GLint ShaderProgram::loadShader(const std::string &shader_file, GLint type) {
// Create shaders
auto shader_id = glCreateShader(type);
auto result = GL_FALSE;
auto info_length = 0;
// Load shader code
std::ifstream shader_stream(shader_file);
std::string shader_code((std::istreambuf_iterator<char>(shader_stream)), std::istreambuf_iterator<char>());
// Compile shader
std::cout << "Compiling Shader ..." << shader_file << std::endl;
auto shader_code_ptr = shader_code.c_str();
glShaderSource(shader_id, 1, &shader_code_ptr, NULL);
glCompileShader(shader_id);
// Check vertex shader log
glGetShaderiv(shader_id, GL_COMPILE_STATUS, &result);
if (result == GL_FALSE) {
glGetShaderiv(shader_id, GL_INFO_LOG_LENGTH, &info_length);
std::string vertex_shader_log((unsigned int)info_length, ' ');
glGetShaderInfoLog(shader_id, info_length, NULL, &vertex_shader_log[0]);
std::cout << vertex_shader_log << std::endl;
}
return shader_id;
}
Shader::Shader(const std::string &vertex_shader_code, const std::string &fragment_shader_code) {
// Create shaders
auto vertex_shader_id = glCreateShader(GL_VERTEX_SHADER);
auto fragment_shader_id = glCreateShader(GL_FRAGMENT_SHADER);
auto result = GL_FALSE;
auto info_length = 0;
// Compile vertex shader
auto vertex_shader_code_ptr = vertex_shader_code.c_str();
glShaderSource(vertex_shader_id, 1, &vertex_shader_code_ptr, NULL);
glCompileShader(vertex_shader_id);
// Check vertex shader log
glGetShaderiv(vertex_shader_id, GL_COMPILE_STATUS, &result);
if (result == GL_FALSE) {
glGetShaderiv(vertex_shader_id, GL_INFO_LOG_LENGTH, &info_length);
std::string vertex_shader_log((unsigned int) info_length, ' ');
glGetShaderInfoLog(vertex_shader_id, info_length, NULL,
&vertex_shader_log[0]);
std::cout << "Error Compiling Vertex Shader ..." << std::endl;
std::cout << vertex_shader_log << std::endl;
}
// Compile fragment shader
auto fragment_shader_code_ptr = fragment_shader_code.c_str();
glShaderSource(fragment_shader_id, 1, &fragment_shader_code_ptr, NULL);
glCompileShader(fragment_shader_id);
// Check fragment shader log
glGetShaderiv(fragment_shader_id, GL_COMPILE_STATUS, &result);
if (result == GL_FALSE) {
glGetShaderiv(fragment_shader_id, GL_INFO_LOG_LENGTH, &info_length);
std::string fragment_shader_log((unsigned long) info_length, ' ');
glGetShaderInfoLog(fragment_shader_id, info_length, NULL,
&fragment_shader_log[0]);
std::cout << "Error Compiling Fragment Shader ..." << std::endl;
std::cout << fragment_shader_log << std::endl;
}
// Create and link the program
auto program_id = glCreateProgram();
glAttachShader(program_id, vertex_shader_id);
glAttachShader(program_id, fragment_shader_id);
glBindFragDataLocation(program_id, 0, "FragmentColor");
glLinkProgram(program_id);
// Check program log
glGetProgramiv(program_id, GL_LINK_STATUS, &result);
if (result == GL_FALSE) {
glGetProgramiv(program_id, GL_INFO_LOG_LENGTH, &info_length);
std::string program_log((unsigned long) info_length, ' ');
glGetProgramInfoLog(program_id, info_length, NULL, &program_log[0]);
std::cout << "Error Linking Shader Program ..." << std::endl;
std::cout << program_log << std::endl;
}
glDeleteShader(vertex_shader_id);
glDeleteShader(fragment_shader_id);
program = program_id;
}