Clean up DrawingBuffer.

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 109 matching lines @@
 WebGLRenderingContextBaseMap& forciblyEvictedContexts()
 {
     DEFINE_STATIC_LOCAL(WebGLRenderingContextBaseMap, forciblyEvictedContexts, ());
     return forciblyEvictedContexts;
 }
 
 } // namespace
 
 ScopedRGBEmulationColorMask::ScopedRGBEmulationColorMask(gpu::gles2::GLES2Interface* contextGL, GLboolean* colorMask, DrawingBuffer* drawingBuffer)
     : m_contextGL(contextGL)
-    , m_requiresEmulation(drawingBuffer->requiresRGBEmulation())
+    , m_requiresEmulation(drawingBuffer->requiresAlphaChannelToBePreserved())
 {
     if (m_requiresEmulation) {
         memcpy(m_colorMask, colorMask, 4 * sizeof(GLboolean));
         m_contextGL->ColorMask(m_colorMask[0], m_colorMask[1], m_colorMask[2], false);
     }
 }
 
 ScopedRGBEmulationColorMask::~ScopedRGBEmulationColorMask()
 {
     if (m_requiresEmulation)
@@ skipping 1016 matching lines @@
 
     contextGL()->Disable(GL_SCISSOR_TEST);
     if (combinedClear && (mask & GL_COLOR_BUFFER_BIT)) {
         contextGL()->ClearColor(m_colorMask[0] ? m_clearColor[0] : 0,
             m_colorMask[1] ? m_clearColor[1] : 0,
             m_colorMask[2] ? m_clearColor[2] : 0,
             m_colorMask[3] ? m_clearColor[3] : 0);
     } else {
         contextGL()->ClearColor(0, 0, 0, 0);
     }
-    contextGL()->ColorMask(true, true, true, !drawingBuffer()->requiresRGBEmulation());
+    contextGL()->ColorMask(true, true, true, !drawingBuffer()->requiresAlphaChannelToBePreserved());
     GLbitfield clearMask = GL_COLOR_BUFFER_BIT;
     if (contextAttributes.get().depth()) {
         if (!combinedClear || !m_depthMask || !(mask & GL_DEPTH_BUFFER_BIT))
             contextGL()->ClearDepthf(1.0f);
         clearMask |= GL_DEPTH_BUFFER_BIT;
         contextGL()->DepthMask(true);
     }
     if (contextAttributes.get().stencil() || drawingBuffer()->hasImplicitStencilBuffer()) {
         if (combinedClear && (mask & GL_STENCIL_BUFFER_BIT))
             contextGL()->ClearStencil(m_clearStencil & m_stencilMask);
@@ skipping 119 matching lines @@
     int currentArea = width * height;
     if (currentArea > maxArea) {
         // If we've exceeded the area limit scale the buffer down, preserving ascpect ratio, until it fits.
         float scaleFactor = sqrtf(static_cast<float>(maxArea) / static_cast<float>(currentArea));
         width = std::max(1, static_cast<int>(width * scaleFactor));
         height = std::max(1, static_cast<int>(height * scaleFactor));
     }
 
     // We don't have to mark the canvas as dirty, since the newly created image buffer will also start off
     // clear (and this matches what reshape will do).
-    bool wantDepthOrStencilBuffer = m_requestedAttributes.depth() || m_requestedAttributes.stencil();
-    drawingBuffer()->reset(IntSize(width, height), wantDepthOrStencilBuffer);
+    drawingBuffer()->reset(IntSize(width, height));
     restoreStateAfterClear();
 
     contextGL()->BindTexture(GL_TEXTURE_2D, objectOrZero(m_textureUnits[m_activeTextureUnit].m_texture2DBinding.get()));
     contextGL()->BindRenderbuffer(GL_RENDERBUFFER, objectOrZero(m_renderbufferBinding.get()));
     drawingBuffer()->restoreFramebufferBindings();
 }
 
 int WebGLRenderingContextBase::drawingBufferWidth() const
 {
     return isContextLost() ? 0 : drawingBuffer()->size().width();
@@ skipping 1268 matching lines @@
         return ScriptValue::createNull(scriptState);
     const int intZero = 0;
     switch (pname) {
     case GL_ACTIVE_TEXTURE:
         return getUnsignedIntParameter(scriptState, pname);
     case GL_ALIASED_LINE_WIDTH_RANGE:
         return getWebGLFloatArrayParameter(scriptState, pname);
     case GL_ALIASED_POINT_SIZE_RANGE:
         return getWebGLFloatArrayParameter(scriptState, pname);
     case GL_ALPHA_BITS:
-        if (m_drawingBuffer->requiresRGBEmulation())
+        if (m_drawingBuffer->requiresAlphaChannelToBePreserved())
             return WebGLAny(scriptState, 0);
         return getIntParameter(scriptState, pname);
     case GL_ARRAY_BUFFER_BINDING:
         return WebGLAny(scriptState, m_boundArrayBuffer.get());
     case GL_BLEND:
         return getBooleanParameter(scriptState, pname);
     case GL_BLEND_COLOR:
         return getWebGLFloatArrayParameter(scriptState, pname);
     case GL_BLEND_DST_ALPHA:
         return getUnsignedIntParameter(scriptState, pname);
@@ skipping 3699 matching lines @@
         contextGL()->PixelStorei(GL_UNPACK_ALIGNMENT, 1);
 }
 
 void WebGLRenderingContextBase::restoreUnpackParameters()
 {
     if (m_unpackAlignment != 1)
         contextGL()->PixelStorei(GL_UNPACK_ALIGNMENT, m_unpackAlignment);
 }
 
 } // namespace blink