Chapter 10. Stored Texture Shaders

Texture mapping is a powerful mechanism built into OpenGL. At the time OpenGL was initially defined (1992), texture-mapping hardware was just starting to be available on commercial products. Nowadays, texture mapping is available on graphics hardware at all price points, even entry-level consumer graphics boards.

When OpenGL 1.0 was defined, texture mapping had a fairly narrow definition. It was simply a way to apply an image to the surface of an object. Since then, hardware has become capable of doing much more in this area, and researchers have come up with a lot of interesting things to do with textures other than just plastering images on surfaces. The scope of texture mapping has also been extended in OpenGL. Texture objects were one of the key additions in OpenGL 1.1. Three-dimensional textures were made part of the standard in OpenGL 1.2. The capability of hardware to access two or more textures simultaneously was exposed in OpenGL 1.3, along with cube map textures and a framework for supporting compressed textures formats. OpenGL 1.4 added support for depth textures and shadows, automatic mipmap generation, and another texture wrap mode (mirrored repeat). If you need a quick review of how texturing works in OpenGL, refer to Section 1.10.