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* dielectric.c - shading function for transparent materials. |
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*/ |
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|
|
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/* ==================================================================== |
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* The Radiance Software License, Version 1.0 |
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* |
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* Copyright (c) 1990 - 2002 The Regents of the University of California, |
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* through Lawrence Berkeley National Laboratory. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* |
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* 3. The end-user documentation included with the redistribution, |
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* if any, must include the following acknowledgment: |
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* "This product includes Radiance software |
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* (http://radsite.lbl.gov/) |
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* developed by the Lawrence Berkeley National Laboratory |
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* (http://www.lbl.gov/)." |
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* Alternately, this acknowledgment may appear in the software itself, |
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* if and wherever such third-party acknowledgments normally appear. |
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* |
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* 4. The names "Radiance," "Lawrence Berkeley National Laboratory" |
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* and "The Regents of the University of California" must |
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* not be used to endorse or promote products derived from this |
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* software without prior written permission. For written |
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* permission, please contact [email protected]. |
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* |
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* 5. Products derived from this software may not be called "Radiance", |
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* nor may "Radiance" appear in their name, without prior written |
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* permission of Lawrence Berkeley National Laboratory. |
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* |
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR |
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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* ==================================================================== |
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* |
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* This software consists of voluntary contributions made by many |
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* individuals on behalf of Lawrence Berkeley National Laboratory. For more |
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* information on Lawrence Berkeley National Laboratory, please see |
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* <http://www.lbl.gov/>. |
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*/ |
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#include "copyright.h" |
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|
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|
#include "ray.h" |
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|
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|
#include "otypes.h" |
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#include "rtotypes.h" |
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|
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#ifdef DISPERSE |
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#include "source.h" |
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static disperse(); |
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static int lambda(); |
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static int disperse(OBJREC *m,RAY *r,FVECT vt,double tr,COLOR cet,COLOR abt); |
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static int lambda(OBJREC *m, FVECT v2, FVECT dv, FVECT lr); |
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#endif |
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|
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static double mylog(double x); |
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|
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|
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/* |
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* Explicit calculations for Fresnel's equation are performed, |
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* but only one square root computation is necessary. |
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|
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|
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static double |
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mylog(x) /* special log for extinction coefficients */ |
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double x; |
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mylog( /* special log for extinction coefficients */ |
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> |
double x |
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) |
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{ |
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if (x < 1e-40) |
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return(-100.); |
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} |
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|
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|
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m_dielectric(m, r) /* color a ray which hit a dielectric interface */ |
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OBJREC *m; |
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register RAY *r; |
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extern int |
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m_dielectric( /* color a ray which hit a dielectric interface */ |
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OBJREC *m, |
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register RAY *r |
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) |
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{ |
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double cos1, cos2, nratio; |
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COLOR ctrans; |
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COLOR talb; |
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int hastexture; |
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double transdist=0, transtest=0; |
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double mirdist=0, mirtest=0; |
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int flatsurface; |
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double refl, trans; |
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FVECT dnorm; |
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double d1, d2; |
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|
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raytexture(r, m->omod); /* get modifiers */ |
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|
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if (hastexture = DOT(r->pert,r->pert) > FTINY*FTINY) |
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if ( (hastexture = DOT(r->pert,r->pert) > FTINY*FTINY) ) |
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cos1 = raynormal(dnorm, r); /* perturb normal */ |
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else { |
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VCOPY(dnorm, r->ron); |
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cos1 = r->rod; |
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} |
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flatsurface = !hastexture && r->ro != NULL && isflat(r->ro->otype); |
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|
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/* index of refraction */ |
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if (m->otype == MAT_DIELECTRIC) |
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|
nratio = m->oargs.farg[3] + m->oargs.farg[4]/MLAMBDA; |
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|
|
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|
trans *= nratio*nratio; /* solid angle ratio */ |
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|
|
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if (rayorigin(&p, r, REFRACTED, trans) == 0) { |
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> |
setcolor(p.rcoef, trans, trans, trans); |
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|
|
169 |
+ |
if (rayorigin(&p, REFRACTED, r, p.rcoef) == 0) { |
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+ |
|
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|
/* compute refracted ray */ |
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d1 = nratio*cos1 - cos2; |
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for (i = 0; i < 3; i++) |
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|
p.rdir[i] = nratio*r->rdir[i] + |
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|
d1*r->ron[i]; |
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|
normalize(p.rdir); /* not exact */ |
183 |
< |
} |
183 |
> |
} else |
184 |
> |
checknorm(p.rdir); |
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|
#ifdef DISPERSE |
186 |
|
if (m->otype != MAT_DIELECTRIC |
187 |
|
|| r->rod > 0.0 |
195 |
|
copycolor(p.cext, ctrans); |
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|
copycolor(p.albedo, talb); |
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|
rayvalue(&p); |
198 |
< |
scalecolor(p.rcol, trans); |
198 |
> |
multcolor(p.rcol, p.rcoef); |
199 |
|
addcolor(r->rcol, p.rcol); |
200 |
< |
if (nratio >= 1.0-FTINY && nratio <= 1.0+FTINY) |
201 |
< |
r->rt = r->rot + p.rt; |
200 |
> |
/* virtual distance */ |
201 |
> |
if (flatsurface || |
202 |
> |
(1.-FTINY <= nratio && |
203 |
> |
nratio <= 1.+FTINY)) { |
204 |
> |
transtest = 2*bright(p.rcol); |
205 |
> |
transdist = r->rot + p.rt; |
206 |
> |
} |
207 |
|
} |
208 |
|
} |
209 |
|
} |
210 |
< |
|
210 |
> |
setcolor(p.rcoef, refl, refl, refl); |
211 |
> |
|
212 |
|
if (!(r->crtype & SHADOW) && |
213 |
< |
rayorigin(&p, r, REFLECTED, refl) == 0) { |
213 |
> |
rayorigin(&p, REFLECTED, r, p.rcoef) == 0) { |
214 |
|
|
215 |
|
/* compute reflected ray */ |
216 |
< |
for (i = 0; i < 3; i++) |
252 |
< |
p.rdir[i] = r->rdir[i] + 2.0*cos1*dnorm[i]; |
216 |
> |
VSUM(p.rdir, r->rdir, dnorm, 2.*cos1); |
217 |
|
/* accidental penetration? */ |
218 |
|
if (hastexture && DOT(p.rdir,r->ron)*hastexture <= FTINY) |
219 |
< |
for (i = 0; i < 3; i++) /* ignore texture */ |
220 |
< |
p.rdir[i] = r->rdir[i] + 2.0*r->rod*r->ron[i]; |
257 |
< |
|
219 |
> |
VSUM(p.rdir, r->rdir, r->ron, 2.*r->rod); |
220 |
> |
checknorm(p.rdir); |
221 |
|
rayvalue(&p); /* reflected ray value */ |
222 |
|
|
223 |
< |
scalecolor(p.rcol, refl); /* color contribution */ |
223 |
> |
multcolor(p.rcol, p.rcoef); /* color contribution */ |
224 |
|
addcolor(r->rcol, p.rcol); |
225 |
+ |
/* virtual distance */ |
226 |
+ |
if (flatsurface) { |
227 |
+ |
mirtest = 2*bright(p.rcol); |
228 |
+ |
mirdist = r->rot + p.rt; |
229 |
+ |
} |
230 |
|
} |
231 |
+ |
/* check distance to return */ |
232 |
+ |
d1 = bright(r->rcol); |
233 |
+ |
if (transtest > d1) |
234 |
+ |
r->rt = transdist; |
235 |
+ |
else if (mirtest > d1) |
236 |
+ |
r->rt = mirdist; |
237 |
|
/* rayvalue() computes absorption */ |
238 |
|
return(1); |
239 |
|
} |
241 |
|
|
242 |
|
#ifdef DISPERSE |
243 |
|
|
244 |
< |
static |
245 |
< |
disperse(m, r, vt, tr, cet, abt) /* check light sources for dispersion */ |
246 |
< |
OBJREC *m; |
247 |
< |
RAY *r; |
248 |
< |
FVECT vt; |
249 |
< |
double tr; |
250 |
< |
COLOR cet, abt; |
244 |
> |
static int |
245 |
> |
disperse( /* check light sources for dispersion */ |
246 |
> |
OBJREC *m, |
247 |
> |
RAY *r, |
248 |
> |
FVECT vt, |
249 |
> |
double tr, |
250 |
> |
COLOR cet, |
251 |
> |
COLOR abt |
252 |
> |
) |
253 |
|
{ |
254 |
< |
RAY sray, *entray; |
254 |
> |
RAY sray; |
255 |
> |
const RAY *entray; |
256 |
|
FVECT v1, v2, n1, n2; |
257 |
|
FVECT dv, v2Xdv; |
258 |
|
double v2Xdvv2Xdv; |
307 |
|
VCOPY(n2, r->ron); |
308 |
|
|
309 |
|
/* first order dispersion approx. */ |
310 |
< |
dtmp1 = DOT(n1, v1); |
311 |
< |
dtmp2 = DOT(n2, v2); |
310 |
> |
dtmp1 = 1./DOT(n1, v1); |
311 |
> |
dtmp2 = 1./DOT(n2, v2); |
312 |
|
for (i = 0; i < 3; i++) |
313 |
< |
dv[i] = v1[i] + v2[i] - n1[i]/dtmp1 - n2[i]/dtmp2; |
313 |
> |
dv[i] = v1[i] + v2[i] - n1[i]*dtmp1 - n2[i]*dtmp2; |
314 |
|
|
315 |
|
if (DOT(dv, dv) <= FTINY) /* null effect */ |
316 |
|
return(0); |
353 |
|
dtmp1 = sqrt(si.dom / v2Xdvv2Xdv / PI); |
354 |
|
|
355 |
|
/* compute first ray */ |
356 |
< |
for (i = 0; i < 3; i++) |
380 |
< |
vtmp2[i] = sray.rdir[i] + dtmp1*vtmp1[i]; |
356 |
> |
VSUM(vtmp2, sray.rdir, vtmp1, dtmp1); |
357 |
|
|
358 |
|
l1 = lambda(m, v2, dv, vtmp2); /* first lambda */ |
359 |
|
if (l1 < 0) |
360 |
|
continue; |
361 |
|
/* compute second ray */ |
362 |
< |
for (i = 0; i < 3; i++) |
387 |
< |
vtmp2[i] = sray.rdir[i] - dtmp1*vtmp1[i]; |
362 |
> |
VSUM(vtmp2, sray.rdir, vtmp1, -dtmp1); |
363 |
|
|
364 |
|
l2 = lambda(m, v2, dv, vtmp2); /* second lambda */ |
365 |
|
if (l2 < 0) |
379 |
|
|
380 |
|
|
381 |
|
static int |
382 |
< |
lambda(m, v2, dv, lr) /* compute lambda for material */ |
383 |
< |
register OBJREC *m; |
384 |
< |
FVECT v2, dv, lr; |
382 |
> |
lambda( /* compute lambda for material */ |
383 |
> |
register OBJREC *m, |
384 |
> |
FVECT v2, |
385 |
> |
FVECT dv, |
386 |
> |
FVECT lr |
387 |
> |
) |
388 |
|
{ |
389 |
|
FVECT lrXdv, v2Xlr; |
390 |
|
double dtmp, denom; |
392 |
|
|
393 |
|
fcross(lrXdv, lr, dv); |
394 |
|
for (i = 0; i < 3; i++) |
395 |
< |
if (lrXdv[i] > FTINY || lrXdv[i] < -FTINY) |
395 |
> |
if ((lrXdv[i] > FTINY) | (lrXdv[i] < -FTINY)) |
396 |
|
break; |
397 |
|
if (i >= 3) |
398 |
|
return(-1); |