# opengl-glew

Bindings to OpenGL with GLEW extension loading.

Chicken's other [opengl](http://wiki.call-cc.org/eggref/4/opengl) bindings are based on the old fixed function pipeline OpenGL. These bindings generated by [bind](http://wiki.call-cc.org/eggref/4/bind) with the OpenGL [core header file](http://www.opengl.org/registry/api/GL/glcorearb.h). Additionally, bindings to [GLEW](http://glew.sourceforge.net/) are provided for extension management.

## Installation
This repository is a [Chicken Scheme](http://call-cc.org/) egg.

It is part of the [Chicken egg index](http://wiki.call-cc.org/chicken-projects/egg-index-4.html) and can be installed with `chicken-install opengl-glew`.

## Requirements
- make
- bind

## Documentation
All functions and constants from the OpenGL [core header file](http://www.opengl.org/registry/api/GL/glcorearb.h) are exported. Scheme style names are provided (underscores and camelCase replaced with hyphens), the `gl` prefix is removed from names, functions starting with `is` instead end in question marks, and constants are bookended by `+`s (e.g. `delete-texture`, `enabled?`, `+arb-viewport-array+`). The terms `1D`, `2D` and `3D` are additionally hyphen separated in order to match their constant counterparts (e.g. `tex-image-2d` and `+texture-2d+`).

Functions whose C counterparts accept or return `GLboolean` accept or return a Scheme boolean value. *Do not* pass `+true+` or `+false+` to these functions.

### GLEW functions

    [procedure] (init)

Required to initialize GLEW/OpenGL. An OpenGL context must be created before this is called.

    [procedure] (supported? EXTENSION-NAME)

Query whether the OpenGL extension, given as a string, is supported.

## Example
For numerous examples of opengl-glew usage, look at the [gl-utils](http://wiki.call-cc.org/eggref/4/gl-utils) egg, [glls](http://wiki.call-cc.org/eggref/4/glls) egg, or the [noise](http://wiki.call-cc.org/eggref/4/noise) egg.

## Version history
### Version 0.8.0
24 August 2014

* Split [gl-utils](http://wiki.call-cc.org/eggref/4/gl-utils) into its own egg
* Hyphen-separate `2D`, `3D`, and `4D` in name conversion

### Version 0.7.0
8 August 2014

* Export `->pointer`, `size`
* Improve shader error messages

### Version 0.6.0
17 June 2014

* Remove gl-math module (which is now its own egg: [gl-math](http://wiki.call-cc.org/eggref/4/gl-math))

### Version 0.5.0
3 June 2014

* `make-vao` accepts vectors and blobs
* `load-ply` returns u8vectors rather than blobs
* gl-utils exports a non-garbage collected by default version of srfi-4
* gl-math can create non-garbage collected matrices

### Version 0.4.4
2 June 2014

* `load-ply-vao` now returns buffer data (which is important to keep around!)

**Version 0.4.3**

30 May 2014

* Add optional program argument to `make-program`
* gl-math short-circuits rotations of 0

**Version 0.4.2**

24 May 2014

* Fix segfaults caused by glewExperimental not being set (thanks, Terpri!)

**Version 0.4.1**

12 May 2014

* Remove rogue print statement

**Version 0.4.0**

11 May 2014

* Add gl-math module
* Add gl-utils module
* Add `check-error`

### Version 0.3.0
* Add single element `gen` and `delete` functions

### Version 0.2.0
* Add glcorearb.h - no longer downloaded at install time

### Version 0.1.0
* Initial release

## Source repository
Source available on [GitHub](https://github.com/AlexCharlton/chicken-opengl-glew).

Bug reports and patches welcome! Bugs can be reported via GitHub or to alex.n.charlton at gmail.

## Author
Alex Charlton

## Licence
BSD