root/mojo/apps/js/bindings/gl/context.cc

DEFINITIONS

1. Create
2. BufferData
3. CompileShader
4. CreateBuffer
5. DrawElements
6. GetAttribLocation
7. GetProgramInfoLog
8. GetShaderInfoLog
9. GetUniformLocation
10. ShaderSource
11. UniformMatrix4fv
12. VertexAttribPointer
13. GetObjectTemplateBuilder
14. ContextLost
15. ContextLostThunk

// Copyright 2013 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 "mojo/apps/js/bindings/gl/context.h"

#include <GLES2/gl2.h>

#include "gin/arguments.h"
#include "gin/array_buffer.h"
#include "gin/object_template_builder.h"
#include "gin/per_context_data.h"
#include "mojo/public/c/gles2/gles2.h"

namespace gin {
template<>
struct Converter<GLboolean> {
  static bool FromV8(v8::Isolate* isolate, v8::Handle<v8::Value> val,
                     GLboolean* out) {
    bool bool_val = false;
    if (!Converter<bool>::FromV8(isolate, val, &bool_val))
      return false;
    *out = static_cast<GLboolean>(bool_val);
    return true;
  }
};
}

namespace mojo {
namespace js {
namespace gl {

gin::WrapperInfo Context::kWrapperInfo = { gin::kEmbedderNativeGin };

gin::Handle<Context> Context::Create(
    v8::Isolate* isolate,
    mojo::Handle handle,
    v8::Handle<v8::Function> context_lost_callback) {
  return gin::CreateHandle(isolate,
                           new Context(isolate, handle, context_lost_callback));
}

void Context::BufferData(GLenum target, const gin::ArrayBufferView& buffer,
                         GLenum usage) {
  glBufferData(target, static_cast<GLsizeiptr>(buffer.num_bytes()),
               buffer.bytes(), usage);
}

void Context::CompileShader(const gin::Arguments& args, GLuint shader) {
  glCompileShader(shader);
  GLint compiled = 0;
  glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
  if (!compiled) {
    args.ThrowTypeError(std::string("Could not compile shader: ") +
                        GetShaderInfoLog(shader));
  }
}

GLuint Context::CreateBuffer() {
  GLuint result = 0;
  glGenBuffers(1, &result);
  return result;
}

void Context::DrawElements(GLenum mode, GLsizei count, GLenum type,
                           uint64_t indices) {
  // This looks scary, but it's what WebGL does too:
  // http://www.khronos.org/registry/webgl/specs/latest/1.0/#5.1
  glDrawElements(mode, count, type, reinterpret_cast<void*>(indices));
}

GLint Context::GetAttribLocation(GLuint program, const std::string& name) {
  return glGetAttribLocation(program, name.c_str());
}

std::string Context::GetProgramInfoLog(GLuint program) {
  GLint info_log_length = 0;
  glGetProgramiv(program, GL_INFO_LOG_LENGTH, &info_log_length);
  std::string info_log(info_log_length, 0);
  glGetProgramInfoLog(program, info_log_length, NULL, &info_log.at(0));
  return info_log;
}

std::string Context::GetShaderInfoLog(GLuint shader) {
  GLint info_log_length = 0;
  glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &info_log_length);
  std::string info_log(info_log_length, 0);
  glGetShaderInfoLog(shader, info_log_length, NULL, &info_log.at(0));
  return info_log;
}

GLint Context::GetUniformLocation(GLuint program, const std::string& name) {
  return glGetUniformLocation(program, name.c_str());
}

void Context::ShaderSource(GLuint shader, const std::string& source) {
  const char* source_chars = source.c_str();
  glShaderSource(shader, 1, &source_chars, NULL);
}

void Context::UniformMatrix4fv(GLint location, GLboolean transpose,
                               const gin::ArrayBufferView& buffer) {
  glUniformMatrix4fv(location, 1, transpose,
                     static_cast<float*>(buffer.bytes()));
}

void Context::VertexAttribPointer(GLuint index, GLint size, GLenum type,
                                  GLboolean normalized, GLsizei stride,
                                  uint64_t offset) {
  glVertexAttribPointer(index, size, type, normalized, stride,
                        reinterpret_cast<void*>(offset));
}

gin::ObjectTemplateBuilder Context::GetObjectTemplateBuilder(
    v8::Isolate* isolate) {
  return gin::ObjectTemplateBuilder(isolate)
      .SetValue("ARRAY_BUFFER", GL_ARRAY_BUFFER)
      .SetValue("COLOR_BUFFER_BIT", GL_COLOR_BUFFER_BIT)
      .SetValue("ELEMENT_ARRAY_BUFFER", GL_ELEMENT_ARRAY_BUFFER)
      .SetValue("FLOAT", GL_FLOAT)
      .SetValue("FRAGMENT_SHADER", GL_FRAGMENT_SHADER)
      .SetValue("STATIC_DRAW", GL_STATIC_DRAW)
      .SetValue("TRIANGLES", GL_TRIANGLES)
      .SetValue("UNSIGNED_SHORT", GL_UNSIGNED_SHORT)
      .SetValue("VERTEX_SHADER", GL_VERTEX_SHADER)
      .SetMethod("attachShader", glAttachShader)
      .SetMethod("bindBuffer", glBindBuffer)
      .SetMethod("bufferData", BufferData)
      .SetMethod("clear", glClear)
      .SetMethod("clearColor", glClearColor)
      .SetMethod("compileShader", CompileShader)
      .SetMethod("createBuffer", CreateBuffer)
      .SetMethod("createProgram", glCreateProgram)
      .SetMethod("createShader", glCreateShader)
      .SetMethod("deleteShader", glDeleteShader)
      .SetMethod("drawElements", DrawElements)
      .SetMethod("enableVertexAttribArray", glEnableVertexAttribArray)
      .SetMethod("getAttribLocation", GetAttribLocation)
      .SetMethod("getProgramInfoLog", GetProgramInfoLog)
      .SetMethod("getShaderInfoLog", GetShaderInfoLog)
      .SetMethod("getUniformLocation", GetUniformLocation)
      .SetMethod("linkProgram", glLinkProgram)
      .SetMethod("shaderSource", ShaderSource)
      .SetMethod("swapBuffers", MojoGLES2SwapBuffers)
      .SetMethod("uniformMatrix4fv", UniformMatrix4fv)
      .SetMethod("useProgram", glUseProgram)
      .SetMethod("vertexAttribPointer", VertexAttribPointer)
      .SetMethod("viewport", glViewport);
}

Context::Context(v8::Isolate* isolate,
                 mojo::Handle handle,
                 v8::Handle<v8::Function> context_lost_callback) {
  v8::Handle<v8::Context> context = isolate->GetCurrentContext();
  runner_ = gin::PerContextData::From(context)->runner()->GetWeakPtr();
  context_lost_callback_.Reset(isolate, context_lost_callback);
  context_ = MojoGLES2CreateContext(
      handle.value(),
      &ContextLostThunk,
      NULL,
      this);
  MojoGLES2MakeCurrent(context_);
}

Context::~Context() {
  MojoGLES2DestroyContext(context_);
}

void Context::ContextLost() {
  if (!runner_)
    return;
  gin::Runner::Scope scope(runner_.get());
  v8::Isolate* isolate = runner_->GetContextHolder()->isolate();

  v8::Handle<v8::Function> callback = v8::Local<v8::Function>::New(
      isolate, context_lost_callback_);

  runner_->Call(callback, runner_->global(), 0, NULL);
}

void Context::ContextLostThunk(void* closure) {
  static_cast<Context*>(closure)->ContextLost();
}

}  // namespace gl
}  // namespace js
}  // namespace mojo