1 /*
2 Copyright (C) 1996-1997 Id Software, Inc.
3
4 This program is free software; you can redistribute it and/or
5 modify it under the terms of the GNU General Public License
6 as published by the Free Software Foundation; either version 2
7 of the License, or (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12
13 See the GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18
19 */
20 // r_light.c
21
22 #include "quakedef.h"
23 #include "r_local.h"
24
25 int r_dlightframecount;
26
27
28 /*
29 ==================
30 R_AnimateLight
31 ==================
32 */
R_AnimateLight(void)33 void R_AnimateLight (void)
34 {
35 int i,j,k;
36
37 //
38 // light animations
39 // 'm' is normal light, 'a' is no light, 'z' is double bright
40 i = (int)(cl.time*10);
41 for (j=0 ; j<MAX_LIGHTSTYLES ; j++)
42 {
43 if (!cl_lightstyle[j].length)
44 {
45 d_lightstylevalue[j] = 256;
46 continue;
47 }
48 k = i % cl_lightstyle[j].length;
49 k = cl_lightstyle[j].map[k] - 'a';
50 k = k*22;
51 d_lightstylevalue[j] = k;
52 }
53 }
54
55
56 /*
57 =============================================================================
58
59 DYNAMIC LIGHTS
60
61 =============================================================================
62 */
63
64 /*
65 =============
66 R_MarkLights
67 =============
68 */
R_MarkLights(dlight_t * light,int bit,mnode_t * node)69 void R_MarkLights (dlight_t *light, int bit, mnode_t *node)
70 {
71 mplane_t *splitplane;
72 float dist;
73 msurface_t *surf;
74 int i;
75
76 if (node->contents < 0)
77 return;
78
79 splitplane = node->plane;
80 dist = DotProduct (light->origin, splitplane->normal) - splitplane->dist;
81
82 if (dist > light->radius)
83 {
84 R_MarkLights (light, bit, node->children[0]);
85 return;
86 }
87 if (dist < -light->radius)
88 {
89 R_MarkLights (light, bit, node->children[1]);
90 return;
91 }
92
93 // mark the polygons
94 surf = cl.worldmodel->surfaces + node->firstsurface;
95 for (i=0 ; i<node->numsurfaces ; i++, surf++)
96 {
97 if (surf->dlightframe != r_dlightframecount)
98 {
99 surf->dlightbits = 0;
100 surf->dlightframe = r_dlightframecount;
101 }
102 surf->dlightbits |= bit;
103 }
104
105 R_MarkLights (light, bit, node->children[0]);
106 R_MarkLights (light, bit, node->children[1]);
107 }
108
109
110 /*
111 =============
112 R_PushDlights
113 =============
114 */
R_PushDlights(void)115 void R_PushDlights (void)
116 {
117 int i;
118 dlight_t *l;
119
120 r_dlightframecount = r_framecount + 1; // because the count hasn't
121 // advanced yet for this frame
122 l = cl_dlights;
123
124 for (i=0 ; i<MAX_DLIGHTS ; i++, l++)
125 {
126 if (l->die < cl.time || !l->radius)
127 continue;
128 R_MarkLights ( l, 1<<i, cl.worldmodel->nodes );
129 }
130 }
131
132
133 /*
134 =============================================================================
135
136 LIGHT SAMPLING
137
138 =============================================================================
139 */
140
RecursiveLightPoint(mnode_t * node,vec3_t start,vec3_t end)141 int RecursiveLightPoint (mnode_t *node, vec3_t start, vec3_t end)
142 {
143 int r;
144 float front, back, frac;
145 int side;
146 mplane_t *plane;
147 vec3_t mid;
148 msurface_t *surf;
149 int s, t, ds, dt;
150 int i;
151 mtexinfo_t *tex;
152 byte *lightmap;
153 unsigned scale;
154 int maps;
155
156 if (node->contents < 0)
157 return -1; // didn't hit anything
158
159 // calculate mid point
160
161 // FIXME: optimize for axial
162 plane = node->plane;
163 front = DotProduct (start, plane->normal) - plane->dist;
164 back = DotProduct (end, plane->normal) - plane->dist;
165 side = front < 0;
166
167 if ( (back < 0) == side)
168 return RecursiveLightPoint (node->children[side], start, end);
169
170 frac = front / (front-back);
171 mid[0] = start[0] + (end[0] - start[0])*frac;
172 mid[1] = start[1] + (end[1] - start[1])*frac;
173 mid[2] = start[2] + (end[2] - start[2])*frac;
174
175 // go down front side
176 r = RecursiveLightPoint (node->children[side], start, mid);
177 if (r >= 0)
178 return r; // hit something
179
180 if ( (back < 0) == side )
181 return -1; // didn't hit anuthing
182
183 // check for impact on this node
184
185 surf = cl.worldmodel->surfaces + node->firstsurface;
186 for (i=0 ; i<node->numsurfaces ; i++, surf++)
187 {
188 if (surf->flags & SURF_DRAWTILED)
189 continue; // no lightmaps
190
191 tex = surf->texinfo;
192
193 s = DotProduct (mid, tex->vecs[0]) + tex->vecs[0][3];
194 t = DotProduct (mid, tex->vecs[1]) + tex->vecs[1][3];;
195
196 if (s < surf->texturemins[0] ||
197 t < surf->texturemins[1])
198 continue;
199
200 ds = s - surf->texturemins[0];
201 dt = t - surf->texturemins[1];
202
203 if ( ds > surf->extents[0] || dt > surf->extents[1] )
204 continue;
205
206 if (!surf->samples)
207 return 0;
208
209 ds >>= 4;
210 dt >>= 4;
211
212 lightmap = surf->samples;
213 r = 0;
214 if (lightmap)
215 {
216
217 lightmap += dt * ((surf->extents[0]>>4)+1) + ds;
218
219 for (maps = 0 ; maps < MAXLIGHTMAPS && surf->styles[maps] != 255 ;
220 maps++)
221 {
222 scale = d_lightstylevalue[surf->styles[maps]];
223 r += *lightmap * scale;
224 lightmap += ((surf->extents[0]>>4)+1) *
225 ((surf->extents[1]>>4)+1);
226 }
227
228 r >>= 8;
229 }
230
231 return r;
232 }
233
234 // go down back side
235 return RecursiveLightPoint (node->children[!side], mid, end);
236 }
237
R_LightPoint(vec3_t p)238 int R_LightPoint (vec3_t p)
239 {
240 vec3_t end;
241 int r;
242
243 if (!cl.worldmodel->lightdata)
244 return 255;
245
246 end[0] = p[0];
247 end[1] = p[1];
248 end[2] = p[2] - 2048;
249
250 r = RecursiveLightPoint (cl.worldmodel->nodes, p, end);
251
252 if (r == -1)
253 r = 0;
254
255 if (r < r_refdef.ambientlight)
256 r = r_refdef.ambientlight;
257
258 return r;
259 }
260
261