Add the old Bullet 2.x obsolete demos, and CMake buildsystem files, and gradually move them to newer Bullet 3.x structure

Use statically linked freeglut, instead of dynamic glut for the obsolete Bullet 2.x demos
Add the 'reset' method to b3GpuDynamicsWorld, and use it in the BasicGpuDemo (pretty slow in debug mode, use release mode)
Don't crash in btCollisionWorld, if there is no collision dispatcher

ObsoleteDemos/NativeClient/shader_util.cc

@@ -0,0 +1,95 @@
+// Copyright (c) 2011 The Native Client 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 "shader_util.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+namespace shader_util {
+
+GLuint CreateShaderOfType(GLenum type, const char *shader_src) {
+  GLuint shader;
+  GLint compiled;
+
+  // Create the shader object
+  shader = glCreateShader(type);
+
+  if (shader == 0)
+    return 0;
+
+  // Load and compile the shader source
+  glShaderSource(shader, 1, &shader_src, NULL);
+  glCompileShader(shader);
+
+  // Check the compile status
+  glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+  if (compiled == 0) {
+    GLint info_len = 0;
+    glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &info_len);
+    if (info_len > 1) {
+      char* info_log = reinterpret_cast<char*>(malloc(sizeof(char) * info_len));
+      glGetShaderInfoLog(shader, info_len, NULL, info_log);
+      // TODO(dspringer): We could really use a logging API.
+      printf("Error compiling shader:\n%s\n", info_log);
+      free(info_log);
+    }
+    glDeleteShader(shader);
+    return 0;
+  }
+
+  return shader;
+}
+
+GLuint CreateProgramFromVertexAndFragmentShaders(
+    const char *vertex_shader_src, const char *fragment_shader_src) {
+  GLuint vertex_shader;
+  GLuint fragment_shader;
+  GLuint program_object;
+  GLint linked;
+
+  // Load the vertex/fragment shaders
+  vertex_shader = CreateShaderOfType(GL_VERTEX_SHADER, vertex_shader_src);
+  if (vertex_shader == 0)
+    return 0;
+  fragment_shader = CreateShaderOfType(GL_FRAGMENT_SHADER, fragment_shader_src);
+  if (fragment_shader == 0) {
+    glDeleteShader(vertex_shader);
+    return 0;
+  }
+
+  // Create the program object and attach the shaders.
+  program_object = glCreateProgram();
+  if (program_object == 0)
+    return 0;
+  glAttachShader(program_object, vertex_shader);
+  glAttachShader(program_object, fragment_shader);
+
+  // Link the program
+  glLinkProgram(program_object);
+
+  // Check the link status
+  glGetProgramiv(program_object, GL_LINK_STATUS, &linked);
+  if (linked == 0) {
+    GLint info_len = 0;
+    glGetProgramiv(program_object, GL_INFO_LOG_LENGTH, &info_len);
+    if (info_len > 1) {
+      char* info_log = reinterpret_cast<char*>(malloc(info_len));
+      glGetProgramInfoLog(program_object, info_len, NULL, info_log);
+      // TODO(dspringer): We could really use a logging API.
+      printf("Error linking program:\n%s\n", info_log);
+      free(info_log);
+    }
+    glDeleteProgram(program_object);
+    return 0;
+  }
+
+  // Delete these here because they are attached to the program object.
+  glDeleteShader(vertex_shader);
+  glDeleteShader(fragment_shader);
+
+  return program_object;
+}
+
+}  // namespace shader_util