From 73119e27b31e7d5b48e1cd3fcbe2f6edf049da5d Mon Sep 17 00:00:00 2001
From: Eirik Aavitsland <eirik.aavitsland@qt.io>
Date: Fri, 15 Oct 2021 12:14:28 +0200
Subject: Handle DPR in QPainter's drawing methods taking a brush parameter
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The emulation paint engine is required not only for non-LogicalMode
gradient brushes, but also for texture (pixmap/image) brushes with
DPR != 1. fillRect(), strokePath() etc. would check for the former
case, but not the latter.

Fix by factoring out a common checking function.

Pick-to: 6.2 5.15
Fixes: QTBUG-89101
Change-Id: I3cddf8a86a321de97b12c85a187069e77d2acea6
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
---
 src/gui/painting/qpainter.cpp | 66 ++++++++++++++++++++-----------------------
 1 file changed, 31 insertions(+), 35 deletions(-)

(limited to 'src/gui/painting')

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 83fc66c50d..e5caf0813b 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -180,6 +180,23 @@ static bool qt_painter_thread_test(int devType, int engineType, const char *what
 }
 #endif
 
+static bool needsEmulation(const QBrush &brush)
+{
+    bool res = false;
+
+    const QGradient *bg = brush.gradient();
+    if (bg) {
+        res = (bg->coordinateMode() > QGradient::LogicalMode);
+    } else if (brush.style() == Qt::TexturePattern) {
+        if (qHasPixmapTexture(brush))
+            res = !qFuzzyCompare(brush.texture().devicePixelRatio(), qreal(1.0));
+        else
+            res = !qFuzzyCompare(brush.textureImage().devicePixelRatio(), qreal(1.0));
+    }
+
+    return res;
+}
+
 void QPainterPrivate::checkEmulation()
 {
     Q_ASSERT(extended);
@@ -187,21 +204,12 @@ void QPainterPrivate::checkEmulation()
     if (state->bgMode == Qt::OpaqueMode)
         doEmulation = true;
 
-    const QGradient *bg = state->brush.gradient();
-    if (bg && bg->coordinateMode() > QGradient::LogicalMode)
+    if (needsEmulation(state->brush))
         doEmulation = true;
 
-    const QGradient *pg = qpen_brush(state->pen).gradient();
-    if (pg && pg->coordinateMode() > QGradient::LogicalMode)
+    if (needsEmulation(qpen_brush(state->pen)))
         doEmulation = true;
 
-    if (state->brush.style() == Qt::TexturePattern) {
-        if (qHasPixmapTexture(state->brush))
-            doEmulation |= !qFuzzyCompare(state->brush.texture().devicePixelRatio(), qreal(1.0));
-        else
-            doEmulation |= !qFuzzyCompare(state->brush.textureImage().devicePixelRatio(), qreal(1.0));
-    }
-
     if (doEmulation && extended->flags() & QPaintEngineEx::DoNotEmulate)
         return;
 
@@ -3083,12 +3091,9 @@ void QPainter::strokePath(const QPainterPath &path, const QPen &pen)
     if (path.isEmpty())
         return;
 
-    if (d->extended) {
-        const QGradient *g = qpen_brush(pen).gradient();
-        if (!g || g->coordinateMode() == QGradient::LogicalMode) {
-            d->extended->stroke(qtVectorPathForPath(path), pen);
-            return;
-        }
+    if (d->extended && !needsEmulation(pen.brush())) {
+        d->extended->stroke(qtVectorPathForPath(path), pen);
+        return;
     }
 
     QBrush oldBrush = d->state->brush;
@@ -3126,12 +3131,9 @@ void QPainter::fillPath(const QPainterPath &path, const QBrush &brush)
     if (path.isEmpty())
         return;
 
-    if (d->extended) {
-        const QGradient *g = brush.gradient();
-        if (!g || g->coordinateMode() == QGradient::LogicalMode) {
-            d->extended->fill(qtVectorPathForPath(path), brush);
-            return;
-        }
+    if (d->extended && !needsEmulation(brush)) {
+        d->extended->fill(qtVectorPathForPath(path), brush);
+        return;
     }
 
     QBrush oldBrush = d->state->brush;
@@ -6641,12 +6643,9 @@ void QPainter::fillRect(const QRectF &r, const QBrush &brush)
     if (!d->engine)
         return;
 
-    if (d->extended) {
-        const QGradient *g = brush.gradient();
-        if (!g || g->coordinateMode() == QGradient::LogicalMode) {
-            d->extended->fillRect(r, brush);
-            return;
-        }
+    if (d->extended && !needsEmulation(brush)) {
+        d->extended->fillRect(r, brush);
+        return;
     }
 
     QPen oldPen = pen();
@@ -6679,12 +6678,9 @@ void QPainter::fillRect(const QRect &r, const QBrush &brush)
     if (!d->engine)
         return;
 
-    if (d->extended) {
-        const QGradient *g = brush.gradient();
-        if (!g || g->coordinateMode() == QGradient::LogicalMode) {
-            d->extended->fillRect(r, brush);
-            return;
-        }
+    if (d->extended && !needsEmulation(brush)) {
+        d->extended->fillRect(r, brush);
+        return;
     }
 
     QPen oldPen = pen();
-- 
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