gecko/gfx/layers/opengl/ColorLayerOGL.cpp

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 * Contributor(s):
 *   Robert O'Callahan <robert@ocallahan.org>
 *   Vladimir Vukicevic <vladimir@pobox.com>
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#include "ColorLayerOGL.h"

namespace mozilla {
namespace layers {

Layer*
ColorLayerOGL::GetLayer()
{
  return this;
}

void
ColorLayerOGL::RenderLayer(int,
                           const nsIntPoint& aOffset)
{
  mOGLManager->MakeCurrent();

  // XXX we might be able to improve performance by using glClear

  nsIntRect visibleRect = mVisibleRegion.GetBounds();
  
  /* Multiply color by the layer opacity, as the shader
   * ignores layer opacity and expects a final color to
   * write to the color buffer.  This saves a needless
   * multiply in the fragment shader.
   */
  float opacity = GetOpacity();
  gfxRGBA color(mColor);
  color.r *= opacity;
  color.g *= opacity;
  color.b *= opacity;
  color.a *= opacity;

  SolidColorLayerProgram *program = mOGLManager->GetColorLayerProgram();
  program->Activate();
  program->SetLayerQuadRect(visibleRect);
  program->SetLayerTransform(mTransform);
  program->SetRenderOffset(aOffset);
  program->SetRenderColor(color);

  mOGLManager->BindAndDrawQuad(program);

  DEBUG_GL_ERROR_CHECK(gl());
}

} /* layers */
} /* mozilla */