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
_mesa_Fogf(GLenum pname,GLfloat param)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
_mesa_Fogi(GLenum pname,GLint param)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
_mesa_Fogiv(GLenum pname,const GLint * params)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       case GL_FOG_DISTANCE_MODE_NV:
66 	 p[0] = (GLfloat) *params;
67 	 break;
68       case GL_FOG_COLOR:
69 	 p[0] = INT_TO_FLOAT( params[0] );
70 	 p[1] = INT_TO_FLOAT( params[1] );
71 	 p[2] = INT_TO_FLOAT( params[2] );
72 	 p[3] = INT_TO_FLOAT( params[3] );
73 	 break;
74       default:
75          /* Error will be caught later in _mesa_Fogfv */
76          ASSIGN_4V(p, 0.0F, 0.0F, 0.0F, 0.0F);
77    }
78    _mesa_Fogfv(pname, p);
79 }
80 
81 
82 void GLAPIENTRY
_mesa_Fogfv(GLenum pname,const GLfloat * params)83 _mesa_Fogfv( GLenum pname, const GLfloat *params )
84 {
85    GET_CURRENT_CONTEXT(ctx);
86    GLenum m;
87 
88    switch (pname) {
89       case GL_FOG_MODE:
90          m = (GLenum) (GLint) *params;
91 	 switch (m) {
92 	 case GL_LINEAR:
93 	    ctx->Fog._PackedMode = FOG_LINEAR;
94 	    break;
95 	 case GL_EXP:
96 	    ctx->Fog._PackedMode = FOG_EXP;
97 	    break;
98 	 case GL_EXP2:
99 	    ctx->Fog._PackedMode = FOG_EXP2;
100 	    break;
101 	 default:
102 	    _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
103             return;
104 	 }
105 	 if (ctx->Fog.Mode == m)
106 	    return;
107 	 FLUSH_VERTICES(ctx, _NEW_FOG, GL_FOG_BIT);
108 	 ctx->Fog.Mode = m;
109          if (ctx->Fog.Enabled) {
110             ctx->Fog._PackedEnabledMode = ctx->Fog._PackedMode;
111             ctx->NewState |= _NEW_FF_FRAG_PROGRAM;
112          }
113 	 break;
114       case GL_FOG_DENSITY:
115 	 if (*params<0.0F) {
116 	    _mesa_error( ctx, GL_INVALID_VALUE, "glFog" );
117             return;
118 	 }
119 	 if (ctx->Fog.Density == *params)
120 	    return;
121 	 FLUSH_VERTICES(ctx, _NEW_FOG, GL_FOG_BIT);
122 	 ctx->Fog.Density = *params;
123 	 break;
124       case GL_FOG_START:
125          if (ctx->Fog.Start == *params)
126             return;
127          FLUSH_VERTICES(ctx, _NEW_FOG, GL_FOG_BIT);
128          ctx->Fog.Start = *params;
129          break;
130       case GL_FOG_END:
131          if (ctx->Fog.End == *params)
132             return;
133          FLUSH_VERTICES(ctx, _NEW_FOG, GL_FOG_BIT);
134          ctx->Fog.End = *params;
135          break;
136       case GL_FOG_INDEX:
137          if (ctx->API != API_OPENGL_COMPAT)
138             goto invalid_pname;
139  	 if (ctx->Fog.Index == *params)
140 	    return;
141 	 FLUSH_VERTICES(ctx, _NEW_FOG, GL_FOG_BIT);
142  	 ctx->Fog.Index = *params;
143 	 break;
144       case GL_FOG_COLOR:
145 	 if (TEST_EQ_4V(ctx->Fog.Color, params))
146 	    return;
147 	 FLUSH_VERTICES(ctx, _NEW_FOG, GL_FOG_BIT);
148 	 ctx->Fog.ColorUnclamped[0] = params[0];
149 	 ctx->Fog.ColorUnclamped[1] = params[1];
150 	 ctx->Fog.ColorUnclamped[2] = params[2];
151 	 ctx->Fog.ColorUnclamped[3] = params[3];
152 	 ctx->Fog.Color[0] = CLAMP(params[0], 0.0F, 1.0F);
153 	 ctx->Fog.Color[1] = CLAMP(params[1], 0.0F, 1.0F);
154 	 ctx->Fog.Color[2] = CLAMP(params[2], 0.0F, 1.0F);
155 	 ctx->Fog.Color[3] = CLAMP(params[3], 0.0F, 1.0F);
156          break;
157       case GL_FOG_COORDINATE_SOURCE_EXT: {
158 	 GLenum p = (GLenum) (GLint) *params;
159          if (ctx->API != API_OPENGL_COMPAT ||
160              (p != GL_FOG_COORDINATE_EXT && p != GL_FRAGMENT_DEPTH_EXT)) {
161 	    _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
162 	    return;
163 	 }
164 	 if (ctx->Fog.FogCoordinateSource == p)
165 	    return;
166 	 FLUSH_VERTICES(ctx, _NEW_FOG | _NEW_FF_VERT_PROGRAM, GL_FOG_BIT);
167 	 ctx->Fog.FogCoordinateSource = p;
168 	 break;
169       }
170       case GL_FOG_DISTANCE_MODE_NV: {
171 	 GLenum p = (GLenum) (GLint) *params;
172          if (ctx->API != API_OPENGL_COMPAT || !ctx->Extensions.NV_fog_distance ||
173              (p != GL_EYE_RADIAL_NV && p != GL_EYE_PLANE && p != GL_EYE_PLANE_ABSOLUTE_NV)) {
174 	    _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
175 	    return;
176 	 }
177 	 if (ctx->Fog.FogDistanceMode == p)
178 	    return;
179 	 FLUSH_VERTICES(ctx, _NEW_FOG | _NEW_FF_VERT_PROGRAM, GL_FOG_BIT);
180 	 ctx->Fog.FogDistanceMode = p;
181 	 break;
182       }
183       default:
184          goto invalid_pname;
185    }
186 
187    if (ctx->Driver.Fogfv) {
188       ctx->Driver.Fogfv( ctx, pname, params );
189    }
190 
191    return;
192 
193 invalid_pname:
194    _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
195    return;
196 }
197 
198 
199 /**********************************************************************/
200 /*****                      Initialization                        *****/
201 /**********************************************************************/
202 
_mesa_init_fog(struct gl_context * ctx)203 void _mesa_init_fog( struct gl_context * ctx )
204 {
205    /* Fog group */
206    ctx->Fog.Enabled = GL_FALSE;
207    ctx->Fog.Mode = GL_EXP;
208    ctx->Fog._PackedMode = FOG_EXP;
209    ctx->Fog._PackedEnabledMode = FOG_NONE;
210    ASSIGN_4V( ctx->Fog.Color, 0.0, 0.0, 0.0, 0.0 );
211    ASSIGN_4V( ctx->Fog.ColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
212    ctx->Fog.Index = 0.0;
213    ctx->Fog.Density = 1.0;
214    ctx->Fog.Start = 0.0;
215    ctx->Fog.End = 1.0;
216    ctx->Fog.ColorSumEnabled = GL_FALSE;
217    ctx->Fog.FogCoordinateSource = GL_FRAGMENT_DEPTH_EXT;
218    ctx->Fog.FogDistanceMode = GL_EYE_PLANE_ABSOLUTE_NV;
219 }
220