| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: srcsupp.c,v 2.24 2022/08/04 22:43:46 greg Exp $"; |
| 3 |
#endif |
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/* |
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* Support routines for source objects and materials |
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* |
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* External symbols declared in source.h |
| 8 |
*/ |
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|
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#include "copyright.h" |
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|
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#include "ray.h" |
| 13 |
|
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#include "otypes.h" |
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|
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#include "source.h" |
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|
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#include "cone.h" |
| 19 |
|
| 20 |
#include "face.h" |
| 21 |
|
| 22 |
#define SRCINC 32 /* realloc increment for array */ |
| 23 |
|
| 24 |
SRCREC *source = NULL; /* our list of sources */ |
| 25 |
int nsources = 0; /* the number of sources */ |
| 26 |
|
| 27 |
SRCFUNC sfun[NUMOTYPE]; /* source dispatch table */ |
| 28 |
|
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|
| 30 |
void |
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initstypes(void) /* initialize source dispatch table */ |
| 32 |
{ |
| 33 |
extern VSMATERIAL mirror_vs, direct1_vs, direct2_vs; |
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static SOBJECT fsobj = {fsetsrc, flatpart, fgetplaneq, fgetmaxdisk}; |
| 35 |
static SOBJECT ssobj = {ssetsrc, nopart}; |
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static SOBJECT sphsobj = {sphsetsrc, nopart}; |
| 37 |
static SOBJECT cylsobj = {cylsetsrc, cylpart}; |
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static SOBJECT rsobj = {rsetsrc, flatpart, rgetplaneq, rgetmaxdisk}; |
| 39 |
|
| 40 |
sfun[MAT_MIRROR].mf = &mirror_vs; |
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sfun[MAT_DIRECT1].mf = &direct1_vs; |
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sfun[MAT_DIRECT2].mf = &direct2_vs; |
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sfun[OBJ_FACE].of = &fsobj; |
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sfun[OBJ_SOURCE].of = &ssobj; |
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sfun[OBJ_SPHERE].of = &sphsobj; |
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sfun[OBJ_CYLINDER].of = &cylsobj; |
| 47 |
sfun[OBJ_RING].of = &rsobj; |
| 48 |
} |
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|
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|
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int |
| 52 |
newsource(void) /* allocate new source in our array */ |
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{ |
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if (nsources == 0) |
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source = (SRCREC *)malloc(SRCINC*sizeof(SRCREC)); |
| 56 |
else if (nsources%SRCINC == 0) |
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source = (SRCREC *)realloc((void *)source, |
| 58 |
(unsigned)(nsources+SRCINC)*sizeof(SRCREC)); |
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if (source == NULL) |
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return(-1); |
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source[nsources].sflags = 0; |
| 62 |
source[nsources].nhits = 1; |
| 63 |
source[nsources].ntests = 2; /* initial hit probability = 50% */ |
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#if SHADCACHE |
| 65 |
source[nsources].obscache = NULL; |
| 66 |
#endif |
| 67 |
return(nsources++); |
| 68 |
} |
| 69 |
|
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|
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void |
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setflatss( /* set sampling for a flat source */ |
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SRCREC *src |
| 74 |
) |
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{ |
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double mult; |
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int i; |
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|
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getperpendicular(src->ss[SU], src->snorm, rand_samp); |
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mult = .5 * sqrt( src->ss2 ); |
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for (i = 0; i < 3; i++) |
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src->ss[SU][i] *= mult; |
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fcross(src->ss[SV], src->snorm, src->ss[SU]); |
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} |
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|
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|
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void |
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fsetsrc( /* set a face as a source */ |
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SRCREC *src, |
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OBJREC *so |
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) |
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{ |
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FACE *f; |
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int i, j; |
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double d; |
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|
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
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src->so = so; |
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/* get the face */ |
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f = getface(so); |
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if (f->area == 0.) |
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objerror(so, USER, "zero source area"); |
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/* find the center */ |
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for (j = 0; j < 3; j++) { |
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src->sloc[j] = 0.0; |
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for (i = 0; i < f->nv; i++) |
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src->sloc[j] += VERTEX(f,i)[j]; |
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src->sloc[j] /= (double)f->nv; |
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} |
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if (!inface(src->sloc, f)) |
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objerror(so, USER, "cannot hit source center"); |
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src->sflags |= SFLAT; |
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VCOPY(src->snorm, f->norm); |
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src->ss2 = f->area; |
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/* find maximum radius */ |
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src->srad = 0.; |
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for (i = 0; i < f->nv; i++) { |
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d = dist2(VERTEX(f,i), src->sloc); |
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if (d > src->srad) |
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src->srad = d; |
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} |
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src->srad = sqrt(src->srad); |
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/* compute size vectors */ |
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if (f->nv == 4) { /* parallelogram case */ |
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for (j = 0; j < 3; j++) { |
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src->ss[SU][j] = .5*(VERTEX(f,1)[j]-VERTEX(f,0)[j]); |
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src->ss[SV][j] = .5*(VERTEX(f,3)[j]-VERTEX(f,0)[j]); |
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} |
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} else if (f->nv == 3) { /* triangle case */ |
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int near0 = 2; |
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double dmin = dist2line(src->sloc, VERTEX(f,2), VERTEX(f,0)); |
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for (i = 0; i < 2; i++) { |
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double d2 = dist2line(src->sloc, VERTEX(f,i), VERTEX(f,i+1)); |
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if (d2 >= dmin) |
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continue; |
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near0 = i; |
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dmin = d2; /* radius = min distance */ |
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} |
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if (dmin < .08*f->area) |
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objerror(so, WARNING, "triangular source with poor aspect"); |
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i = (near0 + 1) % 3; |
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for (j = 0; j < 3; j++) |
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src->ss[SU][j] = VERTEX(f,i)[j] - VERTEX(f,near0)[j]; |
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normalize(src->ss[SU]); |
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dmin = sqrt(dmin); |
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for (j = 0; j < 3; j++) |
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src->ss[SU][j] *= dmin; |
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fcross(src->ss[SV], f->norm, src->ss[SU]); |
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} else |
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setflatss(src); /* hope for convex! */ |
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} |
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|
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|
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void |
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ssetsrc( /* set a source as a source */ |
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SRCREC *src, |
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OBJREC *so |
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) |
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{ |
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double theta; |
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|
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
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src->so = so; |
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if (so->oargs.nfargs != 4) |
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objerror(so, USER, "bad arguments"); |
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src->sflags |= (SDISTANT|SCIR); |
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VCOPY(src->sloc, so->oargs.farg); |
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if (normalize(src->sloc) == 0.0) |
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objerror(so, USER, "zero direction"); |
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theta = PI/180.0/2.0 * so->oargs.farg[3]; |
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if (theta <= FTINY) |
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objerror(so, USER, "zero size"); |
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src->ss2 = 2.0*PI * (1.0 - cos(theta)); |
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/* the following is approximate */ |
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src->srad = sqrt(src->ss2/PI); |
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VCOPY(src->snorm, src->sloc); |
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setflatss(src); /* hey, whatever works */ |
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src->ss[SW][0] = src->ss[SW][1] = src->ss[SW][2] = 0.0; |
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} |
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|
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|
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void |
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sphsetsrc( /* set a sphere as a source */ |
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SRCREC *src, |
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OBJREC *so |
| 186 |
) |
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{ |
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int i; |
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|
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
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src->so = so; |
| 192 |
if (so->oargs.nfargs != 4) |
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objerror(so, USER, "bad # arguments"); |
| 194 |
if (so->oargs.farg[3] <= FTINY) |
| 195 |
objerror(so, USER, "illegal source radius"); |
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src->sflags |= SCIR; |
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VCOPY(src->sloc, so->oargs.farg); |
| 198 |
src->srad = so->oargs.farg[3]; |
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src->ss2 = PI * src->srad * src->srad; |
| 200 |
memset(src->ss, 0, sizeof(src->ss)); |
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for (i = 0; i < 3; i++) |
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src->ss[i][i] = 0.7236 * so->oargs.farg[3]; |
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} |
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|
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|
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void |
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rsetsrc( /* set a ring (disk) as a source */ |
| 208 |
SRCREC *src, |
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OBJREC *so |
| 210 |
) |
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{ |
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CONE *co; |
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|
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
| 215 |
src->so = so; |
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/* get the ring */ |
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co = getcone(so, 0); |
| 218 |
if (co == NULL) |
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objerror(so, USER, "illegal source"); |
| 220 |
if (CO_R1(co) <= FTINY) |
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objerror(so, USER, "illegal source radius"); |
| 222 |
VCOPY(src->sloc, CO_P0(co)); |
| 223 |
if (CO_R0(co) > 0.0) |
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objerror(so, USER, "cannot hit source center"); |
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src->sflags |= (SFLAT|SCIR); |
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VCOPY(src->snorm, co->ad); |
| 227 |
src->srad = CO_R1(co); |
| 228 |
src->ss2 = PI * src->srad * src->srad; |
| 229 |
setflatss(src); |
| 230 |
} |
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|
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|
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void |
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cylsetsrc( /* set a cylinder as a source */ |
| 235 |
SRCREC *src, |
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OBJREC *so |
| 237 |
) |
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{ |
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CONE *co; |
| 240 |
int i; |
| 241 |
|
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src->sa.success = 4*AIMREQT-1; /* bitch on fourth failure */ |
| 243 |
src->so = so; |
| 244 |
/* get the cylinder */ |
| 245 |
co = getcone(so, 0); |
| 246 |
if (co == NULL) |
| 247 |
objerror(so, USER, "illegal source"); |
| 248 |
if (CO_R0(co) <= FTINY) |
| 249 |
objerror(so, USER, "illegal source radius"); |
| 250 |
if (CO_R0(co) > .2*co->al) /* heuristic constraint */ |
| 251 |
objerror(so, WARNING, "source aspect too small"); |
| 252 |
src->sflags |= SCYL; |
| 253 |
for (i = 0; i < 3; i++) |
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src->sloc[i] = .5 * (CO_P1(co)[i] + CO_P0(co)[i]); |
| 255 |
src->srad = .5*co->al; |
| 256 |
src->ss2 = 2.*CO_R0(co)*co->al; |
| 257 |
/* set sampling vectors */ |
| 258 |
for (i = 0; i < 3; i++) |
| 259 |
src->ss[SU][i] = .5 * co->al * co->ad[i]; |
| 260 |
getperpendicular(src->ss[SW], co->ad, rand_samp); |
| 261 |
for (i = 0; i < 3; i++) |
| 262 |
src->ss[SW][i] *= .8559 * CO_R0(co); |
| 263 |
fcross(src->ss[SV], src->ss[SW], co->ad); |
| 264 |
} |
| 265 |
|
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|
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SPOT * |
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makespot( /* make a spotlight */ |
| 269 |
OBJREC *m |
| 270 |
) |
| 271 |
{ |
| 272 |
SPOT *ns; |
| 273 |
|
| 274 |
if ((ns = (SPOT *)m->os) != NULL) |
| 275 |
return(ns); |
| 276 |
if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
| 277 |
return(NULL); |
| 278 |
if (m->oargs.farg[3] <= FTINY) |
| 279 |
objerror(m, USER, "zero angle"); |
| 280 |
ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3])); |
| 281 |
VCOPY(ns->aim, m->oargs.farg+4); |
| 282 |
if ((ns->flen = normalize(ns->aim)) == 0.0) |
| 283 |
objerror(m, USER, "zero focus vector"); |
| 284 |
m->os = (char *)ns; |
| 285 |
return(ns); |
| 286 |
} |
| 287 |
|
| 288 |
|
| 289 |
int |
| 290 |
spotout( /* check if we're outside spot region */ |
| 291 |
RAY *r, |
| 292 |
SPOT *s |
| 293 |
) |
| 294 |
{ |
| 295 |
double d; |
| 296 |
FVECT vd; |
| 297 |
|
| 298 |
if (s == NULL) |
| 299 |
return(0); |
| 300 |
if (s->flen < -FTINY) { /* distant source */ |
| 301 |
vd[0] = s->aim[0] - r->rorg[0]; |
| 302 |
vd[1] = s->aim[1] - r->rorg[1]; |
| 303 |
vd[2] = s->aim[2] - r->rorg[2]; |
| 304 |
d = DOT(r->rdir,vd); |
| 305 |
/* wrong side? |
| 306 |
if (d <= FTINY) |
| 307 |
return(1); */ |
| 308 |
d = DOT(vd,vd) - d*d; |
| 309 |
if (PI*d > s->siz) |
| 310 |
return(1); /* out */ |
| 311 |
return(0); /* OK */ |
| 312 |
} |
| 313 |
/* local source */ |
| 314 |
if (s->siz < 2.0*PI * (1.0 + DOT(s->aim,r->rdir))) |
| 315 |
return(1); /* out */ |
| 316 |
return(0); /* OK */ |
| 317 |
} |
| 318 |
|
| 319 |
|
| 320 |
double |
| 321 |
fgetmaxdisk( /* get center and squared radius of face */ |
| 322 |
FVECT ocent, |
| 323 |
OBJREC *op |
| 324 |
) |
| 325 |
{ |
| 326 |
double maxrad2; |
| 327 |
double d; |
| 328 |
int i, j; |
| 329 |
FACE *f; |
| 330 |
|
| 331 |
f = getface(op); |
| 332 |
if (f->area == 0.) |
| 333 |
return(0.); |
| 334 |
for (i = 0; i < 3; i++) { |
| 335 |
ocent[i] = 0.; |
| 336 |
for (j = 0; j < f->nv; j++) |
| 337 |
ocent[i] += VERTEX(f,j)[i]; |
| 338 |
ocent[i] /= (double)f->nv; |
| 339 |
} |
| 340 |
d = DOT(ocent,f->norm); |
| 341 |
for (i = 0; i < 3; i++) |
| 342 |
ocent[i] += (f->offset - d)*f->norm[i]; |
| 343 |
maxrad2 = 0.; |
| 344 |
for (j = 0; j < f->nv; j++) { |
| 345 |
d = dist2(VERTEX(f,j), ocent); |
| 346 |
if (d > maxrad2) |
| 347 |
maxrad2 = d; |
| 348 |
} |
| 349 |
return(maxrad2); |
| 350 |
} |
| 351 |
|
| 352 |
|
| 353 |
double |
| 354 |
rgetmaxdisk( /* get center and squared radius of ring */ |
| 355 |
FVECT ocent, |
| 356 |
OBJREC *op |
| 357 |
) |
| 358 |
{ |
| 359 |
CONE *co; |
| 360 |
|
| 361 |
co = getcone(op, 0); |
| 362 |
if (co == NULL) |
| 363 |
return(0.); |
| 364 |
VCOPY(ocent, CO_P0(co)); |
| 365 |
return(CO_R1(co)*CO_R1(co)); |
| 366 |
} |
| 367 |
|
| 368 |
|
| 369 |
double |
| 370 |
fgetplaneq( /* get plane equation for face */ |
| 371 |
FVECT nvec, |
| 372 |
OBJREC *op |
| 373 |
) |
| 374 |
{ |
| 375 |
FACE *fo; |
| 376 |
|
| 377 |
fo = getface(op); |
| 378 |
VCOPY(nvec, fo->norm); |
| 379 |
return(fo->offset); |
| 380 |
} |
| 381 |
|
| 382 |
|
| 383 |
double |
| 384 |
rgetplaneq( /* get plane equation for ring */ |
| 385 |
FVECT nvec, |
| 386 |
OBJREC *op |
| 387 |
) |
| 388 |
{ |
| 389 |
CONE *co; |
| 390 |
|
| 391 |
co = getcone(op, 0); |
| 392 |
if (co == NULL) { |
| 393 |
memset(nvec, 0, sizeof(FVECT)); |
| 394 |
return(0.); |
| 395 |
} |
| 396 |
VCOPY(nvec, co->ad); |
| 397 |
return(DOT(nvec, CO_P0(co))); |
| 398 |
} |
| 399 |
|
| 400 |
|
| 401 |
int |
| 402 |
commonspot( /* set sp1 to intersection of sp1 and sp2 */ |
| 403 |
SPOT *sp1, |
| 404 |
SPOT *sp2, |
| 405 |
FVECT org |
| 406 |
) |
| 407 |
{ |
| 408 |
FVECT cent; |
| 409 |
double rad2, cos1, cos2; |
| 410 |
|
| 411 |
cos1 = 1. - sp1->siz/(2.*PI); |
| 412 |
cos2 = 1. - sp2->siz/(2.*PI); |
| 413 |
if (sp2->siz >= 2.*PI-FTINY) /* BIG, just check overlap */ |
| 414 |
return(DOT(sp1->aim,sp2->aim) >= cos1*cos2 - |
| 415 |
sqrt((1.-cos1*cos1)*(1.-cos2*cos2))); |
| 416 |
/* compute and check disks */ |
| 417 |
rad2 = intercircle(cent, sp1->aim, sp2->aim, |
| 418 |
1./(cos1*cos1) - 1., 1./(cos2*cos2) - 1.); |
| 419 |
if (rad2 <= FTINY || normalize(cent) == 0.) |
| 420 |
return(0); |
| 421 |
VCOPY(sp1->aim, cent); |
| 422 |
sp1->siz = 2.*PI*(1. - 1./sqrt(1.+rad2)); |
| 423 |
return(1); |
| 424 |
} |
| 425 |
|
| 426 |
|
| 427 |
int |
| 428 |
commonbeam( /* set sp1 to intersection of sp1 and sp2 */ |
| 429 |
SPOT *sp1, |
| 430 |
SPOT *sp2, |
| 431 |
FVECT dir |
| 432 |
) |
| 433 |
{ |
| 434 |
FVECT cent, c1, c2; |
| 435 |
double rad2, d; |
| 436 |
/* move centers to common plane */ |
| 437 |
d = DOT(sp1->aim, dir); |
| 438 |
VSUM(c1, sp1->aim, dir, -d); |
| 439 |
d = DOT(sp2->aim, dir); |
| 440 |
VSUM(c2, sp2->aim, dir, -d); |
| 441 |
/* compute overlap */ |
| 442 |
rad2 = intercircle(cent, c1, c2, sp1->siz/PI, sp2->siz/PI); |
| 443 |
if (rad2 <= FTINY) |
| 444 |
return(0); |
| 445 |
VCOPY(sp1->aim, cent); |
| 446 |
sp1->siz = PI*rad2; |
| 447 |
return(1); |
| 448 |
} |
| 449 |
|
| 450 |
|
| 451 |
int |
| 452 |
checkspot( /* check spotlight for behind source */ |
| 453 |
SPOT *sp, /* spotlight */ |
| 454 |
FVECT nrm /* source surface normal */ |
| 455 |
) |
| 456 |
{ |
| 457 |
double d, d1; |
| 458 |
|
| 459 |
d = DOT(sp->aim, nrm); |
| 460 |
if (d > FTINY) /* center in front? */ |
| 461 |
return(1); |
| 462 |
/* else check horizon */ |
| 463 |
d1 = 1. - sp->siz/(2.*PI); |
| 464 |
return(1.-FTINY-d*d < d1*d1); |
| 465 |
} |
| 466 |
|
| 467 |
|
| 468 |
double |
| 469 |
spotdisk( /* intersect spot with object op */ |
| 470 |
FVECT oc, |
| 471 |
OBJREC *op, |
| 472 |
SPOT *sp, |
| 473 |
FVECT pos |
| 474 |
) |
| 475 |
{ |
| 476 |
FVECT onorm; |
| 477 |
double offs, d, dist; |
| 478 |
|
| 479 |
offs = getplaneq(onorm, op); |
| 480 |
d = -DOT(onorm, sp->aim); |
| 481 |
if (d >= -FTINY && d <= FTINY) |
| 482 |
return(0.); |
| 483 |
dist = (DOT(pos, onorm) - offs)/d; |
| 484 |
if (dist < 0.) |
| 485 |
return(0.); |
| 486 |
VSUM(oc, pos, sp->aim, dist); |
| 487 |
return(sp->siz*dist*dist/PI/(d*d)); |
| 488 |
} |
| 489 |
|
| 490 |
|
| 491 |
double |
| 492 |
beamdisk( /* intersect beam with object op */ |
| 493 |
FVECT oc, |
| 494 |
OBJREC *op, |
| 495 |
SPOT *sp, |
| 496 |
FVECT dir |
| 497 |
) |
| 498 |
{ |
| 499 |
FVECT onorm; |
| 500 |
double offs, d, dist; |
| 501 |
|
| 502 |
offs = getplaneq(onorm, op); |
| 503 |
d = -DOT(onorm, dir); |
| 504 |
if (d >= -FTINY && d <= FTINY) |
| 505 |
return(0.); |
| 506 |
dist = (DOT(sp->aim, onorm) - offs)/d; |
| 507 |
VSUM(oc, sp->aim, dir, dist); |
| 508 |
return(sp->siz/PI/(d*d)); |
| 509 |
} |
| 510 |
|
| 511 |
|
| 512 |
double |
| 513 |
intercircle( /* intersect two circles */ |
| 514 |
FVECT cc, /* midpoint (return value) */ |
| 515 |
FVECT c1, /* circle centers */ |
| 516 |
FVECT c2, |
| 517 |
double r1s, /* radii squared */ |
| 518 |
double r2s |
| 519 |
) |
| 520 |
{ |
| 521 |
double a2, d2, l; |
| 522 |
FVECT disp; |
| 523 |
|
| 524 |
VSUB(disp, c2, c1); |
| 525 |
d2 = DOT(disp,disp); |
| 526 |
/* circle within overlap? */ |
| 527 |
if (r1s < r2s) { |
| 528 |
if (r2s >= r1s + d2) { |
| 529 |
VCOPY(cc, c1); |
| 530 |
return(r1s); |
| 531 |
} |
| 532 |
} else { |
| 533 |
if (r1s >= r2s + d2) { |
| 534 |
VCOPY(cc, c2); |
| 535 |
return(r2s); |
| 536 |
} |
| 537 |
} |
| 538 |
a2 = .25*(2.*(r1s+r2s) - d2 - (r2s-r1s)*(r2s-r1s)/d2); |
| 539 |
/* no overlap? */ |
| 540 |
if (a2 <= 0.) |
| 541 |
return(0.); |
| 542 |
/* overlap, compute center */ |
| 543 |
l = sqrt((r1s - a2)/d2); |
| 544 |
VSUM(cc, c1, disp, l); |
| 545 |
return(a2); |
| 546 |
} |
