Name EXT_texture_env_add Name Strings GL_EXT_texture_env_add Contact Michael Gold, NVIDIA (gold 'at' nvidia.com) Tom Frisinger, ATI (tfrisinger 'at' atitech.com) Status Shipping (version 1.7) Version $Date: 1999/03/22 17:28:00 $ $Revision: 1.1 $ Number 185 Dependencies None Overview New texture environment function ADD is supported with the following equation: Cv = min(1, Cf + Ct) New function may be specified by calling TexEnv with ADD token. New Procedures and Functions None New Tokens Accepted by the parameter of TexEnvf, TexEnvi, TexEnvfv, and TexEnvfi when the parameter value is GL_TEXTURE_ENV_MODE ADD Additions to Chapter 2 of the GL Specification (OpenGL Operation) None Additions to Chapter 3 of the GL Specification (Rasterization) Texture Environment ------------------- Base Texture Format REPLACE MODULATE BLEND DECAL ADD ------------------- ------- -------- ----- ----- --- ALPHA ... ... ... ... Rv = Rf ... ... ... ... Gv = Gf ... ... ... ... Bv = Bf ... ... ... ... Av = AfAt LUMINANCE ... ... ... ... Rv = min(1, Rf+Lt) ... ... ... ... Gv = min(1, Gf+Lt) ... ... ... ... Bv = min(1, Bf+Lt) ... ... ... ... Av = Af LUMINANCE_ALPHA ... ... ... ... Rv = min(1, Rf+Lt) ... ... ... ... Gv = min(1, Gf+Lt) ... ... ... ... Bv = min(1, Bf+Lt) ... ... ... ... Av = AfAt INTENSITY ... ... ... ... Rv = min(1, Rf+It) ... ... ... ... Gv = min(1, Gf+It) ... ... ... ... Bv = min(1, Bf+It) ... ... ... ... Av = min(1, Af+It) RGB ... ... ... ... Rv = min(1, Rf+Rt) ... ... ... ... Gv = min(1, Gf+Gt) ... ... ... ... Bv = min(1, Bf+Bt) ... ... ... ... Av = Af RGBA ... ... ... ... Rv = min(1, Rf+Rt) ... ... ... ... Gv = min(1, Gf+Gt) ... ... ... ... Bv = min(1, Bf+Bt) ... ... ... ... Av = AfAt Table 3.11: Texture functions. Additions to Chapter 4 of the GL Specification (Per-Fragment Operations and the Framebuffer) None Additions to Chapter 5 of the GL Specification (Special Functions) None Additions to Chapter 6 of the GL Specification (State and State Requests) None Additions to the GLX / WGL / AGL Specifications None GLX Protocol None Errors None New State None New Implementation Dependent State None Revision History Rev. Date Author Changes ---- -------- -------- -------------------------------------------- 1.7 08/13/08 mjk Add missing "clamping to 1" behavior.