Native bindings to the NV_point_sprite extension.

Applications such as particle systems usually must use OpenGL quads rather than points to render their geometry, since they would like to use a custom-drawn texture for each particle, rather than the traditional OpenGL round antialiased points, and each fragment in a point has the same texture coordinates as every other fragment.

Unfortunately, specifying the geometry for these quads can be quite expensive, since it quadruples the amount of geometry required, and it may also require the application to do extra processing to compute the location of each vertex.

The goal of this extension is to allow such apps to use points rather than quads. When POINT_SPRITE_NV is enabled, the state of point antialiasing is ignored. For each texture unit, the app can then specify whether to replace the existing texture coordinates with point sprite texture coordinates, which are interpolated across the point. Finally, the app can set a global parameter for the way to generate the R coordinate for point sprites; the R coordinate can either be zero, the input S coordinate, or the input R coordinate. This allows applications to use a 3D texture to represent a point sprite that goes through an animation, with filtering between frames, for example.

Requires EXT_point_parameters.