shaderClass.cpp

#include "shaderClass.h"

std::string get_file_contents(const char* filename)
{
    std::ifstream in(filename, std::ios::in | std::ios::binary);
    if (in)
    {
        std::string contents;
        in.seekg(0, std::ios::end);
        contents.resize(in.tellg());
        in.seekg(0, std::ios::beg);
        in.read(&contents[0], contents.size());
        in.close();
        return(contents);
    }
    throw(errno);
}

Shader::Shader(const char* vertexFile, const char* fragmentFile)
{
    std::string vertexCode = get_file_contents(vertexFile);
    std::string fragmentCode = get_file_contents(fragmentFile);

    const char* vertexSource = vertexCode.c_str();
    const char* fragmentSource = fragmentCode.c_str();

    // creating the vertex shader
    GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexShader, 1, &vertexSource, NULL);
    glCompileShader(vertexShader);

    // creating the fragment shader
    GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShader, 1, &fragmentSource, NULL);
    glCompileShader(fragmentShader);

    // makeing the shader program and adding all the shaders to it
    ID = glCreateProgram();
    glAttachShader(ID, vertexShader);
    glAttachShader(ID, fragmentShader);
    glLinkProgram(ID);

    // clean up the shaders
    glDeleteShader(vertexShader);
    glDeleteShader(fragmentShader);
}

void Shader::Activate()
{
    glUseProgram(ID);
}

void Shader::Delete()
{
    glDeleteProgram(ID);
}