ui/gl/gl_fence_nv.cc

// Copyright 2014 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_fence_nv.h"

#include "ui/gl/gl_bindings.h"

namespace gl {

GLFenceNV::GLFenceNV() {
  // What if either of these GL calls fails? TestFenceNV will return true.
  // See spec:
  // http://www.opengl.org/registry/specs/NV/fence.txt
  //
  // What should happen if TestFenceNV is called for a name before SetFenceNV
  // is called?
  //     We generate an INVALID_OPERATION error, and return TRUE.
  //     This follows the semantics for texture object names before
  //     they are bound, in that they acquire their state upon binding.
  //     We will arbitrarily return TRUE for consistency.
  glGenFencesNV(1, &fence_);
  ResetState();
}

bool GLFenceNV::ResetSupported() {
  return true;
}

void GLFenceNV::ResetState() {
  glSetFenceNV(fence_, GL_ALL_COMPLETED_NV);
  DCHECK(glIsFenceNV(fence_));
  glFlush();
}

bool GLFenceNV::HasCompleted() {
  DCHECK(glIsFenceNV(fence_));
  return !!glTestFenceNV(fence_);
}

void GLFenceNV::ClientWait() {
  DCHECK(glIsFenceNV(fence_));
  glFinishFenceNV(fence_);
}

void GLFenceNV::ServerWait() {
  DCHECK(glIsFenceNV(fence_));
  ClientWait();
}

GLFenceNV::~GLFenceNV() {
  if (fence_) {
    DCHECK(glIsFenceNV(fence_));
    glDeleteFencesNV(1, &fence_);
  }
}

void GLFenceNV::Invalidate() {
  fence_ = 0;
}

}  // namespace gl