static void init_shader_program()
{
GLuint vertex_shader, fragment_shader;
GLint program_ok;
vertex_shader = init_shader(GL_VERTEX_SHADER, "shaders/vertex.glsl");
fragment_shader = init_shader(GL_FRAGMENT_SHADER, "shaders/fragment.glsl");
if (vertex_shader == 0 || fragment_shader == 0) {
Log("Could not init shaders\n");
}
program = glCreateProgram();
glAttachShader(program, vertex_shader);
glAttachShader(program, fragment_shader);
glLinkProgram(program);
glGetProgramiv(program, GL_LINK_STATUS, &program_ok);
if (!program_ok) {
Log("Failed to link shader program.");
Log("Vertex shader log: %s", get_shader_log(vertex_shader));
Log("Fragment shader log: %s", get_shader_log(fragment_shader));
Engine_print_program_log();
glDeleteProgram(program);
}
glUseProgram(program);
}
void shader_program::add_shader(const char* shader, const char* fname, GLenum type) {
GLuint s = glCreateShader (type);
glShaderSource(s, 1, &shader, NULL);
glCompileShader(s);
int result;
glGetShaderiv(s, GL_COMPILE_STATUS, &result);
if (result != GL_TRUE) {
printf("Error compiling %s\n%s\n",fname,
get_shader_log(s).c_str());
backtrace();
exit(1);
}
glAttachShader(program_id, s);
attached.push_back(s);
}
static GLuint init_shader(GLenum type, const char *filename)
{
GLchar *version;
GLchar *source;
GLuint shader;
GLint length, shader_ok;
// My linux laptop only has 300es support.
#ifdef __APPLE__
version = "#version 330\n";
#elif __linux__
version = "#version 300 es\n";
#endif
source = Loader_get_file_contents(filename, &length);
if (!source) {
Log("Failed to load shader file: %s\n", filename);
return 0;
}
shader = glCreateShader(type);
if (shader == 0) {
Log("Could not create shader %d\n", type);
return 0;
}
const char *sources[2] = { version, source };
GLint lengths[2] = { strlen(version), length };
glShaderSource(shader, 2, sources, lengths);
free(source);
glCompileShader(shader);
glGetShaderiv(shader, GL_COMPILE_STATUS, &shader_ok);
if (!shader_ok) {
char *log = get_shader_log(shader);
Log("Compilation error in shader %s: %s\n", filename, log);
glDeleteShader(shader);
return 0;
}
return shader;
}