3 files changed, 68 insertions, 1 deletions

diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index 6336b2943e..e0dd789dfd 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -2502,10 +2502,13 @@ void QRasterPaintEngine::drawTiledPixmap(const QRectF &r, const QPixmap &pixmap,
     if (image.depth() == 1)
         image = d->rasterBuffer->colorizeBitmap(image, s->pen.color());
 
-    if (s->matrix.type() > QTransform::TxTranslate) {
+    const qreal pixmapDevicePixelRatio = pixmap.devicePixelRatio();
+    if (s->matrix.type() > QTransform::TxTranslate || pixmapDevicePixelRatio > qreal(1.0)) {
         QTransform copy = s->matrix;
         copy.translate(r.x(), r.y());
         copy.translate(-sr.x(), -sr.y());
+        const qreal inverseDpr = qreal(1.0) / pixmapDevicePixelRatio;
+        copy.scale(inverseDpr, inverseDpr);
         d->image_filler_xform.clip = d->clip();
         d->image_filler_xform.initTexture(&image, s->intOpacity, QTextureData::Tiled);
         if (!d->image_filler_xform.blend)
diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index a0a58cc157..a37511ff0a 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -6664,6 +6664,16 @@ QRectF QPainter::boundingRect(const QRectF &r, const QString &text, const QTextO
     potentially much more efficient depending on the underlying window
     system.
 
+    drawTiledPixmap() will produce the same visual tiling pattern on
+    high-dpi displays (with devicePixelRatio > 1), compared to normal-
+    dpi displays. Set the devicePixelRatio on the \a pixmap to control
+    the tile size. For example, setting it to 2 halves the tile width
+    and height (on both 1x and 2x displays), and produces high-resolution
+    output on 2x displays.
+
+    The \a position offset is always in the painter coordinate system,
+    indepentent of display devicePixelRatio.
+
     \sa drawPixmap()
 */
 void QPainter::drawTiledPixmap(const QRectF &r, const QPixmap &pixmap, const QPointF &sp)
diff --git a/tests/manual/highdpi/main.cpp b/tests/manual/highdpi/main.cpp
index bd6af75b16..6f854a68d4 100644
--- a/tests/manual/highdpi/main.cpp
+++ b/tests/manual/highdpi/main.cpp
@@ -334,6 +334,59 @@ void PixmapPainter::paintEvent(QPaintEvent *)
     x+=dx * 2; p.drawImage(QRect(x, y, pixmapPointSize * 2, pixmapPointSize * 2), imageLarge);
  }
 
+class TiledPixmapPainter : public QWidget
+{
+public:
+    QPixmap pixmap1X;
+    QPixmap pixmap2X;
+    QPixmap pixmapLarge;
+
+    TiledPixmapPainter();
+    void paintEvent(QPaintEvent *event);
+};
+
+TiledPixmapPainter::TiledPixmapPainter()
+{
+    pixmap1X = QPixmap(":/qticon32.png");
+    pixmap2X = QPixmap(":/qticon32@2x.png");
+    pixmapLarge = QPixmap(":/qticon64.png");
+}
+
+void TiledPixmapPainter::paintEvent(QPaintEvent *event)
+{
+    QPainter p(this);
+
+    int xoff = 10;
+    int yoff = 10;
+    int tiles = 4;
+    int pixmapEdge = 32;
+    int tileAreaEdge = pixmapEdge * tiles;
+
+    // Expected behavior for both 1x and 2x dislays:
+    // 1x pixmap   : 4 x 4 tiles
+    // large pixmap: 2 x 2 tiles
+    // 2x pixmap   : 4 x 4 tiles
+    //
+    // On a 2x display the 2x pimxap tiles
+    // will be drawn in high resolution.
+    p.drawTiledPixmap(QRect(xoff, yoff, tileAreaEdge, tileAreaEdge), pixmap1X);
+    yoff += tiles * pixmapEdge + 10;
+    p.drawTiledPixmap(QRect(xoff, yoff, tileAreaEdge, tileAreaEdge), pixmapLarge);
+    yoff += tiles * pixmapEdge + 10;
+    p.drawTiledPixmap(QRect(xoff, yoff, tileAreaEdge, tileAreaEdge), pixmap2X);
+
+    // Again, with an offset. The offset is in
+    // device-independent pixels.
+    QPoint offset(40, 40); // larger than the pixmap edge size to exercise that code path
+    yoff = 10;
+    xoff = 20 + tiles * pixmapEdge ;
+    p.drawTiledPixmap(QRect(xoff, yoff, tileAreaEdge, tileAreaEdge), pixmap1X, offset);
+    yoff += tiles * pixmapEdge + 10;
+    p.drawTiledPixmap(QRect(xoff, yoff, tileAreaEdge, tileAreaEdge), pixmapLarge, offset);
+    yoff += tiles * pixmapEdge + 10;
+    p.drawTiledPixmap(QRect(xoff, yoff, tileAreaEdge, tileAreaEdge), pixmap2X, offset);
+}
+
 class Labels : public QWidget
 {
 public:
@@ -1119,6 +1172,7 @@ int main(int argc, char **argv)
 
     DemoContainerList demoList;
     demoList << new DemoContainer<PixmapPainter>("pixmap", "Test pixmap painter");
+    demoList << new DemoContainer<TiledPixmapPainter>("tiledpixmap", "Test tiled pixmap painter");
     demoList << new DemoContainer<Labels>("label", "Test Labels");
     demoList << new DemoContainer<MainWindow>("mainwindow", "Test QMainWindow");
     demoList << new DemoContainer<StandardIcons>("standard-icons", "Test standard icons");