1 |
greg |
1.1 |
#ifndef lint |
2 |
greg |
2.24 |
static const char RCSid[] = "$Id: srcsupp.c,v 2.23 2016/04/21 00:40:35 greg Exp $"; |
3 |
greg |
1.1 |
#endif |
4 |
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/* |
5 |
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* Support routines for source objects and materials |
6 |
greg |
2.9 |
* |
7 |
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* External symbols declared in source.h |
8 |
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*/ |
9 |
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10 |
greg |
2.10 |
#include "copyright.h" |
11 |
greg |
1.1 |
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12 |
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#include "ray.h" |
13 |
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14 |
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#include "otypes.h" |
15 |
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16 |
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#include "source.h" |
17 |
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18 |
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#include "cone.h" |
19 |
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20 |
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#include "face.h" |
21 |
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22 |
greg |
2.19 |
#define SRCINC 32 /* realloc increment for array */ |
23 |
greg |
1.1 |
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24 |
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SRCREC *source = NULL; /* our list of sources */ |
25 |
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int nsources = 0; /* the number of sources */ |
26 |
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27 |
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SRCFUNC sfun[NUMOTYPE]; /* source dispatch table */ |
28 |
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29 |
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30 |
greg |
2.9 |
void |
31 |
greg |
2.20 |
initstypes(void) /* initialize source dispatch table */ |
32 |
greg |
1.1 |
{ |
33 |
greg |
1.9 |
extern VSMATERIAL mirror_vs, direct1_vs, direct2_vs; |
34 |
greg |
1.14 |
static SOBJECT fsobj = {fsetsrc, flatpart, fgetplaneq, fgetmaxdisk}; |
35 |
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static SOBJECT ssobj = {ssetsrc, nopart}; |
36 |
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static SOBJECT sphsobj = {sphsetsrc, nopart}; |
37 |
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static SOBJECT cylsobj = {cylsetsrc, cylpart}; |
38 |
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static SOBJECT rsobj = {rsetsrc, flatpart, rgetplaneq, rgetmaxdisk}; |
39 |
greg |
1.1 |
|
40 |
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sfun[MAT_MIRROR].mf = &mirror_vs; |
41 |
greg |
1.9 |
sfun[MAT_DIRECT1].mf = &direct1_vs; |
42 |
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sfun[MAT_DIRECT2].mf = &direct2_vs; |
43 |
greg |
1.1 |
sfun[OBJ_FACE].of = &fsobj; |
44 |
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sfun[OBJ_SOURCE].of = &ssobj; |
45 |
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sfun[OBJ_SPHERE].of = &sphsobj; |
46 |
greg |
1.14 |
sfun[OBJ_CYLINDER].of = &cylsobj; |
47 |
greg |
1.1 |
sfun[OBJ_RING].of = &rsobj; |
48 |
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} |
49 |
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50 |
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51 |
greg |
1.2 |
int |
52 |
greg |
2.20 |
newsource(void) /* allocate new source in our array */ |
53 |
greg |
1.1 |
{ |
54 |
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if (nsources == 0) |
55 |
greg |
1.13 |
source = (SRCREC *)malloc(SRCINC*sizeof(SRCREC)); |
56 |
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else if (nsources%SRCINC == 0) |
57 |
greg |
2.11 |
source = (SRCREC *)realloc((void *)source, |
58 |
greg |
1.13 |
(unsigned)(nsources+SRCINC)*sizeof(SRCREC)); |
59 |
greg |
1.1 |
if (source == NULL) |
60 |
greg |
1.2 |
return(-1); |
61 |
greg |
1.1 |
source[nsources].sflags = 0; |
62 |
greg |
2.14 |
source[nsources].nhits = 1; |
63 |
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source[nsources].ntests = 2; /* initial hit probability = 50% */ |
64 |
greg |
2.12 |
#if SHADCACHE |
65 |
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source[nsources].obscache = NULL; |
66 |
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#endif |
67 |
greg |
1.2 |
return(nsources++); |
68 |
greg |
1.1 |
} |
69 |
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70 |
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71 |
greg |
2.9 |
void |
72 |
greg |
2.20 |
setflatss( /* set sampling for a flat source */ |
73 |
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SRCREC *src |
74 |
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) |
75 |
greg |
1.14 |
{ |
76 |
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double mult; |
77 |
greg |
2.20 |
int i; |
78 |
greg |
1.14 |
|
79 |
greg |
2.22 |
getperpendicular(src->ss[SU], src->snorm, rand_samp); |
80 |
greg |
2.21 |
mult = .5 * sqrt( src->ss2 ); |
81 |
greg |
1.14 |
for (i = 0; i < 3; i++) |
82 |
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src->ss[SU][i] *= mult; |
83 |
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fcross(src->ss[SV], src->snorm, src->ss[SU]); |
84 |
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} |
85 |
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86 |
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87 |
greg |
2.9 |
void |
88 |
greg |
2.20 |
fsetsrc( /* set a face as a source */ |
89 |
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SRCREC *src, |
90 |
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OBJREC *so |
91 |
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) |
92 |
greg |
1.1 |
{ |
93 |
greg |
2.20 |
FACE *f; |
94 |
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int i, j; |
95 |
greg |
1.14 |
double d; |
96 |
greg |
1.1 |
|
97 |
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
98 |
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src->so = so; |
99 |
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/* get the face */ |
100 |
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f = getface(so); |
101 |
greg |
2.23 |
if (f->area == 0.) |
102 |
greg |
2.16 |
objerror(so, USER, "zero source area"); |
103 |
greg |
1.1 |
/* find the center */ |
104 |
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for (j = 0; j < 3; j++) { |
105 |
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src->sloc[j] = 0.0; |
106 |
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for (i = 0; i < f->nv; i++) |
107 |
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src->sloc[j] += VERTEX(f,i)[j]; |
108 |
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src->sloc[j] /= (double)f->nv; |
109 |
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} |
110 |
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if (!inface(src->sloc, f)) |
111 |
greg |
2.16 |
objerror(so, USER, "cannot hit source center"); |
112 |
greg |
1.1 |
src->sflags |= SFLAT; |
113 |
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VCOPY(src->snorm, f->norm); |
114 |
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src->ss2 = f->area; |
115 |
greg |
1.14 |
/* find maximum radius */ |
116 |
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src->srad = 0.; |
117 |
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for (i = 0; i < f->nv; i++) { |
118 |
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d = dist2(VERTEX(f,i), src->sloc); |
119 |
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if (d > src->srad) |
120 |
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src->srad = d; |
121 |
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} |
122 |
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src->srad = sqrt(src->srad); |
123 |
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/* compute size vectors */ |
124 |
greg |
2.24 |
if (f->nv == 4) { /* parallelogram case */ |
125 |
greg |
1.14 |
for (j = 0; j < 3; j++) { |
126 |
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src->ss[SU][j] = .5*(VERTEX(f,1)[j]-VERTEX(f,0)[j]); |
127 |
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src->ss[SV][j] = .5*(VERTEX(f,3)[j]-VERTEX(f,0)[j]); |
128 |
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} |
129 |
greg |
2.24 |
} else if (f->nv == 3) { /* triangle case */ |
130 |
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int near0 = 2; |
131 |
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double dmin = dist2line(src->sloc, VERTEX(f,2), VERTEX(f,0)); |
132 |
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for (i = 0; i < 2; i++) { |
133 |
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double d2 = dist2line(src->sloc, VERTEX(f,i), VERTEX(f,i+1)); |
134 |
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if (d2 >= dmin) |
135 |
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continue; |
136 |
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near0 = i; |
137 |
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dmin = d2; /* radius = min distance */ |
138 |
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} |
139 |
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if (dmin < .08*f->area) |
140 |
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objerror(so, WARNING, "triangular source with poor aspect"); |
141 |
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i = (near0 + 1) % 3; |
142 |
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for (j = 0; j < 3; j++) |
143 |
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src->ss[SU][j] = VERTEX(f,i)[j] - VERTEX(f,near0)[j]; |
144 |
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normalize(src->ss[SU]); |
145 |
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dmin = sqrt(dmin); |
146 |
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for (j = 0; j < 3; j++) |
147 |
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src->ss[SU][j] *= dmin; |
148 |
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fcross(src->ss[SV], f->norm, src->ss[SU]); |
149 |
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} else |
150 |
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setflatss(src); /* hope for convex! */ |
151 |
greg |
1.1 |
} |
152 |
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153 |
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154 |
greg |
2.9 |
void |
155 |
greg |
2.20 |
ssetsrc( /* set a source as a source */ |
156 |
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SRCREC *src, |
157 |
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OBJREC *so |
158 |
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) |
159 |
greg |
1.1 |
{ |
160 |
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double theta; |
161 |
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162 |
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
163 |
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src->so = so; |
164 |
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if (so->oargs.nfargs != 4) |
165 |
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objerror(so, USER, "bad arguments"); |
166 |
greg |
2.17 |
src->sflags |= (SDISTANT|SCIR); |
167 |
greg |
1.1 |
VCOPY(src->sloc, so->oargs.farg); |
168 |
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if (normalize(src->sloc) == 0.0) |
169 |
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objerror(so, USER, "zero direction"); |
170 |
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theta = PI/180.0/2.0 * so->oargs.farg[3]; |
171 |
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if (theta <= FTINY) |
172 |
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objerror(so, USER, "zero size"); |
173 |
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src->ss2 = 2.0*PI * (1.0 - cos(theta)); |
174 |
greg |
1.14 |
/* the following is approximate */ |
175 |
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src->srad = sqrt(src->ss2/PI); |
176 |
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VCOPY(src->snorm, src->sloc); |
177 |
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setflatss(src); /* hey, whatever works */ |
178 |
greg |
1.1 |
} |
179 |
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180 |
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181 |
greg |
2.9 |
void |
182 |
greg |
2.20 |
sphsetsrc( /* set a sphere as a source */ |
183 |
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SRCREC *src, |
184 |
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OBJREC *so |
185 |
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) |
186 |
greg |
1.1 |
{ |
187 |
greg |
2.20 |
int i; |
188 |
greg |
1.14 |
|
189 |
greg |
1.1 |
src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
190 |
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src->so = so; |
191 |
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if (so->oargs.nfargs != 4) |
192 |
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objerror(so, USER, "bad # arguments"); |
193 |
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if (so->oargs.farg[3] <= FTINY) |
194 |
greg |
2.16 |
objerror(so, USER, "illegal source radius"); |
195 |
greg |
2.17 |
src->sflags |= SCIR; |
196 |
greg |
1.1 |
VCOPY(src->sloc, so->oargs.farg); |
197 |
greg |
1.14 |
src->srad = so->oargs.farg[3]; |
198 |
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src->ss2 = PI * src->srad * src->srad; |
199 |
greg |
2.24 |
memset(src->ss, 0, sizeof(src->ss)); |
200 |
greg |
1.14 |
for (i = 0; i < 3; i++) |
201 |
greg |
2.17 |
src->ss[i][i] = 0.7236 * so->oargs.farg[3]; |
202 |
greg |
1.1 |
} |
203 |
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204 |
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205 |
greg |
2.9 |
void |
206 |
greg |
2.20 |
rsetsrc( /* set a ring (disk) as a source */ |
207 |
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SRCREC *src, |
208 |
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OBJREC *so |
209 |
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) |
210 |
greg |
1.1 |
{ |
211 |
greg |
2.20 |
CONE *co; |
212 |
greg |
1.1 |
|
213 |
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
214 |
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src->so = so; |
215 |
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/* get the ring */ |
216 |
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co = getcone(so, 0); |
217 |
greg |
2.23 |
if (co == NULL) |
218 |
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objerror(so, USER, "illegal source"); |
219 |
greg |
2.16 |
if (CO_R1(co) <= FTINY) |
220 |
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objerror(so, USER, "illegal source radius"); |
221 |
greg |
1.1 |
VCOPY(src->sloc, CO_P0(co)); |
222 |
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if (CO_R0(co) > 0.0) |
223 |
greg |
2.16 |
objerror(so, USER, "cannot hit source center"); |
224 |
greg |
2.17 |
src->sflags |= (SFLAT|SCIR); |
225 |
greg |
1.1 |
VCOPY(src->snorm, co->ad); |
226 |
greg |
1.14 |
src->srad = CO_R1(co); |
227 |
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src->ss2 = PI * src->srad * src->srad; |
228 |
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setflatss(src); |
229 |
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} |
230 |
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231 |
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232 |
greg |
2.9 |
void |
233 |
greg |
2.20 |
cylsetsrc( /* set a cylinder as a source */ |
234 |
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SRCREC *src, |
235 |
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OBJREC *so |
236 |
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) |
237 |
greg |
1.14 |
{ |
238 |
greg |
2.20 |
CONE *co; |
239 |
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int i; |
240 |
greg |
1.14 |
|
241 |
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src->sa.success = 4*AIMREQT-1; /* bitch on fourth failure */ |
242 |
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src->so = so; |
243 |
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/* get the cylinder */ |
244 |
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co = getcone(so, 0); |
245 |
greg |
2.23 |
if (co == NULL) |
246 |
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objerror(so, USER, "illegal source"); |
247 |
greg |
2.16 |
if (CO_R0(co) <= FTINY) |
248 |
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objerror(so, USER, "illegal source radius"); |
249 |
greg |
1.14 |
if (CO_R0(co) > .2*co->al) /* heuristic constraint */ |
250 |
|
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objerror(so, WARNING, "source aspect too small"); |
251 |
greg |
1.15 |
src->sflags |= SCYL; |
252 |
greg |
1.14 |
for (i = 0; i < 3; i++) |
253 |
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src->sloc[i] = .5 * (CO_P1(co)[i] + CO_P0(co)[i]); |
254 |
greg |
1.15 |
src->srad = .5*co->al; |
255 |
greg |
1.14 |
src->ss2 = 2.*CO_R0(co)*co->al; |
256 |
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/* set sampling vectors */ |
257 |
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for (i = 0; i < 3; i++) |
258 |
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src->ss[SU][i] = .5 * co->al * co->ad[i]; |
259 |
greg |
2.22 |
getperpendicular(src->ss[SW], co->ad, rand_samp); |
260 |
greg |
1.14 |
for (i = 0; i < 3; i++) |
261 |
greg |
1.15 |
src->ss[SW][i] *= .8559 * CO_R0(co); |
262 |
greg |
1.14 |
fcross(src->ss[SV], src->ss[SW], co->ad); |
263 |
greg |
1.1 |
} |
264 |
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265 |
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266 |
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SPOT * |
267 |
greg |
2.20 |
makespot( /* make a spotlight */ |
268 |
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OBJREC *m |
269 |
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) |
270 |
greg |
1.1 |
{ |
271 |
greg |
2.20 |
SPOT *ns; |
272 |
greg |
1.1 |
|
273 |
greg |
2.5 |
if ((ns = (SPOT *)m->os) != NULL) |
274 |
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return(ns); |
275 |
greg |
1.1 |
if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
276 |
|
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return(NULL); |
277 |
greg |
2.16 |
if (m->oargs.farg[3] <= FTINY) |
278 |
|
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objerror(m, USER, "zero angle"); |
279 |
greg |
1.1 |
ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3])); |
280 |
|
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VCOPY(ns->aim, m->oargs.farg+4); |
281 |
|
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if ((ns->flen = normalize(ns->aim)) == 0.0) |
282 |
|
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objerror(m, USER, "zero focus vector"); |
283 |
greg |
2.5 |
m->os = (char *)ns; |
284 |
greg |
1.1 |
return(ns); |
285 |
|
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} |
286 |
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|
287 |
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|
288 |
greg |
2.9 |
int |
289 |
greg |
2.20 |
spotout( /* check if we're outside spot region */ |
290 |
|
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RAY *r, |
291 |
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SPOT *s |
292 |
|
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) |
293 |
greg |
2.5 |
{ |
294 |
|
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double d; |
295 |
|
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FVECT vd; |
296 |
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|
297 |
|
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if (s == NULL) |
298 |
|
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return(0); |
299 |
greg |
2.8 |
if (s->flen < -FTINY) { /* distant source */ |
300 |
greg |
2.5 |
vd[0] = s->aim[0] - r->rorg[0]; |
301 |
|
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vd[1] = s->aim[1] - r->rorg[1]; |
302 |
|
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vd[2] = s->aim[2] - r->rorg[2]; |
303 |
|
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d = DOT(r->rdir,vd); |
304 |
|
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/* wrong side? |
305 |
|
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if (d <= FTINY) |
306 |
|
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return(1); */ |
307 |
|
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d = DOT(vd,vd) - d*d; |
308 |
|
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if (PI*d > s->siz) |
309 |
|
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return(1); /* out */ |
310 |
|
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return(0); /* OK */ |
311 |
|
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} |
312 |
|
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/* local source */ |
313 |
|
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if (s->siz < 2.0*PI * (1.0 + DOT(s->aim,r->rdir))) |
314 |
|
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return(1); /* out */ |
315 |
|
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return(0); /* OK */ |
316 |
|
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} |
317 |
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|
318 |
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|
319 |
greg |
1.1 |
double |
320 |
greg |
2.20 |
fgetmaxdisk( /* get center and squared radius of face */ |
321 |
|
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FVECT ocent, |
322 |
|
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OBJREC *op |
323 |
|
|
) |
324 |
greg |
1.1 |
{ |
325 |
|
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double maxrad2; |
326 |
greg |
1.5 |
double d; |
327 |
greg |
2.20 |
int i, j; |
328 |
|
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FACE *f; |
329 |
greg |
1.1 |
|
330 |
|
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f = getface(op); |
331 |
greg |
1.5 |
if (f->area == 0.) |
332 |
|
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return(0.); |
333 |
greg |
1.1 |
for (i = 0; i < 3; i++) { |
334 |
|
|
ocent[i] = 0.; |
335 |
|
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for (j = 0; j < f->nv; j++) |
336 |
|
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ocent[i] += VERTEX(f,j)[i]; |
337 |
|
|
ocent[i] /= (double)f->nv; |
338 |
|
|
} |
339 |
greg |
1.5 |
d = DOT(ocent,f->norm); |
340 |
|
|
for (i = 0; i < 3; i++) |
341 |
|
|
ocent[i] += (f->offset - d)*f->norm[i]; |
342 |
greg |
1.1 |
maxrad2 = 0.; |
343 |
|
|
for (j = 0; j < f->nv; j++) { |
344 |
greg |
1.5 |
d = dist2(VERTEX(f,j), ocent); |
345 |
|
|
if (d > maxrad2) |
346 |
|
|
maxrad2 = d; |
347 |
greg |
1.1 |
} |
348 |
|
|
return(maxrad2); |
349 |
|
|
} |
350 |
|
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|
351 |
|
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|
352 |
|
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double |
353 |
greg |
2.20 |
rgetmaxdisk( /* get center and squared radius of ring */ |
354 |
|
|
FVECT ocent, |
355 |
|
|
OBJREC *op |
356 |
|
|
) |
357 |
greg |
1.1 |
{ |
358 |
greg |
2.20 |
CONE *co; |
359 |
greg |
1.1 |
|
360 |
|
|
co = getcone(op, 0); |
361 |
greg |
2.23 |
if (co == NULL) |
362 |
|
|
return(0.); |
363 |
greg |
1.1 |
VCOPY(ocent, CO_P0(co)); |
364 |
|
|
return(CO_R1(co)*CO_R1(co)); |
365 |
|
|
} |
366 |
|
|
|
367 |
|
|
|
368 |
|
|
double |
369 |
greg |
2.20 |
fgetplaneq( /* get plane equation for face */ |
370 |
|
|
FVECT nvec, |
371 |
|
|
OBJREC *op |
372 |
|
|
) |
373 |
greg |
1.1 |
{ |
374 |
greg |
2.20 |
FACE *fo; |
375 |
greg |
1.1 |
|
376 |
|
|
fo = getface(op); |
377 |
|
|
VCOPY(nvec, fo->norm); |
378 |
|
|
return(fo->offset); |
379 |
|
|
} |
380 |
|
|
|
381 |
|
|
|
382 |
|
|
double |
383 |
greg |
2.20 |
rgetplaneq( /* get plane equation for ring */ |
384 |
|
|
FVECT nvec, |
385 |
|
|
OBJREC *op |
386 |
|
|
) |
387 |
greg |
1.1 |
{ |
388 |
greg |
2.20 |
CONE *co; |
389 |
greg |
1.1 |
|
390 |
|
|
co = getcone(op, 0); |
391 |
greg |
2.23 |
if (co == NULL) { |
392 |
|
|
memset(nvec, 0, sizeof(FVECT)); |
393 |
|
|
return(0.); |
394 |
|
|
} |
395 |
greg |
1.1 |
VCOPY(nvec, co->ad); |
396 |
|
|
return(DOT(nvec, CO_P0(co))); |
397 |
greg |
1.4 |
} |
398 |
|
|
|
399 |
|
|
|
400 |
greg |
2.9 |
int |
401 |
greg |
2.20 |
commonspot( /* set sp1 to intersection of sp1 and sp2 */ |
402 |
|
|
SPOT *sp1, |
403 |
|
|
SPOT *sp2, |
404 |
|
|
FVECT org |
405 |
|
|
) |
406 |
greg |
1.4 |
{ |
407 |
|
|
FVECT cent; |
408 |
|
|
double rad2, cos1, cos2; |
409 |
|
|
|
410 |
|
|
cos1 = 1. - sp1->siz/(2.*PI); |
411 |
|
|
cos2 = 1. - sp2->siz/(2.*PI); |
412 |
|
|
if (sp2->siz >= 2.*PI-FTINY) /* BIG, just check overlap */ |
413 |
|
|
return(DOT(sp1->aim,sp2->aim) >= cos1*cos2 - |
414 |
|
|
sqrt((1.-cos1*cos1)*(1.-cos2*cos2))); |
415 |
|
|
/* compute and check disks */ |
416 |
|
|
rad2 = intercircle(cent, sp1->aim, sp2->aim, |
417 |
|
|
1./(cos1*cos1) - 1., 1./(cos2*cos2) - 1.); |
418 |
|
|
if (rad2 <= FTINY || normalize(cent) == 0.) |
419 |
|
|
return(0); |
420 |
|
|
VCOPY(sp1->aim, cent); |
421 |
|
|
sp1->siz = 2.*PI*(1. - 1./sqrt(1.+rad2)); |
422 |
|
|
return(1); |
423 |
|
|
} |
424 |
|
|
|
425 |
|
|
|
426 |
greg |
2.9 |
int |
427 |
greg |
2.20 |
commonbeam( /* set sp1 to intersection of sp1 and sp2 */ |
428 |
|
|
SPOT *sp1, |
429 |
|
|
SPOT *sp2, |
430 |
|
|
FVECT dir |
431 |
|
|
) |
432 |
greg |
1.4 |
{ |
433 |
|
|
FVECT cent, c1, c2; |
434 |
|
|
double rad2, d; |
435 |
|
|
/* move centers to common plane */ |
436 |
|
|
d = DOT(sp1->aim, dir); |
437 |
greg |
2.18 |
VSUM(c1, sp1->aim, dir, -d); |
438 |
greg |
1.4 |
d = DOT(sp2->aim, dir); |
439 |
greg |
2.18 |
VSUM(c2, sp2->aim, dir, -d); |
440 |
greg |
1.4 |
/* compute overlap */ |
441 |
|
|
rad2 = intercircle(cent, c1, c2, sp1->siz/PI, sp2->siz/PI); |
442 |
|
|
if (rad2 <= FTINY) |
443 |
|
|
return(0); |
444 |
|
|
VCOPY(sp1->aim, cent); |
445 |
|
|
sp1->siz = PI*rad2; |
446 |
|
|
return(1); |
447 |
|
|
} |
448 |
|
|
|
449 |
|
|
|
450 |
greg |
2.9 |
int |
451 |
greg |
2.20 |
checkspot( /* check spotlight for behind source */ |
452 |
|
|
SPOT *sp, /* spotlight */ |
453 |
|
|
FVECT nrm /* source surface normal */ |
454 |
|
|
) |
455 |
greg |
1.4 |
{ |
456 |
|
|
double d, d1; |
457 |
|
|
|
458 |
|
|
d = DOT(sp->aim, nrm); |
459 |
|
|
if (d > FTINY) /* center in front? */ |
460 |
greg |
1.8 |
return(1); |
461 |
greg |
1.4 |
/* else check horizon */ |
462 |
|
|
d1 = 1. - sp->siz/(2.*PI); |
463 |
greg |
1.8 |
return(1.-FTINY-d*d < d1*d1); |
464 |
greg |
1.4 |
} |
465 |
|
|
|
466 |
|
|
|
467 |
|
|
double |
468 |
greg |
2.20 |
spotdisk( /* intersect spot with object op */ |
469 |
|
|
FVECT oc, |
470 |
|
|
OBJREC *op, |
471 |
|
|
SPOT *sp, |
472 |
|
|
FVECT pos |
473 |
|
|
) |
474 |
greg |
1.6 |
{ |
475 |
|
|
FVECT onorm; |
476 |
|
|
double offs, d, dist; |
477 |
|
|
|
478 |
|
|
offs = getplaneq(onorm, op); |
479 |
|
|
d = -DOT(onorm, sp->aim); |
480 |
|
|
if (d >= -FTINY && d <= FTINY) |
481 |
|
|
return(0.); |
482 |
|
|
dist = (DOT(pos, onorm) - offs)/d; |
483 |
|
|
if (dist < 0.) |
484 |
|
|
return(0.); |
485 |
greg |
2.18 |
VSUM(oc, pos, sp->aim, dist); |
486 |
greg |
1.6 |
return(sp->siz*dist*dist/PI/(d*d)); |
487 |
|
|
} |
488 |
|
|
|
489 |
|
|
|
490 |
|
|
double |
491 |
greg |
2.20 |
beamdisk( /* intersect beam with object op */ |
492 |
|
|
FVECT oc, |
493 |
|
|
OBJREC *op, |
494 |
|
|
SPOT *sp, |
495 |
|
|
FVECT dir |
496 |
|
|
) |
497 |
greg |
1.6 |
{ |
498 |
|
|
FVECT onorm; |
499 |
|
|
double offs, d, dist; |
500 |
|
|
|
501 |
|
|
offs = getplaneq(onorm, op); |
502 |
|
|
d = -DOT(onorm, dir); |
503 |
|
|
if (d >= -FTINY && d <= FTINY) |
504 |
|
|
return(0.); |
505 |
|
|
dist = (DOT(sp->aim, onorm) - offs)/d; |
506 |
greg |
2.18 |
VSUM(oc, sp->aim, dir, dist); |
507 |
greg |
1.6 |
return(sp->siz/PI/(d*d)); |
508 |
|
|
} |
509 |
|
|
|
510 |
|
|
|
511 |
|
|
double |
512 |
greg |
2.20 |
intercircle( /* intersect two circles */ |
513 |
|
|
FVECT cc, /* midpoint (return value) */ |
514 |
|
|
FVECT c1, /* circle centers */ |
515 |
|
|
FVECT c2, |
516 |
|
|
double r1s, /* radii squared */ |
517 |
|
|
double r2s |
518 |
|
|
) |
519 |
greg |
1.4 |
{ |
520 |
|
|
double a2, d2, l; |
521 |
|
|
FVECT disp; |
522 |
|
|
|
523 |
greg |
2.18 |
VSUB(disp, c2, c1); |
524 |
greg |
1.4 |
d2 = DOT(disp,disp); |
525 |
|
|
/* circle within overlap? */ |
526 |
|
|
if (r1s < r2s) { |
527 |
|
|
if (r2s >= r1s + d2) { |
528 |
|
|
VCOPY(cc, c1); |
529 |
|
|
return(r1s); |
530 |
|
|
} |
531 |
|
|
} else { |
532 |
|
|
if (r1s >= r2s + d2) { |
533 |
|
|
VCOPY(cc, c2); |
534 |
|
|
return(r2s); |
535 |
|
|
} |
536 |
|
|
} |
537 |
|
|
a2 = .25*(2.*(r1s+r2s) - d2 - (r2s-r1s)*(r2s-r1s)/d2); |
538 |
|
|
/* no overlap? */ |
539 |
|
|
if (a2 <= 0.) |
540 |
|
|
return(0.); |
541 |
|
|
/* overlap, compute center */ |
542 |
|
|
l = sqrt((r1s - a2)/d2); |
543 |
greg |
2.18 |
VSUM(cc, c1, disp, l); |
544 |
greg |
1.4 |
return(a2); |
545 |
greg |
1.1 |
} |