gecko-dev/gfx/gl/ForceDiscreteGPUHelperCGL.h

35 lines
1.2 KiB
C++

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* 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() : mPixelFormatObj(nullptr) {
// 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_