Beginning of JS Mojo API to GL

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

+// 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/object_template_builder.h"
+#include "gin/per_isolate_data.h"
+#include "mojo/public/gles2/gles2.h"
+
+namespace mojo {
+namespace js {
+namespace gl {
+
+gin::WrapperInfo Context::kWrapperInfo = { gin::kEmbedderNativeGin };
+
+gin::Handle<Context> Context::Create(v8::Isolate* isolate, uint64_t encoded,
+                                     int width, int height) {
+  return CreateHandle(isolate, new Context(encoded, width, height));
+}
+
+v8::Handle<v8::ObjectTemplate> Context::GetObjectTemplate(
+    v8::Isolate* isolate) {
+  gin::PerIsolateData* data = gin::PerIsolateData::From(isolate);
+  v8::Local<v8::ObjectTemplate> templ = data->GetObjectTemplate(&kWrapperInfo);
+  if (templ.IsEmpty()) {
+    templ = gin::ObjectTemplateBuilder(isolate)
+        .SetValue("VERTEX_SHADER", GL_VERTEX_SHADER)
+        .SetMethod("createShader", CreateShader)
+        .SetMethod("shaderSource", ShaderSource)
+        .SetMethod("compileShader", CompileShader)
+        .Build();
+    templ->SetInternalFieldCount(gin::kNumberOfInternalFields);
+    data->SetObjectTemplate(&kWrapperInfo, templ);
+  }
+  return templ;
+}
+
+gin::Handle<Shader> Context::CreateShader(const gin::Arguments& args,
+                                          GLenum type) {
+  gin::Handle<Shader> result;
+  GLuint glshader = glCreateShader(type);
+  if (glshader != 0u) {
+    result = Opaque::Create(args.isolate(), glshader);
+  }
+  return result;
+}
+
+void Context::ShaderSource(gin::Handle<Shader> shader,
+                           const std::string& source) {
+  const char* source_chars = source.c_str();
+  glShaderSource(shader->value(), 1, &source_chars, NULL);
+}
+
+void Context::CompileShader(const gin::Arguments& args,
+                            gin::Handle<Shader> shader) {
+  glCompileShader(shader->value());
+  GLint compiled = 0;
+  glGetShaderiv(shader->value(), GL_COMPILE_STATUS, &compiled);
+  if (!compiled) {
+    // Or should |shader| do it when it is destroyed?
+    glDeleteShader(shader->value());
+    args.ThrowTypeError("Could not compile shader");
+    return;
+  }
+}
+
+Context::Context(uint64_t encoded, int width, int height)
+    : encoded_(encoded) {
+  // TODO(aa): Does this need to be called at the start of every public method?

[abarth-chromium, 2013/12/11 06:24:22]

Probably not.  We only support on GL context right now, so you just need to make
it current once.

[Aaron Boodman, 2013/12/11 07:17:06]

But if we had multiple contexts, we would need to right? Is there any
disadvantage to calling it on every entry now?

+  // If so, perhaps we should have the JS API be something like:
+  // context.with(function() {
+  // });
+  MojoGLES2MakeCurrent(encoded_);
+}
+
+}  // namespace gl
+}  // namespace js
+}  // namespace mojo