Refactor glyph pretransform check

Move paintEngineSupportsTransformations logic from QPainter to paint
engine subclasses. Simplify and consolidate checks for cached drawing
(pretransformed) and path drawing (untransformed) in raster paint
engine. Fix unnecessary transform when paint engines actually take
the path drawing track. Fix scaling and rotation transform in raster
engine for Mac.

Task-number: QTBUG-19086
Change-Id: I1c0c1800a5173d3db765b9fccfd0e7a3628e3815
Reviewed-on: http://codereview.qt.nokia.com/298
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>

1 files changed, 14 insertions, 22 deletions

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 811e59b3b7..e7b5f18112 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -152,14 +152,6 @@ static inline uint line_emulation(uint emulation)
                         | QPaintEngine_OpaqueBackground);
 }
 
-static bool qt_paintengine_supports_transformations(QPaintEngine::Type type)
-{
-    return type == QPaintEngine::OpenGL2
-            || type == QPaintEngine::OpenVG
-            || type == QPaintEngine::OpenGL
-            || type == QPaintEngine::CoreGraphics;
-}
-
 #ifndef QT_NO_DEBUG
 static bool qt_painter_thread_test(int devType, const char *what, bool extraCondition = false)
 {
@@ -5815,20 +5807,19 @@ void QPainter::drawGlyphRun(const QPointF &position, const QGlyphRun &glyphRun)
     int count = qMin(glyphIndexes.size(), glyphPositions.size());
     QVarLengthArray<QFixedPoint, 128> fixedPointPositions(count);
 
-    bool paintEngineSupportsTransformations =
-            d->extended != 0
-            ? qt_paintengine_supports_transformations(d->extended->type())
-            : qt_paintengine_supports_transformations(d->engine->type());
-
-    // If the matrix is not affine, the paint engine will fall back to
-    // drawing the glyphs as paths, which in turn means we should not
-    // preprocess the glyph positions
-    if (!d->state->matrix.isAffine())
-        paintEngineSupportsTransformations = true;
+    QRawFontPrivate *fontD = QRawFontPrivate::get(font);
+    bool supportsTransformations;
+    if (d->extended != 0) {
+        supportsTransformations = d->extended->supportsTransformations(fontD->fontEngine->fontDef.pixelSize,
+                                                                       d->state->matrix);
+    } else {
+        supportsTransformations = d->engine->type() == QPaintEngine::CoreGraphics
+                                  || d->state->matrix.isAffine();
+    }
 
     for (int i=0; i<count; ++i) {
         QPointF processedPosition = position + glyphPositions.at(i);
-        if (!paintEngineSupportsTransformations)
+        if (!supportsTransformations)
             processedPosition = d->state->transform().map(processedPosition);
         fixedPointPositions[i] = QFixedPoint::fromPointF(processedPosition);
     }
@@ -6004,11 +5995,12 @@ void QPainter::drawStaticText(const QPointF &topLeftPosition, const QStaticText
         return;
     }
 
-    bool paintEngineSupportsTransformations = qt_paintengine_supports_transformations(d->extended->type());
-    if (paintEngineSupportsTransformations && !staticText_d->untransformedCoordinates) {
+    bool supportsTransformations = d->extended->supportsTransformations(staticText_d->font.pixelSize(),
+                                                                        d->state->matrix);
+    if (supportsTransformations && !staticText_d->untransformedCoordinates) {
         staticText_d->untransformedCoordinates = true;
         staticText_d->needsRelayout = true;
-    } else if (!paintEngineSupportsTransformations && staticText_d->untransformedCoordinates) {
+    } else if (!supportsTransformations && staticText_d->untransformedCoordinates) {
         staticText_d->untransformedCoordinates = false;
         staticText_d->needsRelayout = true;
     }