// 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 "gpu/command_buffer/service/texture_definition.h"

#include <list>

#include "base/memory/linked_ptr.h"
#include "base/memory/scoped_ptr.h"
#include "base/synchronization/lock.h"
#include "gpu/command_buffer/service/texture_manager.h"
#include "ui/gl/gl_image.h"
#include "ui/gl/gl_implementation.h"
#include "ui/gl/scoped_binders.h"

#if !defined(OS_MACOSX)
#include "ui/gl/gl_surface_egl.h"
#endif

namespace gpu {
namespace gles2 {

namespace {

class GLImageSync : public gfx::GLImage {
 public:
  explicit GLImageSync(const scoped_refptr<NativeImageBuffer>& buffer,
                       const gfx::Size& size);

  // Implement GLImage.
  void Destroy(bool have_context) override;
  gfx::Size GetSize() override;
  bool BindTexImage(unsigned target) override;
  void ReleaseTexImage(unsigned target) override;
  bool CopyTexImage(unsigned target) override;
  void WillUseTexImage() override;
  void WillModifyTexImage() override;
  void DidModifyTexImage() override;
  void DidUseTexImage() override;
  bool ScheduleOverlayPlane(gfx::AcceleratedWidget widget,
                            int z_order,
                            gfx::OverlayTransform transform,
                            const gfx::Rect& bounds_rect,
                            const gfx::RectF& crop_rect) override;

 protected:
  ~GLImageSync() override;

 private:
  scoped_refptr<NativeImageBuffer> buffer_;
  gfx::Size size_;

  DISALLOW_COPY_AND_ASSIGN(GLImageSync);
};

GLImageSync::GLImageSync(const scoped_refptr<NativeImageBuffer>& buffer,
                         const gfx::Size& size)
    : buffer_(buffer), size_(size) {
  if (buffer.get())
    buffer->AddClient(this);
}

GLImageSync::~GLImageSync() {
  if (buffer_.get())
    buffer_->RemoveClient(this);
}

void GLImageSync::Destroy(bool have_context) {
}

gfx::Size GLImageSync::GetSize() {
  return size_;
}

bool GLImageSync::BindTexImage(unsigned target) {
  NOTREACHED();
  return false;
}

void GLImageSync::ReleaseTexImage(unsigned target) {
  NOTREACHED();
}

bool GLImageSync::CopyTexImage(unsigned target) {
  return false;
}

void GLImageSync::WillUseTexImage() {
}

void GLImageSync::DidUseTexImage() {
}

void GLImageSync::WillModifyTexImage() {
}

void GLImageSync::DidModifyTexImage() {
}

bool GLImageSync::ScheduleOverlayPlane(gfx::AcceleratedWidget widget,
                                       int z_order,
                                       gfx::OverlayTransform transform,
                                       const gfx::Rect& bounds_rect,
                                       const gfx::RectF& crop_rect) {
  NOTREACHED();
  return false;
}

#if !defined(OS_MACOSX)
class NativeImageBufferEGL : public NativeImageBuffer {
 public:
  static scoped_refptr<NativeImageBufferEGL> Create(GLuint texture_id);

 private:
  NativeImageBufferEGL(EGLDisplay display, EGLImageKHR image);
  ~NativeImageBufferEGL() override;
  void AddClient(gfx::GLImage* client) override;
  void RemoveClient(gfx::GLImage* client) override;
  bool IsClient(gfx::GLImage* client) override;
  void BindToTexture(GLenum target) override;

  EGLDisplay egl_display_;
  EGLImageKHR egl_image_;

  base::Lock lock_;

  struct ClientInfo {
    explicit ClientInfo(gfx::GLImage* client);
    ~ClientInfo();

    gfx::GLImage* client;
    bool needs_wait_before_read;
  };
  std::list<ClientInfo> client_infos_;
  gfx::GLImage* write_client_;

  DISALLOW_COPY_AND_ASSIGN(NativeImageBufferEGL);
};

scoped_refptr<NativeImageBufferEGL> NativeImageBufferEGL::Create(
    GLuint texture_id) {
  EGLDisplay egl_display = gfx::GLSurfaceEGL::GetHardwareDisplay();
  EGLContext egl_context = eglGetCurrentContext();

  DCHECK_NE(EGL_NO_CONTEXT, egl_context);
  DCHECK_NE(EGL_NO_DISPLAY, egl_display);
  DCHECK(glIsTexture(texture_id));

  DCHECK(gfx::g_driver_egl.ext.b_EGL_KHR_image_base &&
         gfx::g_driver_egl.ext.b_EGL_KHR_gl_texture_2D_image &&
         gfx::g_driver_gl.ext.b_GL_OES_EGL_image);

  const EGLint egl_attrib_list[] = {
      EGL_GL_TEXTURE_LEVEL_KHR, 0, EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE};
  EGLClientBuffer egl_buffer = reinterpret_cast<EGLClientBuffer>(texture_id);
  EGLenum egl_target = EGL_GL_TEXTURE_2D_KHR;

  EGLImageKHR egl_image = eglCreateImageKHR(
      egl_display, egl_context, egl_target, egl_buffer, egl_attrib_list);

  if (egl_image == EGL_NO_IMAGE_KHR) {
    LOG(ERROR) << "eglCreateImageKHR for cross-thread sharing failed: 0x"
               << std::hex << eglGetError();
    return NULL;
  }

  return new NativeImageBufferEGL(egl_display, egl_image);
}

NativeImageBufferEGL::ClientInfo::ClientInfo(gfx::GLImage* client)
    : client(client), needs_wait_before_read(true) {}

NativeImageBufferEGL::ClientInfo::~ClientInfo() {}

NativeImageBufferEGL::NativeImageBufferEGL(EGLDisplay display,
                                           EGLImageKHR image)
    : NativeImageBuffer(),
      egl_display_(display),
      egl_image_(image),
      write_client_(NULL) {
  DCHECK(egl_display_ != EGL_NO_DISPLAY);
  DCHECK(egl_image_ != EGL_NO_IMAGE_KHR);
}

NativeImageBufferEGL::~NativeImageBufferEGL() {
  DCHECK(client_infos_.empty());
  if (egl_image_ != EGL_NO_IMAGE_KHR)
    eglDestroyImageKHR(egl_display_, egl_image_);
}

void NativeImageBufferEGL::AddClient(gfx::GLImage* client) {
  base::AutoLock lock(lock_);
  client_infos_.push_back(ClientInfo(client));
}

void NativeImageBufferEGL::RemoveClient(gfx::GLImage* client) {
  base::AutoLock lock(lock_);
  if (write_client_ == client)
    write_client_ = NULL;
  for (std::list<ClientInfo>::iterator it = client_infos_.begin();
       it != client_infos_.end();
       it++) {
    if (it->client == client) {
      client_infos_.erase(it);
      return;
    }
  }
  NOTREACHED();
}

bool NativeImageBufferEGL::IsClient(gfx::GLImage* client) {
  base::AutoLock lock(lock_);
  for (std::list<ClientInfo>::iterator it = client_infos_.begin();
       it != client_infos_.end();
       it++) {
    if (it->client == client)
      return true;
  }
  return false;
}

void NativeImageBufferEGL::BindToTexture(GLenum target) {
  DCHECK(egl_image_ != EGL_NO_IMAGE_KHR);
  glEGLImageTargetTexture2DOES(target, egl_image_);
  DCHECK_EQ(static_cast<EGLint>(EGL_SUCCESS), eglGetError());
  DCHECK_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
}

#endif

class NativeImageBufferStub : public NativeImageBuffer {
 public:
  NativeImageBufferStub() : NativeImageBuffer() {}

 private:
  ~NativeImageBufferStub() override {}
  void AddClient(gfx::GLImage* client) override {}
  void RemoveClient(gfx::GLImage* client) override {}
  bool IsClient(gfx::GLImage* client) override { return true; }
  void BindToTexture(GLenum target) override {}

  DISALLOW_COPY_AND_ASSIGN(NativeImageBufferStub);
};

}  // anonymous namespace

// static
scoped_refptr<NativeImageBuffer> NativeImageBuffer::Create(GLuint texture_id) {
  switch (gfx::GetGLImplementation()) {
#if !defined(OS_MACOSX)
    case gfx::kGLImplementationEGLGLES2:
      return NativeImageBufferEGL::Create(texture_id);
#endif
    case gfx::kGLImplementationMockGL:
      return new NativeImageBufferStub;
    default:
      NOTREACHED();
      return NULL;
  }
}

TextureDefinition::LevelInfo::LevelInfo()
    : target(0),
      internal_format(0),
      width(0),
      height(0),
      depth(0),
      border(0),
      format(0),
      type(0),
      cleared(false) {
}

TextureDefinition::LevelInfo::LevelInfo(GLenum target,
                                        GLenum internal_format,
                                        GLsizei width,
                                        GLsizei height,
                                        GLsizei depth,
                                        GLint border,
                                        GLenum format,
                                        GLenum type,
                                        bool cleared)
    : target(target),
      internal_format(internal_format),
      width(width),
      height(height),
      depth(depth),
      border(border),
      format(format),
      type(type),
      cleared(cleared) {}

TextureDefinition::LevelInfo::~LevelInfo() {}

TextureDefinition::TextureDefinition()
    : version_(0),
      target_(0),
      min_filter_(0),
      mag_filter_(0),
      wrap_s_(0),
      wrap_t_(0),
      usage_(0),
      immutable_(true) {
}

TextureDefinition::TextureDefinition(
    Texture* texture,
    unsigned int version,
    const scoped_refptr<NativeImageBuffer>& image_buffer)
    : version_(version),
      target_(texture->target()),
      image_buffer_(image_buffer),
      min_filter_(texture->min_filter()),
      mag_filter_(texture->mag_filter()),
      wrap_s_(texture->wrap_s()),
      wrap_t_(texture->wrap_t()),
      usage_(texture->usage()),
      immutable_(texture->IsImmutable()),
      defined_(texture->IsDefined()) {
  DCHECK_IMPLIES(image_buffer_.get(), defined_);
  if (!image_buffer_.get() && defined_) {
    image_buffer_ = NativeImageBuffer::Create(texture->service_id());
    DCHECK(image_buffer_.get());
  }

  const Texture::FaceInfo& first_face = texture->face_infos_[0];
  if (image_buffer_.get()) {
    scoped_refptr<gfx::GLImage> gl_image(
        new GLImageSync(image_buffer_,
                        gfx::Size(first_face.level_infos[0].width,
                                  first_face.level_infos[0].height)));
    texture->SetLevelImage(NULL, target_, 0, gl_image.get());
  }

  const Texture::LevelInfo& level = first_face.level_infos[0];
  level_info_ = LevelInfo(level.target, level.internal_format, level.width,
                          level.height, level.depth, level.border, level.format,
                          level.type, level.cleared);
}

TextureDefinition::~TextureDefinition() {
}

Texture* TextureDefinition::CreateTexture() const {
  GLuint texture_id;
  glGenTextures(1, &texture_id);

  Texture* texture(new Texture(texture_id));
  UpdateTexture(texture);

  return texture;
}

void TextureDefinition::UpdateTexture(Texture* texture) const {
  gfx::ScopedTextureBinder texture_binder(target_, texture->service_id());
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, min_filter_);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, mag_filter_);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrap_s_);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrap_t_);
  if (image_buffer_.get())
    image_buffer_->BindToTexture(target_);
  // We have to make sure the changes are visible to other clients in this share
  // group. As far as the clients are concerned, the mailbox semantics only
  // demand a single flush from the client after changes are first made,
  // and it is not visible to them when another share group boundary is crossed.
  // We could probably track this and be a bit smarter about when to flush
  // though.
  glFlush();

  if (defined_) {
    texture->face_infos_.resize(1);
    texture->face_infos_[0].level_infos.resize(1);
    texture->SetLevelInfo(NULL, level_info_.target, 0,
                          level_info_.internal_format, level_info_.width,
                          level_info_.height, level_info_.depth,
                          level_info_.border, level_info_.format,
                          level_info_.type, level_info_.cleared);
  }

  if (image_buffer_.get()) {
    texture->SetLevelImage(
        NULL,
        target_,
        0,
        new GLImageSync(
            image_buffer_,
            gfx::Size(level_info_.width, level_info_.height)));
  }

  texture->target_ = target_;
  texture->SetImmutable(immutable_);
  texture->min_filter_ = min_filter_;
  texture->mag_filter_ = mag_filter_;
  texture->wrap_s_ = wrap_s_;
  texture->wrap_t_ = wrap_t_;
  texture->usage_ = usage_;
}

bool TextureDefinition::Matches(const Texture* texture) const {
  DCHECK(target_ == texture->target());
  if (texture->min_filter_ != min_filter_ ||
      texture->mag_filter_ != mag_filter_ ||
      texture->wrap_s_ != wrap_s_ ||
      texture->wrap_t_ != wrap_t_ ||
      texture->SafeToRenderFrom() != SafeToRenderFrom()) {
    return false;
  }

  // Texture became defined.
  if (!image_buffer_.get() && texture->IsDefined())
    return false;

  // All structural changes should have orphaned the texture.
  if (image_buffer_.get() && !texture->GetLevelImage(texture->target(), 0))
    return false;

  return true;
}

bool TextureDefinition::SafeToRenderFrom() const {
  return level_info_.cleared;
}

}  // namespace gles2
}  // namespace gpu