Add FBO support in Android WebView

webkit/common/gpu/webgraphicscontext3d_in_process_command_buffer_impl.cc

 // Copyright (c) 2012 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 "webkit/common/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h"
 
 #include <GLES2/gl2.h>
 #ifndef GL_GLEXT_PROTOTYPES
 #define GL_GLEXT_PROTOTYPES 1
 #endif
@@ skipping 55 matching lines @@
 }  // namespace anonymous
 
 // static
 scoped_ptr<WebKit::WebGraphicsContext3D>
 WebGraphicsContext3DInProcessCommandBufferImpl::CreateViewContext(
     const WebKit::WebGraphicsContext3D::Attributes& attributes,
     gfx::AcceleratedWidget window) {
   scoped_ptr<WebKit::WebGraphicsContext3D> context;
   if (gfx::GLSurface::InitializeOneOff()) {
     context.reset(new WebGraphicsContext3DInProcessCommandBufferImpl(
-      attributes, false, window));
+      scoped_ptr< ::gpu::GLInProcessContext>(), attributes, false, window));
   }
   return context.Pass();
 }
 
 // static
 scoped_ptr<WebKit::WebGraphicsContext3D>
 WebGraphicsContext3DInProcessCommandBufferImpl::CreateOffscreenContext(
     const WebKit::WebGraphicsContext3D::Attributes& attributes) {
   return make_scoped_ptr(new WebGraphicsContext3DInProcessCommandBufferImpl(
-      attributes, true, gfx::kNullAcceleratedWidget))
+                             scoped_ptr< ::gpu::GLInProcessContext>(),
+                             attributes,
+                             true,
+                             gfx::kNullAcceleratedWidget))
+      .PassAs<WebKit::WebGraphicsContext3D>();
+}
+
+scoped_ptr<WebKit::WebGraphicsContext3D>
+WebGraphicsContext3DInProcessCommandBufferImpl::WrapContext(
+    scoped_ptr< ::gpu::GLInProcessContext> context,
+    const WebKit::WebGraphicsContext3D::Attributes& attributes) {
+  return make_scoped_ptr(new WebGraphicsContext3DInProcessCommandBufferImpl(
+      context.Pass(),

[joth, 2013/08/04 00:45:16]

nit: make indent consistent with line 86 (I think this one is preferred)

[boliu, 2013/08/05 16:58:24]

clang-formatted both. Not exactly as you suggested.

+      attributes,
+      true /* is_offscreen. Not used. */,
+      gfx::kNullAcceleratedWidget /* window. Not used. */))
       .PassAs<WebKit::WebGraphicsContext3D>();
 }
 
 WebGraphicsContext3DInProcessCommandBufferImpl::
     WebGraphicsContext3DInProcessCommandBufferImpl(
+        scoped_ptr< ::gpu::GLInProcessContext> context,
         const WebKit::WebGraphicsContext3D::Attributes& attributes,
         bool is_offscreen,
         gfx::AcceleratedWidget window)
     : is_offscreen_(is_offscreen),
       window_(window),
       initialized_(false),
       initialize_failed_(false),
+      context_(context.Pass()),
       gl_(NULL),
       context_lost_callback_(NULL),
       context_lost_reason_(GL_NO_ERROR),
       attributes_(attributes),
       cached_width_(0),
       cached_height_(0) {
 }
 
 WebGraphicsContext3DInProcessCommandBufferImpl::
     ~WebGraphicsContext3DInProcessCommandBufferImpl() {
 }
 
 bool WebGraphicsContext3DInProcessCommandBufferImpl::MaybeInitializeGL() {
   if (initialized_)
     return true;
 
   if (initialize_failed_)
     return false;
 
   // Ensure the gles2 library is initialized first in a thread safe way.
   g_gles2_initializer.Get();
 
-  // Convert WebGL context creation attributes into GLInProcessContext / EGL
-  // size requests.
-  const int alpha_size = attributes_.alpha ? 8 : 0;
-  const int depth_size = attributes_.depth ? 24 : 0;
-  const int stencil_size = attributes_.stencil ? 8 : 0;
-  const int samples = attributes_.antialias ? 4 : 0;
-  const int sample_buffers = attributes_.antialias ? 1 : 0;
-  const int32 attribs[] = {
-    GLInProcessContext::ALPHA_SIZE, alpha_size,
-    GLInProcessContext::DEPTH_SIZE, depth_size,
-    GLInProcessContext::STENCIL_SIZE, stencil_size,
-    GLInProcessContext::SAMPLES, samples,
-    GLInProcessContext::SAMPLE_BUFFERS, sample_buffers,
-    GLInProcessContext::NONE,
-  };
+  if (!context_) {
+    // Convert WebGL context creation attributes into GLInProcessContext / EGL
+    // size requests.

[joth, 2013/08/04 00:45:16]

ah ha, here's where it was copied from. I have no suggestion if there is some
way we can share this blob of stuff. Static method on this class? Anyway, unless
it's simple I'm OK with a TODO in the other place to do this as follow up ,

[boliu, 2013/08/04 00:53:32]

Oh I tried static method. But didn't figure out a way to return a fixed size int
array. I could pass one in but can't use the initializer syntax and has to use
[] to access members which is error prone, so I got mad with c++ and just copied
it...

[joth, 2013/08/04 01:15:50]

yeah it's mucky if you want to carry the size info. we sort-of don't need them
due to the nul-terminated approach. So as long as we're happy is is living in
static const data, we can just do

static const int32* GetDefaultSurfaceAttribs() {
  const int alpha_size = attributes_.alpha ? 8 : 0;
  ...
  const static int32 attribs[] = { ... };
  return attribs;
}

+    const int alpha_size = attributes_.alpha ? 8 : 0;
+    const int depth_size = attributes_.depth ? 24 : 0;
+    const int stencil_size = attributes_.stencil ? 8 : 0;
+    const int samples = attributes_.antialias ? 4 : 0;
+    const int sample_buffers = attributes_.antialias ? 1 : 0;
+    const int32 attribs[] = {
+      GLInProcessContext::ALPHA_SIZE, alpha_size,
+      GLInProcessContext::DEPTH_SIZE, depth_size,
+      GLInProcessContext::STENCIL_SIZE, stencil_size,
+      GLInProcessContext::SAMPLES, samples,
+      GLInProcessContext::SAMPLE_BUFFERS, sample_buffers,
+      GLInProcessContext::NONE,
+    };
 
-  const char* preferred_extensions = "*";
+    const char* preferred_extensions = "*";
 
-  // TODO(kbr): More work will be needed in this implementation to
-  // properly support GPU switching. Like in the out-of-process
-  // command buffer implementation, all previously created contexts
-  // will need to be lost either when the first context requesting the
-  // discrete GPU is created, or the last one is destroyed.
-  gfx::GpuPreference gpu_preference = gfx::PreferDiscreteGpu;
+    // TODO(kbr): More work will be needed in this implementation to
+    // properly support GPU switching. Like in the out-of-process
+    // command buffer implementation, all previously created contexts
+    // will need to be lost either when the first context requesting the
+    // discrete GPU is created, or the last one is destroyed.
+    gfx::GpuPreference gpu_preference = gfx::PreferDiscreteGpu;
 
-  base::Closure context_lost_callback =
-      base::Bind(&WebGraphicsContext3DInProcessCommandBufferImpl::OnContextLost,
-                 base::Unretained(this));
+    context_.reset(GLInProcessContext::CreateContext(
+        is_offscreen_,
+        window_,
+        gfx::Size(1, 1),
+        attributes_.shareResources,
+        preferred_extensions,
+        attribs,
+        gpu_preference));
+  }
 
-  context_.reset(GLInProcessContext::CreateContext(
-      is_offscreen_,
-      window_,
-      gfx::Size(1, 1),
-      attributes_.shareResources,
-      preferred_extensions,
-      attribs,
-      gpu_preference,
-      context_lost_callback));
-
-  if (!context_) {
+  if (context_) {
+    base::Closure context_lost_callback = base::Bind(
+        &WebGraphicsContext3DInProcessCommandBufferImpl::OnContextLost,
+        base::Unretained(this));
+    context_->SetContextLostCallback(context_lost_callback);
+  } else {
     initialize_failed_ = true;
     return false;
   }
 
   gl_ = context_->GetImplementation();
 
   if (gl_ && attributes_.noExtensions)
     gl_->EnableFeatureCHROMIUM("webgl_enable_glsl_webgl_validation");
 
   // Set attributes_ from created offscreen context.
@@ skipping 1014 matching lines @@
 
 DELEGATE_TO_GL_9(asyncTexSubImage2DCHROMIUM, AsyncTexSubImage2DCHROMIUM,
     WGC3Denum, WGC3Dint, WGC3Dint, WGC3Dint, WGC3Dsizei, WGC3Dsizei,
     WGC3Denum, WGC3Denum, const void*)
 
 DELEGATE_TO_GL_1(waitAsyncTexImage2DCHROMIUM, WaitAsyncTexImage2DCHROMIUM,
     WGC3Denum)
 
 }  // namespace gpu
 }  // namespace webkit