From 5a9cdc701e6f7a5e9af09dddad9ca3a4834c252b Mon Sep 17 00:00:00 2001 From: Julien Brianceau Date: Wed, 7 Nov 2012 16:35:34 +0100 Subject: qpa: Fix rendering issue in blitter engine (negative scaling factors) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. cherry-picked from qt5/qtbase 07ea3cf0b3883979e84bd91a5dc6a7a126de3123 Change-Id: I0911fd1166a3968d0a1d6bcca47ce2b26866de44 Reviewed-by: Samuel Rødal --- src/gui/painting/qpaintengine_blitter.cpp | 6 +++++- tests/auto/qpainter/tst_qpainter.cpp | 35 +++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 1 deletion(-) diff --git a/src/gui/painting/qpaintengine_blitter.cpp b/src/gui/painting/qpaintengine_blitter.cpp index cbf42bb..5ee2bc9 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/qpainter/tst_qpainter.cpp b/tests/auto/qpainter/tst_qpainter.cpp index fc2d045..f46e508 100644 --- a/tests/auto/qpainter/tst_qpainter.cpp +++ b/tests/auto/qpainter/tst_qpainter.cpp @@ -111,6 +111,7 @@ private slots: void drawBorderPixmap(); void drawPixmapFragments(); + void drawPixmapNegativeScale(); void drawLine_data(); void drawLine(); @@ -1058,6 +1059,40 @@ 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("line"); -- cgit v0.12