ui/gl/gl_surface_mac.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_surface.h"

#include <memory>

#include "base/logging.h"
#include "base/macros.h"
#include "base/trace_event/trace_event.h"
#include "ui/gl/gl_bindings.h"
#include "ui/gl/gl_context.h"
#include "ui/gl/gl_export.h"
#include "ui/gl/gl_implementation.h"
#include "ui/gl/gl_surface_osmesa.h"
#include "ui/gl/gl_surface_stub.h"

namespace gl {
namespace {

// A "no-op" surface. It is not required that a CGLContextObj have an
// associated drawable (pbuffer or fullscreen context) in order to be
// made current. Everywhere this surface type is used, we allocate an
// FBO at the user level as the drawable of the associated context.
class GL_EXPORT NoOpGLSurface : public GLSurface {
 public:
  explicit NoOpGLSurface(const gfx::Size& size) : size_(size) {}

  // Implement GLSurface.
  bool Initialize(GLSurface::Format format) override { return true; }
  void Destroy() override {}
  bool IsOffscreen() override { return true; }
  gfx::SwapResult SwapBuffers() override {
    NOTREACHED() << "Cannot call SwapBuffers on a NoOpGLSurface.";
    return gfx::SwapResult::SWAP_FAILED;
  }
  gfx::Size GetSize() override { return size_; }
  void* GetHandle() override { return NULL; }
  void* GetDisplay() override { return NULL; }
  bool IsSurfaceless() const override { return true; }

 protected:
  ~NoOpGLSurface() override {}

 private:
  gfx::Size size_;

  DISALLOW_COPY_AND_ASSIGN(NoOpGLSurface);
};

}  // namespace

scoped_refptr<GLSurface> GLSurface::CreateViewGLSurface(
    gfx::AcceleratedWidget window) {
  TRACE_EVENT0("gpu", "GLSurface::CreateViewGLSurface");
  switch (GetGLImplementation()) {
    case kGLImplementationDesktopGL:
    case kGLImplementationDesktopGLCoreProfile:
    case kGLImplementationAppleGL: {
      NOTIMPLEMENTED() << "No onscreen support on Mac.";
      return NULL;
    }
    case kGLImplementationOSMesaGL: {
      scoped_refptr<GLSurface> surface(new GLSurfaceOSMesaHeadless());
      if (!surface->Initialize())
        return NULL;
      return surface;
    }
    case kGLImplementationMockGL:
      return new GLSurfaceStub;
    default:
      NOTREACHED();
      return NULL;
  }
}

scoped_refptr<GLSurface> GLSurface::CreateOffscreenGLSurface(
    const gfx::Size& size) {
  TRACE_EVENT0("gpu", "GLSurface::CreateOffscreenGLSurface");
  switch (GetGLImplementation()) {
    case kGLImplementationOSMesaGL: {
      scoped_refptr<GLSurface> surface(
          new GLSurfaceOSMesa(SURFACE_OSMESA_RGBA, size));
      if (!surface->Initialize())
        return NULL;

      return surface;
    }
    case kGLImplementationDesktopGL:
    case kGLImplementationDesktopGLCoreProfile:
    case kGLImplementationAppleGL: {
      scoped_refptr<GLSurface> surface(new NoOpGLSurface(size));
      if (!surface->Initialize())
        return NULL;

      return surface;
    }
    case kGLImplementationMockGL:
      return new GLSurfaceStub;
    default:
      NOTREACHED();
      return NULL;
  }
}

}  // namespace gl