Restore only modified texture state during virtual context switches

ui/gl/gl_gl_api_implementation.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 "ui/gl/gl_gl_api_implementation.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 236 matching lines @@
 
 void RealGLApi::Initialize(DriverGL* driver) {
   InitializeBase(driver);
 }
 
 TraceGLApi::~TraceGLApi() {
 }
 
 VirtualGLApi::VirtualGLApi()
     : real_context_(NULL),
-      current_context_(NULL) {
+      current_context_(NULL),
+      current_active_texture_unit_(GL_TEXTURE0) {
 }
 
 VirtualGLApi::~VirtualGLApi() {
 }
 
 void VirtualGLApi::Initialize(DriverGL* driver, GLContext* real_context) {
   InitializeBase(driver);
   real_context_ = real_context;
 
   DCHECK(real_context->IsCurrent(NULL));
@@ skipping 31 matching lines @@
   DCHECK_EQ(real_context_, GLContext::GetRealCurrent());
   DCHECK(real_context_->IsCurrent(NULL));
   DCHECK(virtual_context->IsCurrent(surface));
 
   if (switched_contexts || virtual_context != current_context_) {
     // There should be no errors from the previous context leaking into the
     // new context.
     DCHECK_EQ(glGetErrorFn(), static_cast<GLenum>(GL_NO_ERROR));
 
     current_context_ = virtual_context;
-    // Set all state that is different from the real state
-    // NOTE: !!! This is a temporary implementation that just restores all
-    // state to let us test that it works.
-    // TODO: ASAP, change this to something that only restores the state
-    // needed for individual GL calls.
+    // Set all state that is different from the real state.
     GLApi* temp = GetCurrentGLApi();
     SetGLToRealGLApi();
-    if (virtual_context->GetGLStateRestorer()->IsInitialized())
-      virtual_context->GetGLStateRestorer()->RestoreState();
+    if (virtual_context->GetGLStateRestorer()->IsInitialized()) {
+      virtual_context->GetGLStateRestorer()->RestoreState(
+          &dirty_texture_state_);
+      // Clear our dirty state after restoring state.
+      ClearDirtyTextureState();
+    }
     SetGLApi(temp);
   }
   SetGLApi(this);
 
   virtual_context->SetCurrent(surface);
   if (!surface->OnMakeCurrent(virtual_context)) {
     LOG(ERROR) << "Could not make GLSurface current.";
     return false;
   }
   return true;
 }
 
 void VirtualGLApi::OnReleaseVirtuallyCurrent(GLContext* virtual_context) {
-  if (current_context_ == virtual_context)
+  if (current_context_ == virtual_context) {
     current_context_ = NULL;
+    ClearDirtyTextureState();
+  }
 }
 
 const GLubyte* VirtualGLApi::glGetStringFn(GLenum name) {
   switch (name) {
     case GL_EXTENSIONS:
       return reinterpret_cast<const GLubyte*>(extensions_.c_str());
     default:
       return driver_->fn.glGetStringFn(name);
   }
 }
 
+void VirtualGLApi::glBindTextureFn(GLenum target, GLuint texture_id) {
+  dirty_texture_state_.AddBinding(current_active_texture_unit_, target);
+  driver_->fn.glBindTextureFn(target, texture_id);
+}
+
+void VirtualGLApi::glActiveTextureFn(GLenum texture_unit) {
+  current_active_texture_unit_ = texture_unit;
+  dirty_texture_state_.UpdateMaxTextureUnit(texture_unit);
+  driver_->fn.glActiveTextureFn(texture_unit);
+}
+
+void VirtualGLApi::ClearDirtyTextureState() {
+  current_active_texture_unit_ = GL_TEXTURE0;
+  dirty_texture_state_.Clear();
+}
+
 }  // namespace gfx