Add painter render hint for brush pattern transformation

[ChangeLog][QtGui][QPainter] In Qt 5, the predefined brush patterns
would always be transformed along with the object being painted. In Qt
6.0 onwards, they would or would not, depending on the
SmoothPixmapTransformation render hint. Instead of this somewhat
surprising behavior, make the default be untransformed
(i.e. cosmetic), which makes sense when it comes to dpr scaling. For
the cases where one wants scaling, a new render hint is introduced to
enable that: NonCosmeticPatternBrushes.

Change-Id: I2208c7a28af9056d7ab97a529b66bf2d502c3c4f
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

3 files changed, 105 insertions, 9 deletions

diff --git a/tests/baseline/painting/scripts/pattern_xform.qps b/tests/baseline/painting/scripts/pattern_xform.qps
new file mode 100644
index 0000000000..a12ae05c72
--- /dev/null
+++ b/tests/baseline/painting/scripts/pattern_xform.qps
@@ -0,0 +1,78 @@
+# Version: 1
+# CheckVsReference: 5%
+
+#define basic block off screen
+save
+translate -1000 -1000
+begin_block drawrects
+setBrush green Dense4Pattern
+drawRect 0 0 40 40
+setBrush green DiagCrossPattern
+drawRect 40 0 40 40
+setBrush green VerPattern
+brushRotate 30
+drawRect 80 0 40 40
+save
+setPen brush 40 SolidLine FlatCap
+setBrush NoBrush
+drawLine 120 20 160 20
+restore
+end_block
+restore
+
+begin_block hintsuite
+save
+setRenderHint NonCosmeticBrushPatterns false
+setRenderHint SmoothPixmapTransform false
+translate 10 10
+repeat_block drawrects
+
+setRenderHint NonCosmeticBrushPatterns false
+setRenderHint SmoothPixmapTransform true
+translate 0 50
+repeat_block drawrects
+
+setRenderHint NonCosmeticBrushPatterns true
+setRenderHint SmoothPixmapTransform false
+translate 0 50
+repeat_block drawrects
+
+setRenderHint NonCosmeticBrushPatterns true
+setRenderHint SmoothPixmapTransform true
+translate 0 50
+repeat_block drawrects
+restore
+end_block
+
+save
+translate 0 200
+scale 2 2
+repeat_block hintsuite
+restore
+
+save
+translate 500 0
+scale 1.5 2.5
+rotate_y 60
+repeat_block hintsuite
+restore
+
+
+translate 0 650
+setBrush blue CrossPattern
+setPen red
+setRenderHint NonCosmeticBrushPatterns false
+
+begin_block dots
+save
+drawRect 0 0 50 50
+setBrushOrigin 12 0
+drawRect 50 0 50 50
+scale 2 1
+drawRect 50 0 50 50
+restore
+end_block dots
+
+setRenderHint NonCosmeticBrushPatterns true
+translate 0 60
+repeat_block dots
diff --git a/tests/baseline/shared/paintcommands.cpp b/tests/baseline/shared/paintcommands.cpp
index daf58a7c2e..4a3de0168b 100644
--- a/tests/baseline/shared/paintcommands.cpp
+++ b/tests/baseline/shared/paintcommands.cpp
@@ -175,6 +175,12 @@ const char *PaintCommands::imageFormatTable[] = {
     "RGBA32FPx4_Premultiplied",
 };
 
+const char *PaintCommands::renderHintTable[] = {
+    "Antialiasing",
+    "SmoothPixmapTransform",
+    "NonCosmeticBrushPatterns"
+};
+
 int PaintCommands::translateEnum(const char *table[], const QString &pattern, int limit)
 {
     QByteArray p = pattern.toLatin1().toLower();
@@ -313,7 +319,7 @@ void PaintCommands::staticInit()
                       "pen_setCosmetic true");
     DECL_PAINTCOMMAND("setRenderHint", command_setRenderHint,
                       "^setRenderHint\\s+([\\w_0-9]*)\\s*(\\w*)$",
-                      "setRenderHint <Antialiasing|SmoothPixmapTransform> <true|false>",
+                      "setRenderHint <hint> <true|false>",
                       "setRenderHint Antialiasing true");
     DECL_PAINTCOMMAND("clearRenderHint", command_clearRenderHint,
                       "^clearRenderHint$",
@@ -665,6 +671,7 @@ void PaintCommands::staticInit()
     ADD_ENUMLIST("image formats", imageFormatTable);
     ADD_ENUMLIST("coordinate modes", coordinateMethodTable);
     ADD_ENUMLIST("size modes", sizeModeTable);
+    ADD_ENUMLIST("render hints", renderHintTable);
 }
 
 #undef DECL_PAINTCOMMAND
@@ -2240,18 +2247,27 @@ void PaintCommands::command_setPen2(QRegularExpressionMatch re)
 void PaintCommands::command_setRenderHint(QRegularExpressionMatch re)
 {
     QString hintString = re.captured(1).toLower();
-    bool on = re.captured(2).isEmpty() || re.captured(2).toLower() == "true";
-    if (hintString.contains("antialiasing")) {
-        if (m_verboseMode)
-            printf(" -(lance) setRenderHint Antialiasing\n");
+    QString setting = re.captured(2).toLower();
 
-        m_painter->setRenderHint(QPainter::Antialiasing, on);
+    bool on = setting.isEmpty() || setting == "true" || setting == "on";
+    QPainter::RenderHint hint;
+    int hintIdx = -1;
+    if (hintString.contains("antialiasing")) {
+        hintIdx = 0;
+        hint = QPainter::Antialiasing;
     } else if (hintString.contains("smoothpixmaptransform")) {
+        hintIdx = 1;
+        hint = QPainter::SmoothPixmapTransform;
+    } else if (hintString.contains("noncosmeticbrushpatterns")) {
+        hintIdx = 2;
+        hint = QPainter::NonCosmeticBrushPatterns;
+    }
+    if (hintIdx >= 0) {
         if (m_verboseMode)
-            printf(" -(lance) setRenderHint SmoothPixmapTransform\n");
-        m_painter->setRenderHint(QPainter::SmoothPixmapTransform, on);
+            printf(" -(lance) setRenderHint %s %s\n", renderHintTable[hintIdx], on ? "true" : "false");
+        m_painter->setRenderHint(hint, on);
     } else {
-        fprintf(stderr, "ERROR(setRenderHint): unknown hint '%s'\n", qPrintable(hintString));
+        fprintf(stderr, "ERROR(setRenderHint): unknown hint '%s'\n", qPrintable(re.captured(1)));
     }
 }
 
@@ -2260,6 +2276,7 @@ void PaintCommands::command_clearRenderHint(QRegularExpressionMatch /*re*/)
 {
     m_painter->setRenderHint(QPainter::Antialiasing, false);
     m_painter->setRenderHint(QPainter::SmoothPixmapTransform, false);
+    m_painter->setRenderHint(QPainter::NonCosmeticBrushPatterns, false);
     if (m_verboseMode)
         printf(" -(lance) clearRenderHint\n");
 }
diff --git a/tests/baseline/shared/paintcommands.h b/tests/baseline/shared/paintcommands.h
index 75f48d3eb7..0d8044fc47 100644
--- a/tests/baseline/shared/paintcommands.h
+++ b/tests/baseline/shared/paintcommands.h
@@ -280,6 +280,7 @@ private:
     static const char *compositionModeTable[];
     static const char *imageFormatTable[];
     static const char *sizeModeTable[];
+    static const char *renderHintTable[];
     static int translateEnum(const char *table[], const QString &pattern, int limit);
 
     // utility