gfx/gl/ForceDiscreteGPUHelperCGL.h
author Rok Garbas <rok@garbas.si>
Thu, 24 Oct 2019 10:46:35 +0300
branchTHUNDERBIRD_60_VERBRANCH
changeset 451336 4f509288cfcabfd5ce6a6f3f6b5e11d239781719
parent 450616 4bcb64fd8fa1aae1bdb7a2a019a283eacb7af4ca
permissions -rw-r--r--
Bug 1590728 - uplifting (Bug 1557255) switch from relengapi-proxy to taskcluster-proxy in taskgraph. a=jorgk DONTBUILD CLOSED TREE Differential Revision: https://phabricator.services.mozilla.com/D50439

/* -*- 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_