glcube

glcube is an OpenGL demo written in C11 that renders a rotating cube using programmable shaders. it depends on gl2_nano, a lightweight helper library that provides a simple vertex and index buffer abstraction, along with utilities for loading, compiling, and linking OpenGL shader programs.

Introduction

glcube is an app skeleton using gl2_nano, a framework for creating apps using the modern OpenGL and GLSL shader pipeline. this work is intended to be used as a template for tiny OpenGL demos. The shader uses the maj2random noise function derived from SHA-2, combined with UVs to create surface noise.

Project Structure

• src/gl2_cube.c - OpenGL 2.1 cube using the gl2_nano.h shader loader.
• src/gl3_cube.c - OpenGL 3.2 cube using the gl2_nano.h shader loader.
• src/gl4_cube.c - OpenGL 4.5 cube using the gl2_nano.h shader loader.
• src/gl2_nano.h - header functions for OpenGL buffers and shaders.
• src/linmath.h - public domain linear algebra header functions.

Build Instructions

glcube has been tested on the following operating systems:

• Ubuntu 24.04 LTS
• FreeBSD 14.3
• Windows 11
• macOS 15

glcube requires the following dependencies:

• Microsoft Windows plus Visual Studio 2022 with CMake and C/C++.
• Apple macOS with XCode Developer Tools and CMake plus Ninja.
• Linux or FreeBSD with GCC or Clang and CMake plus Ninja.

cmake -B build -G Ninja
cmake --build build

Examples

The project includes several versions of glcube ported to multiple APIs.

gl2_cube

gl2_cube is a 3D cube renderer using OpenGL 2.x and GLSL shaders.

gl3_cube

gl3_cube is the same as gl2_cube with the addition of vertex array objects from OpenGL 3.x.

gl4_cube

gl4_cube is the same as gl3_cube with the addition of uniform buffer objects from OpenGL 4.x.