1 files changed, 55 insertions, 0 deletions
diff --git a/src/gui/painting/qcolor.cpp b/src/gui/painting/qcolor.cpp
index 706273c151..b9d3ca888e 100644
--- a/src/gui/painting/qcolor.cpp
+++ b/src/gui/painting/qcolor.cpp
@@ -2499,6 +2499,41 @@ QDataStream &operator>>(QDataStream &stream, QColor &color)
 }
 #endif // QT_NO_DATASTREAM
 
+// A table of precalculated results of 0x00ff00ff/alpha use by qUnpremultiply:
+const uint qt_inv_premul_factor[256] = {
+    0, 16711935, 8355967, 5570645, 4177983, 3342387, 2785322, 2387419,
+    2088991, 1856881, 1671193, 1519266, 1392661, 1285533, 1193709, 1114129,
+    1044495, 983055, 928440, 879575, 835596, 795806, 759633, 726605,
+    696330, 668477, 642766, 618960, 596854, 576273, 557064, 539094,
+    522247, 506422, 491527, 477483, 464220, 451673, 439787, 428511,
+    417798, 407608, 397903, 388649, 379816, 371376, 363302, 355573,
+    348165, 341059, 334238, 327685, 321383, 315319, 309480, 303853,
+    298427, 293191, 288136, 283253, 278532, 273966, 269547, 265268,
+    261123, 257106, 253211, 249431, 245763, 242201, 238741, 235379,
+    232110, 228930, 225836, 222825, 219893, 217038, 214255, 211543,
+    208899, 206320, 203804, 201348, 198951, 196611, 194324, 192091,
+    189908, 187774, 185688, 183647, 181651, 179698, 177786, 175915,
+    174082, 172287, 170529, 168807, 167119, 165464, 163842, 162251,
+    160691, 159161, 157659, 156186, 154740, 153320, 151926, 150557,
+    149213, 147893, 146595, 145321, 144068, 142837, 141626, 140436,
+    139266, 138115, 136983, 135869, 134773, 133695, 132634, 131590,
+    130561, 129549, 128553, 127572, 126605, 125653, 124715, 123792,
+    122881, 121984, 121100, 120229, 119370, 118524, 117689, 116866,
+    116055, 115254, 114465, 113686, 112918, 112160, 111412, 110675,
+    109946, 109228, 108519, 107818, 107127, 106445, 105771, 105106,
+    104449, 103800, 103160, 102527, 101902, 101284, 100674, 100071,
+    99475, 98887, 98305, 97730, 97162, 96600, 96045, 95496,
+    94954, 94417, 93887, 93362, 92844, 92331, 91823, 91322,
+    90825, 90334, 89849, 89368, 88893, 88422, 87957, 87497,
+    87041, 86590, 86143, 85702, 85264, 84832, 84403, 83979,
+    83559, 83143, 82732, 82324, 81921, 81521, 81125, 80733,
+    80345, 79961, 79580, 79203, 78829, 78459, 78093, 77729,
+    77370, 77013, 76660, 76310, 75963, 75619, 75278, 74941,
+    74606, 74275, 73946, 73620, 73297, 72977, 72660, 72346,
+    72034, 71725, 71418, 71114, 70813, 70514, 70218, 69924,
+    69633, 69344, 69057, 68773, 68491, 68211, 67934, 67659,
+    67386, 67116, 66847, 66581, 66317, 66055, 65795, 65537
+};
 
 /*****************************************************************************
   QColor global functions (documentation only)
@@ -2581,6 +2616,26 @@ QDataStream &operator>>(QDataStream &stream, QColor &color)
 */
 
 /*!
+    \fn QRgb qPremultiply(QRgb rgb)
+    \since 5.3
+    \relates QColor
+
+    Converts an unpremultiplied ARGB quadruplet \a rgb into a premultiplied ARGB quadruplet.
+
+    \sa qUnpremultiply()
+*/
+
+/*!
+    \fn QRgb qUnpremultiply(QRgb rgb)
+    \since 5.3
+    \relates QColor
+
+    Converts a premultiplied ARGB quadruplet \a rgb into an unpremultiplied ARGB quadruplet.
+
+    \sa qPremultiply()
+*/
+
+/*!
     \fn QColor QColor::convertTo(Spec colorSpec) const
 
     Creates a copy of \e this color in the format specified by \a colorSpec.