| Name |
| |
| SGIX_texture_add_env |
| |
| Name Strings |
| |
| GL_SGIX_texture_add_env |
| |
| Version |
| |
| $Date: 1996/08/27 19:55:58 $ $Revision: 1.6 $ |
| |
| Number |
| |
| 69 |
| |
| Dependencies |
| |
| None |
| |
| Overview |
| |
| New texture environment function ADD is supported with the following |
| equation: |
| Cv = Cf + CcCt + Cb |
| |
| New function may be specified by calling glTexEnv with GL_ADD token. |
| New parameter Cb (bias) may be specified by calling TexEnv with |
| TEXTURE_ENV_BIAS_SGIX token. |
| |
| |
| New Procedures and Functions |
| |
| None |
| |
| New Tokens |
| |
| Accepted by the <params> parameter of TexEnvf, TexEnvi, TexEnvfv, and |
| TexEnvfi when the <pname> parameter value is GL_TEXTURE_ENV_MODE |
| |
| ADD |
| |
| Accepted by the <pname> parameter of GetBooleanv, GetIntegerv, GetFloatv, |
| and GetDoublev, and by the <pname> parameter of TexEnvfv, and TexEnvfi |
| |
| TEXTURE_ENV_BIAS_SGIX |
| |
| |
| 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 = Rf+LtRc+Rb |
| ... ... ... ... Gv = Gf+LtGc+Gb |
| ... ... ... ... Bv = Bf+LtBc+Bb |
| ... ... ... ... Av = Af |
| |
| LUMINANCE_ALPHA ... ... ... ... Rv = Rf+LtRc+Rb |
| ... ... ... ... Gv = Gf+LtGc+Gb |
| ... ... ... ... Bv = Bf+LtBc+Bb |
| ... ... ... ... Av = AfAt |
| |
| INTENSITY ... ... ... ... Rv = Rf+ItRc+Rb |
| ... ... ... ... Gv = Gf+ItGc+Gb |
| ... ... ... ... Bv = Bf+ItBc+Bb |
| ... ... ... ... Av = Af+ItAc+Ab |
| |
| RGB ... ... ... ... Rv = Rf+RtRc+Rb |
| ... ... ... ... Gv = Gf+GtGc+Gb |
| ... ... ... ... Bv = Bf+BtBc+Bb |
| ... ... ... ... Av = Af |
| |
| RGBA ... ... ... ... Rv = Rf+RtRc+Rb |
| ... ... ... ... Gv = Gf+GtGc+Gb |
| ... ... ... ... Bv = Bf+BtBc+Bb |
| ... ... ... ... 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) |
| |
| The value of the texture environment bias is queried by calling |
| GetBooleanv, GetIntegerv, GetFloatv, and GetDoublev with <pname> set to |
| TEXTURE_ENV_BIAS_SGIX. |
| |
| |
| Additions to the GLX Specification |
| |
| None |
| |
| GLX Protocol |
| |
| None |
| |
| Errors |
| |
| None |
| |
| New State |
| |
| Get Value Get Command Type Initial Value Attribute |
| --------- ----------- ---- ------------- --------- |
| TEXTURE_ENV_BIAS_SGIX GetFloatv C (0, 0, 0, 0) texture |
| |
| |
| New Implementation Dependent State |
| |
| None |