glhash

glhash is an OpenGL compute shader implementing SHA-2-256 in GLSL.

Introduction

glhash is a OpenGL 4.x compute shader demo using gl2_nano, a nano framework for creating apps using the modern OpenGL and GLSL shader pipeline. The CMakeLists.txt is intended to be used as a template for tiny demos.

Project Structure

• src/gl4_hash.c - OpenGL 4.x compute demo using gl2_nano.h loader.
• src/gl2_nano.h - header functions for OpenGL buffers and shaders.

Project Template

This project template uses ExternalProject to build and link the GLFW and Glad libraries. These projects have stable APIs with stable symbols, so in this case it is a deliberate choice to use the latest versions. This has the advantage of avoiding submodules.

It is possible to build using the system GLFW found using PkgConfig, however, we believe ExternalProject is a good choice for OpenGL samples that prefer the latest version of GLFW versus a buggy or misconfigured version bundled with the operating system.

The following cmake configuration options are offered:

• -DVULKAN_SDK=<path_to_vulkan_sdk> (used to find glslangValidator)
• -DSPIRV_BINARIES=OFF (default ON if glslangValidator is found)
• -DEXTERNAL_GLFW=OFF (default ON, if disabled, pkg-config is used)
• -DEXTERNAL_GLAD=OFF (default ON, if disabled, glad is not used)

Example Invocation

To invoke the example using GLSL shader source:

./build/gl4_hash

To invoke the example using SPIR-V binary module:

./build/gl4_hash --spir

Build Instructions

glhash has been tested on the following operating systems:

• Ubuntu 24.04 LTS
• FreeBSD 14.3
• Windows 11

glhash requires the following dependencies:

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

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