Merge branch '4.6' of scm.dev.nokia.troll.no:qt/oslo-staging-2 into 4.6-integration

* '4.6' of scm.dev.nokia.troll.no:qt/oslo-staging-2:
  Clipping with rounded rectangles and QVG_SCISSOR_CLIP

3 files changed, 48 insertions, 6 deletions

diff --git a/doc/src/howtos/openvg.qdoc b/doc/src/howtos/openvg.qdoc
index e448d9c..f4a34cd 100644
--- a/doc/src/howtos/openvg.qdoc
+++ b/doc/src/howtos/openvg.qdoc
@@ -262,7 +262,10 @@
 
     The QVG_SCISSOR_CLIP define will disable clipping with vgMask() or
     vgRenderToMask() and instead use the scissor rectangle list to perform
-    clipping.  Clipping with an arbitrary QPainterPath will not be supported.
+    clipping.  Clipping with an arbitrary QPainterPath will need to convert
+    the path into a series of rectangles.  If the number of rectangles
+    exceeds VG_MAX_SCISSOR_RECTS, then the results will not be exact.
+
     The QVG_SCISSOR_CLIP define should only be used if the OpenVG engine
     does not support vgMask() or vgRenderToMask().
 
diff --git a/doc/src/platforms/emb-openvg.qdocinc b/doc/src/platforms/emb-openvg.qdocinc
index 579af67..877d70c 100644
--- a/doc/src/platforms/emb-openvg.qdocinc
+++ b/doc/src/platforms/emb-openvg.qdocinc
@@ -225,7 +225,9 @@ The QVG_NO_RENDER_TO_MASK define will disable the use of vgRenderToMask().
 
 The QVG_SCISSOR_CLIP define will disable clipping with vgMask() or
 vgRenderToMask() and instead use the scissor rectangle list to perform
-clipping.  Clipping with an arbitrary QPainterPath will not be supported.
+clipping.  Clipping with an arbitrary QPainterPath will need to convert
+the path into a series of rectangles.  If the number of rectangles
+exceeds VG_MAX_SCISSOR_RECTS, then the results will not be exact.
  
 The QVG_SCISSOR_CLIP define should only be used if the OpenVG engine does
 not support vgMask() or vgRenderToMask().
diff --git a/src/openvg/qpaintengine_vg.cpp b/src/openvg/qpaintengine_vg.cpp
index 07f8415..cfc481e 100644
--- a/src/openvg/qpaintengine_vg.cpp
+++ b/src/openvg/qpaintengine_vg.cpp
@@ -1626,11 +1626,48 @@ void QVGPaintEngine::clip(const QVectorPath &path, Qt::ClipOperation op)
         QRectF rect(points[0], points[1], points[2] - points[0],
                     points[5] - points[1]);
         clip(rect.toRect(), op);
-    } else {
-        // The best we can do is clip to the bounding rectangle
-        // of all control points.
-        clip(path.controlPointRect().toRect(), op);
+        return;
+    }
+
+    // Try converting the path into a QRegion that tightly follows
+    // the outline of the path we want to clip with.
+    QRegion region(path.convertToPainterPath().toFillPolygon(QTransform()).toPolygon());
+    switch (op) {
+        case Qt::NoClip:
+        {
+            region = defaultClipRegion();
+        }
+        break;
+
+        case Qt::ReplaceClip:
+        {
+            region = d->transform.map(region);
+        }
+        break;
+
+        case Qt::IntersectClip:
+        {
+            region = s->clipRegion.intersect(d->transform.map(region));
+        }
+        break;
+
+        case Qt::UniteClip:
+        {
+            region = s->clipRegion.unite(d->transform.map(region));
+        }
+        break;
     }
+    if (region.numRects() <= d->maxScissorRects) {
+        // We haven't reached the maximum scissor count yet, so we can
+        // still make use of this region.
+        s->clipRegion = region;
+        updateScissor();
+        return;
+    }
+
+    // The best we can do is clip to the bounding rectangle
+    // of all control points.
+    clip(path.controlPointRect().toRect(), op);
 }
 
 void QVGPaintEngine::clip(const QRect &rect, Qt::ClipOperation op)