skein/src/gfx.cpp

#include "gfx.hpp"

#include <iostream>

#include "io.hpp"

GLuint compileShader(const std::string& shaderPath, GLenum shaderType)
{
    GLuint shader;
    GLint success;

    std::string shaderSource = readFile(shaderPath);
    const char* source = shaderSource.c_str();

    shader = glCreateShader(shaderType);
    glShaderSource(shader, 1, &source, NULL);
    glCompileShader(shader);

    glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
    if (!success)
    {
        GLchar infoLog[512];
        glGetShaderInfoLog(shader, 512, NULL, infoLog);
        std::cerr << "shader compilation failed" << std::endl
            << infoLog << std::endl;
    }

    return shader;
}

GLuint compileShaderProgram(const std::string& fragShaderPath)
{
    GLuint vertShader = compileShader("./vert.glsl", GL_VERTEX_SHADER);
    GLuint fragShader = compileShader(fragShaderPath, GL_FRAGMENT_SHADER);

    GLuint shaderProgram = glCreateProgram();
    glAttachShader(shaderProgram, vertShader);
    glAttachShader(shaderProgram, fragShader);
    glLinkProgram(shaderProgram);

    GLint success;
    GLchar infoLog[512];
    glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
    if (!success)
    {
        glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
        std::cerr << "shader linking failed" << std::endl
            << infoLog << std::endl;
        exit(-1);
    }

    // We no longer need the individual shaders
    glDeleteShader(vertShader);
    glDeleteShader(fragShader);

    return shaderProgram;
}