Use GL_chromium_color_buffer_float extensions

Source/core/html/canvas/WebGLRenderingContext.cpp

Index: Source/core/html/canvas/WebGLRenderingContext.cpp
diff --git a/Source/core/html/canvas/WebGLRenderingContext.cpp b/Source/core/html/canvas/WebGLRenderingContext.cpp
index 56668d64afea6676d30de39aca0c725e38bc20be..e418968e6f3dac4bf7a82b3db7c9374395d675ac 100644
--- a/Source/core/html/canvas/WebGLRenderingContext.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContext.cpp
@@ -3313,6 +3313,18 @@ void WebGLRenderingContext::stencilOpSeparate(GLenum face, GLenum fail, GLenum z
     m_context->stencilOpSeparate(face, fail, zfail, zpass);
 }
 
+GLenum WebGLRenderingContext::convertTexInternalFormat(GLenum internalformat, GLenum type)
+{
+    // Convert to sized internal formats that are renderable with GL_CHROMIUM_color_buffer_float_rgb(a).
+    if (type == GL_FLOAT && internalformat == GL_RGBA
+        && m_contextSupport->isExtensionEnabled("GL_CHROMIUM_color_buffer_float_rgba"))
+        return GL_RGBA32F_EXT;
+    if (type == GL_FLOAT && internalformat == GL_RGB
+        && m_contextSupport->isExtensionEnabled("GL_CHROMIUM_color_buffer_float_rgb"))
+        return GL_RGB32F_EXT;
+    return internalformat;

[Ken Russell (switch to Gerrit), 2014/02/11 23:46:52]

There aren't any queries whose results need to be fixed up in the opposite
direction?

[oetuaho-nv, 2014/02/12 12:45:36]

I couldn't find any other calls where conversions should be needed by looking
through the API.

+}
+
 void WebGLRenderingContext::texImage2DBase(GLenum target, GLint level, GLenum internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const void* pixels, ExceptionState& exceptionState)
 {
     // All calling functions check isContextLost, so a duplicate check is not needed here.
@@ -3322,8 +3334,7 @@ void WebGLRenderingContext::texImage2DBase(GLenum target, GLint level, GLenum in
     ASSERT(tex);
     ASSERT(!level || !WebGLTexture::isNPOT(width, height));
     ASSERT(!pixels || validateSettableTexFormat("texImage2D", internalformat));
-    m_context->texImage2D(target, level, internalformat, width, height,
-                          border, format, type, pixels);
+    m_context->texImage2D(target, level, convertTexInternalFormat(internalformat, type), width, height, border, format, type, pixels);
     tex->setLevelInfo(target, level, internalformat, width, height, type);
 }