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#ifndef lint |
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static const char RCSid[] = "$Id: mkillum2.c,v 2.9 2003/02/22 02:07:24 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 "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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o_default(ob, il, rt, nm) /* default illum action */ |
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OBJREC *ob; |
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struct illum_args *il; |
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struct rtproc *rt; |
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char *nm; |
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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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} |
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|
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|
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o_face(ob, il, rt, nm) /* make an illum face */ |
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OBJREC *ob; |
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struct illum_args *il; |
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struct rtproc *rt; |
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char *nm; |
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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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float *distarr; |
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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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o_default(ob, il, rt, nm); |
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return; |
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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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distarr = (float *)calloc(n, 3*sizeof(float)); |
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if (distarr == NULL) |
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error(SYSTEM, "out of memory in o_face"); |
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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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rt->nrays = 0; |
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freeface(ob); |
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free((void *)distarr); |
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o_default(ob, il, rt, nm); |
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return; |
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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(distarr+3*(dim[1]*nazi+dim[2]), org, dir, rt); |
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} |
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rayflush(rt); |
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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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free((void *)distarr); |
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#undef MAXMISS |
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} |
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|
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|
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o_sphere(ob, il, rt, nm) /* make an illum sphere */ |
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register OBJREC *ob; |
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struct illum_args *il; |
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struct rtproc *rt; |
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char *nm; |
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{ |
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int dim[3]; |
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int n, nalt, nazi; |
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float *distarr; |
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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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distarr = (float *)calloc(n, 3*sizeof(float)); |
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if (distarr == NULL) |
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error(SYSTEM, "out of memory in o_sphere"); |
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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(distarr+3*(dim[1]*nazi+dim[2]), org, dir, rt); |
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} |
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rayflush(rt); |
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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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free((void *)distarr); |
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} |
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|
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|
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o_ring(ob, il, rt, nm) /* make an illum ring */ |
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OBJREC *ob; |
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struct illum_args *il; |
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struct rtproc *rt; |
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char *nm; |
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{ |
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int dim[3]; |
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int n, nalt, nazi; |
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float *distarr; |
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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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distarr = (float *)calloc(n, 3*sizeof(float)); |
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if (distarr == NULL) |
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error(SYSTEM, "out of memory in o_ring"); |
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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]; |
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/* 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(distarr+3*(dim[1]*nazi+dim[2]), org, dir, rt); |
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} |
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rayflush(rt); |
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/* write out the ring 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, co->ad); |
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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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freecone(ob); |
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free((void *)distarr); |
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} |
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|
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|
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raysamp(res, org, dir, rt) /* compute a ray sample */ |
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float res[3]; |
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FVECT org, dir; |
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register struct rtproc *rt; |
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{ |
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register float *fp; |
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|
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if (rt->nrays == rt->bsiz) |
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rayflush(rt); |
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rt->dest[rt->nrays] = res; |
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fp = rt->buf + 6*rt->nrays++; |
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*fp++ = org[0]; *fp++ = org[1]; *fp++ = org[2]; |
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*fp++ = dir[0]; *fp++ = dir[1]; *fp = dir[2]; |
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} |
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|
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|
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rayflush(rt) /* flush buffered rays */ |
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register struct rtproc *rt; |
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{ |
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register int i; |
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|
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if (rt->nrays <= 0) |
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return; |
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bzero(rt->buf+6*rt->nrays, 6*sizeof(float)); |
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errno = 0; |
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if ( process(&(rt->pd), (char *)rt->buf, (char *)rt->buf, |
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3*sizeof(float)*(rt->nrays+1), |
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6*sizeof(float)*(rt->nrays+1)) < |
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3*sizeof(float)*(rt->nrays+1) ) |
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error(SYSTEM, "error reading from rtrace process"); |
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i = rt->nrays; |
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while (i--) { |
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rt->dest[i][0] += rt->buf[3*i]; |
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rt->dest[i][1] += rt->buf[3*i+1]; |
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rt->dest[i][2] += rt->buf[3*i+2]; |
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} |
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rt->nrays = 0; |
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} |
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|
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|
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mkaxes(u, v, n) /* compute u and v to go with n */ |
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FVECT u, v, n; |
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{ |
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register int i; |
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|
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v[0] = v[1] = v[2] = 0.0; |
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for (i = 0; i < 3; i++) |
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if (n[i] < 0.6 && n[i] > -0.6) |
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break; |
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v[i] = 1.0; |
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fcross(u, v, n); |
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normalize(u); |
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fcross(v, n, u); |
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} |
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|
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|
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rounddir(dv, alt, azi) /* compute uniform spherical direction */ |
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register FVECT dv; |
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double alt, azi; |
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{ |
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double d1, d2; |
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|
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dv[2] = 1. - 2.*alt; |
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d1 = sqrt(1. - dv[2]*dv[2]); |
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d2 = 2.*PI * azi; |
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dv[0] = d1*cos(d2); |
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dv[1] = d1*sin(d2); |
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} |
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|
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|
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flatdir(dv, alt, azi) /* compute uniform hemispherical direction */ |
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register FVECT dv; |
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double alt, azi; |
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{ |
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double d1, d2; |
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|
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d1 = sqrt(alt); |
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d2 = 2.*PI * azi; |
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dv[0] = d1*cos(d2); |
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dv[1] = d1*sin(d2); |
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dv[2] = sqrt(1. - alt); |
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} |
