Shader.cpp

//
// Created by iak on 10.01.17.
//

#include "Shader.hpp"

Shader::Shader(GLchar const *vertexPath, GLchar const *fragmentPath) {

    std::ifstream vertexShaderFile;
    std::ifstream fragmentShaderFile;

    vertexShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
    fragmentShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);

    std::string vShaderSourceString, fShaderSourceString;

    try {
        vertexShaderFile.open(vertexPath);
        fragmentShaderFile.open(fragmentPath);

        std::stringstream vertexShaderSourceStream, fragmentShaderSourceStream;

        vertexShaderSourceStream << vertexShaderFile.rdbuf();
        fragmentShaderSourceStream << fragmentShaderFile.rdbuf();

        vShaderSourceString = vertexShaderSourceStream.str();
        fShaderSourceString = fragmentShaderSourceStream.str();
    }
    catch (std::ifstream::failure e) {
        std::cout << "ERROR::SHADER::FILE_READ_FAILURE" << std::endl;
    }

    const GLchar* vShaderCode = vShaderSourceString.c_str();
    const GLchar* fShaderCode = fShaderSourceString.c_str();

    GLuint vertexObj, fragmentObj;
    GLint success;
    GLchar infoLog[512];

    vertexObj = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexObj, 1, &vShaderCode, NULL);
    glCompileShader(vertexObj);
    glGetShaderiv(vertexObj, GL_COMPILE_STATUS, &success);
    if (!success) {
        glGetShaderInfoLog(vertexObj, 512, NULL, infoLog);
        std::cout << "ERROR::SHADER::COMPILATION_FAILED\n" << infoLog << std::endl;
    }

    fragmentObj = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentObj, 1, &fShaderCode, NULL);
    glCompileShader(fragmentObj);
    glGetShaderiv(fragmentObj, GL_COMPILE_STATUS, &success);
    if (!success) {
        glGetShaderInfoLog(fragmentObj, 512, NULL, infoLog);
        std::cout << "ERROR::SHADER::COMPILATION_FAILED\n" << infoLog << std::endl;
    }

    program = glCreateProgram();
    glAttachShader(program, vertexObj);
    glAttachShader(program, fragmentObj);
    glLinkProgram(program);

    glGetProgramiv(program, GL_LINK_STATUS, &success);
    if (!success) {
        glGetProgramInfoLog(program, 512, NULL, infoLog);
        std::cout << "ERROR::SHADER::LINK_FAILED\n" << infoLog << std::endl;
    }

    glDeleteShader(vertexObj);
    glDeleteShader(fragmentObj);
}

void Shader::deleteProgram() {
    glDeleteProgram(program);
}

void Shader::use() {
    glUseProgram(program);
}

GLuint Shader::getProgram() {
    return program;
}