Support rrect clips in analysis canvas

skia/ext/analysis_canvas.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
 #include "skia/ext/analysis_canvas.h"
 #include "third_party/skia/include/core/SkDraw.h"
 #include "third_party/skia/include/core/SkPath.h"
 #include "third_party/skia/include/core/SkRRect.h"
@@ skipping 392 matching lines @@
   INHERITED::onClipRect(rect, op, edge_style);
 }
 
 void AnalysisCanvas::onClipPath(const SkPath& path,
                                 SkRegion::Op op,
                                 ClipEdgeStyle edge_style) {
   OnComplexClip();
   INHERITED::onClipRect(path.getBounds(), op, edge_style);
 }
 
+bool doesCoverCanvas(const SkRRect& rr,
+                     const SkMatrix& total_matrix,
+                     const SkIRect& clip_device_bounds) {
+  const SkRect& bounding_rect = rr.rect();
+
+  // We cannot handle non axis aligned rectangles at the moment.
+  if (!total_matrix.isScaleTranslate()) {
+    return false;
+  }
+
+  SkMatrix inverse;
+  if (!total_matrix.invert(&inverse)) {
+    return false;
+  }
+
+  SkRect clip_rect = SkRect::Make(clip_device_bounds);
+  inverse.mapRectScaleTranslate(&clip_rect, clip_rect);
+  return rr.contains(clip_rect);
+}
+
 void AnalysisCanvas::onClipRRect(const SkRRect& rrect,
                                  SkRegion::Op op,
                                  ClipEdgeStyle edge_style) {
+  SkIRect clip_device_bounds;
+  if (getClipDeviceBounds(&clip_device_bounds) &&
+      doesCoverCanvas(rrect, getTotalMatrix(), clip_device_bounds)) {
+    // If the canvas is fully contained within the clip, it is as if we weren't
+    // clipped at all, so bail early.
+    return;
+  }
+
   OnComplexClip();
   INHERITED::onClipRect(rrect.getBounds(), op, edge_style);
 }
 
 void AnalysisCanvas::onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op) {
   const ClipEdgeStyle edge_style = kHard_ClipEdgeStyle;
   if (deviceRgn.isRect()) {
     onClipRect(SkRect::MakeFromIRect(deviceRgn.getBounds()), op, edge_style);
     return;
   }
@@ skipping 60 matching lines @@
       force_not_transparent_stack_level_ = kNoLayer;
     }
   }
 
   INHERITED::willRestore();
 }
 
 }  // namespace skia