1 /* 2 * Mesa 3-D graphics library 3 * 4 * Copyright (C) 1999-2003 Brian Paul All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included 14 * in all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 22 * OTHER DEALINGS IN THE SOFTWARE. 23 */ 24 25 26 #include "glheader.h" 27 #include "context.h" 28 #include "fog.h" 29 #include "macros.h" 30 #include "mtypes.h" 31 32 33 34 void GLAPIENTRY 35 _mesa_Fogf(GLenum pname, GLfloat param) 36 { 37 GLfloat fparam[4]; 38 fparam[0] = param; 39 fparam[1] = fparam[2] = fparam[3] = 0.0F; 40 _mesa_Fogfv(pname, fparam); 41 } 42 43 44 void GLAPIENTRY 45 _mesa_Fogi(GLenum pname, GLint param ) 46 { 47 GLfloat fparam[4]; 48 fparam[0] = (GLfloat) param; 49 fparam[1] = fparam[2] = fparam[3] = 0.0F; 50 _mesa_Fogfv(pname, fparam); 51 } 52 53 54 void GLAPIENTRY 55 _mesa_Fogiv(GLenum pname, const GLint *params ) 56 { 57 GLfloat p[4]; 58 switch (pname) { 59 case GL_FOG_MODE: 60 case GL_FOG_DENSITY: 61 case GL_FOG_START: 62 case GL_FOG_END: 63 case GL_FOG_INDEX: 64 case GL_FOG_COORDINATE_SOURCE_EXT: 65 p[0] = (GLfloat) *params; 66 break; 67 case GL_FOG_COLOR: 68 p[0] = INT_TO_FLOAT( params[0] ); 69 p[1] = INT_TO_FLOAT( params[1] ); 70 p[2] = INT_TO_FLOAT( params[2] ); 71 p[3] = INT_TO_FLOAT( params[3] ); 72 break; 73 default: 74 /* Error will be caught later in _mesa_Fogfv */ 75 ASSIGN_4V(p, 0.0F, 0.0F, 0.0F, 0.0F); 76 } 77 _mesa_Fogfv(pname, p); 78 } 79 80 81 /** 82 * Update the gl_fog_attrib::_Scale field. 83 */ 84 static void 85 update_fog_scale(struct gl_context *ctx) 86 { 87 if (ctx->Fog.End == ctx->Fog.Start) 88 ctx->Fog._Scale = 1.0f; 89 else 90 ctx->Fog._Scale = 1.0f / (ctx->Fog.End - ctx->Fog.Start); 91 } 92 93 94 void GLAPIENTRY 95 _mesa_Fogfv( GLenum pname, const GLfloat *params ) 96 { 97 GET_CURRENT_CONTEXT(ctx); 98 GLenum m; 99 100 switch (pname) { 101 case GL_FOG_MODE: 102 m = (GLenum) (GLint) *params; 103 switch (m) { 104 case GL_LINEAR: 105 case GL_EXP: 106 case GL_EXP2: 107 break; 108 default: 109 _mesa_error( ctx, GL_INVALID_ENUM, "glFog" ); 110 return; 111 } 112 if (ctx->Fog.Mode == m) 113 return; 114 FLUSH_VERTICES(ctx, _NEW_FOG); 115 ctx->Fog.Mode = m; 116 break; 117 case GL_FOG_DENSITY: 118 if (*params<0.0F) { 119 _mesa_error( ctx, GL_INVALID_VALUE, "glFog" ); 120 return; 121 } 122 if (ctx->Fog.Density == *params) 123 return; 124 FLUSH_VERTICES(ctx, _NEW_FOG); 125 ctx->Fog.Density = *params; 126 break; 127 case GL_FOG_START: 128 if (ctx->Fog.Start == *params) 129 return; 130 FLUSH_VERTICES(ctx, _NEW_FOG); 131 ctx->Fog.Start = *params; 132 update_fog_scale(ctx); 133 break; 134 case GL_FOG_END: 135 if (ctx->Fog.End == *params) 136 return; 137 FLUSH_VERTICES(ctx, _NEW_FOG); 138 ctx->Fog.End = *params; 139 update_fog_scale(ctx); 140 break; 141 case GL_FOG_INDEX: 142 if (ctx->API != API_OPENGL_COMPAT) 143 goto invalid_pname; 144 if (ctx->Fog.Index == *params) 145 return; 146 FLUSH_VERTICES(ctx, _NEW_FOG); 147 ctx->Fog.Index = *params; 148 break; 149 case GL_FOG_COLOR: 150 if (TEST_EQ_4V(ctx->Fog.Color, params)) 151 return; 152 FLUSH_VERTICES(ctx, _NEW_FOG); 153 ctx->Fog.ColorUnclamped[0] = params[0]; 154 ctx->Fog.ColorUnclamped[1] = params[1]; 155 ctx->Fog.ColorUnclamped[2] = params[2]; 156 ctx->Fog.ColorUnclamped[3] = params[3]; 157 ctx->Fog.Color[0] = CLAMP(params[0], 0.0F, 1.0F); 158 ctx->Fog.Color[1] = CLAMP(params[1], 0.0F, 1.0F); 159 ctx->Fog.Color[2] = CLAMP(params[2], 0.0F, 1.0F); 160 ctx->Fog.Color[3] = CLAMP(params[3], 0.0F, 1.0F); 161 break; 162 case GL_FOG_COORDINATE_SOURCE_EXT: { 163 GLenum p = (GLenum) (GLint) *params; 164 if (ctx->API != API_OPENGL_COMPAT || 165 (p != GL_FOG_COORDINATE_EXT && p != GL_FRAGMENT_DEPTH_EXT)) { 166 _mesa_error(ctx, GL_INVALID_ENUM, "glFog"); 167 return; 168 } 169 if (ctx->Fog.FogCoordinateSource == p) 170 return; 171 FLUSH_VERTICES(ctx, _NEW_FOG); 172 ctx->Fog.FogCoordinateSource = p; 173 break; 174 } 175 case GL_FOG_DISTANCE_MODE_NV: { 176 GLenum p = (GLenum) (GLint) *params; 177 if (ctx->API != API_OPENGL_COMPAT || !ctx->Extensions.NV_fog_distance || 178 (p != GL_EYE_RADIAL_NV && p != GL_EYE_PLANE && p != GL_EYE_PLANE_ABSOLUTE_NV)) { 179 _mesa_error(ctx, GL_INVALID_ENUM, "glFog"); 180 return; 181 } 182 if (ctx->Fog.FogDistanceMode == p) 183 return; 184 FLUSH_VERTICES(ctx, _NEW_FOG); 185 ctx->Fog.FogDistanceMode = p; 186 break; 187 } 188 default: 189 goto invalid_pname; 190 } 191 192 if (ctx->Driver.Fogfv) { 193 ctx->Driver.Fogfv( ctx, pname, params ); 194 } 195 196 return; 197 198 invalid_pname: 199 _mesa_error( ctx, GL_INVALID_ENUM, "glFog" ); 200 return; 201 } 202 203 204 /**********************************************************************/ 205 /***** Initialization *****/ 206 /**********************************************************************/ 207 208 void _mesa_init_fog( struct gl_context * ctx ) 209 { 210 /* Fog group */ 211 ctx->Fog.Enabled = GL_FALSE; 212 ctx->Fog.Mode = GL_EXP; 213 ASSIGN_4V( ctx->Fog.Color, 0.0, 0.0, 0.0, 0.0 ); 214 ASSIGN_4V( ctx->Fog.ColorUnclamped, 0.0, 0.0, 0.0, 0.0 ); 215 ctx->Fog.Index = 0.0; 216 ctx->Fog.Density = 1.0; 217 ctx->Fog.Start = 0.0; 218 ctx->Fog.End = 1.0; 219 ctx->Fog.ColorSumEnabled = GL_FALSE; 220 ctx->Fog.FogCoordinateSource = GL_FRAGMENT_DEPTH_EXT; 221 ctx->Fog._Scale = 1.0f; 222 ctx->Fog.FogDistanceMode = GL_EYE_PLANE_ABSOLUTE_NV; 223 } 224