WebGL 2: add read/write framebuffer binding points to related APIs

Source/core/html/canvas/WebGL2RenderingContextBase.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/html/canvas/WebGL2RenderingContextBase.h"
 
 #include "bindings/core/v8/WebGLAny.h"
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLImageElement.h"
@@ skipping 1550 matching lines @@
         m_readFramebufferBinding = buffer;
         break;
     default:
         synthesizeGLError(GL_INVALID_ENUM, "bindFramebuffer", "invalid target");
         return;
     }
 
     setFramebuffer(target, buffer);
 }
 
+void WebGL2RenderingContextBase::deleteFramebuffer(WebGLFramebuffer* framebuffer)
+{
+    if (!deleteObject(framebuffer))
+        return;
+    GLenum target = 0;
+    if (framebuffer == m_framebufferBinding) {
+        if (framebuffer == m_readFramebufferBinding) {
+            target = GL_FRAMEBUFFER;
+            m_framebufferBinding = nullptr;
+            m_readFramebufferBinding = nullptr;
+        } else {
+            target = GL_DRAW_FRAMEBUFFER;
+            m_framebufferBinding = nullptr;
+        }
+    } else if (framebuffer == m_readFramebufferBinding) {
+        target = GL_READ_FRAMEBUFFER;
+        m_readFramebufferBinding = nullptr;
+    }
+    if (target) {
+        drawingBuffer()->setFramebufferBinding(target, 0);
+        // Have to call drawingBuffer()->bind() here to bind back to internal fbo.
+        drawingBuffer()->bind(target);
+    }
+}
+
 ScriptValue WebGL2RenderingContextBase::getParameter(ScriptState* scriptState, GLenum pname)
 {
     if (isContextLost())
         return ScriptValue::createNull(scriptState);
     switch (pname) {
     case GL_SHADING_LANGUAGE_VERSION:
         return WebGLAny(scriptState, "WebGL GLSL ES 3.00 (" + String(webContext()->getString(GL_SHADING_LANGUAGE_VERSION)) + ")");
     case GL_VERSION:
         return WebGLAny(scriptState, "WebGL 2.0 (" + String(webContext()->getString(GL_VERSION)) + ")");
 
@@ skipping 503 matching lines @@
     if (m_boundPixelUnpackBuffer == buffer)
         m_boundPixelUnpackBuffer = nullptr;
     if (m_boundTransformFeedbackBuffer == buffer)
         m_boundTransformFeedbackBuffer = nullptr;
     if (m_boundUniformBuffer == buffer)
         m_boundUniformBuffer = nullptr;
 
     WebGLRenderingContextBase::removeBoundBuffer(buffer);
 }
 
+void WebGL2RenderingContextBase::restoreCurrentFramebuffer()
+{
+    bindFramebuffer(GL_DRAW_FRAMEBUFFER, m_framebufferBinding.get());
+    bindFramebuffer(GL_READ_FRAMEBUFFER, m_readFramebufferBinding.get());
+}
+
+GLenum WebGL2RenderingContextBase::boundFramebufferColorFormat()
+{
+    if (m_readFramebufferBinding && m_readFramebufferBinding->object())
+        return m_readFramebufferBinding->colorBufferFormat();
+    if (m_requestedAttributes.alpha())
+        return GL_RGBA;
+    return GL_RGB;
+}
+
 } // namespace blink