// 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 <algorithm>
#include <vector>

#include "base/command_line.h"
#include "base/debug/trace_event.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/threading/thread_local.h"
#include "ui/gl/gl_context.h"
#include "ui/gl/gl_implementation.h"
#include "ui/gl/gl_switches.h"

#if defined(USE_X11)
#include <X11/Xlib.h>
#endif

namespace gfx {

namespace {
base::LazyInstance<base::ThreadLocalPointer<GLSurface> >::Leaky
    current_surface_ = LAZY_INSTANCE_INITIALIZER;
}  // namespace

// static
bool GLSurface::InitializeOneOff() {
  DCHECK_EQ(kGLImplementationNone, GetGLImplementation());

  TRACE_EVENT0("gpu", "GLSurface::InitializeOneOff");

  std::vector<GLImplementation> allowed_impls;
  GetAllowedGLImplementations(&allowed_impls);
  DCHECK(!allowed_impls.empty());

  CommandLine* cmd = CommandLine::ForCurrentProcess();

  // The default implementation is always the first one in list.
  GLImplementation impl = allowed_impls[0];
  bool fallback_to_osmesa = false;
  if (cmd->HasSwitch(switches::kOverrideUseGLWithOSMesaForTests)) {
    impl = kGLImplementationOSMesaGL;
  } else if (cmd->HasSwitch(switches::kUseGL)) {
    std::string requested_implementation_name =
        cmd->GetSwitchValueASCII(switches::kUseGL);
    if (requested_implementation_name == "any") {
      fallback_to_osmesa = true;
    } else if (requested_implementation_name == "swiftshader") {
      impl = kGLImplementationEGLGLES2;
    } else {
      impl = GetNamedGLImplementation(requested_implementation_name);
      if (std::find(allowed_impls.begin(),
                    allowed_impls.end(),
                    impl) == allowed_impls.end()) {
        LOG(ERROR) << "Requested GL implementation is not available.";
        return false;
      }
    }
  }

  bool gpu_service_logging = cmd->HasSwitch(switches::kEnableGPUServiceLogging);
  bool disable_gl_drawing = cmd->HasSwitch(switches::kDisableGLDrawingForTests);

  return InitializeOneOffImplementation(
      impl, fallback_to_osmesa, gpu_service_logging, disable_gl_drawing);
}

// static
bool GLSurface::InitializeOneOffImplementation(GLImplementation impl,
                                               bool fallback_to_osmesa,
                                               bool gpu_service_logging,
                                               bool disable_gl_drawing) {
  bool initialized =
      InitializeStaticGLBindings(impl) && InitializeOneOffInternal();
  if (!initialized && fallback_to_osmesa) {
    ClearGLBindings();
    initialized = InitializeStaticGLBindings(kGLImplementationOSMesaGL) &&
                  InitializeOneOffInternal();
  }
  if (!initialized)
    ClearGLBindings();

  if (initialized) {
    DVLOG(1) << "Using "
             << GetGLImplementationName(GetGLImplementation())
             << " GL implementation.";
    if (gpu_service_logging)
      InitializeDebugGLBindings();
    if (disable_gl_drawing)
      InitializeNullDrawGLBindings();
  }
  return initialized;
}

// static
void GLSurface::InitializeOneOffForTests() {
  DCHECK_EQ(kGLImplementationNone, GetGLImplementation());

#if defined(USE_X11)
  XInitThreads();
#endif

  bool use_osmesa = true;

  // We usually use OSMesa as this works on all bots. The command line can
  // override this behaviour to use hardware GL.
  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseGpuInTests))
    use_osmesa = false;

#if defined(OS_ANDROID)
  // On Android we always use hardware GL.
  use_osmesa = false;
#endif

  std::vector<GLImplementation> allowed_impls;
  GetAllowedGLImplementations(&allowed_impls);
  DCHECK(!allowed_impls.empty());

  GLImplementation impl = allowed_impls[0];
  if (use_osmesa)
    impl = kGLImplementationOSMesaGL;

  DCHECK(!CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseGL))
      << "kUseGL has not effect in tests";

  bool fallback_to_osmesa = false;
  bool gpu_service_logging = false;
  bool disable_gl_drawing = true;

  CHECK(InitializeOneOffImplementation(
      impl, fallback_to_osmesa, gpu_service_logging, disable_gl_drawing));
}

// static
void GLSurface::InitializeOneOffWithMockBindingsForTests() {
  DCHECK(!CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseGL))
      << "kUseGL has not effect in tests";

  // This method may be called multiple times in the same process to set up
  // mock bindings in different ways.
  ClearGLBindings();

  bool fallback_to_osmesa = false;
  bool gpu_service_logging = false;
  bool disable_gl_drawing = false;

  CHECK(InitializeOneOffImplementation(kGLImplementationMockGL,
                                       fallback_to_osmesa,
                                       gpu_service_logging,
                                       disable_gl_drawing));
}

// static
void GLSurface::InitializeDynamicMockBindingsForTests(GLContext* context) {
  CHECK(InitializeDynamicGLBindings(kGLImplementationMockGL, context));
}

GLSurface::GLSurface() {}

bool GLSurface::Initialize() {
  return true;
}

bool GLSurface::Resize(const gfx::Size& size) {
  NOTIMPLEMENTED();
  return false;
}

bool GLSurface::Recreate() {
  NOTIMPLEMENTED();
  return false;
}

bool GLSurface::DeferDraws() {
  return false;
}

bool GLSurface::SupportsPostSubBuffer() {
  return false;
}

unsigned int GLSurface::GetBackingFrameBufferObject() {
  return 0;
}

bool GLSurface::PostSubBuffer(int x, int y, int width, int height) {
  return false;
}

bool GLSurface::OnMakeCurrent(GLContext* context) {
  return true;
}

bool GLSurface::SetBackbufferAllocation(bool allocated) {
  return true;
}

void GLSurface::SetFrontbufferAllocation(bool allocated) {
}

void* GLSurface::GetShareHandle() {
  NOTIMPLEMENTED();
  return NULL;
}

void* GLSurface::GetDisplay() {
  NOTIMPLEMENTED();
  return NULL;
}

void* GLSurface::GetConfig() {
  NOTIMPLEMENTED();
  return NULL;
}

unsigned GLSurface::GetFormat() {
  NOTIMPLEMENTED();
  return 0;
}

VSyncProvider* GLSurface::GetVSyncProvider() {
  return NULL;
}

GLSurface* GLSurface::GetCurrent() {
  return current_surface_.Pointer()->Get();
}

GLSurface::~GLSurface() {
  if (GetCurrent() == this)
    SetCurrent(NULL);
}

void GLSurface::SetCurrent(GLSurface* surface) {
  current_surface_.Pointer()->Set(surface);
}

bool GLSurface::ExtensionsContain(const char* c_extensions, const char* name) {
  DCHECK(name);
  if (!c_extensions)
    return false;
  std::string extensions(c_extensions);
  extensions += " ";

  std::string delimited_name(name);
  delimited_name += " ";

  return extensions.find(delimited_name) != std::string::npos;
}

GLSurfaceAdapter::GLSurfaceAdapter(GLSurface* surface) : surface_(surface) {}

bool GLSurfaceAdapter::Initialize() {
  return surface_->Initialize();
}

void GLSurfaceAdapter::Destroy() {
  surface_->Destroy();
}

bool GLSurfaceAdapter::Resize(const gfx::Size& size) {
  return surface_->Resize(size);
}

bool GLSurfaceAdapter::Recreate() {
  return surface_->Recreate();
}

bool GLSurfaceAdapter::DeferDraws() {
  return surface_->DeferDraws();
}

bool GLSurfaceAdapter::IsOffscreen() {
  return surface_->IsOffscreen();
}

bool GLSurfaceAdapter::SwapBuffers() {
  return surface_->SwapBuffers();
}

bool GLSurfaceAdapter::PostSubBuffer(int x, int y, int width, int height) {
  return surface_->PostSubBuffer(x, y, width, height);
}

bool GLSurfaceAdapter::SupportsPostSubBuffer() {
  return surface_->SupportsPostSubBuffer();
}

gfx::Size GLSurfaceAdapter::GetSize() {
  return surface_->GetSize();
}

void* GLSurfaceAdapter::GetHandle() {
  return surface_->GetHandle();
}

unsigned int GLSurfaceAdapter::GetBackingFrameBufferObject() {
  return surface_->GetBackingFrameBufferObject();
}

bool GLSurfaceAdapter::OnMakeCurrent(GLContext* context) {
  return surface_->OnMakeCurrent(context);
}

bool GLSurfaceAdapter::SetBackbufferAllocation(bool allocated) {
  return surface_->SetBackbufferAllocation(allocated);
}

void GLSurfaceAdapter::SetFrontbufferAllocation(bool allocated) {
  surface_->SetFrontbufferAllocation(allocated);
}

void* GLSurfaceAdapter::GetShareHandle() {
  return surface_->GetShareHandle();
}

void* GLSurfaceAdapter::GetDisplay() {
  return surface_->GetDisplay();
}

void* GLSurfaceAdapter::GetConfig() {
  return surface_->GetConfig();
}

unsigned GLSurfaceAdapter::GetFormat() {
  return surface_->GetFormat();
}

VSyncProvider* GLSurfaceAdapter::GetVSyncProvider() {
  return surface_->GetVSyncProvider();
}

GLSurfaceAdapter::~GLSurfaceAdapter() {}

}  // namespace gfx