1 /*
2 Copyright (C) 1996-2001 Id Software, Inc.
3 Copyright (C) 2002-2009 John Fitzgibbons and others
4
5 This program is free software; you can redistribute it and/or
6 modify it under the terms of the GNU General Public License
7 as published by the Free Software Foundation; either version 2
8 of the License, or (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
13
14 See the GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 */
20 //gl_fog.c -- global and volumetric fog
21
22 #ifdef HAVE_CONFIG_H
23 # include "config.h"
24 #endif
25
26 #define NH_DEFINE
27 #include "namehack.h"
28
29 #ifdef HAVE_STRING_H
30 # include <string.h>
31 #endif
32 #ifdef HAVE_STRINGS_H
33 # include <strings.h>
34 #endif
35
36 #include "QF/cmd.h"
37 #include "QF/qfplist.h"
38 #include "QF/render.h"
39 #include "QF/sys.h"
40
41 #include "QF/GL/defines.h"
42 #include "QF/GL/funcs.h"
43
44 #include "compat.h"
45 #include "r_internal.h"
46
47 //==============================================================================
48 //
49 // GLOBAL FOG
50 //
51 //==============================================================================
52
53 static float fog_density;
54 static float fog_red;
55 static float fog_green;
56 static float fog_blue;
57
58 static float old_density;
59 static float old_red;
60 static float old_green;
61 static float old_blue;
62
63 static float fade_time; //duration of fade
64 static float fade_done; //time when fade will be done
65
66 /*
67 Fog_Update
68
69 update internal variables
70 */
71 void
gl_Fog_Update(float density,float red,float green,float blue,float time)72 gl_Fog_Update (float density, float red, float green, float blue, float time)
73 {
74 //save previous settings for fade
75 if (time > 0) {
76 //check for a fade in progress
77 if (fade_done > vr_data.realtime) {
78 float f;
79
80 f = (fade_done - vr_data.realtime) / fade_time;
81 old_density = f * old_density + (1.0 - f) * fog_density;
82 old_red = f * old_red + (1.0 - f) * fog_red;
83 old_green = f * old_green + (1.0 - f) * fog_green;
84 old_blue = f * old_blue + (1.0 - f) * fog_blue;
85 } else {
86 old_density = fog_density;
87 old_red = fog_red;
88 old_green = fog_green;
89 old_blue = fog_blue;
90 }
91 }
92
93 fog_density = density;
94 fog_red = red;
95 fog_green = green;
96 fog_blue = blue;
97 fade_time = time;
98 fade_done = vr_data.realtime + time;
99 }
100
101 /*
102 Fog_FogCommand_f
103
104 handle the 'fog' console command
105 */
106 static void
Fog_FogCommand_f(void)107 Fog_FogCommand_f (void)
108 {
109 float density = fog_density;
110 float red = fog_red;
111 float green = fog_green;
112 float blue = fog_blue;
113 float time = 0.0;
114
115 switch (Cmd_Argc ()) {
116 default:
117 case 1:
118 Sys_Printf ("usage:\n");
119 Sys_Printf (" fog <density>\n");
120 Sys_Printf (" fog <red> <green> <blue>\n");
121 Sys_Printf (" fog <density> <red> <green> <blue>\n");
122 Sys_Printf ("current values:\n");
123 Sys_Printf (" \"density\" is \"%f\"\n", fog_density);
124 Sys_Printf (" \"red\" is \"%f\"\n", fog_red);
125 Sys_Printf (" \"green\" is \"%f\"\n", fog_green);
126 Sys_Printf (" \"blue\" is \"%f\"\n", fog_blue);
127 return;
128 case 2:
129 density = atof (Cmd_Argv(1));
130 break;
131 case 3: //TEST
132 density = atof (Cmd_Argv(1));
133 time = atof (Cmd_Argv(2));
134 break;
135 case 4:
136 red = atof (Cmd_Argv(1));
137 green = atof (Cmd_Argv(2));
138 blue = atof (Cmd_Argv(3));
139 break;
140 case 5:
141 density = atof (Cmd_Argv(1));
142 red = atof (Cmd_Argv(2));
143 green = atof (Cmd_Argv(3));
144 blue = atof (Cmd_Argv(4));
145 break;
146 case 6: //TEST
147 density = atof (Cmd_Argv(1));
148 red = atof (Cmd_Argv(2));
149 green = atof (Cmd_Argv(3));
150 blue = atof (Cmd_Argv(4));
151 time = atof (Cmd_Argv(5));
152 break;
153 }
154 density = max (0.0, density);
155 red = bound (0.0, red, 1.0);
156 green = bound (0.0, green, 1.0);
157 blue = bound (0.0, blue, 1.0);
158 gl_Fog_Update (density, red, green, blue, time);
159 }
160
161 /*
162 Fog_ParseWorldspawn
163
164 called at map load
165 */
166 void
gl_Fog_ParseWorldspawn(plitem_t * worldspawn)167 gl_Fog_ParseWorldspawn (plitem_t *worldspawn)
168 {
169 plitem_t *fog;
170 const char *value;
171
172 //initially no fog
173 fog_density = 0.0;
174 old_density = 0.0;
175 fade_time = 0.0;
176 fade_done = 0.0;
177
178 if (!worldspawn)
179 return; // error
180 if ((fog = PL_ObjectForKey (worldspawn, "fog"))
181 && (value = PL_String (fog))) {
182 sscanf (value, "%f %f %f %f", &fog_density,
183 &fog_red, &fog_green, &fog_blue);
184 }
185 }
186
187 /*
188 Fog_GetColor
189
190 calculates fog color for this frame, taking into account fade times
191 */
192 float *
gl_Fog_GetColor(void)193 gl_Fog_GetColor (void)
194 {
195 static float c[4];
196 float f;
197 int i;
198
199 if (fade_done > vr_data.realtime) {
200 f = (fade_done - vr_data.realtime) / fade_time;
201 c[0] = f * old_red + (1.0 - f) * fog_red;
202 c[1] = f * old_green + (1.0 - f) * fog_green;
203 c[2] = f * old_blue + (1.0 - f) * fog_blue;
204 c[3] = 1.0;
205 } else {
206 c[0] = fog_red;
207 c[1] = fog_green;
208 c[2] = fog_blue;
209 c[3] = 1.0;
210 }
211
212 //find closest 24-bit RGB value, so solid-colored sky can match the fog
213 //perfectly
214 for (i = 0; i < 3; i++)
215 c[i] = (float) (rint (c[i] * 255)) / 255.0f;
216
217 return c;
218 }
219
220 /*
221 Fog_GetDensity
222
223 returns current density of fog
224 */
225 float
gl_Fog_GetDensity(void)226 gl_Fog_GetDensity (void)
227 {
228 float f;
229
230 if (fade_done > vr_data.realtime) {
231 f = (fade_done - vr_data.realtime) / fade_time;
232 return f * old_density + (1.0 - f) * fog_density;
233 } else {
234 return fog_density;
235 }
236 }
237
238 /*
239 Fog_SetupFrame
240
241 called at the beginning of each frame
242 */
243 void
gl_Fog_SetupFrame(void)244 gl_Fog_SetupFrame (void)
245 {
246 qfglFogfv (GL_FOG_COLOR, gl_Fog_GetColor ());
247 qfglFogf (GL_FOG_DENSITY, gl_Fog_GetDensity () / 64.0);
248 }
249
250 /*
251 Fog_EnableGFog
252
253 called before drawing stuff that should be fogged
254 */
255 void
gl_Fog_EnableGFog(void)256 gl_Fog_EnableGFog (void)
257 {
258 if (gl_Fog_GetDensity () > 0)
259 qfglEnable (GL_FOG);
260 }
261
262 /*
263 Fog_DisableGFog
264
265 called after drawing stuff that should be fogged
266 */
267 void
gl_Fog_DisableGFog(void)268 gl_Fog_DisableGFog (void)
269 {
270 if (gl_Fog_GetDensity () > 0)
271 qfglDisable (GL_FOG);
272 }
273
274 /*
275 Fog_StartAdditive
276
277 called before drawing stuff that is additive blended -- sets fog color
278 to black
279 */
280 void
gl_Fog_StartAdditive(void)281 gl_Fog_StartAdditive (void)
282 {
283 vec3_t color = {0, 0, 0};
284
285 if (gl_Fog_GetDensity () > 0)
286 qfglFogfv (GL_FOG_COLOR, color);
287 }
288
289 /*
290 Fog_StopAdditive
291
292 called after drawing stuff that is additive blended -- restores fog color
293 */
294 void
gl_Fog_StopAdditive(void)295 gl_Fog_StopAdditive (void)
296 {
297 if (gl_Fog_GetDensity () > 0)
298 qfglFogfv (GL_FOG_COLOR, gl_Fog_GetColor ());
299 }
300
301 //==============================================================================
302 //
303 // VOLUMETRIC FOG
304 //
305 //==============================================================================
306
307 //cvar_t r_vfog = {"r_vfog", "1"};
308
309 //void Fog_DrawVFog (void) {}
310 //void Fog_MarkModels (void) {}
311
312 //==============================================================================
313 //
314 // INIT
315 //
316 //==============================================================================
317
318 /*
319 Fog_NewMap
320
321 called whenever a map is loaded
322 */
323 #if 0
324 void
325 gl_Fog_NewMap (void)
326 {
327 Fog_ParseWorldspawn (); //for global fog
328 Fog_MarkModels (); //for volumetric fog
329 }
330 #endif
331
332 /*
333 Fog_Init
334
335 called when quake initializes
336 */
337 void
gl_Fog_Init(void)338 gl_Fog_Init (void)
339 {
340 Cmd_AddCommand ("fog", Fog_FogCommand_f, "");
341
342 //Cvar_RegisterVariable (&r_vfog, NULL);
343
344 //set up global fog
345 fog_density = 0.0;
346 fog_red = 0.3;
347 fog_green = 0.3;
348 fog_blue = 0.3;
349
350 qfglFogi (GL_FOG_MODE, GL_EXP2);
351 }
352