Fixed some inconsistencies for image drawing on non-integer coords.

Don't use aliased coordinate delta for image drawing.
Related to change fde7475bcf9c10522a8170e6eb8fb9a8fadc21cd.

Task-number: 251561
Reviewed-by: Trond

2 files changed, 7 insertions, 11 deletions

diff --git a/src/gui/painting/qblendfunctions.cpp b/src/gui/painting/qblendfunctions.cpp
index dd7b0161be..93f11e14b7 100644
--- a/src/gui/painting/qblendfunctions.cpp
+++ b/src/gui/painting/qblendfunctions.cpp
@@ -44,8 +44,6 @@
 
 QT_BEGIN_NAMESPACE
 
-static const qreal aliasedCoordinateDelta = 0.5 - 0.015625;
-
 struct SourceOnlyAlpha
 {
     inline uchar alpha(uchar src) const { return src; }
@@ -140,14 +138,11 @@ struct Blend_ARGB32_on_RGB16_SourceAndConstAlpha {
 template <typename SRC, typename T>
 void qt_scale_image_16bit(uchar *destPixels, int dbpl,
                           const uchar *srcPixels, int sbpl,
-                          const QRectF &target,
+                          const QRectF &targetRect,
                           const QRectF &srcRect,
                           const QRect &clip,
                           T blender)
 {
-    const QRectF targetRect = target.translated(aliasedCoordinateDelta,
-                                                aliasedCoordinateDelta);
-
     qreal sx = targetRect.width() / (qreal) srcRect.width();
     qreal sy = targetRect.height() / (qreal) srcRect.height();
 
@@ -618,14 +613,11 @@ struct Blend_ARGB32_on_ARGB32_SourceAndConstAlpha {
 
 template <typename T> void qt_scale_image_32bit(uchar *destPixels, int dbpl,
                                                 const uchar *srcPixels, int sbpl,
-                                                const QRectF &target,
+                                                const QRectF &targetRect,
                                                 const QRectF &srcRect,
                                                 const QRect &clip,
                                                 T blender)
 {
-    const QRectF targetRect = target.translated(aliasedCoordinateDelta,
-                                                aliasedCoordinateDelta);
-
     qreal sx = targetRect.width() / (qreal) srcRect.width();
     qreal sy = targetRect.height() / (qreal) srcRect.height();
 
diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index 788b722a86..cbfd5e3eea 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -2573,7 +2573,11 @@ void QRasterPaintEngine::drawImage(const QRectF &r, const QImage &img, const QRe
     QRasterPaintEngineState *s = state();
     const bool aa = s->flags.antialiased || s->flags.bilinear;
     if (!aa && sr.size() == QSize(1, 1)) {
-        fillRect(r, QColor::fromRgba(img.pixel(sr.x(), sr.y())));
+        // as fillRect will apply the aliased coordinate delta we need to
+        // subtract it here as we don't use it for image drawing
+        const QRectF targetRect = r.translated(-aliasedCoordinateDelta,
+                                               -aliasedCoordinateDelta);
+        fillRect(targetRect, QColor::fromRgba(img.pixel(sr.x(), sr.y())));
         return;
     }