+const ourGLchar *vertexShaderSource[] = {
+ "#version 140\n",
+ "uniform mat4 fg_ProjectionMatrix;\n",
+ "in vec4 fg_Color;\n",
+ "in vec4 fg_Vertex;\n",
+ "smooth out vec4 fg_SmoothColor;\n",
+ "void main()\n",
+ "{\n",
+ " fg_SmoothColor = fg_Color;\n",
+ " gl_Position = fg_ProjectionMatrix * fg_Vertex;\n",
+ "}\n"
+};
+
+const ourGLchar *fragmentShaderSource[] = {
+ "#version 140\n",
+ "smooth in vec4 fg_SmoothColor;\n",
+ "out vec4 fg_FragColor;\n",
+ "void main(void)\n",
+ "{\n",
+ " fg_FragColor = fg_SmoothColor;\n",
+ "}\n"
+};
+
+void compileAndCheck(GLuint shader)
+{
+ GLint status;
+ gl_CompileShader (shader);
+ gl_GetShaderiv (shader, GL_COMPILE_STATUS, &status);
+ if (status == GL_FALSE) {
+ GLint infoLogLength;
+ ourGLchar *infoLog;
+ gl_GetShaderiv (shader, GL_INFO_LOG_LENGTH, &infoLogLength);
+ infoLog = (ourGLchar*) malloc (infoLogLength);
+ gl_GetShaderInfoLog (shader, infoLogLength, NULL, infoLog);
+ fprintf (stderr, "compile log: %s\n", infoLog);
+ free (infoLog);
+ }
+}
+
+GLuint compileShaderSource(GLenum type, GLsizei count, const ourGLchar **string)
+{
+ GLuint shader = gl_CreateShader (type);
+ gl_ShaderSource (shader, count, string, NULL);
+ compileAndCheck (shader);
+ return shader;
+}
+
+void linkAndCheck(GLuint program)
+{
+ GLint status;
+ gl_LinkProgram (program);
+ gl_GetProgramiv (program, GL_LINK_STATUS, &status);
+ if (status == GL_FALSE) {
+ GLint infoLogLength;
+ ourGLchar *infoLog;
+ gl_GetProgramiv (program, GL_INFO_LOG_LENGTH, &infoLogLength);
+ infoLog = (ourGLchar*) malloc (infoLogLength);
+ gl_GetProgramInfoLog (program, infoLogLength, NULL, infoLog);
+ fprintf (stderr, "link log: %s\n", infoLog);
+ free (infoLog);
+ }
+}
+
+GLuint createProgram(GLuint vertexShader, GLuint fragmentShader)
+{
+ GLuint program = gl_CreateProgram ();
+ if (vertexShader != 0) {
+ gl_AttachShader (program, vertexShader);
+ }
+ if (fragmentShader != 0) {
+ gl_AttachShader (program, fragmentShader);
+ }
+ linkAndCheck (program);
+ return program;
+}
+
+GLuint fgProjectionMatrixIndex;
+GLuint fgColorIndex;
+GLuint fgVertexIndex;
+
+void initShader(void)
+{
+ const GLsizei vertexShaderLines = sizeof(vertexShaderSource) / sizeof(ourGLchar*);
+ GLuint vertexShader =
+ compileShaderSource (GL_VERTEX_SHADER, vertexShaderLines, vertexShaderSource);
+
+ const GLsizei fragmentShaderLines = sizeof(fragmentShaderSource) / sizeof(ourGLchar*);
+ GLuint fragmentShader =
+ compileShaderSource (GL_FRAGMENT_SHADER, fragmentShaderLines, fragmentShaderSource);
+
+ GLuint program = createProgram (vertexShader, fragmentShader);
+
+ gl_UseProgram (program);
+
+ fgProjectionMatrixIndex = gl_GetUniformLocation(program, "fg_ProjectionMatrix");
+
+ fgColorIndex = gl_GetAttribLocation(program, "fg_Color");
+ gl_EnableVertexAttribArray (fgColorIndex);
+
+ fgVertexIndex = gl_GetAttribLocation(program, "fg_Vertex");
+ gl_EnableVertexAttribArray (fgVertexIndex);
+
+ checkError ("initShader");
+}
+