Add private circular reveal API on View/RenderNode

Change-Id: I139c8e12b354083149a665f6768f3f6931a8dd15
diff --git a/libs/hwui/RevealClip.h b/libs/hwui/RevealClip.h
new file mode 100644
index 0000000..ece8498
--- /dev/null
+++ b/libs/hwui/RevealClip.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2014 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 REVEALCLIP_H
+#define REVEALCLIP_H
+
+#include <SkPath.h>
+
+#include "Rect.h"
+
+namespace android {
+namespace uirenderer {
+
+class RevealClip {
+public:
+    RevealClip()
+            : mShouldClip(false)
+            , mInverseClip(false)
+            , mX(0)
+            , mY(0)
+            , mRadius(0) {}
+
+    void set(bool shouldClip, bool inverseClip, float x, float y, float radius) {
+        mShouldClip = shouldClip;
+        mInverseClip = inverseClip;
+        mX = x;
+        mY = y;
+        mRadius = radius;
+
+        mPath.rewind();
+        if (mShouldClip) {
+            mPath.addCircle(x, y, radius);
+        }
+    }
+
+    bool hasConvexClip() const {
+        return mShouldClip && !mInverseClip;
+    }
+
+    bool isInverseClip() const {
+        return mInverseClip;
+    }
+
+    bool willClip() const {
+        return mShouldClip;
+    }
+
+    const SkPath* getPath() const {
+        if (!mShouldClip) return NULL;
+
+        return &mPath;
+    }
+
+private:
+    bool mShouldClip;
+    bool mInverseClip;
+    float mX;
+    float mY;
+    float mRadius;
+    SkPath mPath;
+};
+
+} /* namespace uirenderer */
+} /* namespace android */
+
+#endif /* REVEALCLIP_H */