Revert "Revert "Add more support for transformed clip rects and paths""

This reverts commit a8557d2169e14997637f57bc897640c8882d4a46.

Change-Id: I36d4883d548fc47ba6c0b4a42012107d0d2f85a6

9 files changed, 189 insertions, 77 deletions

diff --git a/core/jni/android_view_GLES20Canvas.cpp b/core/jni/android_view_GLES20Canvas.cpp
index 9fc73a4..3538fef 100644
--- a/core/jni/android_view_GLES20Canvas.cpp
+++ b/core/jni/android_view_GLES20Canvas.cpp
@@ -46,6 +46,7 @@
 #include <OpenGLRenderer.h>
 #include <SkiaShader.h>
 #include <SkiaColorFilter.h>
+#include <Stencil.h>
 #include <Rect.h>
 
 #include <TextLayout.h>
@@ -150,7 +151,7 @@ static void android_view_GLES20Canvas_finish(JNIEnv* env, jobject clazz,
 }
 
 static jint android_view_GLES20Canvas_getStencilSize(JNIEnv* env, jobject clazz) {
-    return OpenGLRenderer::getStencilSize();
+    return Stencil::getStencilSize();
 }
 
 // ----------------------------------------------------------------------------
diff --git a/libs/hwui/Android.mk b/libs/hwui/Android.mk
index 1947c32..c3a07a1 100644
--- a/libs/hwui/Android.mk
+++ b/libs/hwui/Android.mk
@@ -28,6 +28,7 @@ ifeq ($(USE_OPENGL_RENDERER),true)
 		SkiaColorFilter.cpp \
 		SkiaShader.cpp \
 		Snapshot.cpp \
+		Stencil.cpp \
 		TextureCache.cpp \
 		TextDropShadowCache.cpp
 	
diff --git a/libs/hwui/Caches.h b/libs/hwui/Caches.h
index f4f56d6..b9a6336 100644
--- a/libs/hwui/Caches.h
+++ b/libs/hwui/Caches.h
@@ -38,6 +38,7 @@
 #include "TextDropShadowCache.h"
 #include "FboCache.h"
 #include "ResourceCache.h"
+#include "Stencil.h"
 #include "Dither.h"
 
 namespace android {
@@ -252,10 +253,14 @@ public:
     TextDropShadowCache dropShadowCache;
     FboCache fboCache;
     ResourceCache resourceCache;
-    Dither dither;
 
     GammaFontRenderer* fontRenderer;
 
+    Dither dither;
+#if STENCIL_BUFFER_SIZE
+    Stencil stencil;
+#endif
+
     // Debug methods
     PFNGLINSERTEVENTMARKEREXTPROC eventMark;
     PFNGLPUSHGROUPMARKEREXTPROC startMark;
diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index 8da9f66..2f43be8 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -139,10 +139,6 @@ void OpenGLRenderer::endMark() const {
 // Setup
 ///////////////////////////////////////////////////////////////////////////////
 
-uint32_t OpenGLRenderer::getStencilSize() {
-    return STENCIL_BUFFER_SIZE;
-}
-
 bool OpenGLRenderer::isDeferred() {
     return false;
 }
diff --git a/libs/hwui/OpenGLRenderer.h b/libs/hwui/OpenGLRenderer.h
index 2369f47..4c7cf0a 100644
--- a/libs/hwui/OpenGLRenderer.h
+++ b/libs/hwui/OpenGLRenderer.h
@@ -208,12 +208,6 @@ public:
     SkPaint* filterPaint(SkPaint* paint);
 
     /**
-     * Returns the desired size for the stencil buffer. If the returned value
-     * is 0, then no stencil buffer is required.
-     */
-    ANDROID_API static uint32_t getStencilSize();
-
-    /**
      * Sets the alpha on the current snapshot. This alpha value will be modulated
      * with other alpha values when drawing primitives.
      */
diff --git a/libs/hwui/Snapshot.cpp b/libs/hwui/Snapshot.cpp
index 5d5961a..4484676 100644
--- a/libs/hwui/Snapshot.cpp
+++ b/libs/hwui/Snapshot.cpp
@@ -57,7 +57,7 @@ Snapshot::Snapshot(const sp<Snapshot>& s, int saveFlags):
         clipRect = &mClipRectRoot;
 #if STENCIL_BUFFER_SIZE
         if (s->clipRegion) {
-            mClipRegionRoot.merge(*s->clipRegion);
+            mClipRegionRoot.op(*s->clipRegion, SkRegion::kUnion_Op);
             clipRegion = &mClipRegionRoot;
         }
 #endif
@@ -84,8 +84,7 @@ void Snapshot::ensureClipRegion() {
 #if STENCIL_BUFFER_SIZE
     if (!clipRegion) {
         clipRegion = &mClipRegionRoot;
-        android::Rect tmp(clipRect->left, clipRect->top, clipRect->right, clipRect->bottom);
-        clipRegion->set(tmp);
+        clipRegion->setRect(clipRect->left, clipRect->top, clipRect->right, clipRect->bottom);
     }
 #endif
 }
@@ -93,11 +92,11 @@ void Snapshot::ensureClipRegion() {
 void Snapshot::copyClipRectFromRegion() {
 #if STENCIL_BUFFER_SIZE
     if (!clipRegion->isEmpty()) {
-        android::Rect bounds(clipRegion->bounds());
-        clipRect->set(bounds.left, bounds.top, bounds.right, bounds.bottom);
+        const SkIRect& bounds = clipRegion->getBounds();
+        clipRect->set(bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
 
         if (clipRegion->isRect()) {
-            clipRegion->clear();
+            clipRegion->setEmpty();
             clipRegion = NULL;
         }
     } else {
@@ -107,43 +106,11 @@ void Snapshot::copyClipRectFromRegion() {
 #endif
 }
 
-bool Snapshot::clipRegionOr(float left, float top, float right, float bottom) {
+bool Snapshot::clipRegionOp(float left, float top, float right, float bottom, SkRegion::Op op) {
 #if STENCIL_BUFFER_SIZE
-    android::Rect tmp(left, top, right, bottom);
-    clipRegion->orSelf(tmp);
-    copyClipRectFromRegion();
-    return true;
-#else
-    return false;
-#endif
-}
-
-bool Snapshot::clipRegionXor(float left, float top, float right, float bottom) {
-#if STENCIL_BUFFER_SIZE
-    android::Rect tmp(left, top, right, bottom);
-    clipRegion->xorSelf(tmp);
-    copyClipRectFromRegion();
-    return true;
-#else
-    return false;
-#endif
-}
-
-bool Snapshot::clipRegionAnd(float left, float top, float right, float bottom) {
-#if STENCIL_BUFFER_SIZE
-    android::Rect tmp(left, top, right, bottom);
-    clipRegion->andSelf(tmp);
-    copyClipRectFromRegion();
-    return true;
-#else
-    return false;
-#endif
-}
-
-bool Snapshot::clipRegionNand(float left, float top, float right, float bottom) {
-#if STENCIL_BUFFER_SIZE
-    android::Rect tmp(left, top, right, bottom);
-    clipRegion->subtractSelf(tmp);
+    SkIRect tmp;
+    tmp.set(left, top, right, bottom);
+    clipRegion->op(tmp, op);
     copyClipRectFromRegion();
     return true;
 #else
@@ -161,14 +128,9 @@ bool Snapshot::clipTransformed(const Rect& r, SkRegion::Op op) {
     bool clipped = false;
 
     switch (op) {
-        case SkRegion::kDifference_Op: {
-            ensureClipRegion();
-            clipped = clipRegionNand(r.left, r.top, r.right, r.bottom);
-            break;
-        }
         case SkRegion::kIntersect_Op: {
             if (CC_UNLIKELY(clipRegion)) {
-                clipped = clipRegionOr(r.left, r.top, r.right, r.bottom);
+                clipped = clipRegionOp(r.left, r.top, r.right, r.bottom, SkRegion::kIntersect_Op);
             } else {
                 clipped = clipRect->intersect(r);
                 if (!clipped) {
@@ -180,26 +142,22 @@ bool Snapshot::clipTransformed(const Rect& r, SkRegion::Op op) {
         }
         case SkRegion::kUnion_Op: {
             if (CC_UNLIKELY(clipRegion)) {
-                clipped = clipRegionAnd(r.left, r.top, r.right, r.bottom);
+                clipped = clipRegionOp(r.left, r.top, r.right, r.bottom, SkRegion::kUnion_Op);
             } else {
                 clipped = clipRect->unionWith(r);
             }
             break;
         }
-        case SkRegion::kXOR_Op: {
-            ensureClipRegion();
-            clipped = clipRegionXor(r.left, r.top, r.right, r.bottom);
-            break;
-        }
-        case SkRegion::kReverseDifference_Op: {
-            // TODO!!!!!!!
-            break;
-        }
         case SkRegion::kReplace_Op: {
             setClip(r.left, r.top, r.right, r.bottom);
             clipped = true;
             break;
         }
+        default: {
+            ensureClipRegion();
+            clipped = clipRegionOp(r.left, r.top, r.right, r.bottom, op);
+            break;
+        }
     }
 
     if (clipped) {
@@ -213,7 +171,7 @@ void Snapshot::setClip(float left, float top, float right, float bottom) {
     clipRect->set(left, top, right, bottom);
 #if STENCIL_BUFFER_SIZE
     if (clipRegion) {
-        clipRegion->clear();
+        clipRegion->setEmpty();
         clipRegion = NULL;
     }
 #endif
diff --git a/libs/hwui/Snapshot.h b/libs/hwui/Snapshot.h
index 30b03fc..a89b740 100644
--- a/libs/hwui/Snapshot.h
+++ b/libs/hwui/Snapshot.h
@@ -198,7 +198,7 @@ public:
      *
      * This field is used only if STENCIL_BUFFER_SIZE is > 0.
      */
-    Region* clipRegion;
+    SkRegion* clipRegion;
 
     /**
      * The ancestor layer's dirty region.
@@ -223,17 +223,14 @@ private:
     void ensureClipRegion();
     void copyClipRectFromRegion();
 
-    bool clipRegionOr(float left, float top, float right, float bottom);
-    bool clipRegionXor(float left, float top, float right, float bottom);
-    bool clipRegionAnd(float left, float top, float right, float bottom);
-    bool clipRegionNand(float left, float top, float right, float bottom);
+    bool clipRegionOp(float left, float top, float right, float bottom, SkRegion::Op op);
 
     mat4 mTransformRoot;
     Rect mClipRectRoot;
     Rect mLocalClip;
 
 #if STENCIL_BUFFER_SIZE
-    Region mClipRegionRoot;
+    SkRegion mClipRegionRoot;
 #endif
 
 }; // class Snapshot
diff --git a/libs/hwui/Stencil.cpp b/libs/hwui/Stencil.cpp
new file mode 100644
index 0000000..9d2c86f
--- /dev/null
+++ b/libs/hwui/Stencil.cpp
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+#include <GLES2/gl2.h>
+
+#include "Properties.h"
+#include "Stencil.h"
+
+namespace android {
+namespace uirenderer {
+
+Stencil::Stencil(): mState(kDisabled) {
+}
+
+uint32_t Stencil::getStencilSize() {
+    return STENCIL_BUFFER_SIZE;
+}
+
+void Stencil::clear() {
+    glClearStencil(0);
+    glClear(GL_STENCIL_BUFFER_BIT);
+}
+
+void Stencil::enableTest() {
+    if (mState != kTest) {
+        enable();
+        glStencilFunc(GL_LESS, 0x0, 0x1);
+        // We only want to test, let's keep everything
+        glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
+        mState = kTest;
+    }
+}
+
+void Stencil::enableWrite() {
+    if (mState != kWrite) {
+        enable();
+        glStencilFunc(GL_ALWAYS, 0x1, 0x1);
+        // The test always passes so the first two values are meaningless
+        glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
+        mState = kWrite;
+    }
+}
+
+void Stencil::enable() {
+    if (!mState == kDisabled) {
+        glEnable(GL_STENCIL_TEST);
+    }
+}
+
+void Stencil::disable() {
+    if (mState != kDisabled) {
+        glDisable(GL_STENCIL_TEST);
+        mState = kDisabled;
+    }
+}
+
+}; // namespace uirenderer
+}; // namespace android
diff --git a/libs/hwui/Stencil.h b/libs/hwui/Stencil.h
new file mode 100644
index 0000000..67ccc78
--- /dev/null
+++ b/libs/hwui/Stencil.h
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2012 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 ANDROID_HWUI_STENCIL_H
+#define ANDROID_HWUI_STENCIL_H
+
+#ifndef LOG_TAG
+    #define LOG_TAG "OpenGLRenderer"
+#endif
+
+#include <cutils/compiler.h>
+
+namespace android {
+namespace uirenderer {
+
+///////////////////////////////////////////////////////////////////////////////
+// Stencil buffer management
+///////////////////////////////////////////////////////////////////////////////
+
+class ANDROID_API Stencil {
+public:
+    Stencil();
+
+    /**
+     * Returns the desired size for the stencil buffer. If the returned value
+     * is 0, then no stencil buffer is required.
+     */
+    ANDROID_API static uint32_t getStencilSize();
+
+    /**
+     * Clears the stencil buffer.
+     */
+    void clear();
+
+    /**
+     * Enables stencil test. When the stencil test is enabled the stencil
+     * buffer is not written into.
+     */
+    void enableTest();
+
+    /**
+     * Enables stencil write. When stencil write is enabled, the stencil
+     * test always succeeds and the value 0x1 is written in the stencil
+     * buffer for each fragment.
+     */
+    void enableWrite();
+
+    /**
+     * Disables stencil test and write.
+     */
+    void disable();
+
+    /**
+     * Indicates whether either test or write is enabled.
+     */
+    bool isEnabled() {
+        return mState != kDisabled;
+    }
+
+private:
+    void enable();
+
+    enum StencilState {
+        kDisabled,
+        kTest,
+        kWrite
+    };
+
+    StencilState mState;
+
+}; // class Stencil
+
+}; // namespace uirenderer
+}; // namespace android
+
+#endif // ANDROID_HWUI_STENCIL_H