Merge "Selectively enable and disable GL_BLEND for better performance."

5 files changed, 56 insertions, 15 deletions

diff --git a/WebCore/platform/graphics/android/BaseLayerAndroid.cpp b/WebCore/platform/graphics/android/BaseLayerAndroid.cpp
index 35c3b36..d2c41dc 100644
--- a/WebCore/platform/graphics/android/BaseLayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/BaseLayerAndroid.cpp
@@ -267,8 +267,6 @@ bool BaseLayerAndroid::drawGL(IntRect& viewRect, SkRect& visibleRect,
                  (float)m_color.green() / 255.0,
                  (float)m_color.blue() / 255.0, 1);
     glClear(GL_COLOR_BUFFER_BIT);
-    glEnable(GL_BLEND);
-    glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 
     glViewport(left, top, width, height);
     ShaderProgram* shader = TilesManager::instance()->shader();
@@ -280,6 +278,7 @@ bool BaseLayerAndroid::drawGL(IntRect& viewRect, SkRect& visibleRect,
     glUniform1i(shader->textureSampler(), 0);
     shader->setViewRect(viewRect);
     shader->setViewport(visibleRect);
+    shader->resetBlending();
 
     double currentTime = WTF::currentTime();
     ret = drawBasePictureInGL(visibleRect, scale, currentTime);
diff --git a/WebCore/platform/graphics/android/LayerAndroid.cpp b/WebCore/platform/graphics/android/LayerAndroid.cpp
index 7375cba..e000ab1 100644
--- a/WebCore/platform/graphics/android/LayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/LayerAndroid.cpp
@@ -868,9 +868,10 @@ bool LayerAndroid::drawGL(SkMatrix& matrix)
                  uniqueId(), this, getWidth(), getHeight(),
                  m_drawingTexture, textureRect.x(), textureRect.y(),
                  textureRect.width(), textureRect.height());
+            //TODO determine when drawing if the alpha value is used.
             TilesManager::instance()->shader()->drawLayerQuad(m, bounds,
                                                               textureInfo->m_textureId,
-                                                              m_drawOpacity);
+                                                              m_drawOpacity, true);
         }
         m_drawingTexture->consumerRelease();
     }
diff --git a/WebCore/platform/graphics/android/MediaLayer.cpp b/WebCore/platform/graphics/android/MediaLayer.cpp
index 7a4c02d..ad4fc76 100644
--- a/WebCore/platform/graphics/android/MediaLayer.cpp
+++ b/WebCore/platform/graphics/android/MediaLayer.cpp
@@ -84,19 +84,26 @@ bool MediaLayer::drawGL(SkMatrix& matrix)
     if (m_bufferedTexture) {
         TextureInfo* textureInfo = m_bufferedTexture->consumerLock();
         if (textureInfo) {
-            // the layer's shader draws the content inverted so we must undo
-            // that change in the transformation matrix
-            TransformationMatrix m = drawTransform();
-            if (!m_isContentInverted) {
-                m.flipY();
-                m.translate(0, -getSize().height());
-            }
 
             SkRect rect;
             rect.set(0, 0, getSize().width(), getSize().height());
-            TilesManager::instance()->shader()->drawLayerQuad(m, rect,
-                                                              textureInfo->m_textureId,
-                                                              1.0f); //TODO fix this m_drawOpacity
+
+            if (textureInfo->m_width != 0 && textureInfo->m_height != 0) {
+                // the layer's shader draws the content inverted so we must undo
+                // that change in the transformation matrix
+                TransformationMatrix m = drawTransform();
+                if (!m_isContentInverted) {
+                    m.flipY();
+                    m.translate(0, -getSize().height());
+                }
+
+                bool forceBlending = textureInfo->m_internalFormat == GL_RGBA ||
+                                     textureInfo->m_internalFormat == GL_ALPHA;
+                TilesManager::instance()->shader()->drawLayerQuad(m, rect,
+                                                                  textureInfo->m_textureId,
+                                                                  1.0f, forceBlending);
+            }
+
             if (!rect.isEmpty())
                 needsInval = false;
         }
diff --git a/WebCore/platform/graphics/android/ShaderProgram.cpp b/WebCore/platform/graphics/android/ShaderProgram.cpp
index c4129f1..828cc37 100644
--- a/WebCore/platform/graphics/android/ShaderProgram.cpp
+++ b/WebCore/platform/graphics/android/ShaderProgram.cpp
@@ -146,6 +146,7 @@ GLuint ShaderProgram::createProgram(const char* pVertexSource, const char* pFrag
 }
 
 ShaderProgram::ShaderProgram()
+    : m_blendingEnabled(false)
 {
     init();
 }
@@ -181,6 +182,27 @@ void ShaderProgram::init()
     glBufferData(GL_ARRAY_BUFFER, 2 * 4 * sizeof(GLfloat), coord, GL_STATIC_DRAW);
 }
 
+void ShaderProgram::resetBlending()
+{
+    glDisable(GL_BLEND);
+    glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+    glBlendEquation(GL_FUNC_ADD);
+    m_blendingEnabled = false;
+}
+
+void ShaderProgram::setBlendingState(bool enableBlending)
+{
+    if (enableBlending == m_blendingEnabled)
+        return;
+
+    if (enableBlending)
+        glEnable(GL_BLEND);
+    else
+        glDisable(GL_BLEND);
+
+    m_blendingEnabled = enableBlending;
+}
+
 /////////////////////////////////////////////////////////////////////////////////////////
 // Drawing
 /////////////////////////////////////////////////////////////////////////////////////////
@@ -222,6 +244,7 @@ void ShaderProgram::drawQuad(SkRect& geometry, int textureId, float opacity)
     glVertexAttribPointer(m_hPosition, 2, GL_FLOAT, GL_FALSE, 0, 0);
     glUniform1f(alpha(), opacity);
 
+    setBlendingState(opacity < 1.0);
     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 
     GLUtils::checkGlError("drawQuad");
@@ -278,7 +301,8 @@ IntRect ShaderProgram::clippedRectWithViewport(const IntRect& rect, int margin)
 }
 
 void ShaderProgram::drawLayerQuad(const TransformationMatrix& drawMatrix,
-                                  SkRect& geometry, int textureId, float opacity)
+                                  SkRect& geometry, int textureId, float opacity,
+                                  bool forceBlending)
 {
 
     TransformationMatrix renderMatrix = drawMatrix;
@@ -297,6 +321,7 @@ void ShaderProgram::drawLayerQuad(const TransformationMatrix& drawMatrix,
     glVertexAttribPointer(m_hPosition, 2, GL_FLOAT, GL_FALSE, 0, 0);
     glUniform1f(alpha(), opacity);
 
+    setBlendingState(forceBlending || opacity < 1.0);
     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 }
 
@@ -317,12 +342,14 @@ void ShaderProgram::drawVideoLayerQuad(const TransformationMatrix& drawMatrix,
     glUniformMatrix4fv(m_hVideoProjectionMatrix, 1, GL_FALSE, projectionMatrix);
     glUniformMatrix4fv(m_hVideoTextureMatrix, 1, GL_FALSE, textureMatrix);
 
+    glActiveTexture(GL_TEXTURE0);
     glBindTexture(GL_TEXTURE_EXTERNAL_OES, textureId);
 
     glBindBuffer(GL_ARRAY_BUFFER, m_textureBuffer[0]);
     glEnableVertexAttribArray(m_hVideoPosition);
     glVertexAttribPointer(m_hVideoPosition, 2, GL_FLOAT, GL_FALSE, 0, 0);
 
+    setBlendingState(false);
     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 
     // switch back to our normal rendering program
diff --git a/WebCore/platform/graphics/android/ShaderProgram.h b/WebCore/platform/graphics/android/ShaderProgram.h
index 5e2045c..9419511 100644
--- a/WebCore/platform/graphics/android/ShaderProgram.h
+++ b/WebCore/platform/graphics/android/ShaderProgram.h
@@ -40,7 +40,8 @@ class ShaderProgram {
     void setViewport(SkRect& viewport);
     void drawQuad(SkRect& geometry, int textureId, float opacity);
     void drawLayerQuad(const TransformationMatrix& drawMatrix,
-                     SkRect& geometry, int textureId, float opacity);
+                     SkRect& geometry, int textureId, float opacity,
+                     bool forceBlending = false);
     void drawVideoLayerQuad(const TransformationMatrix& drawMatrix,
                      float* textureMatrix, SkRect& geometry, int textureId);
     void setViewRect(const IntRect& viewRect);
@@ -49,11 +50,17 @@ class ShaderProgram {
     void clip(const FloatRect& rect);
     IntRect clippedRectWithViewport(const IntRect& rect, int margin = 0);
 
+    void resetBlending();
+
  private:
     GLuint loadShader(GLenum shaderType, const char* pSource);
     GLuint createProgram(const char* vertexSource, const char* fragmentSource);
     void setProjectionMatrix(SkRect& geometry);
 
+    void setBlendingState(bool enableBlending);
+
+    bool m_blendingEnabled;
+
     int m_program;
     int m_videoProgram;