Resubmit 35500: Added an application framework for demos. Ported hellotriangl...

gpu/demos/app_framework/gles2_utils.cc

+// Copyright (c) 2006-2009 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/demos/app_framework/gles2_utils.h"
+
+namespace {
+static const int kInfoBufferLength = 1024;
+}  // namespace
+
+namespace gpu_demos {
+namespace gles2_utils {
+
+GLuint LoadShader(GLenum type, const char* shader_src) {
+  GLuint shader = glCreateShader(type);
+  if (shader == 0) return 0;
+
+  // Load the shader source
+  glShaderSource(shader, 1, &shader_src, NULL);
+  // Compile the shader
+  glCompileShader(shader);
+  // Check the compile status
+  GLint value;
+  glGetShaderiv(shader, GL_COMPILE_STATUS, &value);
+  if (value == 0) {
+    char buffer[kInfoBufferLength];
+    GLsizei length;
+    glGetShaderInfoLog(shader, sizeof(buffer), &length, buffer);
+    std::string log(buffer, length);
+    DLOG(ERROR) << "Error compiling shader:" << log;
+    glDeleteShader(shader);
+    shader = 0;
+  }
+  return shader;
+}
+
+GLuint LoadProgram(const char* v_shader_src, const char* f_shader_src) {
+  GLuint v_shader = LoadShader(GL_VERTEX_SHADER, v_shader_src);
+  if (v_shader == 0) return 0;
+
+  GLuint f_shader = LoadShader(GL_FRAGMENT_SHADER, f_shader_src);
+  if (f_shader == 0) return 0;
+
+  // Create the program object
+  GLuint program_object = glCreateProgram();
+  if (program_object == 0) return 0;
+
+  // Link the program and check status.
+  glAttachShader(program_object, v_shader);
+  glAttachShader(program_object, f_shader);
+  glLinkProgram(program_object);
+  GLint linked = 0;
+  glGetProgramiv(program_object, GL_LINK_STATUS, &linked);
+  if (linked == 0) {
+    char buffer[kInfoBufferLength];
+    GLsizei length;
+    glGetProgramInfoLog(program_object, sizeof(buffer), &length, buffer);
+    std::string log(buffer, length);
+    DLOG(ERROR) << "Error linking program:" << log;
+    glDeleteProgram(program_object);
+    program_object = 0;
+  }
+  return program_object;
+}
+
+}  // namespace gles2_utils
+}  // namespace gpu_demos