OpenGL for Idris
This project contains low-level bindings for the OpenGL graphics system.
It comes with some bells and whistles:
- An OBJ-Loader for loading 3D-Models
- PNG-Texure Loading
- Utilities for creating view / perspective / transformation matrices
- a few convenience functions for shader initialisation, model to gpu transfer etc.
- Effects (upcoming)
Currently this project only provides OpenGL version 4.1 because I'm on a mac, and version only 4.1 is provided.
The low-level bindings are generated from the OpenGL API Registry. Currently the generator is too stupid to handle all the cases so there are still some commands missing.
Requirements
- OpenGL OpenGL itself.
- GLEW OpenGL initialisation and extension loading
- pkg-config for providing the include and lib flags to the compiler
- Idris at least version 0.9.18
- Lightyear for OBJ file parsing
- libpng for texture loading
Installation
Please follow the individual installation instructions for each of the required components.
If you are on a mac you can get away with brew install for GLEW, pkg-config and libpng.
OpenGL is already installed.
This project contains a small C file for easier integration. The Makefile for the FFI is platform dependent and will currently work only on MacOS:
Specifically it says in `src/MakefileGl'
echo "%flag C \"-framework OpenGL\"" >> Graphics/Rendering/Config.idr
You might need to change -framework OpenGL to whatever is needed for the C flags on your system.
How to use it
There are two examples in the example folder.
To run these examples you need to install more libraries, since OpenGL provides
no means to open a window or process user input.
The first examples uses GLFW while the second uses SDL2
For the GLFW example you need an additional Idris libray found here: https://github.com/eckart/glfw-idris For the SDL2 example you obviously also need an additional library: https://github.com/eckart/SDL2-idris
Is is safe to use it yet?
I primarily did all this because I wanted to lear Idris and thought I'd do it by drawing things. Right now I am still on working on it, so it is not abandoned.
It might even be stable enough even if lots of things are still missing.
The real low-level stuff sits in the module Graphics.Rendering.Gl.Gl41.id which is a fairly
direct translation of the OpenGL stuff except for the enums, which I have tried to group into data types.
I'm still not clear whether this was a good idea or not.
However I have no plans to change any of that stuff any time soon.
Is it safe to use it? I don't know..