Shader.cpp

#include "Shader.h"
#include <fstream>

Shader::Shader()
{
    shaderId = 0;
    compiled = false;
}

void Shader::initFromSource(const ShaderType type, const std::string &source)
{
    const char *sourcePtr = source.c_str();
    GLint status;
    char buffer[512];

    switch (type)
    {
    case VERTEX_SHADER:
        shaderId = glCreateShader(GL_VERTEX_SHADER);
        break;
    case FRAGMENT_SHADER:
        shaderId = glCreateShader(GL_FRAGMENT_SHADER);
        break;
    }
    if (shaderId == 0)
        return;
    glShaderSource(shaderId, 1, &sourcePtr, NULL);
    glCompileShader(shaderId);
    glGetShaderiv(shaderId, GL_COMPILE_STATUS, &status);
    compiled = (status == GL_TRUE);
    glGetShaderInfoLog(shaderId, 512, NULL, buffer);
    errorLog.assign(buffer);
}

bool Shader::initFromFile(const ShaderType type, const std::string &filename)
{
    std::string shaderSource;

    if (!loadShaderSource(filename, shaderSource))
        return false;
    initFromSource(type, shaderSource);

    return true;
}

void Shader::free()
{
    glDeleteShader(shaderId);
    shaderId = 0;
    compiled = false;
}

GLuint Shader::getId() const
{
    return shaderId;
}

bool Shader::isCompiled() const
{
    return compiled;
}

const std::string &Shader::log() const
{
    return errorLog;
}

bool Shader::loadShaderSource(const std::string &filename, std::string &shaderSource)
{
    std::ifstream fin;

    fin.open(filename.c_str());
    if (!fin.is_open())
        return false;
    shaderSource.assign(std::istreambuf_iterator<char>(fin), std::istreambuf_iterator<char>());

    return true;
}