Merge "Improve rendering speed by disabling scissor tests"

Author: Romain Guy

libs/hwui/Caches.cpp

@@ -74,6 +74,7 @@ void Caches::init() {
 
     mTexCoordsArrayEnabled = false;
 
+    scissorEnabled = false;
     mScissorX = mScissorY = mScissorWidth = mScissorHeight = 0;
 
     glActiveTexture(gTextureUnits[0]);
@@ -352,7 +353,9 @@ void Caches::activeTexture(GLuint textureUnit) {
 }
 
 void Caches::setScissor(GLint x, GLint y, GLint width, GLint height) {
-    if (x != mScissorX || y != mScissorY || width != mScissorWidth || height != mScissorHeight) {
+    if (scissorEnabled && (x != mScissorX || y != mScissorY ||
+            width != mScissorWidth || height != mScissorHeight)) {
+
         glScissor(x, y, width, height);
 
         mScissorX = x;
@@ -362,6 +365,28 @@ void Caches::setScissor(GLint x, GLint y, GLint width, GLint height) {
     }
 }
 
+void Caches::enableScissor() {
+    if (!scissorEnabled) {
+        glEnable(GL_SCISSOR_TEST);
+        scissorEnabled = true;
+    }
+}
+
+void Caches::disableScissor() {
+    if (scissorEnabled) {
+        glDisable(GL_SCISSOR_TEST);
+        scissorEnabled = false;
+    }
+}
+
+void Caches::setScissorEnabled(bool enabled) {
+    if (scissorEnabled != enabled) {
+        if (enabled) glEnable(GL_SCISSOR_TEST);
+        else glDisable(GL_SCISSOR_TEST);
+        scissorEnabled = enabled;
+    }
+}
+
 void Caches::resetScissor() {
     mScissorX = mScissorY = mScissorWidth = mScissorHeight = 0;
 }

libs/hwui/Caches.h

@@ -204,6 +204,10 @@ class ANDROID_API Caches: public Singleton<Caches> {
      */
     void resetScissor();
 
+    void enableScissor();
+    void disableScissor();
+    void setScissorEnabled(bool enabled);
+
     /**
      * Returns the mesh used to draw regions. Calling this method will
      * bind a VBO of type GL_ELEMENT_ARRAY_BUFFER that contains the
@@ -221,6 +225,7 @@ class ANDROID_API Caches: public Singleton<Caches> {
     GLenum lastSrcMode;
     GLenum lastDstMode;
     Program* currentProgram;
+    bool scissorEnabled;
 
     // VBO to draw with
     GLuint meshBuffer;

libs/hwui/LayerRenderer.cpp

@@ -233,9 +233,8 @@ Layer* LayerRenderer::createLayer(uint32_t width, uint32_t height, bool isOpaque
     glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
             layer->getTexture(), 0);
 
-    glDisable(GL_SCISSOR_TEST);
+    caches.disableScissor();
     glClear(GL_COLOR_BUFFER_BIT);
-    glEnable(GL_SCISSOR_TEST);
 
     glBindFramebuffer(GL_FRAMEBUFFER, previousFbo);
 
@@ -431,7 +430,7 @@ bool LayerRenderer::copyLayer(Layer* layer, SkBitmap* bitmap) {
             renderer.OpenGLRenderer::prepareDirty(0.0f, 0.0f,
                     bitmap->width(), bitmap->height(), !layer->isBlend());
 
-            glDisable(GL_SCISSOR_TEST);
+            caches.disableScissor();
             renderer.translate(0.0f, bitmap->height());
             renderer.scale(1.0f, -1.0f);
 
@@ -460,8 +459,6 @@ bool LayerRenderer::copyLayer(Layer* layer, SkBitmap* bitmap) {
         }
 
 error:
-        glEnable(GL_SCISSOR_TEST);
-
 #if DEBUG_OPENGL
         if (error != GL_NO_ERROR) {
             ALOGD("GL error while copying layer into bitmap = 0x%x", error);

libs/hwui/OpenGLRenderer.cpp

@@ -157,7 +157,6 @@ void OpenGLRenderer::setViewport(int width, int height) {
     mFirstSnapshot->viewport.set(0, 0, width, height);
 
     glDisable(GL_DITHER);
-    glEnable(GL_SCISSOR_TEST);
     glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
 
     glEnableVertexAttribArray(Program::kBindingPosition);
@@ -181,6 +180,7 @@ int OpenGLRenderer::prepareDirty(float left, float top, float right, float botto
     syncState();
 
     if (!opaque) {
+        mCaches.enableScissor();
         mCaches.setScissor(left, mSnapshot->height - bottom, right - left, bottom - top);
         glClear(GL_COLOR_BUFFER_BIT);
         return DrawGlInfo::kStatusDrew;
@@ -250,7 +250,7 @@ void OpenGLRenderer::resume() {
     glViewport(0, 0, snapshot->viewport.getWidth(), snapshot->viewport.getHeight());
     glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
 
-    glEnable(GL_SCISSOR_TEST);
+    mCaches.enableScissor();
     mCaches.resetScissor();
     dirtyClip();
 
@@ -651,6 +651,7 @@ bool OpenGLRenderer::createFboLayer(Layer* layer, Rect& bounds, sp<Snapshot> sna
 #endif
 
     // Clear the FBO, expand the clear region by 1 to get nice bilinear filtering
+    mCaches.enableScissor();
     mCaches.setScissor(clip.left - 1.0f, bounds.getHeight() - clip.bottom - 1.0f,
             clip.getWidth() + 2.0f, clip.getHeight() + 2.0f);
     glClear(GL_COLOR_BUFFER_BIT);
@@ -981,7 +982,7 @@ void OpenGLRenderer::clearLayerRegions() {
         // The list contains bounds that have already been clipped
         // against their initial clip rect, and the current clip
         // is likely different so we need to disable clipping here
-        glDisable(GL_SCISSOR_TEST);
+        mCaches.disableScissor();
 
         Vertex mesh[count * 6];
         Vertex* vertex = mesh;
@@ -1008,8 +1009,6 @@ void OpenGLRenderer::clearLayerRegions() {
         setupDrawVertices(&mesh[0].position[0]);
 
         glDrawArrays(GL_TRIANGLES, 0, count * 6);
-
-        glEnable(GL_SCISSOR_TEST);
     } else {
         for (uint32_t i = 0; i < count; i++) {
             delete mLayers.itemAt(i);
@@ -1088,7 +1087,12 @@ bool OpenGLRenderer::quickReject(float left, float top, float right, float botto
     Rect clipRect(*mSnapshot->clipRect);
     clipRect.snapToPixelBoundaries();
 
-    return !clipRect.intersects(r);
+    bool rejected = !clipRect.intersects(r);
+    if (!isDeferred() && !rejected) {
+        mCaches.setScissorEnabled(!clipRect.contains(r));
+    }
+
+    return rejected;
 }
 
 bool OpenGLRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {

libs/hwui/Rect.h

@@ -125,11 +125,11 @@ class Rect {
         return intersect(r.left, r.top, r.right, r.bottom);
     }
 
-    bool contains(float l, float t, float r, float b) {
+    inline bool contains(float l, float t, float r, float b) {
         return l >= left && t >= top && r <= right && b <= bottom;
     }
 
-    bool contains(const Rect& r) {
+    inline bool contains(const Rect& r) {
         return contains(r.left, r.top, r.right, r.bottom);
     }