1Name 2 3 SGIX_texture_add_env 4 5Name Strings 6 7 GL_SGIX_texture_add_env 8 9Version 10 11 $Date: 1996/08/27 19:55:58 $ $Revision: 1.6 $ 12 13Number 14 15 69 16 17Dependencies 18 19 None 20 21Overview 22 23 New texture environment function ADD is supported with the following 24 equation: 25 Cv = Cf + CcCt + Cb 26 27 New function may be specified by calling glTexEnv with GL_ADD token. 28 New parameter Cb (bias) may be specified by calling TexEnv with 29 TEXTURE_ENV_BIAS_SGIX token. 30 31 32New Procedures and Functions 33 34 None 35 36New Tokens 37 38 Accepted by the <params> parameter of TexEnvf, TexEnvi, TexEnvfv, and 39 TexEnvfi when the <pname> parameter value is GL_TEXTURE_ENV_MODE 40 41 ADD 42 43 Accepted by the <pname> parameter of GetBooleanv, GetIntegerv, GetFloatv, 44 and GetDoublev, and by the <pname> parameter of TexEnvfv, and TexEnvfi 45 46 TEXTURE_ENV_BIAS_SGIX 47 48 49Additions to Chapter 2 of the GL Specification (OpenGL Operation) 50 51 None 52 53Additions to Chapter 3 of the GL Specification (Rasterization) 54 55 56 Texture Environment 57 ------------------- 58 59 Base Texture Format REPLACE MODULATE BLEND DECAL ADD 60 ------------------- ------- -------- ----- ----- --- 61 62 ALPHA ... ... ... ... Rv = Rf 63 ... ... ... ... Gv = Gf 64 ... ... ... ... Bv = Bf 65 ... ... ... ... Av = AfAt 66 67 LUMINANCE ... ... ... ... Rv = Rf+LtRc+Rb 68 ... ... ... ... Gv = Gf+LtGc+Gb 69 ... ... ... ... Bv = Bf+LtBc+Bb 70 ... ... ... ... Av = Af 71 72 LUMINANCE_ALPHA ... ... ... ... Rv = Rf+LtRc+Rb 73 ... ... ... ... Gv = Gf+LtGc+Gb 74 ... ... ... ... Bv = Bf+LtBc+Bb 75 ... ... ... ... Av = AfAt 76 77 INTENSITY ... ... ... ... Rv = Rf+ItRc+Rb 78 ... ... ... ... Gv = Gf+ItGc+Gb 79 ... ... ... ... Bv = Bf+ItBc+Bb 80 ... ... ... ... Av = Af+ItAc+Ab 81 82 RGB ... ... ... ... Rv = Rf+RtRc+Rb 83 ... ... ... ... Gv = Gf+GtGc+Gb 84 ... ... ... ... Bv = Bf+BtBc+Bb 85 ... ... ... ... Av = Af 86 87 RGBA ... ... ... ... Rv = Rf+RtRc+Rb 88 ... ... ... ... Gv = Gf+GtGc+Gb 89 ... ... ... ... Bv = Bf+BtBc+Bb 90 ... ... ... ... Av = AfAt 91 92 93 Table 3.11: Texture functions. 94 95 96Additions to Chapter 4 of the GL Specification (Per-Fragment Operations 97and the Framebuffer) 98 99 None 100 101Additions to Chapter 5 of the GL Specification (Special Functions) 102 103 None 104 105Additions to Chapter 6 of the GL Specification (State and State Requests) 106 107 The value of the texture environment bias is queried by calling 108 GetBooleanv, GetIntegerv, GetFloatv, and GetDoublev with <pname> set to 109 TEXTURE_ENV_BIAS_SGIX. 110 111 112Additions to the GLX Specification 113 114 None 115 116GLX Protocol 117 118 None 119 120Errors 121 122 None 123 124New State 125 126 Get Value Get Command Type Initial Value Attribute 127 --------- ----------- ---- ------------- --------- 128 TEXTURE_ENV_BIAS_SGIX GetFloatv C (0, 0, 0, 0) texture 129 130 131New Implementation Dependent State 132 133 None 134