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authorJulien Brianceau <jbrianceau@nds.com>2012-11-07 11:01:08 +0100
committerThe Qt Project <gerrit-noreply@qt-project.org>2012-11-07 14:19:00 +0100
commit07ea3cf0b3883979e84bd91a5dc6a7a126de3123 (patch)
tree0f7164f0dafc3b4c637f07f445e6945884930386
parent2027f204b5deba93135349da27e58c9d6f6a8aed (diff)
qpa: Fix rendering issue in blitter engine (negative scaling factors)
A 180° rotation results in a TxScale QTransform with negative scaling factors (x=-1.0 y=-1.0). This is not properly handled by blitter paint engine yet, so use software rendering fallback in this case. This rendering issue can be seen when using "-webkit-transform" CSS property in WebKit with DirectFB QPA platform. Change-Id: Iee496b6bf0c90ffe36c4235ceaa2c80f296b2ca4 Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>
-rw-r--r--src/gui/painting/qpaintengine_blitter.cpp6
-rw-r--r--tests/auto/gui/painting/qpainter/tst_qpainter.cpp35
2 files changed, 40 insertions, 1 deletions
diff --git a/src/gui/painting/qpaintengine_blitter.cpp b/src/gui/painting/qpaintengine_blitter.cpp
index 1acdf8c433..c45513b4aa 100644
--- a/src/gui/painting/qpaintengine_blitter.cpp
+++ b/src/gui/painting/qpaintengine_blitter.cpp
@@ -330,7 +330,11 @@ void QBlitterPaintEnginePrivate::updateTransformState(QPainterState *s)
{
QTransform::TransformationType type = s->matrix.type();
- caps.updateState(STATE_XFORM_COMPLEX, type > QTransform::TxScale);
+ // consider scaling operations with a negative factor as "complex" for now.
+ // as some blitters could handle axisymmetrical operations, we should improve blitter
+ // paint engine to handle them as a capability
+ caps.updateState(STATE_XFORM_COMPLEX, (type > QTransform::TxScale) ||
+ ((type == QTransform::TxScale) && ((s->matrix.m11() < 0.0) || (s->matrix.m22() < 0.0))));
caps.updateState(STATE_XFORM_SCALE, type > QTransform::TxTranslate);
hasXForm = type >= QTransform::TxTranslate;
diff --git a/tests/auto/gui/painting/qpainter/tst_qpainter.cpp b/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
index be3e68ad38..51c261fc6a 100644
--- a/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
+++ b/tests/auto/gui/painting/qpainter/tst_qpainter.cpp
@@ -113,6 +113,7 @@ private slots:
void drawBorderPixmap();
#endif
void drawPixmapFragments();
+ void drawPixmapNegativeScale();
void drawLine_data();
void drawLine();
@@ -803,6 +804,40 @@ void tst_QPainter::drawPixmapFragments()
QVERIFY(fragment.opacity == 1);
}
+void tst_QPainter::drawPixmapNegativeScale()
+{
+ // basePixmap is a 16x16 opaque white square ...
+ QPixmap basePixmap(16, 16);
+ basePixmap.fill(QColor(255, 255, 255, 255));
+ // ... with an opaque black 8x16 left strip
+ QPainter p(&basePixmap);
+ p.setCompositionMode(QPainter::CompositionMode_Source);
+ p.fillRect(QRect(0, 0, 8, 16), QColor(0, 0, 0, 255));
+ p.end();
+
+ // verify one pixel value for each strip
+ QImage baseImage = basePixmap.toImage().convertToFormat(QImage::Format_ARGB32);
+ QVERIFY(baseImage.pixel(4, 8) == qRgba(0, 0, 0, 255));
+ QVERIFY(baseImage.pixel(12, 8) == qRgba(255, 255, 255, 255));
+
+ // resultPixmap is a 16x16 square
+ QPixmap resultPixmap(16, 16);
+
+ // draw basePixmap over resultPixmap using x=-1.0 y=-1.0
+ // scaling factors (i.e. 180° rotation)
+ QPainter p2(&resultPixmap);
+ p2.setCompositionMode(QPainter::CompositionMode_Source);
+ p2.scale(qreal(-1.0), qreal(-1.0));
+ p2.translate(-resultPixmap.width(), -resultPixmap.height());
+ p2.drawPixmap(resultPixmap.rect(), basePixmap);
+ p2.end();
+
+ // check result
+ QImage resultImage = resultPixmap.toImage().convertToFormat(QImage::Format_ARGB32);
+ QVERIFY(resultImage.pixel(4, 8) == qRgba(255, 255, 255, 255)); // left strip is now white
+ QVERIFY(resultImage.pixel(12, 8) == qRgba(0, 0, 0, 255)); // and right strip is now black
+}
+
void tst_QPainter::drawLine_data()
{
QTest::addColumn<QLine>("line");