diff -r 000000000000 -r 6474c204b198 gfx/gl/ScopedGLHelpers.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/gl/ScopedGLHelpers.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,296 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GLContext.h"
+#include "ScopedGLHelpers.h"
+
+namespace mozilla {
+namespace gl {
+
+/* ScopedGLState - Wraps glEnable/glDisable. **********************************/
+
+// Use |newState = true| to enable, |false| to disable.
+ScopedGLState::ScopedGLState(GLContext* aGL, GLenum aCapability, bool aNewState)
+    : ScopedGLWrapper<ScopedGLState>(aGL)
+    , mCapability(aCapability)
+{
+    mOldState = mGL->fIsEnabled(mCapability);
+
+    // Early out if we're already in the right state.
+    if (aNewState == mOldState)
+        return;
+
+    if (aNewState) {
+        mGL->fEnable(mCapability);
+    } else {
+        mGL->fDisable(mCapability);
+    }
+}
+
+ScopedGLState::ScopedGLState(GLContext* aGL, GLenum aCapability)
+    : ScopedGLWrapper<ScopedGLState>(aGL)
+    , mCapability(aCapability)
+{
+    mOldState = mGL->fIsEnabled(mCapability);
+}
+
+void
+ScopedGLState::UnwrapImpl()
+{
+    if (mOldState) {
+        mGL->fEnable(mCapability);
+    } else {
+        mGL->fDisable(mCapability);
+    }
+}
+
+
+/* ScopedBindFramebuffer - Saves and restores with GetUserBoundFB and BindUserFB. */
+
+void
+ScopedBindFramebuffer::Init()
+{
+    mOldFB = mGL->GetFB();
+}
+
+ScopedBindFramebuffer::ScopedBindFramebuffer(GLContext* aGL)
+    : ScopedGLWrapper<ScopedBindFramebuffer>(aGL)
+{
+    Init();
+}
+
+ScopedBindFramebuffer::ScopedBindFramebuffer(GLContext* aGL, GLuint aNewFB)
+    : ScopedGLWrapper<ScopedBindFramebuffer>(aGL)
+{
+    Init();
+    mGL->BindFB(aNewFB);
+}
+
+void
+ScopedBindFramebuffer::UnwrapImpl()
+{
+    // Check that we're not falling out of scope after the current context changed.
+    MOZ_ASSERT(mGL->IsCurrent());
+
+    mGL->BindFB(mOldFB);
+}
+
+
+/* ScopedBindTextureUnit ******************************************************/
+
+ScopedBindTextureUnit::ScopedBindTextureUnit(GLContext* aGL, GLenum aTexUnit)
+    : ScopedGLWrapper<ScopedBindTextureUnit>(aGL)
+{
+    MOZ_ASSERT(aTexUnit >= LOCAL_GL_TEXTURE0);
+    mGL->GetUIntegerv(LOCAL_GL_ACTIVE_TEXTURE, &mOldTexUnit);
+    mGL->fActiveTexture(aTexUnit);
+}
+
+void
+ScopedBindTextureUnit::UnwrapImpl() {
+    // Check that we're not falling out of scope after the current context changed.
+    MOZ_ASSERT(mGL->IsCurrent());
+
+    mGL->fActiveTexture(mOldTexUnit);
+}
+
+
+/* ScopedTexture **************************************************************/
+
+ScopedTexture::ScopedTexture(GLContext* aGL)
+    : ScopedGLWrapper<ScopedTexture>(aGL)
+{
+    mGL->fGenTextures(1, &mTexture);
+}
+
+void
+ScopedTexture::UnwrapImpl()
+{
+    // Check that we're not falling out of scope after
+    // the current context changed.
+    MOZ_ASSERT(mGL->IsCurrent());
+
+    mGL->fDeleteTextures(1, &mTexture);
+}
+
+/* ScopedBindTexture **********************************************************/
+void
+ScopedBindTexture::Init(GLenum aTarget)
+{
+    mTarget = aTarget;
+    mOldTex = 0;
+    GLenum bindingTarget = (aTarget == LOCAL_GL_TEXTURE_2D) ? LOCAL_GL_TEXTURE_BINDING_2D
+                         : (aTarget == LOCAL_GL_TEXTURE_RECTANGLE_ARB) ? LOCAL_GL_TEXTURE_BINDING_RECTANGLE_ARB
+                         : (aTarget == LOCAL_GL_TEXTURE_CUBE_MAP) ? LOCAL_GL_TEXTURE_BINDING_CUBE_MAP
+                         : (aTarget == LOCAL_GL_TEXTURE_EXTERNAL) ? LOCAL_GL_TEXTURE_BINDING_EXTERNAL
+                         : LOCAL_GL_NONE;
+    MOZ_ASSERT(bindingTarget != LOCAL_GL_NONE);
+    mGL->GetUIntegerv(bindingTarget, &mOldTex);
+}
+
+ScopedBindTexture::ScopedBindTexture(GLContext* aGL, GLuint aNewTex, GLenum aTarget)
+        : ScopedGLWrapper<ScopedBindTexture>(aGL)
+    {
+        Init(aTarget);
+        mGL->fBindTexture(aTarget, aNewTex);
+    }
+
+void
+ScopedBindTexture::UnwrapImpl()
+{
+    // Check that we're not falling out of scope after the current context changed.
+    MOZ_ASSERT(mGL->IsCurrent());
+
+    mGL->fBindTexture(mTarget, mOldTex);
+}
+
+
+/* ScopedBindRenderbuffer *****************************************************/
+
+void
+ScopedBindRenderbuffer::Init()
+{
+    mOldRB = 0;
+    mGL->GetUIntegerv(LOCAL_GL_RENDERBUFFER_BINDING, &mOldRB);
+}
+
+ScopedBindRenderbuffer::ScopedBindRenderbuffer(GLContext* aGL)
+        : ScopedGLWrapper<ScopedBindRenderbuffer>(aGL)
+{
+    Init();
+}
+
+ScopedBindRenderbuffer::ScopedBindRenderbuffer(GLContext* aGL, GLuint aNewRB)
+    : ScopedGLWrapper<ScopedBindRenderbuffer>(aGL)
+{
+    Init();
+    mGL->fBindRenderbuffer(LOCAL_GL_RENDERBUFFER, aNewRB);
+}
+
+void
+ScopedBindRenderbuffer::UnwrapImpl() {
+    // Check that we're not falling out of scope after the current context changed.
+    MOZ_ASSERT(mGL->IsCurrent());
+
+    mGL->fBindRenderbuffer(LOCAL_GL_RENDERBUFFER, mOldRB);
+}
+
+
+/* ScopedFramebufferForTexture ************************************************/
+ScopedFramebufferForTexture::ScopedFramebufferForTexture(GLContext* aGL,
+                                                         GLuint aTexture,
+                                                         GLenum aTarget)
+    : ScopedGLWrapper<ScopedFramebufferForTexture>(aGL)
+    , mComplete(false)
+    , mFB(0)
+{
+    mGL->fGenFramebuffers(1, &mFB);
+    ScopedBindFramebuffer autoFB(aGL, mFB);
+    mGL->fFramebufferTexture2D(LOCAL_GL_FRAMEBUFFER,
+                               LOCAL_GL_COLOR_ATTACHMENT0,
+                               aTarget,
+                               aTexture,
+                               0);
+
+    GLenum status = mGL->fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER);
+    if (status == LOCAL_GL_FRAMEBUFFER_COMPLETE) {
+        mComplete = true;
+    } else {
+        mGL->fDeleteFramebuffers(1, &mFB);
+        mFB = 0;
+    }
+}
+
+void ScopedFramebufferForTexture::UnwrapImpl()
+{
+    if (!mFB)
+        return;
+
+    mGL->fDeleteFramebuffers(1, &mFB);
+    mFB = 0;
+}
+
+
+/* ScopedFramebufferForRenderbuffer *******************************************/
+
+
+ScopedFramebufferForRenderbuffer::ScopedFramebufferForRenderbuffer(GLContext* aGL,
+                                                                   GLuint aRB)
+    : ScopedGLWrapper<ScopedFramebufferForRenderbuffer>(aGL)
+    , mComplete(false)
+    , mFB(0)
+{
+    mGL->fGenFramebuffers(1, &mFB);
+    ScopedBindFramebuffer autoFB(aGL, mFB);
+    mGL->fFramebufferRenderbuffer(LOCAL_GL_FRAMEBUFFER,
+                                  LOCAL_GL_COLOR_ATTACHMENT0,
+                                  LOCAL_GL_RENDERBUFFER,
+                                  aRB);
+
+    GLenum status = mGL->fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER);
+    if (status == LOCAL_GL_FRAMEBUFFER_COMPLETE) {
+        mComplete = true;
+    } else {
+        mGL->fDeleteFramebuffers(1, &mFB);
+        mFB = 0;
+    }
+}
+
+void
+ScopedFramebufferForRenderbuffer::UnwrapImpl()
+{
+    if (!mFB)
+        return;
+
+    mGL->fDeleteFramebuffers(1, &mFB);
+    mFB = 0;
+}
+
+/* ScopedViewportRect *********************************************************/
+
+ScopedViewportRect::ScopedViewportRect(GLContext* aGL,
+                                       GLint x, GLint y,
+                                       GLsizei width, GLsizei height)
+  : ScopedGLWrapper<ScopedViewportRect>(aGL)
+{
+  mGL->fGetIntegerv(LOCAL_GL_VIEWPORT, mSavedViewportRect);
+  mGL->fViewport(x, y, width, height);
+}
+
+void ScopedViewportRect::UnwrapImpl()
+{
+  mGL->fViewport(mSavedViewportRect[0],
+                 mSavedViewportRect[1],
+                 mSavedViewportRect[2],
+                 mSavedViewportRect[3]);
+}
+
+/* ScopedScissorRect **********************************************************/
+
+ScopedScissorRect::ScopedScissorRect(GLContext* aGL,
+                                     GLint x, GLint y,
+                                     GLsizei width, GLsizei height)
+  : ScopedGLWrapper<ScopedScissorRect>(aGL)
+{
+  mGL->fGetIntegerv(LOCAL_GL_SCISSOR_BOX, mSavedScissorRect);
+  mGL->fScissor(x, y, width, height);
+}
+
+ScopedScissorRect::ScopedScissorRect(GLContext* aGL)
+  : ScopedGLWrapper<ScopedScissorRect>(aGL)
+{
+  mGL->fGetIntegerv(LOCAL_GL_SCISSOR_BOX, mSavedScissorRect);
+}
+
+void ScopedScissorRect::UnwrapImpl()
+{
+  mGL->fScissor(mSavedScissorRect[0],
+                mSavedScissorRect[1],
+                mSavedScissorRect[2],
+                mSavedScissorRect[3]);
+}
+
+} /* namespace gl */
+} /* namespace mozilla */