| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: srcsupp.c,v 2.21 2014/12/04 05:26:28 greg Exp $"; |
| 3 |
#endif |
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/* |
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* Support routines for source objects and materials |
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* |
| 7 |
* 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 |
|
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#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 |
| 31 |
initstypes(void) /* initialize source dispatch table */ |
| 32 |
{ |
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extern VSMATERIAL mirror_vs, direct1_vs, direct2_vs; |
| 34 |
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; |
| 42 |
sfun[MAT_DIRECT2].mf = &direct2_vs; |
| 43 |
sfun[OBJ_FACE].of = &fsobj; |
| 44 |
sfun[OBJ_SOURCE].of = &ssobj; |
| 45 |
sfun[OBJ_SPHERE].of = &sphsobj; |
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sfun[OBJ_CYLINDER].of = &cylsobj; |
| 47 |
sfun[OBJ_RING].of = &rsobj; |
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} |
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|
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|
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int |
| 52 |
newsource(void) /* allocate new source in our array */ |
| 53 |
{ |
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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; |
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#endif |
| 67 |
return(nsources++); |
| 68 |
} |
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|
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|
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void |
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setflatss( /* set sampling for a flat source */ |
| 73 |
SRCREC *src |
| 74 |
) |
| 75 |
{ |
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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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|
| 97 |
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 == 0.0) |
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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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} |
| 110 |
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 |
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setflatss(src); |
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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 |
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) |
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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; |
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if (so->oargs.nfargs != 4) |
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objerror(so, USER, "bad # arguments"); |
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if (so->oargs.farg[3] <= FTINY) |
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objerror(so, USER, "illegal source radius"); |
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src->sflags |= SCIR; |
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VCOPY(src->sloc, so->oargs.farg); |
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src->srad = so->oargs.farg[3]; |
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src->ss2 = PI * src->srad * src->srad; |
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for (i = 0; i < 3; i++) |
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src->ss[SU][i] = src->ss[SV][i] = src->ss[SW][i] = 0.0; |
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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 */ |
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SRCREC *src, |
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OBJREC *so |
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) |
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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 */ |
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src->so = so; |
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/* get the ring */ |
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co = getcone(so, 0); |
| 199 |
if (CO_R1(co) <= FTINY) |
| 200 |
objerror(so, USER, "illegal source radius"); |
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VCOPY(src->sloc, CO_P0(co)); |
| 202 |
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); |
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src->srad = CO_R1(co); |
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src->ss2 = PI * src->srad * src->srad; |
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setflatss(src); |
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} |
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|
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|
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void |
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cylsetsrc( /* set a cylinder as a source */ |
| 214 |
SRCREC *src, |
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OBJREC *so |
| 216 |
) |
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{ |
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CONE *co; |
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int i; |
| 220 |
|
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src->sa.success = 4*AIMREQT-1; /* bitch on fourth failure */ |
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src->so = so; |
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/* get the cylinder */ |
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co = getcone(so, 0); |
| 225 |
if (CO_R0(co) <= FTINY) |
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objerror(so, USER, "illegal source radius"); |
| 227 |
if (CO_R0(co) > .2*co->al) /* heuristic constraint */ |
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objerror(so, WARNING, "source aspect too small"); |
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src->sflags |= SCYL; |
| 230 |
for (i = 0; i < 3; i++) |
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src->sloc[i] = .5 * (CO_P1(co)[i] + CO_P0(co)[i]); |
| 232 |
src->srad = .5*co->al; |
| 233 |
src->ss2 = 2.*CO_R0(co)*co->al; |
| 234 |
/* set sampling vectors */ |
| 235 |
for (i = 0; i < 3; i++) |
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src->ss[SU][i] = .5 * co->al * co->ad[i]; |
| 237 |
getperpendicular(src->ss[SW], co->ad, rand_samp); |
| 238 |
for (i = 0; i < 3; i++) |
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src->ss[SW][i] *= .8559 * CO_R0(co); |
| 240 |
fcross(src->ss[SV], src->ss[SW], co->ad); |
| 241 |
} |
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|
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|
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SPOT * |
| 245 |
makespot( /* make a spotlight */ |
| 246 |
OBJREC *m |
| 247 |
) |
| 248 |
{ |
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SPOT *ns; |
| 250 |
|
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if ((ns = (SPOT *)m->os) != NULL) |
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return(ns); |
| 253 |
if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
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return(NULL); |
| 255 |
if (m->oargs.farg[3] <= FTINY) |
| 256 |
objerror(m, USER, "zero angle"); |
| 257 |
ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3])); |
| 258 |
VCOPY(ns->aim, m->oargs.farg+4); |
| 259 |
if ((ns->flen = normalize(ns->aim)) == 0.0) |
| 260 |
objerror(m, USER, "zero focus vector"); |
| 261 |
m->os = (char *)ns; |
| 262 |
return(ns); |
| 263 |
} |
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|
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|
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int |
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spotout( /* check if we're outside spot region */ |
| 268 |
RAY *r, |
| 269 |
SPOT *s |
| 270 |
) |
| 271 |
{ |
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double d; |
| 273 |
FVECT vd; |
| 274 |
|
| 275 |
if (s == NULL) |
| 276 |
return(0); |
| 277 |
if (s->flen < -FTINY) { /* distant source */ |
| 278 |
vd[0] = s->aim[0] - r->rorg[0]; |
| 279 |
vd[1] = s->aim[1] - r->rorg[1]; |
| 280 |
vd[2] = s->aim[2] - r->rorg[2]; |
| 281 |
d = DOT(r->rdir,vd); |
| 282 |
/* wrong side? |
| 283 |
if (d <= FTINY) |
| 284 |
return(1); */ |
| 285 |
d = DOT(vd,vd) - d*d; |
| 286 |
if (PI*d > s->siz) |
| 287 |
return(1); /* out */ |
| 288 |
return(0); /* OK */ |
| 289 |
} |
| 290 |
/* local source */ |
| 291 |
if (s->siz < 2.0*PI * (1.0 + DOT(s->aim,r->rdir))) |
| 292 |
return(1); /* out */ |
| 293 |
return(0); /* OK */ |
| 294 |
} |
| 295 |
|
| 296 |
|
| 297 |
double |
| 298 |
fgetmaxdisk( /* get center and squared radius of face */ |
| 299 |
FVECT ocent, |
| 300 |
OBJREC *op |
| 301 |
) |
| 302 |
{ |
| 303 |
double maxrad2; |
| 304 |
double d; |
| 305 |
int i, j; |
| 306 |
FACE *f; |
| 307 |
|
| 308 |
f = getface(op); |
| 309 |
if (f->area == 0.) |
| 310 |
return(0.); |
| 311 |
for (i = 0; i < 3; i++) { |
| 312 |
ocent[i] = 0.; |
| 313 |
for (j = 0; j < f->nv; j++) |
| 314 |
ocent[i] += VERTEX(f,j)[i]; |
| 315 |
ocent[i] /= (double)f->nv; |
| 316 |
} |
| 317 |
d = DOT(ocent,f->norm); |
| 318 |
for (i = 0; i < 3; i++) |
| 319 |
ocent[i] += (f->offset - d)*f->norm[i]; |
| 320 |
maxrad2 = 0.; |
| 321 |
for (j = 0; j < f->nv; j++) { |
| 322 |
d = dist2(VERTEX(f,j), ocent); |
| 323 |
if (d > maxrad2) |
| 324 |
maxrad2 = d; |
| 325 |
} |
| 326 |
return(maxrad2); |
| 327 |
} |
| 328 |
|
| 329 |
|
| 330 |
double |
| 331 |
rgetmaxdisk( /* get center and squared radius of ring */ |
| 332 |
FVECT ocent, |
| 333 |
OBJREC *op |
| 334 |
) |
| 335 |
{ |
| 336 |
CONE *co; |
| 337 |
|
| 338 |
co = getcone(op, 0); |
| 339 |
VCOPY(ocent, CO_P0(co)); |
| 340 |
return(CO_R1(co)*CO_R1(co)); |
| 341 |
} |
| 342 |
|
| 343 |
|
| 344 |
double |
| 345 |
fgetplaneq( /* get plane equation for face */ |
| 346 |
FVECT nvec, |
| 347 |
OBJREC *op |
| 348 |
) |
| 349 |
{ |
| 350 |
FACE *fo; |
| 351 |
|
| 352 |
fo = getface(op); |
| 353 |
VCOPY(nvec, fo->norm); |
| 354 |
return(fo->offset); |
| 355 |
} |
| 356 |
|
| 357 |
|
| 358 |
double |
| 359 |
rgetplaneq( /* get plane equation for ring */ |
| 360 |
FVECT nvec, |
| 361 |
OBJREC *op |
| 362 |
) |
| 363 |
{ |
| 364 |
CONE *co; |
| 365 |
|
| 366 |
co = getcone(op, 0); |
| 367 |
VCOPY(nvec, co->ad); |
| 368 |
return(DOT(nvec, CO_P0(co))); |
| 369 |
} |
| 370 |
|
| 371 |
|
| 372 |
int |
| 373 |
commonspot( /* set sp1 to intersection of sp1 and sp2 */ |
| 374 |
SPOT *sp1, |
| 375 |
SPOT *sp2, |
| 376 |
FVECT org |
| 377 |
) |
| 378 |
{ |
| 379 |
FVECT cent; |
| 380 |
double rad2, cos1, cos2; |
| 381 |
|
| 382 |
cos1 = 1. - sp1->siz/(2.*PI); |
| 383 |
cos2 = 1. - sp2->siz/(2.*PI); |
| 384 |
if (sp2->siz >= 2.*PI-FTINY) /* BIG, just check overlap */ |
| 385 |
return(DOT(sp1->aim,sp2->aim) >= cos1*cos2 - |
| 386 |
sqrt((1.-cos1*cos1)*(1.-cos2*cos2))); |
| 387 |
/* compute and check disks */ |
| 388 |
rad2 = intercircle(cent, sp1->aim, sp2->aim, |
| 389 |
1./(cos1*cos1) - 1., 1./(cos2*cos2) - 1.); |
| 390 |
if (rad2 <= FTINY || normalize(cent) == 0.) |
| 391 |
return(0); |
| 392 |
VCOPY(sp1->aim, cent); |
| 393 |
sp1->siz = 2.*PI*(1. - 1./sqrt(1.+rad2)); |
| 394 |
return(1); |
| 395 |
} |
| 396 |
|
| 397 |
|
| 398 |
int |
| 399 |
commonbeam( /* set sp1 to intersection of sp1 and sp2 */ |
| 400 |
SPOT *sp1, |
| 401 |
SPOT *sp2, |
| 402 |
FVECT dir |
| 403 |
) |
| 404 |
{ |
| 405 |
FVECT cent, c1, c2; |
| 406 |
double rad2, d; |
| 407 |
/* move centers to common plane */ |
| 408 |
d = DOT(sp1->aim, dir); |
| 409 |
VSUM(c1, sp1->aim, dir, -d); |
| 410 |
d = DOT(sp2->aim, dir); |
| 411 |
VSUM(c2, sp2->aim, dir, -d); |
| 412 |
/* compute overlap */ |
| 413 |
rad2 = intercircle(cent, c1, c2, sp1->siz/PI, sp2->siz/PI); |
| 414 |
if (rad2 <= FTINY) |
| 415 |
return(0); |
| 416 |
VCOPY(sp1->aim, cent); |
| 417 |
sp1->siz = PI*rad2; |
| 418 |
return(1); |
| 419 |
} |
| 420 |
|
| 421 |
|
| 422 |
int |
| 423 |
checkspot( /* check spotlight for behind source */ |
| 424 |
SPOT *sp, /* spotlight */ |
| 425 |
FVECT nrm /* source surface normal */ |
| 426 |
) |
| 427 |
{ |
| 428 |
double d, d1; |
| 429 |
|
| 430 |
d = DOT(sp->aim, nrm); |
| 431 |
if (d > FTINY) /* center in front? */ |
| 432 |
return(1); |
| 433 |
/* else check horizon */ |
| 434 |
d1 = 1. - sp->siz/(2.*PI); |
| 435 |
return(1.-FTINY-d*d < d1*d1); |
| 436 |
} |
| 437 |
|
| 438 |
|
| 439 |
double |
| 440 |
spotdisk( /* intersect spot with object op */ |
| 441 |
FVECT oc, |
| 442 |
OBJREC *op, |
| 443 |
SPOT *sp, |
| 444 |
FVECT pos |
| 445 |
) |
| 446 |
{ |
| 447 |
FVECT onorm; |
| 448 |
double offs, d, dist; |
| 449 |
|
| 450 |
offs = getplaneq(onorm, op); |
| 451 |
d = -DOT(onorm, sp->aim); |
| 452 |
if (d >= -FTINY && d <= FTINY) |
| 453 |
return(0.); |
| 454 |
dist = (DOT(pos, onorm) - offs)/d; |
| 455 |
if (dist < 0.) |
| 456 |
return(0.); |
| 457 |
VSUM(oc, pos, sp->aim, dist); |
| 458 |
return(sp->siz*dist*dist/PI/(d*d)); |
| 459 |
} |
| 460 |
|
| 461 |
|
| 462 |
double |
| 463 |
beamdisk( /* intersect beam with object op */ |
| 464 |
FVECT oc, |
| 465 |
OBJREC *op, |
| 466 |
SPOT *sp, |
| 467 |
FVECT dir |
| 468 |
) |
| 469 |
{ |
| 470 |
FVECT onorm; |
| 471 |
double offs, d, dist; |
| 472 |
|
| 473 |
offs = getplaneq(onorm, op); |
| 474 |
d = -DOT(onorm, dir); |
| 475 |
if (d >= -FTINY && d <= FTINY) |
| 476 |
return(0.); |
| 477 |
dist = (DOT(sp->aim, onorm) - offs)/d; |
| 478 |
VSUM(oc, sp->aim, dir, dist); |
| 479 |
return(sp->siz/PI/(d*d)); |
| 480 |
} |
| 481 |
|
| 482 |
|
| 483 |
double |
| 484 |
intercircle( /* intersect two circles */ |
| 485 |
FVECT cc, /* midpoint (return value) */ |
| 486 |
FVECT c1, /* circle centers */ |
| 487 |
FVECT c2, |
| 488 |
double r1s, /* radii squared */ |
| 489 |
double r2s |
| 490 |
) |
| 491 |
{ |
| 492 |
double a2, d2, l; |
| 493 |
FVECT disp; |
| 494 |
|
| 495 |
VSUB(disp, c2, c1); |
| 496 |
d2 = DOT(disp,disp); |
| 497 |
/* circle within overlap? */ |
| 498 |
if (r1s < r2s) { |
| 499 |
if (r2s >= r1s + d2) { |
| 500 |
VCOPY(cc, c1); |
| 501 |
return(r1s); |
| 502 |
} |
| 503 |
} else { |
| 504 |
if (r1s >= r2s + d2) { |
| 505 |
VCOPY(cc, c2); |
| 506 |
return(r2s); |
| 507 |
} |
| 508 |
} |
| 509 |
a2 = .25*(2.*(r1s+r2s) - d2 - (r2s-r1s)*(r2s-r1s)/d2); |
| 510 |
/* no overlap? */ |
| 511 |
if (a2 <= 0.) |
| 512 |
return(0.); |
| 513 |
/* overlap, compute center */ |
| 514 |
l = sqrt((r1s - a2)/d2); |
| 515 |
VSUM(cc, c1, disp, l); |
| 516 |
return(a2); |
| 517 |
} |
