KlassischeKeplerKriege/game/glclasses.cpp

#include "glclasses.hpp"

#include <iostream>
#include <vector>
#include <fstream>
#include <sstream>

namespace endofthejedi {
VAO::VAO() { glGenVertexArrays(1, &m_name); }

VAO::~VAO() { glDeleteVertexArrays(1, &m_name); }

void VAO::bind() { glBindVertexArray(m_name); }
void VAO::unbind() { glBindVertexArray(0); }

void VAO::fill(GLuint index, GLint size, GLenum type, GLboolean normalized,
               GLsizei stride, const GLvoid *pointer) {
    glEnableVertexAttribArray(index);
    glVertexAttribPointer(index, size, type, normalized, stride, pointer);
}

Shader::Shader() : m_program(0) {}

Shader::~Shader() {}

void Shader::init() { m_program = glCreateProgram(); }

bool Shader::check() {
    GLint len = 0;
    GLint result = 0;

    glGetProgramiv(m_program, GL_LINK_STATUS, &result);
    glGetProgramiv(m_program, GL_INFO_LOG_LENGTH, &len);

    if (result == GL_FALSE) {
        std::cout << "getting error log:" << std::endl;
        char *error = (char *)malloc(len + 1);
        glGetProgramInfoLog(m_program, len, NULL, error);
        std::string str(error);
        std::cout << str << std::endl;
    }
    // std::cout << "checked program" << std::endl;

    return (bool)result;
}

bool Shader::checkShader(GLuint shader) {
    GLint len = 0;
    GLint result = 0;

    glGetShaderiv(shader, GL_COMPILE_STATUS, &result);

    if (result == GL_FALSE) {
        glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &len);
        char *error = (char *)malloc(len + 1);
        glGetShaderInfoLog(shader, len, NULL, error);
        std::string str(error, error + len);
        std::cout << str << std::endl;
    }

    // std::cout << "checked shader" << std::endl;

    return result != GL_FALSE;
}

void Shader::bind() {
    if (m_program == 0) {
        std::cerr << "error: invalid to bind invalid program (0)! "
                     "use unbind() if that was your purpose!" << std::endl;

        exit(-1);
        return;
    }

    glUseProgram(m_program);
}

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

void Shader::unbind() { glUseProgram(0); }

void Shader::load(const std::string &data, GLenum shadertype) {
    if (m_program == 0) {
        std::cout << "[shader] error: shader program is invalid (0)!"
                  << std::endl;
        exit(-1);
        return;
    }

    GLuint shader = glCreateShader(shadertype);

    const char *shaderdata = data.c_str();
    glShaderSource(shader, 1, &shaderdata, NULL);
    glCompileShader(shader);
    checkShader(shader);

    glAttachShader(m_program, shader);
    glLinkProgram(m_program);
    check();

    glDeleteShader(shader);
}

void Shader::loadFile(const std::string &path, GLenum shadertype) {
    std::string content;
    std::ifstream fileStream(path, std::ios::in);

    if (!fileStream.is_open()) {
        std::cerr << "Could not read file " << path << ". File does not exist."
                  << std::endl;
        return;
    }

    std::string line = "";
    while (!fileStream.eof()) {
        std::getline(fileStream, line);
        content.append(line + "\n");
    }

    fileStream.close();
    load(content, shadertype);
}

GLuint Shader::location(const std::string &name) {
    return glGetUniformLocation(m_program, name.c_str());
}

Texture::Texture() { glGenTextures(1, &m_name); }

Texture::~Texture() { glDeleteTextures(1, &m_name); }

void Texture::bind() { glBindTexture(GL_TEXTURE_2D, m_name); }

void Texture::unbind() { glBindTexture(GL_TEXTURE_2D, 0); }

void Texture::fill(GLenum target, GLint level, GLint internalFormat,
                   GLsizei width, GLsizei height, GLint border, GLenum format,
                   GLenum type, const GLvoid *data) {
    bind();
    glTexImage2D(target, level, internalFormat, width, height, border, format,
                 type, data);
}
GLuint Texture::getName() { return m_name; }

Framebuffer::Framebuffer() { glGenFramebuffers(1, &m_name); }

Framebuffer::~Framebuffer() { glDeleteFramebuffers(1, &m_name); }

void Framebuffer::bind() { glBindFramebuffer(GL_FRAMEBUFFER, m_name); }

void Framebuffer::unbind() { glBindFramebuffer(GL_FRAMEBUFFER, 0); }

void Framebuffer::attachRenderbuffer(GLenum attachment, GLuint rbo) {
    bind();
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, attachment, GL_RENDERBUFFER, rbo);
}

void Framebuffer::attachTexture(GLenum attachment, GLuint tex) {
    bind();
    glFramebufferTexture2D(GL_FRAMEBUFFER, attachment, GL_TEXTURE_2D, tex, 0);
}

Renderbuffer::Renderbuffer() { glGenRenderbuffers(1, &m_name); }

Renderbuffer::~Renderbuffer() { glDeleteRenderbuffers(1, &m_name); }

void Renderbuffer::bind() { glBindRenderbuffer(GL_RENDERBUFFER, m_name); }

void Renderbuffer::unbind() { glBindRenderbuffer(GL_RENDERBUFFER, 0); }

void Renderbuffer::create(GLenum internalformat, GLsizei width,
                          GLsizei height) {
    bind();
    glRenderbufferStorage(GL_RENDERBUFFER, internalformat, width, height);
}
}

void printGlError(GLenum err) {
    if (err != GL_NO_ERROR) {
        std::cout << "opengl error is: " << stringFromGlError(err) << std::endl;
    }
}

void discardLastGlError(bool print) {
    GLenum err = glGetError();
    if (print) {
        printGlError(err);
    }
}

// return false if there's an error
bool checkAndPrintGlError() {
    GLenum err = glGetError();

    printGlError(err);

    return true;
}

const char *stringFromGlError(GLenum err) {
    switch (err) {
    case GL_INVALID_ENUM:
        return "GL_INVALID_ENUM";
        break;
    case GL_INVALID_VALUE:
        return "GL_INVALID_VALUE";
        break;
    case GL_INVALID_OPERATION:
        return "GL_INVALID_OPERATION";
        break;
    case GL_OUT_OF_MEMORY:
        return "GL_OUT_OF_MEMORY";
        break;
    case GL_INVALID_FRAMEBUFFER_OPERATION:
        return "GL_INVALID_FRAMEBUFFER_OPERATION";
        break;
    default:
        return "<unknown>";
        break;
    }
}