Bug 978479 - remove flipped quad texture from mQuadVBO. r=bjacob

gfx/layers/opengl/CompositorOGL.cpp

@@ -372,8 +372,6 @@ CompositorOGL::Initialize()
     0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,
     /* Then quad texcoords */
     0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,
-    /* Then flipped quad texcoords */
-    0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f,
   };
   mGLContext->fBufferData(LOCAL_GL_ARRAY_BUFFER, sizeof(vertices), vertices, LOCAL_GL_STATIC_DRAW);
   mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
@@ -479,7 +477,7 @@ CompositorOGL::BindAndDrawQuadWithTextureRect(ShaderProgramOGL *aProg,
     Matrix4x4 transform;
     ToMatrix4x4(aTextureTransform * textureTransform, transform);
     aProg->SetTextureTransform(transform);
-    BindAndDrawQuad(aProg, false);
+    BindAndDrawQuad(aProg);
   } else {
     Matrix4x4 transform;
     ToMatrix4x4(aTextureTransform, transform);
@@ -988,7 +986,7 @@ CompositorOGL::DrawQuadInternal(const Rect& aRect,
         BindMaskForProgram(program, sourceMask, LOCAL_GL_TEXTURE0, maskQuadTransform);
       }
 
-      BindAndDrawQuad(program, false, aDrawMode);
+      BindAndDrawQuad(program, aDrawMode);
     }
     break;
 
@@ -1072,7 +1070,12 @@ CompositorOGL::DrawQuadInternal(const Rect& aRect,
 
       surface->BindTexture(LOCAL_GL_TEXTURE0, mFBOTextureTarget);
 
-      program->SetTextureTransform(Matrix4x4());
+      // Drawing is always flipped, but when copying between surfaces we want to avoid
+      // this, so apply a flip here to cancel the other one out.
+      Matrix transform;
+      transform.Translate(0.0, 1.0);
+      transform.Scale(1.0f, -1.0f);
+      program->SetTextureTransform(Matrix4x4::From2D(transform));
       program->SetTextureUnit(0);
 
       if (maskType != MaskNone) {
@@ -1089,7 +1092,7 @@ CompositorOGL::DrawQuadInternal(const Rect& aRect,
       // Drawing is always flipped, but when copying between surfaces we want to avoid
       // this. Pass true for the flip parameter to introduce a second flip
       // that cancels the other one out.
-      BindAndDrawQuad(program, true);
+      BindAndDrawQuad(program);
     }
     break;
   case EFFECT_COMPONENT_ALPHA: {
@@ -1429,28 +1432,16 @@ CompositorOGL::QuadVBOTexCoordsAttrib(GLuint aAttribIndex) {
                                     (GLvoid*) QuadVBOTexCoordOffset());
 }
 
-void
-CompositorOGL::QuadVBOFlippedTexCoordsAttrib(GLuint aAttribIndex) {
-  mGLContext->fVertexAttribPointer(aAttribIndex, 2,
-                                    LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0,
-                                    (GLvoid*) QuadVBOFlippedTexCoordOffset());
-}
-
 void
 CompositorOGL::BindAndDrawQuad(GLuint aVertAttribIndex,
                                GLuint aTexCoordAttribIndex,
-                               bool aFlipped,
                                GLuint aDrawMode)
 {
   BindQuadVBO();
   QuadVBOVerticesAttrib(aVertAttribIndex);
 
   if (aTexCoordAttribIndex != GLuint(-1)) {
-    if (aFlipped)
-      QuadVBOFlippedTexCoordsAttrib(aTexCoordAttribIndex);
-    else
-      QuadVBOTexCoordsAttrib(aTexCoordAttribIndex);
-
+    QuadVBOTexCoordsAttrib(aTexCoordAttribIndex);
     mGLContext->fEnableVertexAttribArray(aTexCoordAttribIndex);
   }
 
@@ -1464,13 +1455,12 @@ CompositorOGL::BindAndDrawQuad(GLuint aVertAttribIndex,
 
 void
 CompositorOGL::BindAndDrawQuad(ShaderProgramOGL *aProg,
-                               bool aFlipped,
                                GLuint aDrawMode)
 {
   NS_ASSERTION(aProg->HasInitialized(), "Shader program not correctly initialized");
   BindAndDrawQuad(aProg->AttribLocation(ShaderProgramOGL::VertexCoordAttrib),
                   aProg->AttribLocation(ShaderProgramOGL::TexCoordAttrib),
-                  aFlipped, aDrawMode);
+                  aDrawMode);
 }
 
 GLuint

gfx/layers/opengl/CompositorOGL.h

@@ -311,9 +311,10 @@ private:
   CompositingRenderTargetOGL* mWindowRenderTarget;
 #endif
 
-  /** VBO that has some basics in it for a textured quad,
-   *  including vertex coords and texcoords for both
-   *  flipped and unflipped textures */
+  /**
+   * VBO that has some basics in it for a textured quad, including vertex
+   * coords and texcoords.
+   */
   GLuint mQuadVBO;
 
   /**
@@ -366,18 +367,14 @@ private:
 
   GLintptr QuadVBOVertexOffset() { return 0; }
   GLintptr QuadVBOTexCoordOffset() { return sizeof(float)*4*2; }
-  GLintptr QuadVBOFlippedTexCoordOffset() { return sizeof(float)*8*2; }
 
   void BindQuadVBO();
   void QuadVBOVerticesAttrib(GLuint aAttribIndex);
   void QuadVBOTexCoordsAttrib(GLuint aAttribIndex);
-  void QuadVBOFlippedTexCoordsAttrib(GLuint aAttribIndex);
   void BindAndDrawQuad(GLuint aVertAttribIndex,
                        GLuint aTexCoordAttribIndex,
-                       bool aFlipped = false,
                        GLuint aDrawMode = LOCAL_GL_TRIANGLE_STRIP);
   void BindAndDrawQuad(ShaderProgramOGL *aProg,
-                       bool aFlipped = false,
                        GLuint aDrawMode = LOCAL_GL_TRIANGLE_STRIP);
   void BindAndDrawQuadWithTextureRect(ShaderProgramOGL *aProg,
                                       const gfx3DMatrix& aTextureTransform,