GL ARB multitexture
|Warning: This article describes legacy OpenGL APIs that have been removed from core OpenGL 3.1 and above (they are only deprecated in OpenGL 3.0). It is recommended that you not use this functionality in your programs.|
This extension provides a mechanism for client to use multiple texture objects binded at the same time, providing separate texture mapping coordinates and blending modes for each texture object to achieve effects such as chrome or for shadow mapping. the extension is now part of OpenGL 1.2.1 specification
GL_ARB_multitexture specifies Up to 32 multi texture stages using constants from GL_TEXTURE0_ARB to GL_TEXTURE31_ARB.
Using glActiveTextureARB call the program switches into specific texture stage on which the texture object calls such as glBindTexture and calls that change and modify the textrue blending and alpha testing mode will fom now affect the selected texture stage. By default the selected stage is GL_TEXTURE0_ARB.
As mentioned in the introduction, GL_ARB_multitexture introduces a way to provide the application several advanced rendering effects, it is useful for shadow mapping, reflections, skyboxes, texture blending and so on.
Tips and tricks
- combining multitexturing with glTexCoordPointer requires that you specify each texture coordinates buffer after a call to glClientActiveTextureARB.