Clipping performance improvements
Create a ClipArea class to handle tracking clip regions. This class can
select the most efficient implementation depending on the types of
clipping presented.
ClipArea re-used the rectangle and region-based clipping
implementations as well as adding a "list of rotated rectangles"
approach that is more efficient for rotated views with children.
Change-Id: I2133761a2462ebc0852b394220e265974b3086f0
diff --git a/libs/hwui/ClipArea.h b/libs/hwui/ClipArea.h
new file mode 100644
index 0000000..16e6df9
--- /dev/null
+++ b/libs/hwui/ClipArea.h
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef CLIPAREA_H
+#define CLIPAREA_H
+
+#include <SkRegion.h>
+
+#include "Matrix.h"
+#include "Rect.h"
+#include "utils/Pair.h"
+
+namespace android {
+namespace uirenderer {
+
+Rect transformAndCalculateBounds(const Rect& r, const Matrix4& transform);
+
+class TransformedRectangle {
+public:
+ TransformedRectangle();
+ TransformedRectangle(const Rect& bounds, const Matrix4& transform);
+
+ bool canSimplyIntersectWith(const TransformedRectangle& other) const;
+ bool intersectWith(const TransformedRectangle& other);
+
+ bool isEmpty() const;
+
+ const Rect& getBounds() const {
+ return mBounds;
+ }
+
+ Rect transformedBounds() const {
+ Rect transformedBounds(transformAndCalculateBounds(mBounds, mTransform));
+ return transformedBounds;
+ }
+
+ const Matrix4& getTransform() const {
+ return mTransform;
+ }
+
+private:
+ Rect mBounds;
+ Matrix4 mTransform;
+};
+
+class RectangleList {
+public:
+ RectangleList();
+
+ bool isEmpty() const;
+ int getTransformedRectanglesCount() const;
+ const TransformedRectangle& getTransformedRectangle(int i) const;
+
+ void setEmpty();
+ void set(const Rect& bounds, const Matrix4& transform);
+ bool intersectWith(const Rect& bounds, const Matrix4& transform);
+
+ SkRegion convertToRegion(const SkRegion& clip) const;
+ Rect calculateBounds() const;
+
+private:
+ enum {
+ kMaxTransformedRectangles = 5
+ };
+
+ int mTransformedRectanglesCount;
+ TransformedRectangle mTransformedRectangles[kMaxTransformedRectangles];
+};
+
+class ClipArea {
+public:
+ ClipArea();
+
+ void setViewportDimensions(int width, int height);
+
+ bool isEmpty() const {
+ return mClipRect.isEmpty();
+ }
+
+ void setEmpty();
+ void setClip(float left, float top, float right, float bottom);
+ bool clipRectWithTransform(float left, float top, float right, float bottom,
+ const mat4* transform, SkRegion::Op op = SkRegion::kIntersect_Op);
+ bool clipRectWithTransform(const Rect& r, const mat4* transform,
+ SkRegion::Op op = SkRegion::kIntersect_Op);
+ bool clipRegion(const SkRegion& region, SkRegion::Op op = SkRegion::kIntersect_Op);
+ bool clipPathWithTransform(const SkPath& path, const mat4* transform,
+ SkRegion::Op op);
+
+ const Rect& getClipRect() const {
+ return mClipRect;
+ }
+
+ const SkRegion& getClipRegion() const {
+ return mClipRegion;
+ }
+
+ const RectangleList& getRectangleList() const {
+ return mRectangleList;
+ }
+
+ bool isRegion() const {
+ return kModeRegion == mMode;
+ }
+
+ bool isSimple() const {
+ return mMode == kModeRectangle;
+ }
+
+ bool isRectangleList() const {
+ return mMode == kModeRectangleList;
+ }
+
+private:
+ void enterRectangleMode();
+ bool rectangleModeClipRectWithTransform(const Rect& r, const mat4* transform, SkRegion::Op op);
+ bool rectangleModeClipRectWithTransform(float left, float top, float right,
+ float bottom, const mat4* transform, SkRegion::Op op);
+
+ void enterRectangleListMode();
+ bool rectangleListModeClipRectWithTransform(float left, float top,
+ float right, float bottom, const mat4* transform, SkRegion::Op op);
+ bool rectangleListModeClipRectWithTransform(const Rect& r,
+ const mat4* transform, SkRegion::Op op);
+
+ void enterRegionModeFromRectangleMode();
+ void enterRegionModeFromRectangleListMode();
+ void enterRegionMode();
+ bool regionModeClipRectWithTransform(const Rect& r, const mat4* transform,
+ SkRegion::Op op);
+ bool regionModeClipRectWithTransform(float left, float top, float right,
+ float bottom, const mat4* transform, SkRegion::Op op);
+
+ void ensureClipRegion();
+ void setClipRectToRegionBounds();
+ bool clipRegionOp(float left, float top, float right, float bottom,
+ SkRegion::Op op);
+
+ SkRegion createViewportRegion() {
+ return SkRegion(mViewportBounds.toSkIRect());
+ }
+
+ void regionFromPath(const SkPath& path, SkRegion& pathAsRegion) {
+ pathAsRegion.setPath(path, createViewportRegion());
+ }
+
+ enum Mode {
+ kModeRectangle,
+ kModeRegion,
+ kModeRectangleList
+ };
+
+ Mode mMode;
+ Rect mViewportBounds;
+ Rect mClipRect;
+ SkRegion mClipRegion;
+ RectangleList mRectangleList;
+};
+
+} /* namespace uirenderer */
+} /* namespace android */
+
+#endif /* CLIPAREA_H_ */