evanw/gl

A small C++ library for working with OpenGL

Introduction

This library provides simple C++ wrappers around some OpenGL functionality. It was modified from an OpenGL 4 library created for the Advanced GPU Programming course at Brown University.

Example

#ifdef __APPLE_CC__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
#include "gl.h"

Shader shader;
Buffer<vec2> quad;
VAO layout;

void setup() {
    shader.vertexShader(glsl(
        attribute vec2 vertex;
        varying vec2 coord;
        void main() {
            coord = vertex * 0.5 + 0.5;
            gl_Position = vec4(vertex, 0.0, 1.0);
        }
    )).fragmentShader(glsl(
        varying vec2 coord;
        void main() {
            gl_FragColor = vec4(coord, 0.0, 1.0);
        }
    )).link();

    quad << vec2(-1, -1) << vec2(1, -1) << vec2(-1, 1) << vec2(1, 1);
    quad.upload();
    layout.create(shader, quad).attribute<float>("vertex", 2).check();
}

void draw() {
    glClear(GL_COLOR_BUFFER_BIT);
    shader.use();
    layout.draw(GL_TRIANGLE_STRIP);
    shader.unuse();
    glutSwapBuffers();
}

int main(int argc, char *argv[]) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
    glutCreateWindow("Example");
    glutReshapeWindow(800, 600);
    glutDisplayFunc(draw);
    setup();
    glutMainLoop();
    return 0;
}