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#ifndef lint |
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static const char RCSid[] = "$Id: mkillum2.c,v 2.18 2007/09/13 06:31:21 greg Exp $"; |
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#endif |
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/* |
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* Routines to do the actual calculation for mkillum |
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*/ |
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|
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#include <string.h> |
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|
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#include "mkillum.h" |
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#include "face.h" |
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#include "cone.h" |
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#include "random.h" |
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|
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|
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static void mkaxes(FVECT u, FVECT v, FVECT n); |
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static void rounddir(FVECT dv, double alt, double azi); |
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static void flatdir(FVECT dv, double alt, double azi); |
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|
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|
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static COLORV * distarr = NULL; /* distribution array */ |
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static int distsiz = 0; |
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|
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|
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static void |
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newdist( /* allocate & clear distribution array */ |
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int siz |
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) |
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{ |
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if (siz == 0) { |
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if (distsiz > 0) |
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free((void *)distarr); |
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distarr = NULL; |
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distsiz = 0; |
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return; |
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} |
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if (distsiz < siz) { |
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free((void *)distarr); |
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distarr = (COLORV *)malloc(sizeof(COLORV)*3*siz); |
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if (distarr == NULL) |
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error(SYSTEM, "Out of memory in newdist"); |
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distsiz = siz; |
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} |
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memset(distarr, '\0', sizeof(COLORV)*3*siz); |
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} |
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|
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|
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static int |
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process_ray(RAY *r, int rv) |
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{ |
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COLORV *colp; |
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|
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if (rv == 0) |
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return(0); |
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if (rv < 0) |
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error(USER, "Ray tracing process died"); |
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if (r->rno >= distsiz) |
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error(INTERNAL, "Bad returned index in process_ray"); |
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colp = &distarr[r->rno * 3]; |
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addcolor(colp, r->rcol); |
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return(1); |
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} |
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|
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|
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static void |
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raysamp( /* queue a ray sample */ |
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int ndx, |
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FVECT org, |
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FVECT dir |
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) |
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{ |
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RAY myRay; |
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int rv; |
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|
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if ((ndx < 0) | (ndx >= distsiz)) |
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error(INTERNAL, "Bad index in raysamp"); |
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VCOPY(myRay.rorg, org); |
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VCOPY(myRay.rdir, dir); |
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myRay.rmax = .0; |
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rayorigin(&myRay, PRIMARY, NULL, NULL); |
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myRay.rno = ndx; |
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/* queue ray, check result */ |
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process_ray(&myRay, ray_pqueue(&myRay)); |
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} |
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|
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|
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static void |
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rayclean() /* finish all pending rays */ |
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{ |
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RAY myRay; |
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|
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while (process_ray(&myRay, ray_presult(&myRay, 0))) |
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; |
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} |
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|
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|
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int |
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my_default( /* default illum action */ |
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OBJREC *ob, |
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struct illum_args *il, |
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char *nm |
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) |
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{ |
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sprintf(errmsg, "(%s): cannot make illum for %s \"%s\"", |
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nm, ofun[ob->otype].funame, ob->oname); |
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error(WARNING, errmsg); |
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printobj(il->altmat, ob); |
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return(1); |
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} |
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|
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|
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int |
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my_face( /* make an illum face */ |
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OBJREC *ob, |
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struct illum_args *il, |
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char *nm |
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) |
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{ |
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#define MAXMISS (5*n*il->nsamps) |
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int dim[3]; |
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int n, nalt, nazi, h; |
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double sp[2], r1, r2; |
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FVECT dn, org, dir; |
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FVECT u, v; |
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double ur[2], vr[2]; |
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int nmisses; |
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register FACE *fa; |
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register int i, j; |
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/* get/check arguments */ |
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fa = getface(ob); |
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if (fa->area == 0.0) { |
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freeface(ob); |
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return(my_default(ob, il, nm)); |
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} |
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/* set up sampling */ |
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if (il->sampdens <= 0) |
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nalt = nazi = 1; |
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else { |
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n = PI * il->sampdens; |
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nalt = sqrt(n/PI) + .5; |
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nazi = PI*nalt + .5; |
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} |
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n = nalt*nazi; |
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newdist(n); |
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/* take first edge longer than sqrt(area) */ |
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for (j = fa->nv-1, i = 0; i < fa->nv; j = i++) { |
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u[0] = VERTEX(fa,i)[0] - VERTEX(fa,j)[0]; |
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u[1] = VERTEX(fa,i)[1] - VERTEX(fa,j)[1]; |
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u[2] = VERTEX(fa,i)[2] - VERTEX(fa,j)[2]; |
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if ((r1 = DOT(u,u)) >= fa->area-FTINY) |
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break; |
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} |
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if (i < fa->nv) { /* got one! -- let's align our axes */ |
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r2 = 1.0/sqrt(r1); |
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u[0] *= r2; u[1] *= r2; u[2] *= r2; |
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fcross(v, fa->norm, u); |
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} else /* oh well, we'll just have to wing it */ |
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mkaxes(u, v, fa->norm); |
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/* now, find limits in (u,v) coordinates */ |
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ur[0] = vr[0] = FHUGE; |
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ur[1] = vr[1] = -FHUGE; |
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for (i = 0; i < fa->nv; i++) { |
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r1 = DOT(VERTEX(fa,i),u); |
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if (r1 < ur[0]) ur[0] = r1; |
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if (r1 > ur[1]) ur[1] = r1; |
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r2 = DOT(VERTEX(fa,i),v); |
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if (r2 < vr[0]) vr[0] = r2; |
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if (r2 > vr[1]) vr[1] = r2; |
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} |
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dim[0] = random(); |
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/* sample polygon */ |
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nmisses = 0; |
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for (dim[1] = 0; dim[1] < nalt; dim[1]++) |
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for (dim[2] = 0; dim[2] < nazi; dim[2]++) |
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for (i = 0; i < il->nsamps; i++) { |
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/* random direction */ |
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h = ilhash(dim, 3) + i; |
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multisamp(sp, 2, urand(h)); |
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r1 = (dim[1] + sp[0])/nalt; |
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r2 = (dim[2] + sp[1] - .5)/nazi; |
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flatdir(dn, r1, r2); |
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for (j = 0; j < 3; j++) |
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dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*fa->norm[j]; |
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/* random location */ |
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do { |
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multisamp(sp, 2, urand(h+4862+nmisses)); |
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r1 = ur[0] + (ur[1]-ur[0]) * sp[0]; |
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r2 = vr[0] + (vr[1]-vr[0]) * sp[1]; |
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for (j = 0; j < 3; j++) |
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org[j] = r1*u[j] + r2*v[j] |
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+ fa->offset*fa->norm[j]; |
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} while (!inface(org, fa) && nmisses++ < MAXMISS); |
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if (nmisses > MAXMISS) { |
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objerror(ob, WARNING, "bad aspect"); |
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rayclean(); |
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freeface(ob); |
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free((void *)distarr); |
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return(my_default(ob, il, nm)); |
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} |
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for (j = 0; j < 3; j++) |
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org[j] += .001*fa->norm[j]; |
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/* send sample */ |
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raysamp(dim[1]*nazi+dim[2], org, dir); |
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} |
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rayclean(); |
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/* write out the face and its distribution */ |
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if (average(il, distarr, nalt*nazi)) { |
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if (il->sampdens > 0) |
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flatout(il, distarr, nalt, nazi, u, v, fa->norm); |
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illumout(il, ob); |
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} else |
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printobj(il->altmat, ob); |
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/* clean up */ |
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freeface(ob); |
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return(0); |
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#undef MAXMISS |
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} |
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|
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|
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int |
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my_sphere( /* make an illum sphere */ |
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register OBJREC *ob, |
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struct illum_args *il, |
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char *nm |
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) |
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{ |
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int dim[3]; |
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int n, nalt, nazi; |
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double sp[4], r1, r2, r3; |
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FVECT org, dir; |
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FVECT u, v; |
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register int i, j; |
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/* check arguments */ |
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if (ob->oargs.nfargs != 4) |
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objerror(ob, USER, "bad # of arguments"); |
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/* set up sampling */ |
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if (il->sampdens <= 0) |
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nalt = nazi = 1; |
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else { |
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n = 4.*PI * il->sampdens; |
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nalt = sqrt(2./PI*n) + .5; |
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nazi = PI/2.*nalt + .5; |
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} |
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n = nalt*nazi; |
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newdist(n); |
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dim[0] = random(); |
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/* sample sphere */ |
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for (dim[1] = 0; dim[1] < nalt; dim[1]++) |
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for (dim[2] = 0; dim[2] < nazi; dim[2]++) |
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for (i = 0; i < il->nsamps; i++) { |
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/* next sample point */ |
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multisamp(sp, 4, urand(ilhash(dim,3)+i)); |
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/* random direction */ |
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r1 = (dim[1] + sp[0])/nalt; |
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r2 = (dim[2] + sp[1] - .5)/nazi; |
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rounddir(dir, r1, r2); |
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/* random location */ |
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mkaxes(u, v, dir); /* yuck! */ |
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r3 = sqrt(sp[2]); |
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r2 = 2.*PI*sp[3]; |
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r1 = r3*ob->oargs.farg[3]*cos(r2); |
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r2 = r3*ob->oargs.farg[3]*sin(r2); |
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r3 = ob->oargs.farg[3]*sqrt(1.01-r3*r3); |
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for (j = 0; j < 3; j++) { |
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org[j] = ob->oargs.farg[j] + r1*u[j] + r2*v[j] + |
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r3*dir[j]; |
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dir[j] = -dir[j]; |
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} |
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/* send sample */ |
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raysamp(dim[1]*nazi+dim[2], org, dir); |
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} |
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rayclean(); |
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/* write out the sphere and its distribution */ |
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if (average(il, distarr, nalt*nazi)) { |
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if (il->sampdens > 0) |
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roundout(il, distarr, nalt, nazi); |
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else |
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objerror(ob, WARNING, "diffuse distribution"); |
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illumout(il, ob); |
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} else |
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printobj(il->altmat, ob); |
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/* clean up */ |
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return(1); |
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} |
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|
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|
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int |
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my_ring( /* make an illum ring */ |
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OBJREC *ob, |
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struct illum_args *il, |
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char *nm |
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) |
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{ |
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int dim[3]; |
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int n, nalt, nazi; |
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double sp[4], r1, r2, r3; |
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FVECT dn, org, dir; |
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FVECT u, v; |
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register CONE *co; |
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register int i, j; |
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/* get/check arguments */ |
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co = getcone(ob, 0); |
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/* set up sampling */ |
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if (il->sampdens <= 0) |
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nalt = nazi = 1; |
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else { |
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n = PI * il->sampdens; |
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nalt = sqrt(n/PI) + .5; |
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nazi = PI*nalt + .5; |
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} |
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n = nalt*nazi; |
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newdist(n); |
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mkaxes(u, v, co->ad); |
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dim[0] = random(); |
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/* sample disk */ |
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for (dim[1] = 0; dim[1] < nalt; dim[1]++) |
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for (dim[2] = 0; dim[2] < nazi; dim[2]++) |
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for (i = 0; i < il->nsamps; i++) { |
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/* next sample point */ |
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multisamp(sp, 4, urand(ilhash(dim,3)+i)); |
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/* random direction */ |
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r1 = (dim[1] + sp[0])/nalt; |
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r2 = (dim[2] + sp[1] - .5)/nazi; |
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flatdir(dn, r1, r2); |
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for (j = 0; j < 3; j++) |
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dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*co->ad[j]; |
| 327 |
/* random location */ |
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r3 = sqrt(CO_R0(co)*CO_R0(co) + |
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sp[2]*(CO_R1(co)*CO_R1(co) - CO_R0(co)*CO_R0(co))); |
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r2 = 2.*PI*sp[3]; |
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r1 = r3*cos(r2); |
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r2 = r3*sin(r2); |
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for (j = 0; j < 3; j++) |
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org[j] = CO_P0(co)[j] + r1*u[j] + r2*v[j] + |
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.001*co->ad[j]; |
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|
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/* send sample */ |
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raysamp(dim[1]*nazi+dim[2], org, dir); |
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} |
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rayclean(); |
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/* write out the ring and its distribution */ |
| 342 |
if (average(il, distarr, nalt*nazi)) { |
| 343 |
if (il->sampdens > 0) |
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flatout(il, distarr, nalt, nazi, u, v, co->ad); |
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illumout(il, ob); |
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} else |
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printobj(il->altmat, ob); |
| 348 |
/* clean up */ |
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freecone(ob); |
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return(1); |
| 351 |
} |
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|
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|
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static void |
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mkaxes( /* compute u and v to go with n */ |
| 356 |
FVECT u, |
| 357 |
FVECT v, |
| 358 |
FVECT n |
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) |
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{ |
| 361 |
register int i; |
| 362 |
|
| 363 |
v[0] = v[1] = v[2] = 0.0; |
| 364 |
for (i = 0; i < 3; i++) |
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if (n[i] < 0.6 && n[i] > -0.6) |
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break; |
| 367 |
v[i] = 1.0; |
| 368 |
fcross(u, v, n); |
| 369 |
normalize(u); |
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fcross(v, n, u); |
| 371 |
} |
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|
| 373 |
|
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static void |
| 375 |
rounddir( /* compute uniform spherical direction */ |
| 376 |
register FVECT dv, |
| 377 |
double alt, |
| 378 |
double azi |
| 379 |
) |
| 380 |
{ |
| 381 |
double d1, d2; |
| 382 |
|
| 383 |
dv[2] = 1. - 2.*alt; |
| 384 |
d1 = sqrt(1. - dv[2]*dv[2]); |
| 385 |
d2 = 2.*PI * azi; |
| 386 |
dv[0] = d1*cos(d2); |
| 387 |
dv[1] = d1*sin(d2); |
| 388 |
} |
| 389 |
|
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|
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static void |
| 392 |
flatdir( /* compute uniform hemispherical direction */ |
| 393 |
register FVECT dv, |
| 394 |
double alt, |
| 395 |
double azi |
| 396 |
) |
| 397 |
{ |
| 398 |
double d1, d2; |
| 399 |
|
| 400 |
d1 = sqrt(alt); |
| 401 |
d2 = 2.*PI * azi; |
| 402 |
dv[0] = d1*cos(d2); |
| 403 |
dv[1] = d1*sin(d2); |
| 404 |
dv[2] = sqrt(1. - alt); |
| 405 |
} |
