gfx/gl/ForceDiscreteGPUHelperCGL.h
author Seth Fowler <mark.seth.fowler@gmail.com>
Wed, 22 Jul 2015 22:39:56 -0700
changeset 285945 aaf3459a20b5236b81c5d4f243503c9e1eeff3a6
parent 98529 f4157e8c410708d76703f19e4dfb61859bfe32d8
child 466377 d7d2f08e051c3c355d41dc5c1ce1bd3ca55a43b9
permissions -rw-r--r--
Bug 1184996 (Part 4) - Forbid instantiation of decoders except via DecoderFactory. r=tn

/* -*- Mode: C++; tab-width: 20; 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/. */

#ifndef ForceDiscreteGPUHelperCGL_h_
#define ForceDiscreteGPUHelperCGL_h_

#include <OpenGL/OpenGL.h>

/** This RAII helper guarantees that we're on the discrete GPU during its lifetime.
 * 
 * As long as any ForceDiscreteGPUHelperCGL object is alive, we're on the discrete GPU.
 */
class ForceDiscreteGPUHelperCGL
{
    CGLPixelFormatObj mPixelFormatObj;

public:
    ForceDiscreteGPUHelperCGL()
    {
        // the code in this function is taken from Chromium, src/ui/gfx/gl/gl_context_cgl.cc, r122013
        // BSD-style license, (c) The Chromium Authors
        CGLPixelFormatAttribute attribs[1];
        attribs[0] = static_cast<CGLPixelFormatAttribute>(0);
        GLint num_pixel_formats = 0;
        CGLChoosePixelFormat(attribs, &mPixelFormatObj, &num_pixel_formats);
    }

    ~ForceDiscreteGPUHelperCGL()
    {
        CGLReleasePixelFormat(mPixelFormatObj);
    }
};

#endif // ForceDiscreteGPUHelperCGL_h_