Encode frame number in pixel data for pose sync

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 1118 matching lines @@
 
   m_defaultVertexArrayObject = WebGLVertexArrayObject::create(
       this, WebGLVertexArrayObjectBase::VaoTypeDefault);
   addContextObject(m_defaultVertexArrayObject.get());
 
   m_boundVertexArrayObject = m_defaultVertexArrayObject;
 
   m_vertexAttribType.resize(m_maxVertexAttribs);
 
   contextGL()->Viewport(0, 0, drawingBufferWidth(), drawingBufferHeight());
-  contextGL()->Scissor(0, 0, drawingBufferWidth(), drawingBufferHeight());
+  m_scissorBox[0] = m_scissorBox[1] = 0;
+  m_scissorBox[2] = drawingBufferWidth();
+  m_scissorBox[3] = drawingBufferHeight();
+  contextGL()->Scissor(m_scissorBox[0], m_scissorBox[1], m_scissorBox[2],
+                       m_scissorBox[3]);
 
   drawingBuffer()->contextProvider()->setLostContextCallback(
       convertToBaseCallback(WTF::bind(
           &WebGLRenderingContextBase::forceLostContext,
           wrapWeakPersistent(this), WebGLRenderingContextBase::RealLostContext,
           WebGLRenderingContextBase::Auto)));
   drawingBuffer()->contextProvider()->setErrorMessageCallback(
       convertToBaseCallback(
           WTF::bind(&WebGLRenderingContextBase::onErrorMessage,
                     wrapWeakPersistent(this))));
@@ skipping 218 matching lines @@
   drawingBuffer()->setBufferClearNeeded(false);
 
   return combinedClear ? CombinedClear : JustClear;
 }
 
 void WebGLRenderingContextBase::restoreStateAfterClear() {
   if (isContextLost())
     return;
 
   // Restore the state that the context set.
-  if (m_scissorEnabled)
+  if (m_scissorEnabled) {
     contextGL()->Enable(GL_SCISSOR_TEST);
+    // WebVR's VRDisplay uses a custom scissor box, need to restore that too.
+    contextGL()->Scissor(m_scissorBox[0], m_scissorBox[1], m_scissorBox[2],
+                         m_scissorBox[3]);
+  }
   contextGL()->ClearColor(m_clearColor[0], m_clearColor[1], m_clearColor[2],
                           m_clearColor[3]);
   contextGL()->ColorMask(m_colorMask[0], m_colorMask[1], m_colorMask[2],
                          m_colorMask[3]);
   contextGL()->ClearDepthf(m_clearDepth);
   contextGL()->ClearStencil(m_clearStencil);
   contextGL()->StencilMaskSeparate(GL_FRONT, m_stencilMask);
   contextGL()->DepthMask(m_depthMask);
 }
 
@@ skipping 2759 matching lines @@
     return;
   contextGL()->SampleCoverage(value, invert);
 }
 
 void WebGLRenderingContextBase::scissor(GLint x,
                                         GLint y,
                                         GLsizei width,
                                         GLsizei height) {
   if (isContextLost())
     return;
+  m_scissorBox[0] = x;
+  m_scissorBox[1] = y;
+  m_scissorBox[2] = width;
+  m_scissorBox[3] = height;
   contextGL()->Scissor(x, y, width, height);
 }
 
 void WebGLRenderingContextBase::shaderSource(WebGLShader* shader,
                                              const String& string) {
   if (isContextLost() || !validateWebGLObject("shaderSource", shader))
     return;
   String stringWithoutComments = StripComments(string).result();
   // TODO(danakj): Make validateShaderSource reject characters > 255 (or utf16 Strings)
   // so we don't need to use StringUTF8Adaptor.
@@ skipping 3259 matching lines @@
 
 void WebGLRenderingContextBase::getHTMLOrOffscreenCanvas(
     HTMLCanvasElementOrOffscreenCanvas& result) const {
   if (canvas())
     result.setHTMLCanvasElement(canvas());
   else
     result.setOffscreenCanvas(getOffscreenCanvas());
 }
 
 }  // namespace blink