canvas class manages its 2D graphic area and all the canvas
    items the area contains. The canvas has no visual appearance of
    its own. Instead, it is displayed on screen using a Q3CanvasView.
    Multiple Q3CanvasView widgets may be associated with a canvas to
    provide multiple views of the same canvas.

    The canvas is optimized for large numbers of items, particularly
    where only a small percentage of the items change at any
    one time. If the entire display changes very frequently, you should
    consider using your own custom Q3ScrollView subclass.

    Qt provides a rich
    set of canvas item classes, e.g. Q3CanvasEllipse, Q3CanvasLine,
    Q3CanvasPolygon, Q3CanvasPolygonalItem, Q3CanvasRectangle, Q3CanvasSpline,
    Q3CanvasSprite and Q3CanvasText. You can subclass to create your own
    canvas items; Q3CanvasPolygonalItem is the most common base class used
    for this purpose.

    Items appear on the canvas after their \link Q3CanvasItem::show()
    show()\endlink function has been called (or \link
    Q3CanvasItem::setVisible() setVisible(true)\endlink), and \e after
    update() has been called. The canvas only shows items that are
    \link Q3CanvasItem::setVisible() visible\endlink, and then only if
    \l update() is called. (By default the canvas is white and so are
    canvas items, so if nothing appears try changing colors.)

    If you created the canvas without passing a width and height to
    the constructor you must also call resize().

    Although a canvas may appear to be similar to a widget with child
    widgets, there are several notable differences:

    \list
    \i Canvas items are usually much faster to manipulate and redraw than
    child widgets, with the speed advantage becoming especially great when
    there are \e many canvas items and non-rectangular items. In most
    situations canvas items are also a lot more memory efficient than child
    widgets.

    \i It's easy to detect overlapping items (collision detection).

    \i The canvas can be larger than a widget. A million-by-million canvas
    is perfectly possible. At such a size a widget might be very
    inefficient, and some window systems might not support it at all,
    whereas Q3Canvas scales well. Even with a billion pixels and a million
    items, finding a particular canvas item, detecting collisions, etc.,
    is still fast (though the memory consumption may be prohibitive
    at such extremes).

    \i Two or more Q3CanvasView objects can view the same canvas.

    \i An arbitrary transformation matrix can be set on each Q3CanvasView
    which makes it easy to zoom, rotate or shear the viewed canvas.

    \i Widgets provide a lot more functionality, such as input (QKeyEvent,
    QMouseEvent etc.) and layout management (QGridLayout etc.).

    \endlist

    A canvas consists of a background, a number of canvas items organized by
    x, y and z coordinates, and a foreground. A canvas item's z coordinate
    can be treated as a layer number -- canvas items with a higher z
    coordinate appear in front of canvas items with a lower z coordinate.

    The background is white by default, but can be set to a different color
    using setBackgroundColor(), or to a repeated pixmap using
    setBackgroundPixmap() or to a mosaic of smaller pixmaps using
    setTiles(). Individual tiles can be set with setTile(). There
    are corresponding get functions, e.g. backgroundColor() and
    backgroundPixmap().

    Note that Q3Canvas does not inherit from QWidget, even though it has some
    functions which provide the same functionality as those in QWidget. One
    of these is setBackgroundPixmap(); some others are resize(), size(),
    width() and height(). \l Q3CanvasView is the widget used to display a
    canvas on the screen.

    Canvas items are added to a canvas by constructing them and passing the
    canvas to the canvas item's constructor. An item can be moved to a
    different canvas using Q3CanvasItem::setCanvas().

    Canvas items are movable (and in the case of Q3CanvasSprites, animated)
    objects that inherit Q3CanvasItem. Each canvas item has a position on the
    canvas (x, y coordinates) and a height (z coordinate), all of which are
    held as floating-point numbers. Moving canvas items also have x and y
    velocities. It's possible for a canvas item to be outside the canvas
    (for example Q3CanvasItem::x() is greater than width()). When a canvas
    item is off the canvas, onCanvas() returns false and the canvas
    disregards the item. (Canvas items off the canvas do not slow down any
    of the common operations on the canvas.)

    Canvas items can be moved with Q3CanvasItem::move(). The advance()
    function moves all Q3CanvasItem::animated() canvas items and
    setAdvancePeriod() makes Q3Canvas move them automatically on a periodic
    basis. In the context of the Q3Canvas classes, to `animate' a canvas item
    is to set it in motion, i.e. using Q3CanvasItem::setVelocity(). Animation
    of a canvas item itself, i.e. items which change over time, is enabled
    by calling Q3CanvasSprite::setFrameAnimation(), or more generally by
    subclassing and reimplementing Q3CanvasItem::advance(). To detect collisions
    use one of the Q3CanvasItem::collisions() functions.

    The changed parts of the canvas are redrawn (if they are visible in a
    canvas view) whenever update() is called. You can either call update()
    manually after having changed the contents of the canvas, or force
    periodic updates using setUpdatePeriod(). If you have moving objects on
    the canvas, you must call advance() every time the objects should
    move one step further. Periodic calls to advance() can be forced using
    setAdvancePeriod(). The advance() function will call
    Q3CanvasItem::advance() on every item that is \link
    Q3CanvasItem::animated() animated\endlink and trigger an update of the
    affected areas afterwards. (A canvas item that is `animated' is simply
    a canvas item that is in motion.)

    Q3Canvas organizes its canvas items into \e chunks; these are areas on
    the canvas that are used to speed up most operations. Many operations
    start by eliminating most chunks (i.e. those which haven't changed)
    and then process only the canvas items that are in the few interesting
    (i.e. changed) chunks. A valid chunk, validChunk(), is one which is on
    the canvas.

    The chunk size is a key factor to Q3Canvas's speed: if there are too many
    chunks, the speed benefit of grouping canvas items into chunks is
    reduced. If the chunks are too large, it takes too long to process each
    one. The Q3Canvas constructor tries to pick a suitable size, but you
    can call retune() to change it at any time. The chunkSize() function
    returns the current chunk size. The canvas items always make sure
    they're in the right chunks; all you need to make sure of is that
    the canvas uses the right chunk size. A good rule of thumb is that
    the size should be a bit smaller than the average canvas item
    size. If you have moving objects, the chunk size should be a bit
    smaller than the average size of the moving items.

    The foreground is normally nothing, but if you reimplement
    drawForeground(), you can draw things in front of all the canvas
    items.

    Areas can be set as changed with setChanged() and set unchanged with
    setUnchanged(). The entire canvas can be set as changed with
    setAllChanged(). A list of all the items on the canvas is returned by
    allItems().

    An area can be copied (painted) to a QPainter with drawArea().

    If the canvas is resized it emits the resized() signal.

    The examples/canvas application and the 2D graphics page of the
    examples/demo application demonstrate many of Q3Canvas's facilities.

    \sa Q3CanvasView Q3CanvasItem, QtCanvas, {Porting to Graphics View}
*/
void Q3Canvas::init(int w, int h, int chunksze, int mxclusters)
{
    d = new Q3CanvasData;
    awidth=w;
    aheight=h;
    chunksize=chunksze;
    maxclusters=mxclusters;
    chwidth=(w+chunksize-1)/chunksize;
    chheight=(h+chunksize-1)/chunksize;
    chunks=new Q3CanvasChunk[chwidth*chheight];
    update_timer = 0;
    bgcolor = white;
    grid = 0;
    htiles = 0;
    vtiles = 0;
    dblbuf = false;
    debug_redraw_areas = false;
}

/*!
    Create a Q3Canvas with no size. \a parent and \a name are passed to
    the QObject superclass.

    \warning You \e must call resize() at some time after creation to
    be able to use the canvas.
*/
Q3Canvas::Q3Canvas(QObject* parent, const char* name)
    : QObject(parent, name)
{
    init(0,0);
}

/*!
    Constructs a Q3Canvas that is \a w pixels wide and \a h pixels high.
*/
Q3Canvas::Q3Canvas(int w, int h)
{
    init(w,h);
}

/*!
    Constructs a Q3Canvas which will be composed of \a h tiles
    horizontally and \a v tiles vertically. Each tile will be an image
    \a tilewidth by \a tileheight pixels taken from pixmap \a p.

    The pixmap \a p is a list of tiles, arranged left to right, (and
    in the case of pixmaps that have multiple rows of tiles, top to
    bottom), with tile 0 in the top-left corner, tile 1 next to the
    right, and so on, e.g.

    \table
    \row \i 0 \i 1 \i 2 \i 3
    \row \i 4 \i 5 \i 6 \i 7
    \endtable

    The Q3Canvas is initially sized to show exactly the given number of
    tiles horizontally and vertically. If it is resized to be larger,
    the entire matrix of tiles will be repeated as often as necessary
    to cover the area. If it is smaller, tiles to the right and bottom
    will not be visible.

    \sa setTiles()
*/
Q3Canvas::Q3Canvas(QPixmap p,
	int h, int v, int tilewidth, int tileheight)
{
    init(h*tilewidth, v*tileheight, scm(tilewidth,tileheight));
    setTiles(p, h, v, tilewidth, tileheight);
}

void qt_unview(Q3Canvas* c)
{
    for (Q3CanvasView* view=c->d->viewList.first(); view != 0; view=c->d->viewList.next()) {
	view->viewing = 0;
    }
}

/*!
    Destroys the canvas and all the canvas's canvas items.
*/
Q3Canvas::~Q3Canvas()
{
    qt_unview(this);
    Q3CanvasItemList all = allItems();
    for (Q3CanvasItemList::Iterator it=all.begin(); it!=all.end(); ++it)
	delete *it;
    delete [] chunks;
    delete [] grid;
    delete d;
}

/*!
\internal
Returns the chunk at a chunk position \a i, \a j.
*/
Q3CanvasChunk& Q3Canvas::chunk(int i, int j) const
{
    return chunks[i+chwidth*j];
}

/*!
\internal
Returns the chunk at a pixel position \a x, \a y.
*/
Q3CanvasChunk& Q3Canvas::chunkContaining(int x, int y) const
{
    return chunk(x/chunksize,y/chunksize);
}

/*!
    Returns a list of all the items in the canvas.
*/
Q3CanvasItemList Q3Canvas::allItems()
{
    Q3CanvasItemList list;
    for (Q3PtrDictIterator<void> it=d->itemDict; it.currentKey(); ++it) {
	list.prepend((Q3CanvasItem*)it.currentKey());
    }
    return list;
}


/*!
    Changes the size of the canvas to have a width of \a w and a
    height of \a h. This is a slow operation.
*/
void Q3Canvas::resize(int w, int h)
{
    if (awidth==w && aheight==h)
	return;

    Q3CanvasItem* item;
    Q3PtrList<Q3CanvasItem> hidden;
    for (Q3PtrDictIterator<void> it=d->itemDict; it.currentKey(); ++it) {
	if (((Q3CanvasItem*)it.currentKey())->isVisible()) {
	    ((Q3CanvasItem*)it.currentKey())->hide();
	    hidden.append(((Q3CanvasItem*)it.currentKey()));
	}
    }

    int nchwidth=(w+chunksize-1)/chunksize;
    int nchheight=(h+chunksize-1)/chunksize;

    Q3CanvasChunk* newchunks = new Q3CanvasChunk[nchwidth*nchheight];

    // Commit the new values.
    //
    awidth=w;
    aheight=h;
    chwidth=nchwidth;
    chheight=nchheight;
    delete [] chunks;
    chunks=newchunks;

    for (item=hidden.first(); item != 0; item=hidden.next()) {
	item->show();
    }

    setAllChanged();

    emit resized();
}

/*!
    \fn void Q3Canvas::resized()

    This signal is emitted whenever the canvas is resized. Each
    Q3CanvasView connects to this signal to keep the scrollview's size
    correct.
*/

/*!
    Change the efficiency tuning parameters to \a mxclusters clusters,
    each of size \a chunksze. This is a slow operation if there are
    many objects on the canvas.

    The canvas is divided into chunks which are rectangular areas \a
    chunksze wide by \a chunksze high. Use a chunk size which is about
    the average size of the canvas items. If you choose a chunk size
    which is too small it will increase the amount of calculation
    required when drawing since each change will affect many chunks.
    If you choose a chunk size which is too large the amount of
    drawing required will increase because for each change, a lot of
    drawing will be required since there will be many (unchanged)
    canvas items which are in the same chunk as the changed canvas
    items.

    Internally, a canvas uses a low-resolution "chunk matrix" to keep
    track of all the items in the canvas. A 64x64 chunk matrix is the
    default for a 1024x1024 pixel canvas, where each chunk collects
    canvas items in a 16x16 pixel square. This default is also
    affected by setTiles(). You can tune this default using this
    function. For example if you have a very large canvas and want to
    trade off speed for memory then you might set the chunk size to 32
    or 64.

    The \a mxclusters argument is the number of rectangular groups of
    chunks that will be separately drawn. If the canvas has a large
    number of small, dispersed items, this should be about that
    number. Our testing suggests that a large number of clusters is
    almost always best.

*/
void Q3Canvas::retune(int chunksze, int mxclusters)
{
    maxclusters=mxclusters;

    if (chunksize!=chunksze) {
	Q3PtrList<Q3CanvasItem> hidden;
	for (Q3PtrDictIterator<void> it=d->itemDict; it.currentKey(); ++it) {
	    if (((Q3CanvasItem*)it.currentKey())->isVisible()) {
		((Q3CanvasItem*)it.currentKey())->hide();
		hidden.append(((Q3CanvasItem*)it.currentKey()));
	    }
	}

	chunksize=chunksze;

	int nchwidth=(awidth+chunksize-1)/chunksize;
	int nchheight=(aheight+chunksize-1)/chunksize;

	Q3CanvasChunk* newchunks = new Q3CanvasChunk[nchwidth*nchheight];

	// Commit the new values.
	//
	chwidth=nchwidth;
	chheight=nchheight;
	delete [] chunks;
	chunks=newchunks;

	for (Q3CanvasItem* item=hidden.first(); item != 0; item=hidden.next()) {
	    item->show();
	}
    }
}

/*!
    \fn int Q3Canvas::width() const

    Returns the width of the canvas, in pixels.
*/

/*!
    \fn int Q3Canvas::height() const

    Returns the height of the canvas, in pixels.
*/

/*!
    \fn QSize Q3Canvas::size() const

    Returns the size of the canvas, in pixels.
*/

/*!
    \fn QRect Q3Canvas::rect() const

    Returns a rectangle the size of the canvas.
*/


/*!
    \fn bool Q3Canvas::onCanvas(int x, int y) const

    Returns true if the pixel position (\a x, \a y) is on the canvas;
    otherwise returns false.

    \sa validChunk()
*/

/*!
    \fn bool Q3Canvas::onCanvas(const QPoint& p) const
    \overload

    Returns true if the pixel position \a p is on the canvas;
    otherwise returns false.

    \sa validChunk()
*/

/*!
    \fn bool Q3Canvas::validChunk(int x, int y) const

    Returns true if the chunk position (\a x, \a y) is on the canvas;
    otherwise returns false.

    \sa onCanvas()
*/

/*!
  \fn bool Q3Canvas::validChunk(const QPoint& p) const
  \overload

  Returns true if the chunk position \a p is on the canvas; otherwise
  returns false.

  \sa onCanvas()
*/

/*!
    \fn int Q3Canvas::chunkSize() const

    Returns the chunk size of the canvas.

    \sa retune()
*/

/*!
\fn bool Q3Canvas::sameChunk(int x1, int y1, int x2, int y2) const
\internal
Tells if the points (\a x1, \a y1) and (\a x2, \a y2) are within the same chunk.
*/

/*!
\internal
This method adds an the item \a item to the list of Q3CanvasItem objects
in the Q3Canvas. The Q3CanvasItem class calls this.
*/
void Q3Canvas::addItem(Q3CanvasItem* item)
{
    d->itemDict.insert((void*)item,(void*)1);
}

/*!
\internal
This method adds the item \a item to the list of Q3CanvasItem objects
to be moved. The Q3CanvasItem class calls this.
*/
void Q3Canvas::addAnimation(Q3CanvasItem* item)
{
    d->animDict.insert((void*)item,(void*)1);
}

/*!
\internal
This method adds the item \a item  to the list of Q3CanvasItem objects
which are no longer to be moved. The Q3CanvasItem class calls this.
*/
void Q3Canvas::removeAnimation(Q3CanvasItem* item)
{
    d->animDict.remove((void*)item);
}

/*!
\internal
This method removes the item \a item from the list of Q3CanvasItem objects
in this Q3Canvas. The Q3CanvasItem class calls this.
*/
void Q3Canvas::removeItem(Q3CanvasItem* item)
{
    d->itemDict.remove((void*)item);
}

/*!
\internal
This method adds the view \a view to the list of Q3CanvasView objects
viewing this Q3Canvas. The Q3CanvasView class calls this.
*/
void Q3Canvas::addView(Q3CanvasView* view)
{
    d->viewList.append(view);
    if (htiles>1 || vtiles>1 || pm.isNull())
	view->viewport()->setBackgroundColor(backgroundColor());
}

/*!
\internal
This method removes the view \a view from the list of Q3CanvasView objects
viewing this Q3Canvas. The Q3CanvasView class calls this.
*/
void Q3Canvas::removeView(Q3CanvasView* view)
{
    d->viewList.removeRef(view);
}

/*!
    Sets the canvas to call advance() every \a ms milliseconds. Any
    previous setting by setAdvancePeriod() or setUpdatePeriod() is
    overridden.

    If \a ms is less than 0 advancing will be stopped.
*/
void Q3Canvas::setAdvancePeriod(int ms)
{
    if (ms<0) {
	if (update_timer)
	    update_timer->stop();
    } else {
	if (update_timer)
	    delete update_timer;
	update_timer = new QTimer(this);
	connect(update_timer,SIGNAL(timeout()),this,SLOT(advance()));
	update_timer->start(ms);
    }
}

/*!
    Sets the canvas to call update() every \a ms milliseconds. Any
    previous setting by setAdvancePeriod() or setUpdatePeriod() is
    overridden.

    If \a ms is less than 0 automatic updating will be stopped.
*/
void Q3Canvas::setUpdatePeriod(int ms)
{
    if (ms<0) {
	if (update_timer)
	    update_timer->stop();
    } else {
	if (update_timer)
	    delete update_timer;
	update_timer = new QTimer(this);
	connect(update_timer,SIGNAL(timeout()),this,SLOT(update()));
	update_timer->start(ms);
    }
}

/*!
    Moves all Q3CanvasItem::animated() canvas items on the canvas and
    refreshes all changes to all views of the canvas. (An `animated'
    item is an item that is in motion; see setVelocity().)

    The advance takes place in two phases. In phase 0, the
    Q3CanvasItem::advance() function of each Q3CanvasItem::animated()
    canvas item is called with paramater 0. Then all these canvas
    items are called again, with parameter 1. In phase 0, the canvas
    items should not change position, merely examine other items on
    the canvas for which special processing is required, such as
    collisions between items. In phase 1, all canvas items should
    change positions, ignoring any other items on the canvas. This
    two-phase approach allows for considerations of "fairness",
    although no Q3CanvasItem subclasses supplied with Qt do anything
    interesting in phase 0.

    The canvas can be configured to call this function periodically
    with setAdvancePeriod().

    \sa update()
*/
void Q3Canvas::advance()
{
    Q3PtrDictIterator<void> it=d->animDict;
    while (it.current()) {
	Q3CanvasItem* i = (Q3CanvasItem*)(void*)it.currentKey();
	++it;
	if (i)
	    i->advance(0);
    }
    // we expect the dict contains the exact same items as in the
    // first pass.
    it.toFirst();
    while (it.current()) {
	Q3CanvasItem* i = (Q3CanvasItem*)(void*)it.currentKey();
	++it;
	if (i)
	    i->advance(1);
    }
    update();
}

// Don't call this unless you know what you're doing.
// p is in the content's co-ordinate example.
/*!
  \internal
*/
void Q3Canvas::drawViewArea(Q3CanvasView* view, QPainter* p, const QRect& vr, bool)
{
    QPoint tl = view->contentsToViewport(QPoint(0,0));

#ifndef QT_NO_TRANSFORMATIONS
    QMatrix wm = view->worldMatrix();
    QMatrix iwm = wm.invert();
    // ivr = covers all chunks in vr
    QRect ivr = iwm.map(vr);
    QMatrix twm;
    twm.translate(tl.x(),tl.y());
#else
    QRect ivr = vr;
#endif

    QRect all(0,0,width(),height());

    if (!all.contains(ivr)) {
	// Need to clip with edge of canvas.

#ifndef QT_NO_TRANSFORMATIONS
	// For translation-only transformation, it is safe to include the right
	// and bottom edges, but otherwise, these must be excluded since they
	// are not precisely defined (different bresenham paths).
	Q3PointArray a;
	if (wm.m12()==0.0 && wm.m21()==0.0 && wm.m11() == 1.0 && wm.m22() == 1.0)
	    a = Q3PointArray(QRect(all.x(),all.y(),all.width()+1,all.height()+1));
	else
	    a = Q3PointArray(all);

	a = (wm*twm).map(a);
#else
	Q3PointArray a(QRect(all.x(),all.y(),all.width()+1,all.height()+1));
#endif
	if (view->viewport()->backgroundMode() == NoBackground) {
	    QRect cvr = vr; cvr.moveBy(tl.x(),tl.y());
	    qt_setclipregion(p, QRegion(cvr)-QRegion(a));
	    p->fillRect(vr,view->viewport()->palette()
                        .brush(QPalette::Active,QPalette::Window));
	}
	qt_setclipregion(p, a);
    }

    QRect r = vr; r.moveBy(tl.x(),tl.y()); // move to untransformed co-ords
    if (!all.contains(ivr)) {
        QRegion inside = p->clipRegion() & r;
        //QRegion outside = p->clipRegion() - r;
        //p->setClipRegion(outside);
        //p->fillRect(outside.boundingRect(),red);
        qt_setclipregion(p, inside);
    } else {
        qt_setcliprect(p, r);
    }
#ifndef QT_NO_TRANSFORMATIONS
    p->setWorldMatrix(wm*twm);
#else
#endif
    drawCanvasArea(ivr,p,false);
}

/*!
    Repaints changed areas in all views of the canvas.

    \sa advance()
*/
void Q3Canvas::update()
{
    // ##### fix QT_NO_TRANSFORMATIONS
#ifndef QT_NO_TRANSFORMATIONS
    Q3PtrList<QRect> doneareas;
    doneareas.setAutoDelete(true);
#endif

    Q3PtrListIterator<Q3CanvasView> it(d->viewList);
    Q3CanvasView* view;
    while((view=it.current()) != 0) {
	++it;
#ifndef QT_NO_TRANSFORMATIONS
	QMatrix wm = view->worldMatrix();
#endif
	QRect area(view->contentsX(),view->contentsY(),
		   view->visibleWidth(),view->visibleHeight());
	if (area.width()>0 && area.height()>0) {
#ifndef QT_NO_TRANSFORMATIONS
            // r = Visible area of the canvas where there are changes
            QRect r = changeBounds(view->inverseWorldMatrix().map(area));
            if (!r.isEmpty()) {
                QRect tr = wm.map(r);
                tr.moveBy(-view->contentsX(), -view->contentsY());
                view->viewport()->update(tr);
                doneareas.append(new QRect(r));
            }
#endif
	}
    }

#ifndef QT_NO_TRANSFORMATIONS
    for (QRect* r=doneareas.first(); r != 0; r=doneareas.next())
	setUnchanged(*r);
#endif
}


/*!
    Marks the whole canvas as changed.
    All views of the canvas will be entirely redrawn when
    update() is called next.
*/
void Q3Canvas::setAllChanged()
{
    setChanged(QRect(0,0,width(),height()));
}

/*!
    Marks \a area as changed. This \a area will be redrawn in all
    views that are showing it when update() is called next.
*/
void Q3Canvas::setChanged(const QRect& area)
{
    QRect thearea = area.intersected(QRect(0, 0, width(), height()));

    int mx = (thearea.x()+thearea.width()+chunksize)/chunksize;
    int my = (thearea.y()+thearea.height()+chunksize)/chunksize;
    if (mx>chwidth)
	mx=chwidth;
    if (my>chheight)
	my=chheight;

    int x=thearea.x()/chunksize;
    while(x<mx) {
	int y = thearea.y()/chunksize;
	while(y<my) {
	    chunk(x,y).change();
	    y++;
	}
	x++;
    }
}

/*!
    Marks \a area as \e unchanged. The area will \e not be redrawn in
    the views for the next update(), unless it is marked or changed
    again before the next call to update().
*/
void Q3Canvas::setUnchanged(const QRect& area)
{
    QRect thearea = area.intersected(QRect(0, 0, width(), height()));

    int mx = (thearea.x()+thearea.width()+chunksize)/chunksize;
    int my = (thearea.y()+thearea.height()+chunksize)/chunksize;
    if (mx>chwidth)
	mx=chwidth;
    if (my>chheight)
	my=chheight;

    int x=thearea.x()/chunksize;
    while(x<mx) {
	int y = thearea.y()/chunksize;
	while(y<my) {
	    chunk(x,y).takeChange();
	    y++;
	}
	x++;
    }
}


/*!
  \internal
*/
QRect Q3Canvas::changeBounds(const QRect& inarea)
{
    QRect area = inarea.intersected(QRect(0, 0, width(), height()));

    int mx = (area.x()+area.width()+chunksize)/chunksize;
    int my = (area.y()+area.height()+chunksize)/chunksize;
    if (mx > chwidth)
	mx=chwidth;
    if (my > chheight)
	my=chheight;

    QRect result;

    int x=area.x()/chunksize;
    while(x<mx) {
	int y=area.y()/chunksize;
	while(y<my) {
	    Q3CanvasChunk& ch=chunk(x,y);
	    if (ch.hasChanged())
		result |= QRect(x,y,1,1);
	    y++;
	}
	x++;
    }

    if (!result.isEmpty()) {
	result.rLeft() *= chunksize;
	result.rTop() *= chunksize;
	result.rRight() *= chunksize;
	result.rBottom() *= chunksize;
	result.rRight() += chunksize;
	result.rBottom() += chunksize;
    }

    return result;
}

void Q3Canvas::ensureOffScrSize(int osw, int osh)
{
    if (osw > offscr.width() || osh > offscr.height())
	offscr.resize(QMAX(osw,offscr.width()),
		      QMAX(osh,offscr.height()));
    else if (offscr.width() == 0 || offscr.height() == 0)
	offscr.resize(QMAX(offscr.width(), 1),
		       QMAX(offscr.height(), 1));
}

/*!
    Paints all canvas items that are in the area \a clip to \a
    painter, using double-buffering if \a dbuf is true.

    e.g. to print the canvas to a printer:
    \snippet doc/src/snippets/code/src_qt3support_canvas_q3canvas.cpp 0
*/
void Q3Canvas::drawArea(const QRect& clip, QPainter* painter, bool dbuf)
{
    if (painter)
	drawCanvasArea(clip, painter, dbuf);
}

QT_BEGIN_INCLUDE_NAMESPACE
#include <qdebug.h>
QT_END_INCLUDE_NAMESPACE

/*!
  \internal
*/
void Q3Canvas::drawCanvasArea(const QRect& inarea, QPainter* p, bool /*double_buffer*/)
{
    QRect area=inarea.intersected(QRect(0,0,width(),height()));

    if (!p) return; // Nothing to do.

    int lx=area.x()/chunksize;
    int ly=area.y()/chunksize;
    int mx=area.right()/chunksize;
    int my=area.bottom()/chunksize;
    if (mx>=chwidth)
	mx=chwidth-1;
    if (my>=chheight)
	my=chheight-1;

    Q3CanvasItemList allvisible;

    // Stores the region within area that need to be drawn. It is relative
    // to area.topLeft()  (so as to keep within bounds of 16-bit XRegions)
    QRegion rgn;

    for (int x=lx; x<=mx; x++) {
	for (int y=ly; y<=my; y++) {
	    // Only reset change if all views updating, and
	    // wholy within area. (conservative:  ignore entire boundary)
	    //
	    // Disable this to help debugging.
	    //
	    if (!p) {
		if (chunk(x,y).takeChange()) {
		    // ### should at least make bands
		    rgn |= QRegion(x*chunksize-area.x(),y*chunksize-area.y(),
                                   chunksize,chunksize);
		    allvisible += *chunk(x,y).listPtr();
		}
	    } else {
		allvisible += *chunk(x,y).listPtr();
	    }
	}
    }
    allvisible.sort();

    drawBackground(*p,area);
    allvisible.drawUnique(*p);
    drawForeground(*p,area);
}

/*!
\internal
This method to informs the Q3Canvas that a given chunk is
`dirty' and needs to be redrawn in the next Update.

(\a x,\a y) is a chunk location.

The sprite classes call this. Any new derived class of Q3CanvasItem
must do so too. SetChangedChunkContaining can be used instead.
*/
void Q3Canvas::setChangedChunk(int x, int y)
{
    if (validChunk(x,y)) {
	Q3CanvasChunk& ch=chunk(x,y);
	ch.change();
    }
}

/*!
\internal
This method to informs the Q3Canvas that the chunk containing a given
pixel is `dirty' and needs to be redrawn in the next Update.

(\a x,\a y) is a pixel location.

The item classes call this. Any new derived class of Q3CanvasItem must
do so too. SetChangedChunk can be used instead.
*/
void Q3Canvas::setChangedChunkContaining(int x, int y)
{
    if (x>=0 && x<width() && y>=0 && y<height()) {
	Q3CanvasChunk& chunk=chunkContaining(x,y);
	chunk.change();
    }
}

/*!
\internal
This method adds the Q3CanvasItem \a g to the list of those which need to be
drawn if the given chunk at location (\a x, \a y) is redrawn. Like
SetChangedChunk and SetChangedChunkContaining, this method marks the
chunk as `dirty'.
*/
void Q3Canvas::addItemToChunk(Q3CanvasItem* g, int x, int y)
{
    if (validChunk(x,y)) {
	chunk(x,y).add(g);
    }
}

/*!
\internal
This method removes the Q3CanvasItem \a g from the list of those which need to
be drawn if the given chunk at location (\a x, \a y) is redrawn. Like
SetChangedChunk and SetChangedChunkContaining, this method marks the chunk
as `dirty'.
*/
void Q3Canvas::removeItemFromChunk(Q3CanvasItem* g, int x, int y)
{
    if (validChunk(x,y)) {
	chunk(x,y).remove(g);
    }
}


/*!
\internal
This method adds the Q3CanvasItem \a g to the list of those which need to be
drawn if the chunk containing the given pixel (\a x, \a y) is redrawn. Like
SetChangedChunk and SetChangedChunkContaining, this method marks the
chunk as `dirty'.
*/
void Q3Canvas::addItemToChunkContaining(Q3CanvasItem* g, int x, int y)
{
    if (x>=0 && x<width() && y>=0 && y<height()) {
	chunkContaining(x,y).add(g);
    }
}

/*!
\internal
This method removes the Q3CanvasItem \a g from the list of those which need to
be drawn if the chunk containing the given pixel (\a x, \a y) is redrawn.
Like SetChangedChunk and SetChangedChunkContaining, this method
marks the chunk as `dirty'.
*/
void Q3Canvas::removeItemFromChunkContaining(Q3CanvasItem* g, int x, int y)
{
    if (x>=0 && x<width() && y>=0 && y<height()) {
	chunkContaining(x,y).remove(g);
    }
}

/*!
    Returns the color set by setBackgroundColor(). By default, this is
    white.

    This function is not a reimplementation of
    QWidget::backgroundColor() (Q3Canvas is not a subclass of QWidget),
    but all Q3CanvasViews that are viewing the canvas will set their
    backgrounds to this color.

    \sa setBackgroundColor(), backgroundPixmap()
*/
QColor Q3Canvas::backgroundColor() const
{
    return bgcolor;
}

/*!
    Sets the solid background to be the color \a c.

    \sa backgroundColor(), setBackgroundPixmap(), setTiles()
*/
void Q3Canvas::setBackgroundColor(const QColor& c)
{
    if (bgcolor != c) {
	bgcolor = c;
	Q3CanvasView* view=d->viewList.first();
	while (view != 0) {
	    /* XXX this doesn't look right. Shouldn't this
	       be more like setBackgroundPixmap? : Ian */
	    view->viewport()->setEraseColor(bgcolor);
	    view=d->viewList.next();
	}
	setAllChanged();
    }
}

/*!
    Returns the pixmap set by setBackgroundPixmap(). By default,
    this is a null pixmap.

    \sa setBackgroundPixmap(), backgroundColor()
*/
QPixmap Q3Canvas::backgroundPixmap() const
{
    return pm;
}

/*!
    Sets the solid background to be the pixmap \a p repeated as
    necessary to cover the entire canvas.

    \sa backgroundPixmap(), setBackgroundColor(), setTiles()
*/
void Q3Canvas::setBackgroundPixmap(const QPixmap& p)
{
    setTiles(p, 1, 1, p.width(), p.height());
    Q3CanvasView* view = d->viewList.first();
    while (view != 0) {
	view->updateContents();
	view = d->viewList.next();
    }
}

/*!
    This virtual function is called for all updates of the canvas. It
    renders any background graphics using the painter \a painter, in
    the area \a clip. If the canvas has a background pixmap or a tiled
    background, that graphic is used, otherwise the canvas is cleared
    using the background color.

    If the graphics for an area change, you must explicitly call
    setChanged(const QRect&) for the result to be visible when
    update() is next called.

    \sa setBackgroundColor(), setBackgroundPixmap(), setTiles()
*/
void Q3Canvas::drawBackground(QPainter& painter, const QRect& clip)
{
    if (pm.isNull()) {
	painter.fillRect(clip,bgcolor);
    } else if (!grid) {
	for (int x=clip.x()/pm.width();
	    x<(clip.x()+clip.width()+pm.width()-1)/pm.width(); x++)
	{
	    for (int y=clip.y()/pm.height();
		y<(clip.y()+clip.height()+pm.height()-1)/pm.height(); y++)
	    {
		painter.drawPixmap(x*pm.width(), y*pm.height(),pm);
	    }
	}
    } else {
	const int x1 = clip.left()/tilew;
	int x2 = clip.right()/tilew;
	const int y1 = clip.top()/tileh;
	int y2 = clip.bottom()/tileh;

	const int roww = pm.width()/tilew;

	for (int j=y1; j<=y2; j++) {
	    int jj = j%tilesVertically();
	    for (int i=x1; i<=x2; i++) {
		int t = tile(i%tilesHorizontally(), jj);
		int tx = t % roww;
		int ty = t / roww;
		painter.drawPixmap(i*tilew, j*tileh, pm,
				tx*tilew, ty*tileh, tilew, tileh);
	    }
	}
    }
}

/*!
    This virtual function is called for all updates of the canvas. It
    renders any foreground graphics using the painter \a painter, in
    the area \a clip.

    If the graphics for an area change, you must explicitly call
    setChanged(const QRect&) for the result to be visible when
    update() is next called.

    The default is to draw nothing.
*/
void Q3Canvas::drawForeground(QPainter& painter, const QRect& clip)
{
    if (debug_redraw_areas) {
	painter.setPen(red);
	painter.setBrush(NoBrush);
	painter.drawRect(clip);
    }
}

/*!
    If \a y is true (the default) double-buffering is switched on;
    otherwise double-buffering is switched off.

    Turning off double-buffering causes the redrawn areas to flicker a
    little and also gives a (usually small) performance improvement.
*/
void Q3Canvas::setDoubleBuffering(bool y)
{
    dblbuf = y;
}


/*!
    Sets the Q3Canvas to be composed of \a h tiles horizontally and \a
    v tiles vertically. Each tile will be an image \a tilewidth by \a
    tileheight pixels from pixmap \a p.

    The pixmap \a p is a list of tiles, arranged left to right, (and
    in the case of pixmaps that have multiple rows of tiles, top to
    bottom), with tile 0 in the top-left corner, tile 1 next to the
    right, and so on, e.g.

    \table
    \row \i 0 \i 1 \i 2 \i 3
    \row \i 4 \i 5 \i 6 \i 7
    \endtable

    If the canvas is larger than the matrix of tiles, the entire
    matrix is repeated as necessary to cover the whole canvas. If it
    is smaller, tiles to the right and bottom are not visible.

    The width and height of \a p must be a multiple of \a tilewidth
    and \a tileheight. If they are not the function will do nothing.

    If you want to unset any tiling set, then just pass in a null
    pixmap and 0 for \a h, \a v, \a tilewidth, and
    \a tileheight.
*/
void Q3Canvas::setTiles(QPixmap p,
			int h, int v, int tilewidth, int tileheight)
{
    if (!p.isNull() && (!tilewidth || !tileheight ||
	 p.width() % tilewidth != 0 || p.height() % tileheight != 0))
    	return;

    htiles = h;
    vtiles = v;
    delete[] grid;
    pm = p;
    if (h && v && !p.isNull()) {
	grid = new ushort[h*v];
	memset(grid, 0, h*v*sizeof(ushort));
	tilew = tilewidth;
	tileh = tileheight;
    } else {
	grid = 0;
    }
    if (h + v > 10) {
	int s = scm(tilewidth,tileheight);
	retune(s < 128 ? s : QMAX(tilewidth,tileheight));
    }
    setAllChanged();
}

/*!
    \fn int Q3Canvas::tile(int x, int y) const

    Returns the tile at position (\a x, \a y). Initially, all tiles
    are 0.

    The parameters must be within range, i.e.
	0 \< \a x \< tilesHorizontally() and
	0 \< \a y \< tilesVertically().

    \sa setTile()
*/

/*!
    \fn int Q3Canvas::tilesHorizontally() const

    Returns the number of tiles horizontally.
*/

/*!
    \fn int Q3Canvas::tilesVertically() const

    Returns the number of tiles vertically.
*/

/*!
    \fn int Q3Canvas::tileWidth() const

    Returns the width of each tile.
*/

/*!
    \fn int Q3Canvas::tileHeight() const

    Returns the height of each tile.
*/


/*!
    Sets the tile at (\a x, \a y) to use tile number \a tilenum, which
    is an index into the tile pixmaps. The canvas will update
    appropriately when update() is next called.

    The images are taken from the pixmap set by setTiles() and are
    arranged left to right, (and in the case of pixmaps that have
    multiple rows of tiles, top to bottom), with tile 0 in the
    top-left corner, tile 1 next to the right, and so on, e.g.

    \table
    \row \i 0 \i 1 \i 2 \i 3
    \row \i 4 \i 5 \i 6 \i 7
    \endtable

    \sa tile() setTiles()
*/
void Q3Canvas::setTile(int x, int y, int tilenum)
{
    ushort& t = grid[x+y*htiles];
    if (t != tilenum) {
	t = tilenum;
	if (tilew == tileh && tilew == chunksize)
	    setChangedChunk(x, y);	    // common case
	else
	    setChanged(QRect(x*tilew,y*tileh,tilew,tileh));
    }
}


// lesser-used data in canvas item, plus room for extension.
// Be careful adding to this - check all usages.
class Q3CanvasItemExtra {
    Q3CanvasItemExtra() : vx(0.0), vy(0.0) { }
    double vx,vy;
    friend class Q3CanvasItem;
};


/*!
    \class Q3CanvasItem
    \compat
    \brief The Q3CanvasItem class provides an abstract graphic object on a Q3Canvas.

    A variety of Q3CanvasItem subclasses provide immediately usable
    behaviour. This class is a pure abstract superclass providing the
    behaviour that is shared among all the concrete canvas item classes.
    Q3CanvasItem is not intended for direct subclassing. It is much easier
    to subclass one of its subclasses, e.g. Q3CanvasPolygonalItem (the
    commonest base class), Q3CanvasRectangle, Q3CanvasSprite, Q3CanvasEllipse
    or Q3CanvasText.

    Canvas items are added to a canvas by constructing them and passing the
    canvas to the canvas item's constructor. An item can be moved to a
    different canvas using setCanvas().

    Items appear on the canvas after their \link show() show()\endlink
    function has been called (or \link setVisible()
    setVisible(true)\endlink), and \e after update() has been called. The
    canvas only shows items that are \link setVisible() visible\endlink,
    and then only if \l update() is called. If you created the canvas
    without passing a width and height to the constructor you'll also need
    to call \link Q3Canvas::resize() resize()\endlink. Since the canvas
    background defaults to white and canvas items default to white,
    you may need to change colors to see your items.

    A Q3CanvasItem object can be moved in the x(), y() and z() dimensions
    using functions such as move(), moveBy(), setX(), setY() and setZ(). A
    canvas item can be set in motion, `animated', using setAnimated() and
    given a velocity in the x and y directions with setXVelocity() and
    setYVelocity() -- the same effect can be achieved by calling
    setVelocity(). Use the collidesWith() function to see if the canvas item
    will collide on the \e next advance(1) and use collisions() to see what
    collisions have occurred.

    Use Q3CanvasSprite or your own subclass of Q3CanvasSprite to create canvas
    items which are animated, i.e. which change over time.

    The size of a canvas item is given by boundingRect(). Use
    boundingRectAdvanced() to see what the size of the canvas item will be
    \e after the next advance(1) call.

    The rtti() function is used for identifying subclasses of Q3CanvasItem.
    The canvas() function returns a pointer to the canvas which contains the
    canvas item.

    Q3CanvasItem provides the show() and isVisible() functions like those in
    QWidget.

    Q3CanvasItem also provides the setEnabled(), setActive() and
    setSelected() functions; these functions set the relevant boolean and
    cause a repaint but the boolean values they set are not used in
    Q3CanvasItem itself. You can make use of these booleans in your subclasses.

    By default, canvas items have no velocity, no size, and are not in
    motion. The subclasses provided in Qt do not change these defaults
    except where noted.

    \sa QtCanvas, {Porting to Graphics View}
*/

/*!
    \enum Q3CanvasItem::RttiValues

    This enum is used to name the different types of canvas item.

    \value Rtti_Item Canvas item abstract base class
    \value Rtti_Ellipse
    \value Rtti_Line
    \value Rtti_Polygon
    \value Rtti_PolygonalItem
    \value Rtti_Rectangle
    \value Rtti_Spline
    \value Rtti_Sprite
    \value Rtti_Text

*/

/*!
    \fn void Q3CanvasItem::update()

    Call this function to repaint the canvas's changed chunks.
*/

/*!
    Constructs a Q3CanvasItem on canvas \a canvas.

    \sa setCanvas()
*/
Q3CanvasItem::Q3CanvasItem(Q3Canvas* canvas) :
    cnv(canvas),
    myx(0),myy(0),myz(0)
{
    ani=0;
    vis=0;
    val=0;
    sel=0;
    ena=0;
    act=0;

    ext = 0;
    if (cnv) cnv->addItem(this);
}

/*!
    Destroys the Q3CanvasItem and removes it from its canvas.
*/
Q3CanvasItem::~Q3CanvasItem()
{
    if (cnv) {
	cnv->removeItem(this);
	cnv->removeAnimation(this);
    }
    delete ext;
}

Q3CanvasItemExtra& Q3CanvasItem::extra()
{
    if (!ext)
	ext = new Q3CanvasItemExtra;
    return *ext;
}

/*!
    \fn double Q3CanvasItem::x() const

    Returns the horizontal position of the canvas item. Note that
    subclasses often have an origin other than the top-left corner.
*/

/*!
    \fn double Q3CanvasItem::y() const

    Returns the vertical position of the canvas item. Note that
    subclasses often have an origin other than the top-left corner.
*/

/*!
    \fn double Q3CanvasItem::z() const

    Returns the z index of the canvas item, which is used for visual
    order: higher-z items obscure (are in front of) lower-z items.
*/

/*!
    \fn void Q3CanvasItem::setX(double x)

    Moves the canvas item so that its x-position is \a x.

    \sa x(), move()
*/

/*!
    \fn void Q3CanvasItem::setY(double y)

    Moves the canvas item so that its y-position is \a y.

    \sa y(), move()
*/

/*!
    \fn void Q3CanvasItem::setZ(double z)

    Sets the z index of the canvas item to \a z. Higher-z items
    obscure (are in front of) lower-z items.

    \sa z(), move()
*/


/*!
    Moves the canvas item relative to its current position by (\a dx,
    \a dy).
*/
void Q3CanvasItem::moveBy(double dx, double dy)
{
    if (dx || dy) {
	removeFromChunks();
	myx += dx;
	myy += dy;
	addToChunks();
    }
}


/*!
    Moves the canvas item to the absolute position (\a x, \a y).
*/
void Q3CanvasItem::move(double x, double y)
{
    moveBy(x-myx, y-myy);
}


/*!
    Returns true if the canvas item is in motion; otherwise returns
    false.

    \sa setVelocity(), setAnimated()
*/
bool Q3CanvasItem::animated() const
{
    return (bool)ani;
}

/*!
    Sets the canvas item to be in motion if \a y is true, or not if \a
    y is false. The speed and direction of the motion is set with
    setVelocity(), or with setXVelocity() and setYVelocity().

    \sa advance(), Q3Canvas::advance()
*/
void Q3CanvasItem::setAnimated(bool y)
{
    if (y != (bool)ani) {
	ani = (uint)y;
	if (y) {
	    cnv->addAnimation(this);
	} else {
	    cnv->removeAnimation(this);
	}
    }
}

/*!
    \fn void Q3CanvasItem::setXVelocity(double vx)

    Sets the horizontal component of the canvas item's velocity to \a vx.

    \sa setYVelocity() setVelocity()
*/

/*!
    \fn void Q3CanvasItem::setYVelocity(double vy)

    Sets the vertical component of the canvas item's velocity to \a vy.

    \sa setXVelocity() setVelocity()
*/

/*!
    Sets the canvas item to be in motion, moving by \a vx and \a vy
    pixels in the horizontal and vertical directions respectively.

    \sa advance() setXVelocity() setYVelocity()
*/
void Q3CanvasItem::setVelocity(double vx, double vy)
{
    if (ext || vx!=0.0 || vy!=0.0) {
	if (!ani)
	    setAnimated(true);
	extra().vx = vx;
	extra().vy = vy;
    }
}

/*!
    Returns the horizontal velocity component of the canvas item.
*/
double Q3CanvasItem::xVelocity() const
{
    return ext ? ext->vx : 0;
}

/*!
    Returns the vertical velocity component of the canvas item.
*/
double Q3CanvasItem::yVelocity() const
{
    return ext ? ext->vy : 0;
}

/*!
    The default implementation moves the canvas item, if it is
    animated(), by the preset velocity if \a phase is 1, and does
    nothing if \a phase is 0.

    Note that if you reimplement this function, the reimplementation
    must not change the canvas in any way, for example it must not add
    or remove items.

    \sa Q3Canvas::advance() setVelocity()
*/
void Q3CanvasItem::advance(int phase)
{
    if (ext && phase==1)
	moveBy(ext->vx,ext->vy);
}

/*!
    \fn void Q3CanvasItem::draw(QPainter& painter)

    This abstract virtual function draws the canvas item using \a painter.
*/

/*!
    Sets the Q3Canvas upon which the canvas item is to be drawn to \a c.

    \sa canvas()
*/
void Q3CanvasItem::setCanvas(Q3Canvas* c)
{
    bool v=isVisible();
    setVisible(false);
    if (cnv) {
	if (ext)
	    cnv->removeAnimation(this);
	cnv->removeItem(this);
    }
    cnv=c;
    if (cnv) {
	cnv->addItem(this);
	if (ext)
	    cnv->addAnimation(this);
    }
    setVisible(v);
}

/*!
    \fn Q3Canvas* Q3CanvasItem::canvas() const

    Returns the canvas containing the canvas item.
*/

/*! Shorthand for setVisible(true). */
void Q3CanvasItem::show()
{
    setVisible(true);
}

/*! Shorthand for setVisible(false). */
void Q3CanvasItem::hide()
{
    setVisible(false);
}

/*!
    Makes the canvas item visible if \a yes is true, or invisible if
    \a yes is false. The change takes effect when Q3Canvas::update() is
    next called.
*/
void Q3CanvasItem::setVisible(bool yes)
{
    if ((bool)vis!=yes) {
	if (yes) {
	    vis=(uint)yes;
	    addToChunks();
	} else {
	    removeFromChunks();
	    vis=(uint)yes;
	}
    }
}
/*!
    \obsolete
    \fn bool Q3CanvasItem::visible() const
    Use isVisible() instead.
*/

/*!
    \fn bool Q3CanvasItem::isVisible() const

    Returns true if the canvas item is visible; otherwise returns
    false.

    Note that in this context true does \e not mean that the canvas
    item is currently in a view, merely that if a view is showing the
    area where the canvas item is positioned, and the item is not
    obscured by items with higher z values, and the view is not
    obscured by overlaying windows, it would be visible.

    \sa setVisible(), z()
*/

/*!
    \obsolete
    \fn bool Q3CanvasItem::selected() const
    Use isSelected() instead.
*/

/*!
    \fn bool Q3CanvasItem::isSelected() const

    Returns true if the canvas item is selected; otherwise returns false.
*/

/*!
    Sets the selected flag of the item to \a yes. If this changes the
    item's selected state the item will be redrawn when
    Q3Canvas::update() is next called.

    The Q3Canvas, Q3CanvasItem and the Qt-supplied Q3CanvasItem
    subclasses do not make use of this value. The setSelected()
    function is supplied because many applications need it, but it is
    up to you how you use the isSelected() value.
*/
void Q3CanvasItem::setSelected(bool yes)
{
    if ((bool)sel!=yes) {
	sel=(uint)yes;
	changeChunks();
    }
}

/*!
    \obsolete
    \fn bool Q3CanvasItem::enabled() const
    Use isEnabled() instead.
*/

/*!
    \fn bool Q3CanvasItem::isEnabled() const

    Returns true if the Q3CanvasItem is enabled; otherwise returns false.
*/

/*!
    Sets the enabled flag of the item to \a yes. If this changes the
    item's enabled state the item will be redrawn when
    Q3Canvas::update() is next called.

    The Q3Canvas, Q3CanvasItem and the Qt-supplied Q3CanvasItem
    subclasses do not make use of this value. The setEnabled()
    function is supplied because many applications need it, but it is
    up to you how you use the isEnabled() value.
*/
void Q3CanvasItem::setEnabled(bool yes)
{
    if (ena!=(uint)yes) {
	ena=(uint)yes;
	changeChunks();
    }
}

/*!
    \obsolete
    \fn bool Q3CanvasItem::active() const
    Use isActive() instead.
*/

/*!
    \fn bool Q3CanvasItem::isActive() const

    Returns true if the Q3CanvasItem is active; otherwise returns false.
*/

/*!
    Sets the active flag of the item to \a yes. If this changes the
    item's active state the item will be redrawn when
    Q3Canvas::update() is next called.

    The Q3Canvas, Q3CanvasItem and the Qt-supplied Q3CanvasItem
    subclasses do not make use of this value. The setActive() function
    is supplied because many applications need it, but it is up to you
    how you use the isActive() value.
*/
void Q3CanvasItem::setActive(bool yes)
{
    if (act!=(uint)yes) {
	act=(uint)yes;
	changeChunks();
    }
}

bool qt_testCollision(const Q3CanvasSprite* s1, const Q3CanvasSprite* s2)
{
    const QImage* s2image = s2->imageAdvanced()->collision_mask;
    QRect s2area = s2->boundingRectAdvanced();

    QRect cyourarea(s2area.x(),s2area.y(),
	    s2area.width(),s2area.height());

    QImage* s1image=s1->imageAdvanced()->collision_mask;

    QRect s1area = s1->boundingRectAdvanced();

    QRect ourarea = s1area.intersected(cyourarea);

    if (ourarea.isEmpty())
	return false;

    int x2=ourarea.x()-cyourarea.x();
    int y2=ourarea.y()-cyourarea.y();
    int x1=ourarea.x()-s1area.x();
    int y1=ourarea.y()-s1area.y();
    int w=ourarea.width();
    int h=ourarea.height();

    if (!s2image) {
	if (!s1image)
	    return w>0 && h>0;
	// swap everything around
	int t;
	t=x1; x1=x2; x2=t;
	t=y1; x1=y2; y2=t;
	s2image = s1image;
	s1image = 0;
    }

    // s2image != 0

    // A non-linear search may be more efficient.
    // Perhaps spiralling out from the center, or a simpler
    // vertical expansion from the centreline.

    // We assume that sprite masks don't have
    // different bit orders.
    //
    // Q_ASSERT(s1image->bitOrder()==s2image->bitOrder());

    if (s1image) {
	if (s1image->bitOrder() == QImage::LittleEndian) {
	    for (int j=0; j<h; j++) {
		uchar* ml = s1image->scanLine(y1+j);
		const uchar* yl = s2image->scanLine(y2+j);
		for (int i=0; i<w; i++) {
		    if (*(yl + ((x2+i) >> 3)) & (1 << ((x2+i) & 7))
		    && *(ml + ((x1+i) >> 3)) & (1 << ((x1+i) & 7)))
		    {
			return true;
		    }
		}
	    }
	} else {
	    for (int j=0; j<h; j++) {
		uchar* ml = s1image->scanLine(y1+j);
		const uchar* yl = s2image->scanLine(y2+j);
		for (int i=0; i<w; i++) {
		    if (*(yl + ((x2+i) >> 3)) & (1 << (7-((x2+i) & 7)))
		    && *(ml + ((x1+i) >> 3)) & (1 << (7-((x1+i) & 7))))
		    {
			return true;
		    }
		}
	    }
	}
    } else {
	if (s2image->bitOrder() == QImage::LittleEndian) {
	    for (int j=0; j<h; j++) {
		const uchar* yl = s2image->scanLine(y2+j);
		for (int i=0; i<w; i++) {
		    if (*(yl + ((x2+i) >> 3)) & (1 << ((x2+i) & 7)))
		    {
			return true;
		    }
		}
	    }
	} else {
	    for (int j=0; j<h; j++) {
		const uchar* yl = s2image->scanLine(y2+j);
		for (int i=0; i<w; i++) {
		    if (*(yl + ((x2+i) >> 3)) & (1 << (7-((x2+i) & 7))))
		    {
			return true;
		    }
		}
	    }
	}
    }

    return false;
}

static bool collision_double_dispatch(const Q3CanvasSprite* s1,
				       const Q3CanvasPolygonalItem* p1,
				       const Q3CanvasRectangle* r1,
				       const Q3CanvasEllipse* e1,
				       const Q3CanvasText* t1,
				       const Q3CanvasSprite* s2,
				       const Q3CanvasPolygonalItem* p2,
				       const Q3CanvasRectangle* r2,
				       const Q3CanvasEllipse* e2,
				       const Q3CanvasText* t2)
{
    const Q3CanvasItem* i1 = s1 ?
			    (const Q3CanvasItem*)s1 : p1 ?
			    (const Q3CanvasItem*)p1 : r1 ?
			    (const Q3CanvasItem*)r1 : e1 ?
			    (const Q3CanvasItem*)e1 : (const Q3CanvasItem*)t1;
    const Q3CanvasItem* i2 = s2 ?
			    (const Q3CanvasItem*)s2 : p2 ?
			    (const Q3CanvasItem*)p2 : r2 ?
			    (const Q3CanvasItem*)r2 : e2 ?
			    (const Q3CanvasItem*)e2 : (const Q3CanvasItem*)t2;

    if (s1 && s2) {
	// a
	return qt_testCollision(s1,s2);
    } else if ((r1 || t1 || s1) && (r2 || t2 || s2)) {
	// b
	QRect rc1 = i1->boundingRectAdvanced();
	QRect rc2 = i2->boundingRectAdvanced();
	return rc1.intersects(rc2);
    } else if (e1 && e2
		&& e1->angleLength()>=360*16 && e2->angleLength()>=360*16
		&& e1->width()==e1->height()
		&& e2->width()==e2->height()) {
	// c
	double xd = (e1->x()+e1->xVelocity())-(e2->x()+e1->xVelocity());
	double yd = (e1->y()+e1->yVelocity())-(e2->y()+e1->yVelocity());
	double rd = (e1->width()+e2->width())/2;
	return xd*xd+yd*yd <= rd*rd;
    } else if (p1 && (p2 || s2 || t2)) {
	// d
	Q3PointArray pa1 = p1->areaPointsAdvanced();
	Q3PointArray pa2 = p2 ? p2->areaPointsAdvanced()
			  : Q3PointArray(i2->boundingRectAdvanced());
	bool col= !(QRegion(pa1) & QRegion(pa2,true)).isEmpty();

	return col;
    } else {
	return collision_double_dispatch(s2,p2,r2,e2,t2,
					 s1,p1,r1,e1,t1);
    }
}

/*!
    \fn bool Q3CanvasItem::collidesWith(const Q3CanvasItem* other) const

    Returns true if the canvas item will collide with the \a other
    item \e after they have moved by their current velocities;
    otherwise returns false.

    \sa collisions()
*/


/*!
    \class Q3CanvasSprite
    \compat
    \brief The Q3CanvasSprite class provides an animated canvas item on a Q3Canvas.

    A canvas sprite is an object which can contain any number of images
    (referred to as frames), only one of which is current, i.e.
    displayed, at any one time. The images can be passed in the
    constructor or set or changed later with setSequence(). If you
    subclass Q3CanvasSprite you can change the frame that is displayed
    periodically, e.g. whenever Q3CanvasItem::advance(1) is called to
    create the effect of animation.

    The current frame can be set with setFrame() or with move(). The
    number of frames available is given by frameCount(). The bounding
    rectangle of the current frame is returned by boundingRect().

    The current frame's image can be retrieved with image(); use
    imageAdvanced() to retrieve the image for the frame that will be
    shown after advance(1) is called. Use the image() overload passing
    it an integer index to retrieve a particular image from the list of
    frames.

    Use width() and height() to retrieve the dimensions of the current
    frame.

    Use leftEdge() and rightEdge() to retrieve the current frame's
    left-hand and right-hand x-coordinates respectively. Use
    bottomEdge() and topEdge() to retrieve the current frame's bottom
    and top y-coordinates respectively. These functions have an overload
    which will accept an integer frame number to retrieve the
    coordinates of a particular frame.

    Q3CanvasSprite draws very quickly, at the expense of memory.

    The current frame's image can be drawn on a painter with draw().

    Like any other canvas item, canvas sprites can be moved with
    move() which sets the x and y coordinates and the frame number, as
    well as with Q3CanvasItem::move() and Q3CanvasItem::moveBy(), or by
    setting coordinates with Q3CanvasItem::setX(), Q3CanvasItem::setY()
    and Q3CanvasItem::setZ().

    \sa QtCanvas, {Porting to Graphics View}
*/


/*!
  \reimp
*/
bool Q3CanvasSprite::collidesWith(const Q3CanvasItem* i) const
{
    return i->collidesWith(this,0,0,0,0);
}

/*!
    Returns true if the canvas item collides with any of the given
    items; otherwise returns false. The parameters, \a s, \a p, \a r,
    \a e and \a t, are all the same object, this is just a type
    resolution trick.
*/
bool Q3CanvasSprite::collidesWith(const Q3CanvasSprite* s,
				  const Q3CanvasPolygonalItem* p,
				  const Q3CanvasRectangle* r,
				  const Q3CanvasEllipse* e,
				  const Q3CanvasText* t) const
{
    return collision_double_dispatch(s,p,r,e,t,this,0,0,0,0);
}

/*!
  \reimp
*/
bool Q3CanvasPolygonalItem::collidesWith(const Q3CanvasItem* i) const
{
    return i->collidesWith(0,this,0,0,0);
}

bool Q3CanvasPolygonalItem::collidesWith( const Q3CanvasSprite* s,
				 const Q3CanvasPolygonalItem* p,
				 const Q3CanvasRectangle* r,
				 const Q3CanvasEllipse* e,
				 const Q3CanvasText* t) const
{
    return collision_double_dispatch(s,p,r,e,t,0,this,0,0,0);
}

/*!
  \reimp
*/
bool Q3CanvasRectangle::collidesWith(const Q3CanvasItem* i) const
{
    return i->collidesWith(0,this,this,0,0);
}

bool Q3CanvasRectangle::collidesWith( const Q3CanvasSprite* s,
				 const Q3CanvasPolygonalItem* p,
				 const Q3CanvasRectangle* r,
				 const Q3CanvasEllipse* e,
				 const Q3CanvasText* t) const
{
    return collision_double_dispatch(s,p,r,e,t,0,this,this,0,0);
}


/*!
  \reimp
*/
bool Q3CanvasEllipse::collidesWith(const Q3CanvasItem* i) const
{
    return i->collidesWith(0,this,0,this,0);
}

bool Q3CanvasEllipse::collidesWith( const Q3CanvasSprite* s,
				 const Q3CanvasPolygonalItem* p,
				 const Q3CanvasRectangle* r,
				 const Q3CanvasEllipse* e,
				 const Q3CanvasText* t) const
{
    return collision_double_dispatch(s,p,r,e,t,0,this,0,this,0);
}

/*!
  \reimp
*/
bool Q3CanvasText::collidesWith(const Q3CanvasItem* i) const
{
    return i->collidesWith(0,0,0,0,this);
}

bool Q3CanvasText::collidesWith( const Q3CanvasSprite* s,
				 const Q3CanvasPolygonalItem* p,
				 const Q3CanvasRectangle* r,
				 const Q3CanvasEllipse* e,
				 const Q3CanvasText* t) const
{
    return collision_double_dispatch(s,p,r,e,t,0,0,0,0,this);
}

/*!
    Returns the list of canvas items that this canvas item has
    collided with.

    A collision is generally defined as occurring when the pixels of
    one item draw on the pixels of another item, but not all
    subclasses are so precise. Also, since pixel-wise collision
    detection can be slow, this function works in either exact or
    inexact mode, according to the \a exact parameter.

    If \a exact is true, the canvas items returned have been
    accurately tested for collision with the canvas item.

    If \a exact is false, the canvas items returned are \e near the
    canvas item. You can test the canvas items returned using
    collidesWith() if any are interesting collision candidates. By
    using this approach, you can ignore some canvas items for which
    collisions are not relevant.

    The returned list is a list of Q3CanvasItems, but often you will
    need to cast the items to their subclass types. The safe way to do
    this is to use rtti() before casting. This provides some of the
    functionality of the standard C++ dynamic cast operation even on
    compilers where dynamic casts are not available.

    Note that a canvas item may be `on' a canvas, e.g. it was created
    with the canvas as parameter, even though its coordinates place it
    beyond the edge of the canvas's area. Collision detection only
    works for canvas items which are wholly or partly within the
    canvas's area.

    Note that if items have a velocity (see \l setVelocity()), then
    collision testing is done based on where the item \e will be when
    it moves, not its current location. For example, a "ball" item
    doesn't need to actually embed into a "wall" item before a
    collision is detected. For items without velocity, plain
    intersection is used.
*/
Q3CanvasItemList Q3CanvasItem::collisions(bool exact) const
{
    return canvas()->collisions(chunks(),this,exact);
}

/*!
    Returns a list of canvas items that collide with the point \a p.
    The list is ordered by z coordinates, from highest z coordinate
    (front-most item) to lowest z coordinate (rear-most item).
*/
Q3CanvasItemList Q3Canvas::collisions(const QPoint& p) const
{
    return collisions(QRect(p,QSize(1,1)));
}

/*!
    \overload

    Returns a list of items which collide with the rectangle \a r. The
    list is ordered by z coordinates, from highest z coordinate
    (front-most item) to lowest z coordinate (rear-most item).
*/
Q3CanvasItemList Q3Canvas::collisions(const QRect& r) const
{
    Q3CanvasRectangle i(r,(Q3Canvas*)this);
    i.setPen(NoPen);
    i.show(); // doesn't actually show, since we destroy it
    Q3CanvasItemList l = i.collisions(true);
    l.sort();
    return l;
}

/*!
    \overload

    Returns a list of canvas items which intersect with the chunks
    listed in \a chunklist, excluding \a item. If \a exact is true,
    only those which actually \link Q3CanvasItem::collidesWith()
    collide with\endlink \a item are returned; otherwise canvas items
    are included just for being in the chunks.

    This is a utility function mainly used to implement the simpler
    Q3CanvasItem::collisions() function.
*/
Q3CanvasItemList Q3Canvas::collisions(const Q3PointArray& chunklist,
	    const Q3CanvasItem* item, bool exact) const
{
    Q3PtrDict<void> seen;
    Q3CanvasItemList result;
    for (int i=0; i<(int)chunklist.count(); i++) {
	int x = chunklist[i].x();
	int y = chunklist[i].y();
	if (validChunk(x,y)) {
	    const Q3CanvasItemList* l = chunk(x,y).listPtr();
	    for (Q3CanvasItemList::ConstIterator it=l->begin(); it!=l->end(); ++it) {
		Q3CanvasItem *g=*it;
		if (g != item) {
		    if (!seen.find(g)) {
			seen.replace(g,(void*)1);
			if (!exact || item->collidesWith(g))
			    result.append(g);
		    }
		}
	    }
	}
    }
    return result;
}

/*!
  \internal
  Adds the item to all the chunks it covers.
*/
void Q3CanvasItem::addToChunks()
{
    if (isVisible() && canvas()) {
	Q3PointArray pa = chunks();
	for (int i=0; i<(int)pa.count(); i++)
	    canvas()->addItemToChunk(this,pa[i].x(),pa[i].y());
	val=(uint)true;
    }
}

/*!
  \internal
  Removes the item from all the chunks it covers.
*/
void Q3CanvasItem::removeFromChunks()
{
    if (isVisible() && canvas()) {
	Q3PointArray pa = chunks();
	for (int i=0; i<(int)pa.count(); i++)
	    canvas()->removeItemFromChunk(this,pa[i].x(),pa[i].y());
    }
}

/*!
  \internal
  Sets all the chunks covered by the item to be refreshed with Q3Canvas::update()
  is next called.
*/
void Q3CanvasItem::changeChunks()
{
    if (isVisible() && canvas()) {
	if (!val)
	    addToChunks();
	Q3PointArray pa = chunks();
	for (int i=0; i<(int)pa.count(); i++)
	    canvas()->setChangedChunk(pa[i].x(),pa[i].y());
    }
}

/*!
    \fn QRect Q3CanvasItem::boundingRect() const

    Returns the bounding rectangle in pixels that the canvas item covers.

    \sa boundingRectAdvanced()
*/

/*!
    Returns the bounding rectangle of pixels that the canvas item \e
    will cover after advance(1) is called.

    \sa boundingRect()
*/
QRect Q3CanvasItem::boundingRectAdvanced() const
{
    int dx = int(x()+xVelocity())-int(x());
    int dy = int(y()+yVelocity())-int(y());
    QRect r = boundingRect();
    r.moveBy(dx,dy);
    return r;
}

/*!
    \class Q3CanvasPixmap
    \compat
    \brief The Q3CanvasPixmap class provides pixmaps for Q3CanvasSprites.

    If you want to show a single pixmap on a Q3Canvas use a
    Q3CanvasSprite with just one pixmap.

    When pixmaps are inserted into a Q3CanvasPixmapArray they are held
    as Q3CanvasPixmaps. \l{Q3CanvasSprite}s are used to show pixmaps on
    \l{Q3Canvas}es and hold their pixmaps in a Q3CanvasPixmapArray. If
    you retrieve a frame (pixmap) from a Q3CanvasSprite it will be
    returned as a Q3CanvasPixmap.

    The pixmap is a QPixmap and can only be set in the constructor.
    There are three different constructors, one taking a QPixmap, one
    a QImage and one a file name that refers to a file in any
    supported file format (see QImageReader).

    Q3CanvasPixmap can have a hotspot which is defined in terms of an (x,
    y) offset. When you create a Q3CanvasPixmap from a PNG file or from
    a QImage that has a QImage::offset(), the offset() is initialized
    appropriately, otherwise the constructor leaves it at (0, 0). You
    can set it later using setOffset(). When the Q3CanvasPixmap is used
    in a Q3CanvasSprite, the offset position is the point at
    Q3CanvasItem::x() and Q3CanvasItem::y(), not the top-left corner of
    the pixmap.

    Note that for Q3CanvasPixmap objects created by a Q3CanvasSprite, the
    position of each Q3CanvasPixmap object is set so that the hotspot
    stays in the same position.

    \sa Q3CanvasPixmapArray Q3CanvasItem Q3CanvasSprite, QtCanvas, {Porting to Graphics View}
*/

#ifndef QT_NO_IMAGEIO

/*!
    Constructs a Q3CanvasPixmap that uses the image stored in \a
    datafilename.
*/
Q3CanvasPixmap::Q3CanvasPixmap(const QString& datafilename)
{
    QImage image(datafilename);
    init(image);
}

#endif

/*!
    Constructs a Q3CanvasPixmap from the image \a image.
*/
Q3CanvasPixmap::Q3CanvasPixmap(const QImage& image)
{
    init(image);
}
/*!
    Constructs a Q3CanvasPixmap from the pixmap \a pm using the offset
    \a offset.
*/
Q3CanvasPixmap::Q3CanvasPixmap(const QPixmap& pm, const QPoint& offset)
{
    init(pm,offset.x(),offset.y());
}

void Q3CanvasPixmap::init(const QImage& image)
{
    convertFromImage(image);
    hotx = image.offset().x();
    hoty = image.offset().y();
#ifndef QT_NO_IMAGE_DITHER_TO_1
    if(image.hasAlphaBuffer()) {
	QImage i = image.createAlphaMask();
	collision_mask = new QImage(i);
    } else
#endif
	collision_mask = 0;
}

void Q3CanvasPixmap::init(const QPixmap& pixmap, int hx, int hy)
{
    (QPixmap&)*this = pixmap;
    hotx = hx;
    hoty = hy;
    if(pixmap.hasAlphaChannel())  {
	QImage i = mask().convertToImage();
	collision_mask = new QImage(i);
    } else
	collision_mask = 0;
}

/*!
    Destroys the pixmap.
*/
Q3CanvasPixmap::~Q3CanvasPixmap()
{
    delete collision_mask;
}

/*!
    \fn int Q3CanvasPixmap::offsetX() const

    Returns the x-offset of the pixmap's hotspot.

    \sa setOffset()
*/

/*!
    \fn int Q3CanvasPixmap::offsetY() const

    Returns the y-offset of the pixmap's hotspot.

    \sa setOffset()
*/

/*!
    \fn void Q3CanvasPixmap::setOffset(int x, int y)

    Sets the offset of the pixmap's hotspot to (\a x, \a y).

    \warning Do not call this function if any Q3CanvasSprites are
    currently showing this pixmap.
*/

/*!
    \class Q3CanvasPixmapArray
    \compat
    \brief The Q3CanvasPixmapArray class provides an array of Q3CanvasPixmaps.

    This class is used by Q3CanvasSprite to hold an array of pixmaps.
    It is used to implement animated sprites, i.e. images that change
    over time, with each pixmap in the array holding one frame.

    Depending on the constructor you use you can load multiple pixmaps
    into the array either from a directory (specifying a wildcard
    pattern for the files), or from a list of QPixmaps. You can also
    read in a set of pixmaps after construction using readPixmaps().

    Individual pixmaps can be set with setImage() and retrieved with
    image(). The number of pixmaps in the array is returned by
    count().

    Q3CanvasSprite uses an image's mask for collision detection. You
    can change this by reading in a separate set of image masks using
    readCollisionMasks().

    \sa QtCanvas, {Porting to Graphics View}
*/

/*!
    Constructs an invalid array (i.e. isValid() will return false).
    You must call readPixmaps() before being able to use this
    Q3CanvasPixmapArray.
*/
Q3CanvasPixmapArray::Q3CanvasPixmapArray()
: framecount(0), img(0)
{
}

#ifndef QT_NO_IMAGEIO
/*!
    Constructs a Q3CanvasPixmapArray from files.

    The \a fc parameter sets the number of frames to be loaded for
    this image.

    If \a fc is not 0, \a datafilenamepattern should contain "%1",
    e.g. "foo%1.png". The actual filenames are formed by replacing the
    %1 with four-digit integers from 0 to (fc - 1), e.g. foo0000.png,
    foo0001.png, foo0002.png, etc.

    If \a fc is 0, \a datafilenamepattern is asssumed to be a
    filename, and the image contained in this file will be loaded as
    the first (and only) frame.

    If \a datafilenamepattern does not exist, is not readable, isn't
    an image, or some other error occurs, the array ends up empty and
    isValid() returns false.
*/

Q3CanvasPixmapArray::Q3CanvasPixmapArray(const QString& datafilenamepattern,
					int fc)
: framecount(0), img(0)
{
    readPixmaps(datafilenamepattern,fc);
}
#endif

/*!
  \obsolete
  Use Q3CanvasPixmapArray::Q3CanvasPixmapArray(Q3ValueList<QPixmap>, Q3PointArray)
  instead.

  Constructs a Q3CanvasPixmapArray from the list of QPixmaps \a
  list. The \a hotspots list has to be of the same size as \a list.
*/
Q3CanvasPixmapArray::Q3CanvasPixmapArray(Q3PtrList<QPixmap> list, Q3PtrList<QPoint> hotspots) :
    framecount(list.count()),
    img(new Q3CanvasPixmap*[list.count()])
{
    if (list.count() != hotspots.count()) {
	qWarning("Q3CanvasPixmapArray: lists have different lengths");
	reset();
	img = 0;
    } else {
	list.first();
	hotspots.first();
	for (int i=0; i<framecount; i++) {
	    img[i]=new Q3CanvasPixmap(*list.current(), *hotspots.current());
	    list.next();
	    hotspots.next();
	}
    }
}

/*!
    Constructs a Q3CanvasPixmapArray from the list of QPixmaps in the
    \a list. Each pixmap will get a hotspot according to the \a
    hotspots array. If no hotspots are specified, each one is set to
    be at position (0, 0).

    If an error occurs, isValid() will return false.
*/
Q3CanvasPixmapArray::Q3CanvasPixmapArray(Q3ValueList<QPixmap> list, Q3PointArray hotspots) :
    framecount((int)list.size()),
    img(new Q3CanvasPixmap*[list.size()])
{
    bool have_hotspots = (hotspots.size() != 0);
    if (have_hotspots && list.count() != hotspots.count()) {
	qWarning("Q3CanvasPixmapArray: lists have different lengths");
	reset();
	img = 0;
    } else {
	Q3ValueList<QPixmap>::iterator it;
	it = list.begin();
	for (int i=0; i<framecount; i++) {
	    QPoint hs = have_hotspots ? hotspots[i] : QPoint(0, 0);
	    img[i]=new Q3CanvasPixmap(*it, hs);
	    ++it;
	}
    }
}

/*!
    Destroys the pixmap array and all the pixmaps it contains.
*/
Q3CanvasPixmapArray::~Q3CanvasPixmapArray()
{
    reset();
}

void Q3CanvasPixmapArray::reset()
{
    for (int i=0; i<framecount; i++)
	delete img[i];
    delete [] img;
    img = 0;
    framecount = 0;
}

#ifndef QT_NO_IMAGEIO
/*!
    Reads one or more pixmaps into the pixmap array.

    If \a fc is not 0, \a filenamepattern should contain "%1", e.g.
    "foo%1.png". The actual filenames are formed by replacing the %1
    with four-digit integers from 0 to (fc - 1), e.g. foo0000.png,
    foo0001.png, foo0002.png, etc.

    If \a fc is 0, \a filenamepattern is asssumed to be a filename,
    and the image contained in this file will be loaded as the first
    (and only) frame.

    If \a filenamepattern does not exist, is not readable, isn't an
    image, or some other error occurs, this function will return
    false, and isValid() will return false; otherwise this function
    will return true.

    \sa isValid()
*/
bool Q3CanvasPixmapArray::readPixmaps(const QString& filenamepattern,
				      int fc)
{
    return readPixmaps(filenamepattern,fc,false);
}

/*!
    Reads new collision masks for the array.

    By default, Q3CanvasSprite uses the image mask of a sprite to
    detect collisions. Use this function to set your own collision
    image masks.

    If count() is 1 \a filename must specify a real filename to read
    the mask from. If count() is greater than 1, the \a filename must
    contain a "%1" that will get replaced by the number of the mask to
    be loaded, just like Q3CanvasPixmapArray::readPixmaps().

    All collision masks must be 1-bit images or this function call
    will fail.

    If the file isn't readable, contains the wrong number of images,
    or there is some other error, this function will return false, and
    the array will be flagged as invalid; otherwise this function
    returns true.

    \sa isValid()
*/
bool Q3CanvasPixmapArray::readCollisionMasks(const QString& filename)
{
    return readPixmaps(filename,framecount,true);
}


bool Q3CanvasPixmapArray::readPixmaps(const QString& datafilenamepattern,
				      int fc, bool maskonly)
{
    if (!maskonly) {
	reset();
	framecount = fc;
	if (!framecount)
	    framecount=1;
	img = new Q3CanvasPixmap*[framecount];
    }
    if (!img)
        return false;

    bool ok = true;
    bool arg = fc > 1;
    if (!arg)
	framecount=1;
    for (int i=0; i<framecount; i++) {
	QString r;
	r.sprintf("%04d",i);
	if (maskonly) {
            if (!img[i]->collision_mask)
                img[i]->collision_mask = new QImage();
	    img[i]->collision_mask->load(
		arg ? datafilenamepattern.arg(r) : datafilenamepattern);
	    ok = ok
	       && !img[i]->collision_mask->isNull()
	       && img[i]->collision_mask->depth()==1;
	} else {
	    img[i]=new Q3CanvasPixmap(
		arg ? datafilenamepattern.arg(r) : datafilenamepattern);
	    ok = ok && !img[i]->isNull();
	}
    }
    if (!ok) {
	reset();
    }
    return ok;
}
#endif

/*!
  \obsolete

  Use isValid() instead.

  This returns false if the array is valid, and true if it is not.
*/
bool Q3CanvasPixmapArray::operator!()
{
    return img==0;
}

/*!
    Returns true if the pixmap array is valid; otherwise returns
    false.
*/
bool Q3CanvasPixmapArray::isValid() const
{
    return (img != 0);
}

/*!
    \fn Q3CanvasPixmap* Q3CanvasPixmapArray::image(int i) const

    Returns pixmap \a i in the array, if \a i is non-negative and less
    than than count(), and returns an unspecified value otherwise.
*/

// ### wouldn't it be better to put empty Q3CanvasPixmaps in there instead of
// initializing the additional elements in the array to 0? Lars
/*!
    Replaces the pixmap at index \a i with pixmap \a p.

    The array takes ownership of \a p and will delete \a p when the
    array itself is deleted.

    If \a i is beyond the end of the array the array is extended to at
    least i+1 elements, with elements count() to i-1 being initialized
    to 0.
*/
void Q3CanvasPixmapArray::setImage(int i, Q3CanvasPixmap* p)
{
    if (i >= framecount) {
	Q3CanvasPixmap** newimg = new Q3CanvasPixmap*[i+1];
	memcpy(newimg, img, sizeof(Q3CanvasPixmap *)*framecount);
	memset(newimg + framecount, 0, sizeof(Q3CanvasPixmap *)*(i+1 - framecount));
	framecount = i+1;
	delete [] img;
	img = newimg;
    }
    delete img[i]; img[i]=p;
}

/*!
    \fn uint Q3CanvasPixmapArray::count() const

    Returns the number of pixmaps in the array.
*/

/*!
    Returns the x-coordinate of the current left edge of the sprite.
    (This may change as the sprite animates since different frames may
    have different left edges.)

    \sa rightEdge() bottomEdge() topEdge()
*/
int Q3CanvasSprite::leftEdge() const
{
    return int(x()) - image()->hotx;
}

/*!
    \overload

    Returns what the x-coordinate of the left edge of the sprite would
    be if the sprite (actually its hotspot) were moved to x-position
    \a nx.

    \sa rightEdge() bottomEdge() topEdge()
*/
int Q3CanvasSprite::leftEdge(int nx) const
{
    return nx - image()->hotx;
}

/*!
    Returns the y-coordinate of the top edge of the sprite. (This may
    change as the sprite animates since different frames may have
    different top edges.)

    \sa leftEdge() rightEdge() bottomEdge()
*/
int Q3CanvasSprite::topEdge() const
{
    return int(y()) - image()->hoty;
}

/*!
    \overload

    Returns what the y-coordinate of the top edge of the sprite would
    be if the sprite (actually its hotspot) were moved to y-position
    \a ny.

    \sa leftEdge() rightEdge() bottomEdge()
*/
int Q3CanvasSprite::topEdge(int ny) const
{
    return ny - image()->hoty;
}

/*!
    Returns the x-coordinate of the current right edge of the sprite.
    (This may change as the sprite animates since different frames may
    have different right edges.)

    \sa leftEdge() bottomEdge() topEdge()
*/
int Q3CanvasSprite::rightEdge() const
{
    return leftEdge() + image()->width()-1;
}

/*!
    \overload

    Returns what the x-coordinate of the right edge of the sprite
    would be if the sprite (actually its hotspot) were moved to
    x-position \a nx.

    \sa leftEdge() bottomEdge() topEdge()
*/
int Q3CanvasSprite::rightEdge(int nx) const
{
    return leftEdge(nx) + image()->width()-1;
}

/*!
    Returns the y-coordinate of the current bottom edge of the sprite.
    (This may change as the sprite animates since different frames may
    have different bottom edges.)

    \sa leftEdge() rightEdge() topEdge()
*/
int Q3CanvasSprite::bottomEdge() const
{
    return topEdge() + image()->height()-1;
}

/*!
    \overload

    Returns what the y-coordinate of the top edge of the sprite would
    be if the sprite (actually its hotspot) were moved to y-position
    \a ny.

    \sa leftEdge() rightEdge() topEdge()
*/
int Q3CanvasSprite::bottomEdge(int ny) const
{
    return topEdge(ny) + image()->height()-1;
}

/*!
    \fn Q3CanvasPixmap* Q3CanvasSprite::image() const

    Returns the current frame's image.

    \sa frame(), setFrame()
*/

/*!
    \fn Q3CanvasPixmap* Q3CanvasSprite::image(int f) const
    \overload

    Returns the image for frame \a f. Does not do any bounds checking on \a f.
*/

/*!
    Returns the image the sprite \e will have after advance(1) is
    called. By default this is the same as image().
*/
Q3CanvasPixmap* Q3CanvasSprite::imageAdvanced() const
{
    return image();
}

/*!
    Returns the bounding rectangle for the image in the sprite's
    current frame. This assumes that the images are tightly cropped
    (i.e. do not have transparent pixels all along a side).
*/
QRect Q3CanvasSprite::boundingRect() const
{
    return QRect(leftEdge(), topEdge(), width(), height());
}


/*!
  \internal
  Returns the chunks covered by the item.
*/
Q3PointArray Q3CanvasItem::chunks() const
{
    Q3PointArray r;
    int n=0;
    QRect br = boundingRect();
    if (isVisible() && canvas()) {
	int chunksize=canvas()->chunkSize();
	br &= QRect(0,0,canvas()->width(),canvas()->height());
	if (br.isValid()) {
	    r.resize((br.width()/chunksize+2)*(br.height()/chunksize+2));
	    for (int j=br.top()/chunksize; j<=br.bottom()/chunksize; j++) {
		for (int i=br.left()/chunksize; i<=br.right()/chunksize; i++) {
		    r[n++] = QPoint(i,j);
		}
	    }
	}
    }
    r.resize(n);
    return r;
}


/*!
  \internal
  Add the sprite to the chunks in its Q3Canvas which it overlaps.
*/
void Q3CanvasSprite::addToChunks()
{
    if (isVisible() && canvas()) {
	int chunksize=canvas()->chunkSize();
	for (int j=topEdge()/chunksize; j<=bottomEdge()/chunksize; j++) {
	    for (int i=leftEdge()/chunksize; i<=rightEdge()/chunksize; i++) {
		canvas()->addItemToChunk(this,i,j);
	    }
	}
    }
}

/*!
  \internal
  Remove the sprite from the chunks in its Q3Canvas which it overlaps.

  \sa addToChunks()
*/
void Q3CanvasSprite::removeFromChunks()
{
    if (isVisible() && canvas()) {
	int chunksize=canvas()->chunkSize();
	for (int j=topEdge()/chunksize; j<=bottomEdge()/chunksize; j++) {
	    for (int i=leftEdge()/chunksize; i<=rightEdge()/chunksize; i++) {
		canvas()->removeItemFromChunk(this,i,j);
	    }
	}
    }
}

/*!
    The width of the sprite for the current frame's image.

    \sa frame()
*/
//### mark: Why don't we have width(int) and height(int) to be
//consistent with leftEdge() and leftEdge(int)?
int Q3CanvasSprite::width() const
{
    return image()->width();
}

/*!
    The height of the sprite for the current frame's image.

    \sa frame()
*/
int Q3CanvasSprite::height() const
{
    return image()->height();
}


/*!
    Draws the current frame's image at the sprite's current position
    on painter \a painter.
*/
void Q3CanvasSprite::draw(QPainter& painter)
{
    painter.drawPixmap(leftEdge(),topEdge(),*image());
}

/*!
    \class Q3CanvasView
    \compat
    \brief The Q3CanvasView class provides an on-screen view of a Q3Canvas.

    A Q3CanvasView is widget which provides a view of a Q3Canvas.

    If you want users to be able to interact with a canvas view,
    subclass Q3CanvasView. You might then reimplement
    Q3ScrollView::contentsMousePressEvent(). For example:

    \snippet doc/src/snippets/code/src_qt3support_canvas_q3canvas.cpp 1

    The canvas view shows canvas canvas(); this can be changed using
    setCanvas().

    A transformation matrix can be used to transform the view of the
    canvas in various ways, for example, zooming in or out or rotating.
    For example:

    \snippet doc/src/snippets/code/src_qt3support_canvas_q3canvas.cpp 2

    Use setWorldMatrix() to set the canvas view's world matrix: you must
    ensure that the world matrix is invertible. The current world matrix
    is retrievable with worldMatrix(), and its inversion is retrievable
    with inverseWorldMatrix().

    Example:

    The following code finds the part of the canvas that is visible in
    this view, i.e. the bounding rectangle of the view in canvas coordinates.

    \snippet doc/src/snippets/code/src_qt3support_canvas_q3canvas.cpp 3

    \sa QMatrix QPainter::setWorldMatrix(), QtCanvas, {Porting to Graphics View}
*/

/*!
    Constructs a Q3CanvasView with parent \a parent, and name \a name,
    using the widget flags \a f. The canvas view is not associated
    with a canvas, so you must to call setCanvas() to view a
    canvas.
*/
Q3CanvasView::Q3CanvasView(QWidget* parent, const char* name, Qt::WindowFlags f)
    : Q3ScrollView(parent,name,f|WResizeNoErase|WStaticContents)
{
    d = new Q3CanvasViewData;
    viewing = 0;
    setCanvas(0);
}

/*!
    \overload

    Constructs a Q3CanvasView which views canvas \a canvas, with parent
    \a parent, and name \a name, using the widget flags \a f.
*/
Q3CanvasView::Q3CanvasView(Q3Canvas* canvas, QWidget* parent, const char* name, Qt::WindowFlags f)
    : Q3ScrollView(parent,name,f|WResizeNoErase|WStaticContents)
{
    d = new Q3CanvasViewData;
    viewing = 0;
    setCanvas(canvas);
}

/*!
    Destroys the canvas view. The associated canvas is \e not deleted.
*/
Q3CanvasView::~Q3CanvasView()
{
    delete d;
    d = 0;
    setCanvas(0);
}

/*!
    \fn Q3Canvas* Q3CanvasView::canvas() const

    Returns a pointer to the canvas which the Q3CanvasView is currently
    showing.
*/


/*!
    Sets the canvas that the Q3CanvasView is showing to the canvas \a
    canvas.
*/
void Q3CanvasView::setCanvas(Q3Canvas* canvas)
{
    if (viewing == canvas)
        return;

    if (viewing) {
	disconnect(viewing);
	viewing->removeView(this);
    }
    viewing=canvas;
    if (viewing) {
	connect(viewing,SIGNAL(resized()), this, SLOT(updateContentsSize()));
	viewing->addView(this);
	viewing->setAllChanged();
    }
    if (d) // called by d'tor
        updateContentsSize();
    update();
}

#ifndef QT_NO_TRANSFORMATIONS
/*!
    Returns a reference to the canvas view's current transformation matrix.

    \sa setWorldMatrix() inverseWorldMatrix()
*/
const QMatrix &Q3CanvasView::worldMatrix() const
{
    return d->xform;
}

/*!
    Returns a reference to the inverse of the canvas view's current
    transformation matrix.

    \sa setWorldMatrix() worldMatrix()
*/
const QMatrix &Q3CanvasView::inverseWorldMatrix() const
{
    return d->ixform;
}

/*!
    Sets the transformation matrix of the Q3CanvasView to \a wm. The
    matrix must be invertible (i.e. if you create a world matrix that
    zooms out by 2 times, then the inverse of this matrix is one that
    will zoom in by 2 times).

    When you use this, you should note that the performance of the
    Q3CanvasView will decrease considerably.

    Returns false if \a wm is not invertable; otherwise returns true.

    \sa worldMatrix() inverseWorldMatrix() QMatrix::isInvertible()
*/
bool Q3CanvasView::setWorldMatrix(const QMatrix & wm)
{
    bool ok = wm.isInvertible();
    if (ok) {
	d->xform = wm;
	d->ixform = wm.invert();
	updateContentsSize();
	viewport()->update();
    }
    return ok;
}
#endif

void Q3CanvasView::updateContentsSize()
{
    if (viewing) {
	QRect br;
#ifndef QT_NO_TRANSFORMATIONS
	br = d->xform.map(QRect(0,0,viewing->width(),viewing->height()));
#else
	br = QRect(0,0,viewing->width(),viewing->height());
#endif

	if (br.width() < contentsWidth()) {
	    QRect r(contentsToViewport(QPoint(br.width(),0)),
		    QSize(contentsWidth()-br.width(),contentsHeight()));
            d->eraseRegion = r;
	}
	if (br.height() < contentsHeight()) {
	    QRect r(contentsToViewport(QPoint(0,br.height())),
		    QSize(contentsWidth(),contentsHeight()-br.height()));
            d->eraseRegion |= r;
	}

	resizeContents(br.width(),br.height());
    } else {
        d->eraseRegion = rect();
	resizeContents(1,1);
    }
}

/*!
    Repaints part of the Q3Canvas that the canvas view is showing
    starting at \a cx by \a cy, with a width of \a cw and a height of \a
    ch using the painter \a p.
*/
void Q3CanvasView::drawContents(QPainter *p, int cx, int cy, int cw, int ch)
{
    QRect r(cx,cy,cw,ch);
    if (!d->eraseRegion.isEmpty()) {
        const QVector<QRect> rects = d->eraseRegion.rects();
        for (int i = 0; i < rects.size(); ++i)
            p->eraseRect(rects.at(i));

        d->eraseRegion = QRegion();
    }

    if (viewing) {
        viewing->drawViewArea(this,p,r,false);
    } else {
	p->eraseRect(r);
    }
}

/*!
  \reimp
  \internal

  (Implemented to get rid of a compiler warning.)
*/
void Q3CanvasView::drawContents(QPainter *)
{
}

/*!
    Suggests a size sufficient to view the entire canvas.
*/
QSize Q3CanvasView::sizeHint() const
{
    if (!canvas())
	return Q3ScrollView::sizeHint();
    // should maybe take transformations into account
    return (canvas()->size() + 2 * QSize(frameWidth(), frameWidth()))
	   .boundedTo(3 * QApplication::desktop()->size() / 4);
}

/*!
    \class Q3CanvasPolygonalItem
    \compat
    \brief The Q3CanvasPolygonalItem class provides a polygonal canvas item
    on a Q3Canvas.

    The mostly rectangular classes, such as Q3CanvasSprite and
    Q3CanvasText, use the object's bounding rectangle for movement,
    repainting and collision calculations. For most other items, the
    bounding rectangle can be far too large -- a diagonal line being
    the worst case, and there are many other cases which are also bad.
    Q3CanvasPolygonalItem provides polygon-based bounding rectangle
    handling, etc., which is much faster for non-rectangular items.

    Derived classes should try to define as small an area as possible
    to maximize efficiency, but the polygon must \e definitely be
    contained completely within the polygonal area. Calculating the
    exact requirements is usually difficult, but if you allow a small
    overestimate it can be easy and quick, while still getting almost
    all of Q3CanvasPolygonalItem's speed.

    Note that all subclasses \e must call hide() in their destructor
    since hide() needs to be able to access areaPoints().

    Normally, Q3CanvasPolygonalItem uses the odd-even algorithm for
    determining whether an object intersects this object. You can
    change this to the winding algorithm using setWinding().

    The bounding rectangle is available using boundingRect(). The
    points bounding the polygonal item are retrieved with
    areaPoints(). Use areaPointsAdvanced() to retrieve the bounding
    points the polygonal item \e will have after
    Q3CanvasItem::advance(1) has been called.

    If the shape of the polygonal item is about to change while the
    item is visible, call invalidate() before updating with a
    different result from \l areaPoints().

    By default, Q3CanvasPolygonalItem objects have a black pen and no
    brush (the default QPen and QBrush constructors). You can change
    this with setPen() and setBrush(), but note that some
    Q3CanvasPolygonalItem subclasses only use the brush, ignoring the
    pen setting.

    The polygonal item can be drawn on a painter with draw().
    Subclasses must reimplement drawShape() to draw themselves.

    Like any other canvas item polygonal items can be moved with
    Q3CanvasItem::move() and Q3CanvasItem::moveBy(), or by setting coordinates
    with Q3CanvasItem::setX(), Q3CanvasItem::setY() and Q3CanvasItem::setZ().

    \sa QtCanvas, {Porting to Graphics View}
*/


/*
  Since most polygonal items don't have a pen, the default is
  NoPen and a black brush.
*/
static const QPen& defaultPolygonPen()
{
    static QPen* dp=0;
    if (!dp)
	dp = new QPen;
    return *dp;
}

static const QBrush& defaultPolygonBrush()
{
    static QBrush* db=0;
    if (!db)
	db = new QBrush;
    return *db;
}

/*!
    Constructs a Q3CanvasPolygonalItem on the canvas \a canvas.
*/
Q3CanvasPolygonalItem::Q3CanvasPolygonalItem(Q3Canvas* canvas) :
    Q3CanvasItem(canvas),
    br(defaultPolygonBrush()),
    pn(defaultPolygonPen())
{
    wind=0;
}

/*!
    Note that all subclasses \e must call hide() in their destructor
    since hide() needs to be able to access areaPoints().
*/
Q3CanvasPolygonalItem::~Q3CanvasPolygonalItem()
{
}

/*!
    Returns true if the polygonal item uses the winding algorithm to
    determine the "inside" of the polygon. Returns false if it uses
    the odd-even algorithm.

    The default is to use the odd-even algorithm.

    \sa setWinding()
*/
bool Q3CanvasPolygonalItem::winding() const
{
    return wind;
}

/*!
    If \a enable is true, the polygonal item will use the winding
    algorithm to determine the "inside" of the polygon; otherwise the
    odd-even algorithm will be used.

    The default is to use the odd-even algorithm.

    \sa winding()
*/
void Q3CanvasPolygonalItem::setWinding(bool enable)
{
    wind = enable;
}

/*!
    Invalidates all information about the area covered by the canvas
    item. The item will be updated automatically on the next call that
    changes the item's status, for example, move() or update(). Call
    this function if you are going to change the shape of the item (as
    returned by areaPoints()) while the item is visible.
*/
void Q3CanvasPolygonalItem::invalidate()
{
    val = (uint)false;
    removeFromChunks();
}

/*!
    \fn Q3CanvasPolygonalItem::isValid() const

    Returns true if the polygonal item's area information has not been
    invalidated; otherwise returns false.

    \sa invalidate()
*/

/*!
    Returns the points the polygonal item \e will have after
    Q3CanvasItem::advance(1) is called, i.e. what the points are when
    advanced by the current xVelocity() and yVelocity().
*/
Q3PointArray Q3CanvasPolygonalItem::areaPointsAdvanced() const
{
    int dx = int(x()+xVelocity())-int(x());
    int dy = int(y()+yVelocity())-int(y());
    Q3PointArray r = areaPoints();
    r.detach(); // Explicit sharing is stupid.
    if (dx || dy)
	r.translate(dx,dy);
    return r;
}

//#define QCANVAS_POLYGONS_DEBUG
#ifdef QCANVAS_POLYGONS_DEBUG
static QWidget* dbg_wid=0;
static QPainter* dbg_ptr=0;
#endif

class QPolygonalProcessor {
public:
    QPolygonalProcessor(Q3Canvas* c, const Q3PointArray& pa) :
	canvas(c)
    {
	QRect pixelbounds = pa.boundingRect();
	int cs = canvas->chunkSize();
    QRect canvasbounds = pixelbounds.intersected(canvas->rect());
    bounds.setLeft(canvasbounds.left()/cs);
    bounds.setRight(canvasbounds.right()/cs);
    bounds.setTop(canvasbounds.top()/cs);
    bounds.setBottom(canvasbounds.bottom()/cs);
    bitmap = QImage(bounds.width() + 1, bounds.height(), 1, 2, QImage::LittleEndian);
    pnt = 0;
	bitmap.fill(0);
#ifdef QCANVAS_POLYGONS_DEBUG
	dbg_start();
#endif
    }

    inline void add(int x, int y)
    {
	if (pnt >= (int)result.size()) {
	    result.resize(pnt*2+10);
	}
	result[pnt++] = QPoint(x+bounds.x(),y+bounds.y());
#ifdef QCANVAS_POLYGONS_DEBUG
	if (dbg_ptr) {
	    int cs = canvas->chunkSize();
	    QRect r(x*cs+bounds.x()*cs,y*cs+bounds.y()*cs,cs-1,cs-1);
	    dbg_ptr->setPen(Qt::blue);
	    dbg_ptr->drawRect(r);
	}
#endif
    }

    inline void addBits(int x1, int x2, uchar newbits, int xo, int yo)
    {
	for (int i=x1; i<=x2; i++)
	    if (newbits & (1<<i))
		add(xo+i,yo);
    }

#ifdef QCANVAS_POLYGONS_DEBUG
    void dbg_start()
    {
	if (!dbg_wid) {
	    dbg_wid = new QWidget;
	    dbg_wid->resize(800,600);
	    dbg_wid->show();
	    dbg_ptr = new QPainter(dbg_wid);
	    dbg_ptr->setBrush(Qt::NoBrush);
	}
	dbg_ptr->fillRect(dbg_wid->rect(),Qt::white);
    }
#endif

    void doSpans(int n, QPoint* pt, int* w)
    {
	int cs = canvas->chunkSize();
	for (int j=0; j<n; j++) {
	    int y = pt[j].y()/cs-bounds.y();
        if (y >= bitmap.height() || y < 0) continue;
	    uchar* l = bitmap.scanLine(y);
	    int x = pt[j].x();
	    int x1 = x/cs-bounds.x();
        if (x1 > bounds.width()) continue;
        x1  = QMAX(0,x1);
	    int x2 = (x+w[j])/cs-bounds.x();
        if (x2 < 0) continue;
        x2 = QMIN(bounds.width(), x2);
	    int x1q = x1/8;
	    int x1r = x1%8;
	    int x2q = x2/8;
	    int x2r = x2%8;
#ifdef QCANVAS_POLYGONS_DEBUG
	    if (dbg_ptr) dbg_ptr->setPen(Qt::yellow);
#endif
	    if (x1q == x2q) {
		uchar newbits = (~l[x1q]) & (((2<<(x2r-x1r))-1)<<x1r);
		if (newbits) {
#ifdef QCANVAS_POLYGONS_DEBUG
		    if (dbg_ptr) dbg_ptr->setPen(Qt::darkGreen);
#endif
		    addBits(x1r,x2r,newbits,x1q*8,y);
		    l[x1q] |= newbits;
		}
	    } else {
#ifdef QCANVAS_POLYGONS_DEBUG
		if (dbg_ptr) dbg_ptr->setPen(Qt::blue);
#endif
		uchar newbits1 = (~l[x1q]) & (0xff<<x1r);
		if (newbits1) {
#ifdef QCANVAS_POLYGONS_DEBUG
		    if (dbg_ptr) dbg_ptr->setPen(Qt::green);
#endif
		    addBits(x1r,7,newbits1,x1q*8,y);
		    l[x1q] |= newbits1;
		}
		for (int i=x1q+1; i<x2q; i++) {
		    if (l[i] != 0xff) {
			addBits(0,7,~l[i],i*8,y);
			l[i]=0xff;
		    }
		}
		uchar newbits2 = (~l[x2q]) & (0xff>>(7-x2r));
		if (newbits2) {
#ifdef QCANVAS_POLYGONS_DEBUG
		    if (dbg_ptr) dbg_ptr->setPen(Qt::red);
#endif
		    addBits(0,x2r,newbits2,x2q*8,y);
		    l[x2q] |= newbits2;
		}
	    }
#ifdef QCANVAS_POLYGONS_DEBUG
	    if (dbg_ptr) {
		dbg_ptr->drawLine(pt[j],pt[j]+QPoint(w[j],0));
	    }
#endif
	}
	result.resize(pnt);
    }

    int pnt;
    Q3PointArray result;
    Q3Canvas* canvas;
    QRect bounds;
    QImage bitmap;
};


Q3PointArray Q3CanvasPolygonalItem::chunks() const
{
    Q3PointArray pa = areaPoints();

    if (!pa.size()) {
	pa.detach(); // Explicit sharing is stupid.
	return pa;
    }

    QPolygonalProcessor processor(canvas(),pa);

    scanPolygon(pa, wind, processor);

    return processor.result;
}
/*!
    Simply calls Q3CanvasItem::chunks().
*/
Q3PointArray Q3CanvasRectangle::chunks() const
{
    // No need to do a polygon scan!
    return Q3CanvasItem::chunks();
}

/*!
    Returns the bounding rectangle of the polygonal item, based on
    areaPoints().
*/
QRect Q3CanvasPolygonalItem::boundingRect() const
{
    return areaPoints().boundingRect();
}

/*!
    Reimplemented from Q3CanvasItem, this draws the polygonal item by
    setting the pen and brush for the item on the painter \a p and
    calling drawShape().
*/
void Q3CanvasPolygonalItem::draw(QPainter & p)
{
    p.setPen(pn);
    p.setBrush(br);
    drawShape(p);
}

/*!
    \fn void Q3CanvasPolygonalItem::drawShape(QPainter & p)

    Subclasses must reimplement this function to draw their shape. The
    pen and brush of \a p are already set to pen() and brush() prior
    to calling this function.

    \sa draw()
*/

/*!
    \fn QPen Q3CanvasPolygonalItem::pen() const

    Returns the QPen used to draw the outline of the item, if any.

    \sa setPen()
*/

/*!
    \fn QBrush Q3CanvasPolygonalItem::brush() const

    Returns the QBrush used to fill the item, if filled.

    \sa setBrush()
*/

/*!
    Sets the QPen used when drawing the item to the pen \a p.
    Note that many Q3CanvasPolygonalItems do not use the pen value.

    \sa setBrush(), pen(), drawShape()
*/
void Q3CanvasPolygonalItem::setPen(QPen p)
{
    if (pn != p) {
	removeFromChunks();
	pn = p;
	addToChunks();
    }
}

/*!
    Sets the QBrush used when drawing the polygonal item to the brush \a b.

    \sa setPen(), brush(), drawShape()
*/
void Q3CanvasPolygonalItem::setBrush(QBrush b)
{
    if (br != b) {
	br = b;
	changeChunks();
    }
}


/*!
    \class Q3CanvasPolygon
    \compat
    \brief The Q3CanvasPolygon class provides a polygon on a Q3Canvas.

    Paints a polygon with a QBrush. The polygon's points can be set in
    the constructor or set or changed later using setPoints(). Use
    points() to retrieve the points, or areaPoints() to retrieve the
    points relative to the canvas's origin.

    The polygon can be drawn on a painter with drawShape().

    Like any other canvas item polygons can be moved with
    Q3CanvasItem::move() and Q3CanvasItem::moveBy(), or by setting
    coordinates with Q3CanvasItem::setX(), Q3CanvasItem::setY() and
    Q3CanvasItem::setZ().

    Note: Q3CanvasPolygon does not use the pen.

    \sa QtCanvas, {Porting to Graphics View}
*/

/*!
    Constructs a point-less polygon on the canvas \a canvas. You
    should call setPoints() before using it further.
*/
Q3CanvasPolygon::Q3CanvasPolygon(Q3Canvas* canvas) :
    Q3CanvasPolygonalItem(canvas)
{
}

/*!
    Destroys the polygon.
*/
Q3CanvasPolygon::~Q3CanvasPolygon()
{
    hide();
}

/*!
    Draws the polygon using the painter \a p.

    Note that Q3CanvasPolygon does not support an outline (the pen is
    always NoPen).
*/
void Q3CanvasPolygon::drawShape(QPainter & p)
{
    // ### why can't we draw outlines? We could use drawPolyline for it. Lars
    // ### see other message. Warwick

    p.setPen(NoPen); // since QRegion(Q3PointArray) excludes outline :-()-:
    p.drawPolygon(poly);
}

/*!
    Sets the points of the polygon to be \a pa. These points will have
    their x and y coordinates automatically translated by x(), y() as
    the polygon is moved.
*/
void Q3CanvasPolygon::setPoints(Q3PointArray pa)
{
    removeFromChunks();
    poly = pa;
    poly.detach(); // Explicit sharing is stupid.
    poly.translate((int)x(),(int)y());
    addToChunks();
}

/*!
  \reimp
*/
void Q3CanvasPolygon::moveBy(double dx, double dy)
{
    // Note: does NOT call Q3CanvasPolygonalItem::moveBy(), since that
    // only does half this work.
    //
    int idx = int(x()+dx)-int(x());
    int idy = int(y()+dy)-int(y());
    if (idx || idy) {
	removeFromChunks();
	poly.translate(idx,idy);
    }
    myx+=dx;
    myy+=dy;
    if (idx || idy) {
	addToChunks();
    }
}

/*!
    \class Q3CanvasSpline
    \compat
    \brief The Q3CanvasSpline class provides multi-bezier splines on a Q3Canvas.

    A Q3CanvasSpline is a sequence of 4-point bezier curves joined
    together to make a curved shape.

    You set the control points of the spline with setControlPoints().

    If the bezier is closed(), then the first control point will be
    re-used as the last control point. Therefore, a closed bezier must
    have a multiple of 3 control points and an open bezier must have
    one extra point.

    The beziers are not necessarily joined "smoothly". To ensure this,
    set control points appropriately (general reference texts about
    beziers will explain this in detail).

    Like any other canvas item splines can be moved with
    Q3CanvasItem::move() and Q3CanvasItem::moveBy(), or by setting
    coordinates with Q3CanvasItem::setX(), Q3CanvasItem::setY() and
    Q3CanvasItem::setZ().

    \sa QtCanvas, {Porting to Graphics View}
*/

/*!
    Create a spline with no control points on the canvas \a canvas.

    \sa setControlPoints()
*/
Q3CanvasSpline::Q3CanvasSpline(Q3Canvas* canvas) :
    Q3CanvasPolygon(canvas),
    cl(true)
{
}

/*!
    Destroy the spline.
*/
Q3CanvasSpline::~Q3CanvasSpline()
{
}

/*!
    Set the spline control points to \a ctrl.

    If \a close is true, then the first point in \a ctrl will be
    re-used as the last point, and the number of control points must
    be a multiple of 3. If \a close is false, one additional control
    point is required, and the number of control points must be one of
    (4, 7, 10, 13, ...).

    If the number of control points doesn't meet the above conditions,
    the number of points will be truncated to the largest number of
    points that do meet the requirement.
*/
void Q3CanvasSpline::setControlPoints(Q3PointArray ctrl, bool close)
{
    if ((int)ctrl.count() % 3 != (close ? 0 : 1)) {
	qWarning("Q3CanvasSpline::setControlPoints(): Number of points doesn't fit.");
	int numCurves = (ctrl.count() - (close ? 0 : 1))/ 3;
	ctrl.resize(numCurves*3 + (close ? 0 : 1));
    }

    cl = close;
    bez = ctrl;
    recalcPoly();
}

/*!
    Returns the current set of control points.

    \sa setControlPoints(), closed()
*/
Q3PointArray Q3CanvasSpline::controlPoints() const
{
    return bez;
}

/*!
    Returns true if the control points are a closed set; otherwise
    returns false.
*/
bool Q3CanvasSpline::closed() const
{
    return cl;
}

void Q3CanvasSpline::recalcPoly()
{
    Q3PtrList<Q3PointArray> segs;
    segs.setAutoDelete(true);
    int n=0;
    for (int i=0; i<(int)bez.count()-1; i+=3) {
	Q3PointArray ctrl(4);
	ctrl[0] = bez[i+0];
	ctrl[1] = bez[i+1];
	ctrl[2] = bez[i+2];
	if (cl)
	    ctrl[3] = bez[(i+3)%(int)bez.count()];
	else
	    ctrl[3] = bez[i+3];
	Q3PointArray *seg = new Q3PointArray(ctrl.cubicBezier());
	n += seg->count()-1;
	segs.append(seg);
    }
    Q3PointArray p(n+1);
    n=0;
    for (Q3PointArray* seg = segs.first(); seg; seg = segs.next()) {
	for (int i=0; i<(int)seg->count()-1; i++)
	    p[n++] = seg->point(i);
	if (n == (int)p.count()-1)
	    p[n] = seg->point(seg->count()-1);
    }
    Q3CanvasPolygon::setPoints(p);
}

/*!
    \fn Q3PointArray Q3CanvasPolygonalItem::areaPoints() const

    This function must be reimplemented by subclasses. It \e must
    return the points bounding (i.e. outside and not touching) the
    shape or drawing errors will occur.
*/

/*!
    \fn Q3PointArray Q3CanvasPolygon::points() const

    Returns the vertices of the polygon, not translated by the position.

    \sa setPoints(), areaPoints()
*/
Q3PointArray Q3CanvasPolygon::points() const
{
    Q3PointArray pa = areaPoints();
    pa.translate(int(-x()),int(-y()));
    return pa;
}

/*!
    Returns the vertices of the polygon translated by the polygon's
    current x(), y() position, i.e. relative to the canvas's origin.

    \sa setPoints(), points()
*/
Q3PointArray Q3CanvasPolygon::areaPoints() const
{
    return poly.copy();
}

/*!
    \class Q3CanvasLine
    \compat
    \brief The Q3CanvasLine class provides a line on a Q3Canvas.

    The line inherits functionality from Q3CanvasPolygonalItem, for
    example the setPen() function. The start and end points of the
    line are set with setPoints().

    Like any other canvas item lines can be moved with
    Q3CanvasItem::move() and Q3CanvasItem::moveBy(), or by setting
    coordinates with Q3CanvasItem::setX(), Q3CanvasItem::setY() and
    Q3CanvasItem::setZ().

    \sa QtCanvas, {Porting to Graphics View}
*/

/*!
    Constructs a line from (0,0) to (0,0) on \a canvas.

    \sa setPoints()
*/
Q3CanvasLine::Q3CanvasLine(Q3Canvas* canvas) :
    Q3CanvasPolygonalItem(canvas)
{
    x1 = y1 = x2 = y2 = 0;
}

/*!
    Destroys the line.
*/
Q3CanvasLine::~Q3CanvasLine()
{
    hide();
}

/*!
  \reimp
*/
void Q3CanvasLine::setPen(QPen p)
{
    Q3CanvasPolygonalItem::setPen(p);
}

/*!
    \fn QPoint Q3CanvasLine::startPoint () const

    Returns the start point of the line.

    \sa setPoints(), endPoint()
*/

/*!
    \fn QPoint Q3CanvasLine::endPoint () const

    Returns the end point of the line.

    \sa setPoints(), startPoint()
*/

/*!
    Sets the line's start point to (\a xa, \a ya) and its end point to
    (\a xb, \a yb).
*/
void Q3CanvasLine::setPoints(int xa, int ya, int xb, int yb)
{
    if (x1 != xa || x2 != xb || y1 != ya || y2 != yb) {
	removeFromChunks();
	x1 = xa;
	y1 = ya;
	x2 = xb;
	y2 = yb;
	addToChunks();
    }
}

/*!
  \reimp
*/
void Q3CanvasLine::drawShape(QPainter &p)
{
    p.drawLine((int)(x()+x1), (int)(y()+y1), (int)(x()+x2), (int)(y()+y2));
}

/*!
    \reimp

    Note that the area defined by the line is somewhat thicker than
    the line that is actually drawn.
*/
Q3PointArray Q3CanvasLine::areaPoints() const
{
    Q3PointArray p(4);
    int xi = int(x());
    int yi = int(y());
    int pw = pen().width();
    int dx = QABS(x1-x2);
    int dy = QABS(y1-y2);
    pw = pw*4/3+2; // approx pw*sqrt(2)
    int px = x1<x2 ? -pw : pw ;
    int py = y1<y2 ? -pw : pw ;
    if (dx && dy && (dx > dy ? (dx*2/dy <= 2) : (dy*2/dx <= 2))) {
	// steep
	if (px == py) {
	    p[0] = QPoint(x1+xi   ,y1+yi+py);
	    p[1] = QPoint(x2+xi-px,y2+yi  );
	    p[2] = QPoint(x2+xi   ,y2+yi-py);
	    p[3] = QPoint(x1+xi+px,y1+yi  );
	} else {
	    p[0] = QPoint(x1+xi+px,y1+yi  );
	    p[1] = QPoint(x2+xi   ,y2+yi-py);
	    p[2] = QPoint(x2+xi-px,y2+yi  );
	    p[3] = QPoint(x1+xi   ,y1+yi+py);
	}
    } else if (dx > dy) {
	// horizontal
	p[0] = QPoint(x1+xi+px,y1+yi+py);
	p[1] = QPoint(x2+xi-px,y2+yi+py);
	p[2] = QPoint(x2+xi-px,y2+yi-py);
	p[3] = QPoint(x1+xi+px,y1+yi-py);
    } else {
	// vertical
	p[0] = QPoint(x1+xi+px,y1+yi+py);
	p[1] = QPoint(x2+xi+px,y2+yi-py);
	p[2] = QPoint(x2+xi-px,y2+yi-py);
	p[3] = QPoint(x1+xi-px,y1+yi+py);
    }
    return p;
}

/*!
    \reimp

*/

void Q3CanvasLine::moveBy(double dx, double dy)
{
    Q3CanvasPolygonalItem::moveBy(dx, dy);
}

/*!
    \class Q3CanvasRectangle
    \compat
    \brief The Q3CanvasRectangle class provides a rectangle on a Q3Canvas.

    This item paints a single rectangle which may have any pen() and
    brush(), but may not be tilted/rotated. For rotated rectangles,
    use Q3CanvasPolygon.

    The rectangle's size and initial position can be set in the
    constructor. The size can be set or changed later using setSize().
    Use height() and width() to retrieve the rectangle's dimensions.

    The rectangle can be drawn on a painter with drawShape().

    Like any other canvas item rectangles can be moved with
    Q3CanvasItem::move() and Q3CanvasItem::moveBy(), or by setting
    coordinates with Q3CanvasItem::setX(), Q3CanvasItem::setY() and
    Q3CanvasItem::setZ().

    \sa QtCanvas, {Porting to Graphics View}
*/

/*!
    Constructs a rectangle at position (0,0) with both width and
    height set to 32 pixels on \a canvas.
*/
Q3CanvasRectangle::Q3CanvasRectangle(Q3Canvas* canvas) :
    Q3CanvasPolygonalItem(canvas),
    w(32), h(32)
{
}

/*!
    Constructs a rectangle positioned and sized by \a r on \a canvas.
*/
Q3CanvasRectangle::Q3CanvasRectangle(const QRect& r, Q3Canvas* canvas) :
    Q3CanvasPolygonalItem(canvas),
    w(r.width()), h(r.height())
{
    move(r.x(),r.y());
}

/*!
    Constructs a rectangle at position (\a x, \a y) and size \a width
    by \a height, on \a canvas.
*/
Q3CanvasRectangle::Q3CanvasRectangle(int x, int y, int width, int height,
	Q3Canvas* canvas) :
    Q3CanvasPolygonalItem(canvas),
    w(width), h(height)
{
    move(x,y);
}

/*!
    Destroys the rectangle.
*/
Q3CanvasRectangle::~Q3CanvasRectangle()
{
    hide();
}


/*!
    Returns the width of the rectangle.
*/
int Q3CanvasRectangle::width() const
{
    return w;
}

/*!
    Returns the height of the rectangle.
*/
int Q3CanvasRectangle::height() const
{
    return h;
}

/*!
    Sets the \a width and \a height of the rectangle.
*/
void Q3CanvasRectangle::setSize(int width, int height)
{
    if (w != width || h != height) {
	removeFromChunks();
	w = width;
	h = height;
	addToChunks();
    }
}

/*!
    \fn QSize Q3CanvasRectangle::size() const

    Returns the width() and height() of the rectangle.

    \sa rect(), setSize()
*/

/*!
    \fn QRect Q3CanvasRectangle::rect() const

    Returns the integer-converted x(), y() position and size() of the
    rectangle as a QRect.
*/

/*!
  \reimp
*/
Q3PointArray Q3CanvasRectangle::areaPoints() const
{
    Q3PointArray pa(4);
    int pw = (pen().width()+1)/2;
    if (pw < 1) pw = 1;
    if (pen() == NoPen) pw = 0;
    pa[0] = QPoint((int)x()-pw,(int)y()-pw);
    pa[1] = pa[0] + QPoint(w+pw*2,0);
    pa[2] = pa[1] + QPoint(0,h+pw*2);
    pa[3] = pa[0] + QPoint(0,h+pw*2);
    return pa;
}

/*!
    Draws the rectangle on painter \a p.
*/
void Q3CanvasRectangle::drawShape(QPainter & p)
{
    p.drawRect((int)x(), (int)y(), w, h);
}


/*!
    \class Q3CanvasEllipse
    \compat
    \brief The Q3CanvasEllipse class provides an ellipse or ellipse segment on a Q3Canvas.

    A canvas item that paints an ellipse or ellipse segment with a QBrush.
    The ellipse's height, width, start angle and angle length can be set
    at construction time. The size can be changed at runtime with
    setSize(), and the angles can be changed (if you're displaying an
    ellipse segment rather than a whole ellipse) with setAngles().

    Note that angles are specified in 16ths of a degree.

    \target anglediagram
    \img qcanvasellipse.png Ellipse

    If a start angle and length angle are set then an ellipse segment
    will be drawn. The start angle is the angle that goes from zero in a
    counter-clockwise direction (shown in green in the diagram). The
    length angle is the angle from the start angle in a
    counter-clockwise direction (shown in blue in the diagram). The blue
    segment is the segment of the ellipse that would be drawn. If no
    start angle and length angle are specified the entire ellipse is
    drawn.

    The ellipse can be drawn on a painter with drawShape().

    Like any other canvas item ellipses can be moved with move() and
    moveBy(), or by setting coordinates with setX(), setY() and setZ().

    Note: Q3CanvasEllipse does not use the pen.

    \sa QtCanvas, {Porting to Graphics View}
*/

/*!
    Constructs a 32x32 ellipse, centered at (0, 0) on \a canvas.
*/
Q3CanvasEllipse::Q3CanvasEllipse(Q3Canvas* canvas) :
    Q3CanvasPolygonalItem(canvas),
    w(32), h(32),
    a1(0), a2(360*16)
{
}

/*!
    Constructs a \a width by \a height pixel ellipse, centered at
    (0, 0) on \a canvas.
*/
Q3CanvasEllipse::Q3CanvasEllipse(int width, int height, Q3Canvas* canvas) :
    Q3CanvasPolygonalItem(canvas),
    w(width),h(height),
    a1(0),a2(360*16)
{
}

// ### add a constructor taking degrees in float. 1/16 degrees is stupid. Lars
// ### it's how QPainter does it, so Q3Canvas does too for consistency. If it's
// ###  a good idea, it should be added to QPainter, not just to Q3Canvas. Warwick
/*!
    Constructs a \a width by \a height pixel ellipse, centered at
    (0, 0) on \a canvas. Only a segment of the ellipse is drawn,
    starting at angle \a startangle, and extending for angle \a angle
    (the angle length).

    Note that angles are specified in sixteenths of a degree.
*/
Q3CanvasEllipse::Q3CanvasEllipse(int width, int height,
    int startangle, int angle, Q3Canvas* canvas) :
    Q3CanvasPolygonalItem(canvas),
    w(width),h(height),
    a1(startangle),a2(angle)
{
}

/*!
    Destroys the ellipse.
*/
Q3CanvasEllipse::~Q3CanvasEllipse()
{
    hide();
}

/*!
    Returns the width of the ellipse.
*/
int Q3CanvasEllipse::width() const
{
    return w;
}

/*!
    Returns the height of the ellipse.
*/
int Q3CanvasEllipse::height() const
{
    return h;
}

/*!
    Sets the \a width and \a height of the ellipse.
*/
void Q3CanvasEllipse::setSize(int width, int height)
{
    if (w != width || h != height) {
	removeFromChunks();
	w = width;
	h = height;
	addToChunks();
    }
}

/*!
    \fn int Q3CanvasEllipse::angleStart() const

    Returns the start angle in 16ths of a degree. Initially
    this will be 0.

    \sa setAngles(), angleLength()
*/

/*!
    \fn int Q3CanvasEllipse::angleLength() const

    Returns the length angle (the extent of the ellipse segment) in
    16ths of a degree. Initially this will be 360 * 16 (a complete
    ellipse).

    \sa setAngles(), angleStart()
*/

/*!
    Sets the angles for the ellipse. The start angle is \a start and
    the extent of the segment is \a length (the angle length) from the
    \a start. The angles are specified in 16ths of a degree. By
    default the ellipse will start at 0 and have an angle length of
    360 * 16 (a complete ellipse).

    \sa angleStart(), angleLength()
*/
void Q3CanvasEllipse::setAngles(int start, int length)
{
    if (a1 != start || a2 != length) {
	removeFromChunks();
	a1 = start;
	a2 = length;
	addToChunks();
    }
}

/*!
  \reimp
*/
Q3PointArray Q3CanvasEllipse::areaPoints() const
{
    Q3PointArray r;
    // makeArc at 0,0, then translate so that fixed point math doesn't overflow
    r.makeArc(int(x()-w/2.0+0.5)-1, int(y()-h/2.0+0.5)-1, w+3, h+3, a1, a2);
    r.resize(r.size()+1);
    r.setPoint(r.size()-1,int(x()),int(y()));
    return r;
}

// ### support outlines! Lars
// ### QRegion doesn't, so we cannot (try it). Warwick
/*!
    Draws the ellipse, centered at x(), y() using the painter \a p.

    Note that Q3CanvasEllipse does not support an outline (the pen is
    always NoPen).
*/
void Q3CanvasEllipse::drawShape(QPainter & p)
{
    p.setPen(NoPen); // since QRegion(Q3PointArray) excludes outline :-()-:
    if (!a1 && a2 == 360*16) {
	p.drawEllipse(int(x()-w/2.0+0.5), int(y()-h/2.0+0.5), w, h);
    } else {
	p.drawPie(int(x()-w/2.0+0.5), int(y()-h/2.0+0.5), w, h, a1, a2);
    }
}


/*!
    \class Q3CanvasText
    \compat
    \brief The Q3CanvasText class provides a text object on a Q3Canvas.

    A canvas text item has text with font, color and alignment
    attributes. The text and font can be set in the constructor or set
    or changed later with setText() and setFont(). The color is set
    with setColor() and the alignment with setTextFlags(). The text
    item's bounding rectangle is retrieved with boundingRect().

    The text can be drawn on a painter with draw().

    Like any other canvas item text items can be moved with
    Q3CanvasItem::move() and Q3CanvasItem::moveBy(), or by setting
    coordinates with Q3CanvasItem::setX(), Q3CanvasItem::setY() and
    Q3CanvasItem::setZ().

    \sa QtCanvas, {Porting to Graphics View}
*/

/*!
    Constructs a Q3CanvasText with the text "\<text\>", on \a canvas.
*/
Q3CanvasText::Q3CanvasText(Q3Canvas* canvas) :
    Q3CanvasItem(canvas),
    txt(QLatin1String("<text>")), flags(0)
{
    setRect();
}

// ### add textflags to the constructor? Lars
/*!
    Constructs a Q3CanvasText with the text \a t, on canvas \a canvas.
*/
Q3CanvasText::Q3CanvasText(const QString& t, Q3Canvas* canvas) :
    Q3CanvasItem(canvas),
    txt(t), flags(0)
{
    setRect();
}

// ### see above
/*!
    Constructs a Q3CanvasText with the text \a t and font \a f, on the
    canvas \a canvas.
*/
Q3CanvasText::Q3CanvasText(const QString& t, QFont f, Q3Canvas* canvas) :
    Q3CanvasItem(canvas),
    txt(t), flags(0),
    fnt(f)
{
    setRect();
}

/*!
    Destroys the canvas text item.
*/
Q3CanvasText::~Q3CanvasText()
{
    removeFromChunks();
}

/*!
    Returns the bounding rectangle of the text.
*/
QRect Q3CanvasText::boundingRect() const { return brect; }

void Q3CanvasText::setRect()
{
    brect = QFontMetrics(fnt).boundingRect(int(x()), int(y()), 0, 0, flags, txt);
}

/*!
    \fn int Q3CanvasText::textFlags() const

    Returns the currently set alignment flags.

    \sa setTextFlags() Qt::AlignmentFlag
*/


/*!
    Sets the alignment flags to \a f. These are a bitwise OR of the
    flags available to QPainter::drawText() -- see the
    \l{Qt::AlignmentFlag}s.

    \sa setFont() setColor()
*/
void Q3CanvasText::setTextFlags(int f)
{
    if (flags != f) {
	removeFromChunks();
	flags = f;
	setRect();
	addToChunks();
    }
}

/*!
    Returns the text item's text.

    \sa setText()
*/
QString Q3CanvasText::text() const
{
    return txt;
}


/*!
    Sets the text item's text to \a t. The text may contain newlines.

    \sa text(), setFont(), setColor() setTextFlags()
*/
void Q3CanvasText::setText(const QString& t)
{
    if (txt != t) {
	removeFromChunks();
	txt = t;
	setRect();
	addToChunks();
    }
}

/*!
    Returns the font in which the text is drawn.

    \sa setFont()
*/
QFont Q3CanvasText::font() const
{
    return fnt;
}

/*!
    Sets the font in which the text is drawn to font \a f.

    \sa font()
*/
void Q3CanvasText::setFont(const QFont& f)
{
    if (f != fnt) {
	removeFromChunks();
	fnt = f;
	setRect();
	addToChunks();
    }
}

/*!
    Returns the color of the text.

    \sa setColor()
*/
QColor Q3CanvasText::color() const
{
    return col;
}

/*!
    Sets the color of the text to the color \a c.

    \sa color(), setFont()
*/
void Q3CanvasText::setColor(const QColor& c)
{
    col=c;
    changeChunks();
}


/*!
  \reimp
*/
void Q3CanvasText::moveBy(double dx, double dy)
{
    int idx = int(x()+dx)-int(x());
    int idy = int(y()+dy)-int(y());
    if (idx || idy) {
	removeFromChunks();
    }
    myx+=dx;
    myy+=dy;
    if (idx || idy) {
	brect.moveBy(idx,idy);
	addToChunks();
    }
}

/*!
    Draws the text using the painter \a painter.
*/
void Q3CanvasText::draw(QPainter& painter)
{
    painter.setFont(fnt);
    painter.setPen(col);
    painter.drawText(painter.fontMetrics().boundingRect(int(x()), int(y()), 0, 0, flags, txt), flags, txt);
}

/*!
  \reimp
*/
void Q3CanvasText::changeChunks()
{
    if (isVisible() && canvas()) {
	int chunksize=canvas()->chunkSize();
	for (int j=brect.top()/chunksize; j<=brect.bottom()/chunksize; j++) {
	    for (int i=brect.left()/chunksize; i<=brect.right()/chunksize; i++) {
		canvas()->setChangedChunk(i,j);
	    }
	}
    }
}

/*!
    Adds the text item to the appropriate chunks.
*/
void Q3CanvasText::addToChunks()
{
    if (isVisible() && canvas()) {
	int chunksize=canvas()->chunkSize();
	for (int j=brect.top()/chunksize; j<=brect.bottom()/chunksize; j++) {
	    for (int i=brect.left()/chunksize; i<=brect.right()/chunksize; i++) {
		canvas()->addItemToChunk(this,i,j);
	    }
	}
    }
}

/*!
    Removes the text item from the appropriate chunks.
*/
void Q3CanvasText::removeFromChunks()
{
    if (isVisible() && canvas()) {
	int chunksize=canvas()->chunkSize();
	for (int j=brect.top()/chunksize; j<=brect.bottom()/chunksize; j++) {
	    for (int i=brect.left()/chunksize; i<=brect.right()/chunksize; i++) {
		canvas()->removeItemFromChunk(this,i,j);
	    }
	}
    }
}


/*!
    Returns 0 (Q3CanvasItem::Rtti_Item).

    Make your derived classes return their own values for rtti(), so
    that you can distinguish between objects returned by
    Q3Canvas::at(). You should use values greater than 1000 to allow
    for extensions to this class.

    Overuse of this functionality can damage its extensibility. For
    example, once you have identified a base class of a Q3CanvasItem
    found by Q3Canvas::at(), cast it to that type and call meaningful
    methods rather than acting upon the object based on its rtti
    value.

    For example:

    \snippet doc/src/snippets/code/src_qt3support_canvas_q3canvas.cpp 4
*/
int Q3CanvasItem::rtti() const { return RTTI; }
int Q3CanvasItem::RTTI = Rtti_Item;

/*!
    Returns 1 (Q3CanvasItem::Rtti_Sprite).

    \sa Q3CanvasItem::rtti()
*/
int Q3CanvasSprite::rtti() const { return RTTI; }
int Q3CanvasSprite::RTTI = Rtti_Sprite;

/*!
    Returns 2 (Q3CanvasItem::Rtti_PolygonalItem).

    \sa Q3CanvasItem::rtti()
*/
int Q3CanvasPolygonalItem::rtti() const { return RTTI; }
int Q3CanvasPolygonalItem::RTTI = Rtti_PolygonalItem;

/*!
    Returns 3 (Q3CanvasItem::Rtti_Text).

    \sa Q3CanvasItem::rtti()
*/
int Q3CanvasText::rtti() const { return RTTI; }
int Q3CanvasText::RTTI = Rtti_Text;

/*!
    Returns 4 (Q3CanvasItem::Rtti_Polygon).

    \sa Q3CanvasItem::rtti()
*/
int Q3CanvasPolygon::rtti() const { return RTTI; }
int Q3CanvasPolygon::RTTI = Rtti_Polygon;

/*!
    Returns 5 (Q3CanvasItem::Rtti_Rectangle).

    \sa Q3CanvasItem::rtti()
*/
int Q3CanvasRectangle::rtti() const { return RTTI; }
int Q3CanvasRectangle::RTTI = Rtti_Rectangle;

/*!
    Returns 6 (Q3CanvasItem::Rtti_Ellipse).

    \sa Q3CanvasItem::rtti()
*/
int Q3CanvasEllipse::rtti() const { return RTTI; }
int Q3CanvasEllipse::RTTI = Rtti_Ellipse;

/*!
    Returns 7 (Q3CanvasItem::Rtti_Line).

    \sa Q3CanvasItem::rtti()
*/
int Q3CanvasLine::rtti() const { return RTTI; }
int Q3CanvasLine::RTTI = Rtti_Line;

/*!
    Returns 8 (Q3CanvasItem::Rtti_Spline).

    \sa Q3CanvasItem::rtti()
*/
int Q3CanvasSpline::rtti() const { return RTTI; }
int Q3CanvasSpline::RTTI = Rtti_Spline;

/*!
    Constructs a Q3CanvasSprite which uses images from the
    Q3CanvasPixmapArray \a a.

    The sprite in initially positioned at (0, 0) on \a canvas, using
    frame 0.
*/
Q3CanvasSprite::Q3CanvasSprite(Q3CanvasPixmapArray* a, Q3Canvas* canvas) :
    Q3CanvasItem(canvas),
    frm(0),
    anim_val(0),
    anim_state(0),
    anim_type(0),
    images(a)
{
}


/*!
    Set the array of images used for displaying the sprite to the
    Q3CanvasPixmapArray \a a.

    If the current frame() is larger than the number of images in \a
    a, the current frame will be reset to 0.
*/
void Q3CanvasSprite::setSequence(Q3CanvasPixmapArray* a)
{
    bool isvisible = isVisible();
    if (isvisible && images)
	hide();
    images = a;
    if (frm >= (int)images->count())
	frm = 0;
    if (isvisible)
	show();
}

/*!
\internal

Marks any chunks the sprite touches as changed.
*/
void Q3CanvasSprite::changeChunks()
{
    if (isVisible() && canvas()) {
	int chunksize=canvas()->chunkSize();
	for (int j=topEdge()/chunksize; j<=bottomEdge()/chunksize; j++) {
	    for (int i=leftEdge()/chunksize; i<=rightEdge()/chunksize; i++) {
		canvas()->setChangedChunk(i,j);
	    }
	}
    }
}

/*!
    Destroys the sprite and removes it from the canvas. Does \e not
    delete the images.
*/
Q3CanvasSprite::~Q3CanvasSprite()
{
    removeFromChunks();
}

/*!
    Sets the animation frame used for displaying the sprite to \a f,
    an index into the Q3CanvasSprite's Q3CanvasPixmapArray. The call
    will be ignored if \a f is larger than frameCount() or smaller
    than 0.

    \sa frame() move()
*/
void Q3CanvasSprite::setFrame(int f)
{
    move(x(),y(),f);
}

/*!
    \enum Q3CanvasSprite::FrameAnimationType

    This enum is used to identify the different types of frame
    animation offered by Q3CanvasSprite.

    \value Cycle at each advance the frame number will be incremented by
    1 (modulo the frame count).
    \value Oscillate at each advance the frame number will be
    incremented by 1 up to the frame count then decremented to by 1 to
    0, repeating this sequence forever.
*/

/*!
    Sets the animation characteristics for the sprite.

    For \a type == \c Cycle, the frames will increase by \a step
    at each advance, modulo the frameCount().

    For \a type == \c Oscillate, the frames will increase by \a step
    at each advance, up to the frameCount(), then decrease by \a step
    back to 0, repeating forever.

    The \a state parameter is for internal use.
*/
void Q3CanvasSprite::setFrameAnimation(FrameAnimationType type, int step, int state)
{
    anim_val = step;
    anim_type = type;
    anim_state = state;
    setAnimated(true);
}

/*!
    Extends the default Q3CanvasItem implementation to provide the
    functionality of setFrameAnimation().

    The \a phase is 0 or 1: see Q3CanvasItem::advance() for details.

    \sa Q3CanvasItem::advance() setVelocity()
*/
void Q3CanvasSprite::advance(int phase)
{
    if (phase==1) {
	int nf = frame();
	if (anim_type == Oscillate) {
	    if (anim_state)
		nf += anim_val;
	    else
		nf -= anim_val;
	    if (nf < 0) {
		nf = abs(anim_val);
		anim_state = !anim_state;
	    } else if (nf >= frameCount()) {
		nf = frameCount()-1-abs(anim_val);
		anim_state = !anim_state;
	    }
	} else {
	    nf = (nf + anim_val + frameCount()) % frameCount();
	}
	move(x()+xVelocity(),y()+yVelocity(),nf);
    }
}


/*!
    \fn int Q3CanvasSprite::frame() const

    Returns the index of the current animation frame in the
    Q3CanvasSprite's Q3CanvasPixmapArray.

    \sa setFrame(), move()
*/

/*!
    \fn int Q3CanvasSprite::frameCount() const

    Returns the number of frames in the Q3CanvasSprite's
    Q3CanvasPixmapArray.
*/


/*!
    Moves the sprite to (\a x, \a y).
*/
void Q3CanvasSprite::move(double x, double y) { Q3CanvasItem::move(x,y); }

/*!
    \fn void Q3CanvasSprite::move(double nx, double ny, int nf)

    Moves the sprite to (\a nx, \a ny) and sets the current
    frame to \a nf. \a nf will be ignored if it is larger than
    frameCount() or smaller than 0.
*/
void Q3CanvasSprite::move(double nx, double ny, int nf)
{
    if (isVisible() && canvas()) {
	hide();
	Q3CanvasItem::move(nx,ny);
	if (nf >= 0 && nf < frameCount())
	    frm=nf;
	show();
    } else {
	Q3CanvasItem::move(nx,ny);
	if (nf >= 0 && nf < frameCount())
	    frm=nf;
    }
}

class Q3CanvasPolygonScanner : public Q3PolygonScanner {
    QPolygonalProcessor& processor;
public:
    Q3CanvasPolygonScanner(QPolygonalProcessor& p) :
	processor(p)
    {
    }
    void processSpans(int n, QPoint* point, int* width)
    {
	processor.doSpans(n,point,width);
    }
};

void Q3CanvasPolygonalItem::scanPolygon(const Q3PointArray& pa, int winding, QPolygonalProcessor& process) const
{
    Q3CanvasPolygonScanner scanner(process);
    scanner.scan(pa,winding);
}

QT_END_NAMESPACE