shader.cpp

#include "shader.hpp"

//TODO: better error handling in constructor, what happens if compilation fails? Return value? Exception?

Shader::Shader(const GLchar* vertexPath, const GLchar* fragmentPath) {
	std::string vertexCode;
	std::string fragmentCode;
	std::ifstream vShaderFile;
	std::ifstream fShaderFile;
	vShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
	fShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
	try {
		vShaderFile.open(vertexPath);
		fShaderFile.open(fragmentPath);
		std::stringstream vShaderStream;
		std::stringstream fShaderStream;
		vShaderStream << vShaderFile.rdbuf();
		fShaderStream << fShaderFile.rdbuf();
		vertexCode = vShaderStream.str();
		fragmentCode = fShaderStream.str();
	} catch (std::ifstream::failure e) {
		std::cout << "ERROR::SHADER::FILE_NOT_SUCCESSFULLY_READ" <<std::endl;
	}
	const GLchar* vShaderCode = vertexCode.c_str();
	const GLchar* fShaderCode = fragmentCode.c_str();
	GLuint vertex, fragment;
	GLint success;
	GLchar infoLog[512];
	vertex = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource(vertex,1,&vShaderCode,NULL);
	glCompileShader(vertex);
	glGetShaderiv(vertex,GL_COMPILE_STATUS,&success);
	if (!success) {
		glGetShaderInfoLog(vertex,512,NULL,infoLog);
		std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
	}
	fragment = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource(fragment,1,&fShaderCode,NULL);
	glCompileShader(fragment);
	glGetShaderiv(fragment,GL_COMPILE_STATUS,&success);
	if (!success) {
		glGetShaderInfoLog(fragment,512,NULL,infoLog);
		std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
	}
	this->program = glCreateProgram();
	glAttachShader(this->program, vertex);
	glAttachShader(this->program, fragment);
	glLinkProgram(this->program);
	glGetProgramiv(this->program, GL_LINK_STATUS, &success);
	if (!success) {
		glGetProgramInfoLog(this->program, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::PROGRAM:LINKING_FAILED\n" << infoLog << std::endl;
	}
	glDeleteShader(vertex);
	glDeleteShader(fragment);
}

void Shader::use(void) {
	glUseProgram(this->program);
}