// Copyright (c) 2010 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 "media/tools/player_x11/gles_video_renderer.h"

#include <dlfcn.h>
#include <X11/Xutil.h>
#include <X11/extensions/Xrender.h>
#include <X11/extensions/Xcomposite.h>

#include "media/base/buffers.h"
#include "media/base/pipeline.h"
#include "media/base/filter_host.h"
#include "media/base/yuv_convert.h"

GlesVideoRenderer* GlesVideoRenderer::instance_ = NULL;

GlesVideoRenderer::GlesVideoRenderer(Display* display, Window window)
    : display_(display),
      window_(window),
      new_frame_(false),
      egl_display_(NULL),
      egl_surface_(NULL),
      egl_context_(NULL) {
}

GlesVideoRenderer::~GlesVideoRenderer() {
}

// static
bool GlesVideoRenderer::IsMediaFormatSupported(
    const media::MediaFormat& media_format) {
  int width = 0;
  int height = 0;
  return ParseMediaFormat(media_format, &width, &height);
}

void GlesVideoRenderer::OnStop() {
  // TODO(hclam): Context switching seems to be broek so the following
  // calls may fail. Need to fix them.
  eglMakeCurrent(egl_display_, EGL_NO_SURFACE,
                 EGL_NO_SURFACE, EGL_NO_CONTEXT);
  eglDestroyContext(egl_display_, egl_context_);
  eglDestroySurface(egl_display_, egl_surface_);
}

// Matrix used for the YUV to RGB conversion.
static const float kYUV2RGB[9] = {
  1.f, 1.f, 1.f,
  0.f, -.344f, 1.772f,
  1.403f, -.714f, 0.f,
};

// Vertices for a full screen quad.
static const float kVertices[8] = {
  -1.f, 1.f,
  -1.f, -1.f,
  1.f, 1.f,
  1.f, -1.f,
};

// Texture Coordinates mapping the entire texture.
static const float kTextureCoords[8] = {
  0, 0,
  0, 1,
  1, 0,
  1, 1,
};

// Pass-through vertex shader.
static const char kVertexShader[] =
    "precision highp float; precision highp int;\n"
    "varying vec2 interp_tc;\n"
    "\n"
    "attribute vec4 in_pos;\n"
    "attribute vec2 in_tc;\n"
    "\n"
    "void main() {\n"
    "  interp_tc = in_tc;\n"
    "  gl_Position = in_pos;\n"
    "}\n";

// YUV to RGB pixel shader. Loads a pixel from each plane and pass through the
// matrix.
static const char kFragmentShader[] =
    "precision mediump float; precision mediump int;\n"
    "varying vec2 interp_tc;\n"
    "\n"
    "uniform sampler2D y_tex;\n"
    "uniform sampler2D u_tex;\n"
    "uniform sampler2D v_tex;\n"
    "uniform mat3 yuv2rgb;\n"
    "\n"
    "void main() {\n"
    "  float y = texture2D(y_tex, interp_tc).x;\n"
    "  float u = texture2D(u_tex, interp_tc).r - .5;\n"
    "  float v = texture2D(v_tex, interp_tc).r - .5;\n"
    "  vec3 rgb = yuv2rgb * vec3(y, u, v);\n"
    "  gl_FragColor = vec4(rgb, 1);\n"
    "}\n";

// Buffer size for compile errors.
static const unsigned int kErrorSize = 4096;

bool GlesVideoRenderer::OnInitialize(media::VideoDecoder* decoder) {
  if (!ParseMediaFormat(decoder->media_format(), &width_, &height_))
    return false;

  LOG(INFO) << "Initializing GLES Renderer...";

  // Save this instance.
  DCHECK(!instance_);
  instance_ = this;
  return true;
}

void GlesVideoRenderer::OnFrameAvailable() {
  AutoLock auto_lock(lock_);
  new_frame_ = true;
}

void GlesVideoRenderer::Paint() {
  // Use |new_frame_| to prevent overdraw since Paint() is called more
  // often than needed. It is OK to lock only this flag and we don't
  // want to lock the whole function because this method takes a long
  // time to complete.
  {
    AutoLock auto_lock(lock_);
    if (!new_frame_)
      return;
    new_frame_ = false;
  }

  // Initialize GLES here to avoid context switching. Some drivers doesn't
  // like switching context between threads.
  static bool initialized = false;
  if (!initialized && !InitializeGles()) {
    initialized = true;
    host()->SetError(media::PIPELINE_ERROR_COULD_NOT_RENDER);
    return;
  }
  initialized = true;

  scoped_refptr<media::VideoFrame> video_frame;
  GetCurrentFrame(&video_frame);

  if (!video_frame)
    return;

  // Convert YUV frame to RGB.
  media::VideoSurface frame_in;
  if (video_frame->Lock(&frame_in)) {
    DCHECK(frame_in.format == media::VideoSurface::YV12 ||
           frame_in.format == media::VideoSurface::YV16);
    DCHECK(frame_in.strides[media::VideoSurface::kUPlane] ==
           frame_in.strides[media::VideoSurface::kVPlane]);
    DCHECK(frame_in.planes == media::VideoSurface::kNumYUVPlanes);

    for (unsigned int i = 0; i < media::VideoSurface::kNumYUVPlanes; ++i) {
      unsigned int width = (i == media::VideoSurface::kYPlane) ?
          frame_in.width : frame_in.width / 2;
      unsigned int height = (i == media::VideoSurface::kYPlane ||
                             frame_in.format == media::VideoSurface::YV16) ?
          frame_in.height : frame_in.height / 2;
      glActiveTexture(GL_TEXTURE0 + i);
      // GLES2 supports a fixed set of unpack alignments that should match most
      // of the time what ffmpeg outputs.
      // TODO(piman): check if it is more efficient to prefer higher
      // alignments.
      unsigned int stride = frame_in.strides[i];
      uint8* data = frame_in.data[i];
      if (stride == width) {
        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
      } else if (stride == ((width + 1) & ~1)) {
        glPixelStorei(GL_UNPACK_ALIGNMENT, 2);
      } else if (stride == ((width + 3) & ~3)) {
        glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
      } else if (stride == ((width + 7) & ~7)) {
        glPixelStorei(GL_UNPACK_ALIGNMENT, 8);
      } else {
        // Otherwise do it line-by-line.
        glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, width, height, 0,
                     GL_LUMINANCE, GL_UNSIGNED_BYTE, NULL);
        for (unsigned int y = 0; y < height; ++y) {
          glTexSubImage2D(GL_TEXTURE_2D, 0, 0, y, width, 1,
                          GL_LUMINANCE, GL_UNSIGNED_BYTE, data);
          data += stride;
        }
        continue;
      }
      glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, width, height, 0,
                   GL_LUMINANCE, GL_UNSIGNED_BYTE, data);
    }
    video_frame->Unlock();
  } else {
    NOTREACHED();
  }

  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
  eglSwapBuffers(egl_display_, egl_surface_);
}

bool GlesVideoRenderer::InitializeGles() {
  // Resize the window to fit that of the video.
  XResizeWindow(display_, window_, width_, height_);

  egl_display_ = eglGetDisplay(display_);
  if (eglGetError() != EGL_SUCCESS) {
    DLOG(ERROR) << "eglGetDisplay failed.";
    return false;
  }

  EGLint major;
  EGLint minor;
  if (!eglInitialize(egl_display_, &major, &minor)) {
    DLOG(ERROR) << "eglInitialize failed.";
    return false;
  }
  DLOG(INFO) << "EGL vendor:" << eglQueryString(egl_display_, EGL_VENDOR);
  DLOG(INFO) << "EGL version:" << eglQueryString(egl_display_, EGL_VERSION);
  DLOG(INFO) << "EGL extensions:"
             << eglQueryString(egl_display_, EGL_EXTENSIONS);
  DLOG(INFO) << "EGL client apis:"
             << eglQueryString(egl_display_, EGL_CLIENT_APIS);

  EGLint attribs[] = {
    EGL_RED_SIZE,       5,
    EGL_GREEN_SIZE,     6,
    EGL_BLUE_SIZE,      5,
    EGL_DEPTH_SIZE,     16,
    EGL_STENCIL_SIZE,   0,
    EGL_SURFACE_TYPE,   EGL_WINDOW_BIT,
    EGL_NONE
  };

  EGLint num_configs = -1;
  if (!eglGetConfigs(egl_display_, NULL, 0, &num_configs)) {
    DLOG(ERROR) << "eglGetConfigs failed.";
    return false;
  }

  EGLConfig config;
  if (!eglChooseConfig(egl_display_, attribs, &config, 1, &num_configs)) {
    DLOG(ERROR) << "eglChooseConfig failed.";
    return false;
  }

  EGLint red_size, green_size, blue_size, alpha_size, depth_size, stencil_size;
  eglGetConfigAttrib(egl_display_, config, EGL_RED_SIZE, &red_size);
  eglGetConfigAttrib(egl_display_, config, EGL_GREEN_SIZE, &green_size);
  eglGetConfigAttrib(egl_display_, config, EGL_BLUE_SIZE, &blue_size);
  eglGetConfigAttrib(egl_display_, config, EGL_ALPHA_SIZE, &alpha_size);
  eglGetConfigAttrib(egl_display_, config, EGL_DEPTH_SIZE, &depth_size);
  eglGetConfigAttrib(egl_display_, config, EGL_STENCIL_SIZE, &stencil_size);
  DLOG(INFO) << "R,G,B,A: " << red_size << "," << green_size
             << "," << blue_size << "," << alpha_size << " bits";
  DLOG(INFO) << "Depth: " << depth_size << " bits, Stencil:" << stencil_size
             << "bits";

  egl_surface_ = eglCreateWindowSurface(egl_display_, config, window_, NULL);
  if (!egl_surface_) {
    DLOG(ERROR) << "eglCreateWindowSurface failed.";
    return false;
  }

  egl_context_ = eglCreateContext(egl_display_, config, NULL, NULL);
  if (!egl_context_) {
    DLOG(ERROR) << "eglCreateContext failed.";
    eglDestroySurface(egl_display_, egl_surface_);
    return false;
  }

  if (eglMakeCurrent(egl_display_, egl_surface_,
                     egl_surface_, egl_context_) == EGL_FALSE) {
    eglDestroyContext(egl_display_, egl_context_);
    eglDestroySurface(egl_display_, egl_surface_);
    egl_display_ = NULL;
    egl_surface_ = NULL;
    egl_context_ = NULL;
    return false;
  }

  EGLint width;
  EGLint height;
  eglQuerySurface(egl_display_, egl_surface_, EGL_WIDTH, &width);
  eglQuerySurface(egl_display_, egl_surface_, EGL_HEIGHT, &height);
  glViewport(0, 0, width_, height_);

  // Create 3 textures, one for each plane, and bind them to different
  // texture units.
  glGenTextures(media::VideoSurface::kNumYUVPlanes, textures_);

  glActiveTexture(GL_TEXTURE0);
  glBindTexture(GL_TEXTURE_2D, textures_[0]);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glEnable(GL_TEXTURE_2D);

  glActiveTexture(GL_TEXTURE1);
  glBindTexture(GL_TEXTURE_2D, textures_[1]);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glEnable(GL_TEXTURE_2D);

  glActiveTexture(GL_TEXTURE2);
  glBindTexture(GL_TEXTURE_2D, textures_[2]);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glEnable(GL_TEXTURE_2D);

  GLuint program = glCreateProgram();

  // Create our YUV->RGB shader.
  GLuint vertex_shader = glCreateShader(GL_VERTEX_SHADER);
  const char* vs_source = kVertexShader;
  int vs_size = sizeof(kVertexShader);
  glShaderSource(vertex_shader, 1, &vs_source, &vs_size);
  glCompileShader(vertex_shader);
  int result = GL_FALSE;
  glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &result);
  if (!result) {
    char log[kErrorSize];
    int len;
    glGetShaderInfoLog(vertex_shader, kErrorSize - 1, &len, log);
    log[kErrorSize - 1] = 0;
    LOG(FATAL) << log;
  }
  glAttachShader(program, vertex_shader);
  glDeleteShader(vertex_shader);

  GLuint fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
  const char* ps_source = kFragmentShader;
  int ps_size = sizeof(kFragmentShader);
  glShaderSource(fragment_shader, 1, &ps_source, &ps_size);
  glCompileShader(fragment_shader);
  result = GL_FALSE;
  glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &result);
  if (!result) {
    char log[kErrorSize];
    int len;
    glGetShaderInfoLog(fragment_shader, kErrorSize - 1, &len, log);
    log[kErrorSize - 1] = 0;
    LOG(FATAL) << log;
  }
  glAttachShader(program, fragment_shader);
  glDeleteShader(fragment_shader);

  glLinkProgram(program);
  result = GL_FALSE;
  glGetProgramiv(program, GL_LINK_STATUS, &result);
  if (!result) {
    char log[kErrorSize];
    int len;
    glGetProgramInfoLog(program, kErrorSize - 1, &len, log);
    log[kErrorSize - 1] = 0;
    LOG(FATAL) << log;
  }
  glUseProgram(program);
  glDeleteProgram(program);

  // Bind parameters.
  glUniform1i(glGetUniformLocation(program, "y_tex"), 0);
  glUniform1i(glGetUniformLocation(program, "u_tex"), 1);
  glUniform1i(glGetUniformLocation(program, "v_tex"), 2);
  int yuv2rgb_location = glGetUniformLocation(program, "yuv2rgb");
  glUniformMatrix3fv(yuv2rgb_location, 1, GL_FALSE, kYUV2RGB);

  int pos_location = glGetAttribLocation(program, "in_pos");
  glEnableVertexAttribArray(pos_location);
  glVertexAttribPointer(pos_location, 2, GL_FLOAT, GL_FALSE, 0, kVertices);

  int tc_location = glGetAttribLocation(program, "in_tc");
  glEnableVertexAttribArray(tc_location);
  glVertexAttribPointer(tc_location, 2, GL_FLOAT, GL_FALSE, 0,
                        kTextureCoords);

  // We are getting called on a thread. Release the context so that it can be
  // made current on the main thread.
  // TODO(hclam): Fix this if neccessary. Currently the following call fails
  // for some drivers.
  // eglMakeCurrent(egl_display_, EGL_NO_SURFACE,
  //                EGL_NO_SURFACE, EGL_NO_CONTEXT);
  return true;
}