1 |
greg |
2.1 |
#ifndef lint |
2 |
greg |
2.5 |
static const char RCSid[] = "$Id: mkillum4.c,v 2.4 2007/12/05 05:02:58 greg Exp $"; |
3 |
greg |
2.1 |
#endif |
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/* |
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* Routines for handling BSDF data within mkillum |
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*/ |
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#include "mkillum.h" |
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#include "paths.h" |
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greg |
2.3 |
#include "random.h" |
11 |
greg |
2.2 |
#include "ezxml.h" |
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greg |
2.1 |
|
13 |
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14 |
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struct BSDF_data * |
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load_BSDF( /* load BSDF data from file */ |
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char *fname |
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) |
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{ |
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char *path; |
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greg |
2.2 |
ezxml_t fl, wld, wdb; |
21 |
greg |
2.1 |
struct BSDF_data *dp; |
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path = getpath(fname, getrlibpath(), R_OK); |
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if (path == NULL) { |
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sprintf(errmsg, "cannot find BSDF file \"%s\"", fname); |
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error(WARNING, errmsg); |
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return(NULL); |
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} |
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greg |
2.2 |
fl = ezxml_parse_file(path); |
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if (fl == NULL) { |
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greg |
2.1 |
sprintf(errmsg, "cannot open BSDF \"%s\"", path); |
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error(WARNING, errmsg); |
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return(NULL); |
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} |
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greg |
2.5 |
dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data)); |
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greg |
2.1 |
if (dp == NULL) |
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goto memerr; |
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greg |
2.2 |
for (wld = ezxml_child(fl, "WavelengthData"); |
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fl != NULL; fl = fl->next) { |
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if (strcmp(ezxml_child(wld, "Wavelength")->txt, "Visible")) |
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continue; |
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wdb = ezxml_child(wld, "WavelengthDataBlock"); |
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if (wdb == NULL) continue; |
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if (strcmp(ezxml_child(wdb, "WavelengthDataDirection")->txt, |
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"Transmission Front")) |
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continue; |
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} |
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greg |
2.1 |
/* etc... */ |
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greg |
2.2 |
ezxml_free(fl); |
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greg |
2.1 |
return(dp); |
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memerr: |
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error(SYSTEM, "out of memory in load_BSDF"); |
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return NULL; /* pro forma return */ |
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} |
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void |
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free_BSDF( /* free BSDF data structure */ |
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struct BSDF_data *b |
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) |
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{ |
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if (b == NULL) |
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return; |
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free(b->bsdf); |
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free(b); |
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} |
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void |
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r_BSDF_incvec( /* compute random input vector at given location */ |
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FVECT v, |
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struct BSDF_data *b, |
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int i, |
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double rv, |
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MAT4 xm |
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) |
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{ |
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FVECT pert; |
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double rad; |
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int j; |
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getBSDF_incvec(v, b, i); |
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rad = getBSDF_incrad(b, i); |
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multisamp(pert, 3, rv); |
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for (j = 0; j < 3; j++) |
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v[j] += rad*(2.*pert[j] - 1.); |
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if (xm != NULL) |
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multv3(v, v, xm); |
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normalize(v); |
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} |
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void |
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r_BSDF_outvec( /* compute random output vector at given location */ |
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FVECT v, |
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struct BSDF_data *b, |
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int o, |
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double rv, |
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MAT4 xm |
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) |
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{ |
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FVECT pert; |
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double rad; |
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int j; |
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getBSDF_outvec(v, b, o); |
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rad = getBSDF_outrad(b, o); |
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multisamp(pert, 3, rv); |
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for (j = 0; j < 3; j++) |
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v[j] += rad*(2.*pert[j] - 1.); |
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if (xm != NULL) |
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multv3(v, v, xm); |
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normalize(v); |
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} |
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greg |
2.2 |
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#define FEQ(a,b) ((a)-(b) <= 1e-7 && (b)-(a) <= 1e-7) |
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static int |
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addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */ |
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char *xfarg[], |
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FVECT xp, |
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FVECT yp, |
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FVECT zp |
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) |
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{ |
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static char bufs[3][16]; |
128 |
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int bn = 0; |
129 |
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char **xfp = xfarg; |
130 |
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double theta; |
131 |
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132 |
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theta = atan2(yp[2], zp[2]); |
133 |
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if (!FEQ(theta,0.0)) { |
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*xfp++ = "-rx"; |
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sprintf(bufs[bn], "%f", theta*(180./PI)); |
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*xfp++ = bufs[bn++]; |
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} |
138 |
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theta = asin(-xp[2]); |
139 |
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if (!FEQ(theta,0.0)) { |
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*xfp++ = "-ry"; |
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sprintf(bufs[bn], " %f", theta*(180./PI)); |
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*xfp++ = bufs[bn++]; |
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} |
144 |
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theta = atan2(xp[1], xp[0]); |
145 |
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if (!FEQ(theta,0.0)) { |
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*xfp++ = "-rz"; |
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sprintf(bufs[bn], "%f", theta*(180./PI)); |
148 |
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*xfp++ = bufs[bn++]; |
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} |
150 |
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*xfp = NULL; |
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return(xfp - xfarg); |
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} |
153 |
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154 |
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155 |
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int |
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getBSDF_xfm( /* compute transform for the given surface */ |
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MAT4 xm, |
158 |
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FVECT nrm, |
159 |
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UpDir ud |
160 |
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) |
161 |
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{ |
162 |
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char *xfargs[7]; |
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XF myxf; |
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FVECT updir, xdest, ydest; |
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166 |
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updir[0] = updir[1] = updir[2] = 0.; |
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switch (ud) { |
168 |
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case UDzneg: |
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updir[2] = -1.; |
170 |
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break; |
171 |
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case UDyneg: |
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updir[1] = -1.; |
173 |
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break; |
174 |
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case UDxneg: |
175 |
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updir[0] = -1.; |
176 |
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break; |
177 |
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case UDxpos: |
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updir[0] = 1.; |
179 |
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break; |
180 |
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case UDypos: |
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updir[1] = 1.; |
182 |
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break; |
183 |
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case UDzpos: |
184 |
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updir[2] = 1.; |
185 |
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break; |
186 |
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case UDunknown: |
187 |
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error(WARNING, "unspecified up direction"); |
188 |
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return(0); |
189 |
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} |
190 |
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fcross(xdest, updir, nrm); |
191 |
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if (normalize(xdest) == 0.0) |
192 |
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return(0); |
193 |
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fcross(ydest, nrm, xdest); |
194 |
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xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs); |
195 |
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copymat4(xm, myxf.xfm); |
196 |
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return(1); |
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} |
198 |
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199 |
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200 |
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void |
201 |
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redistribute( /* pass distarr ray sums through BSDF */ |
202 |
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struct BSDF_data *b, |
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int nalt, |
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int nazi, |
205 |
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FVECT u, |
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FVECT v, |
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FVECT w, |
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MAT4 xm |
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) |
210 |
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{ |
211 |
greg |
2.5 |
MAT4 mymat, inmat; |
212 |
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COLORV *idist; |
213 |
greg |
2.2 |
COLORV *cp, *csum; |
214 |
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FVECT dv; |
215 |
greg |
2.5 |
double wt; |
216 |
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int i, j, k, h; |
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COLOR col, cinc; |
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/* copy incoming distribution */ |
219 |
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if (b->ninc != distsiz) |
220 |
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error(INTERNAL, "error 1 in redistribute"); |
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idist = (COLORV *)malloc(sizeof(COLOR)*distsiz); |
222 |
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if (idist == NULL) |
223 |
greg |
2.2 |
error(SYSTEM, "out of memory in redistribute"); |
224 |
greg |
2.5 |
memcpy(idist, distarr, sizeof(COLOR)*distsiz); |
225 |
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/* compose direction transform */ |
226 |
greg |
2.2 |
for (i = 3; i--; ) { |
227 |
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mymat[i][0] = u[i]; |
228 |
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mymat[i][1] = v[i]; |
229 |
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mymat[i][2] = w[i]; |
230 |
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mymat[i][3] = 0.; |
231 |
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} |
232 |
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mymat[3][0] = mymat[3][1] = mymat[3][2] = 0.; |
233 |
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mymat[3][3] = 1.; |
234 |
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if (xm != NULL) |
235 |
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multmat4(mymat, xm, mymat); |
236 |
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for (i = 3; i--; ) { /* make sure it's normalized */ |
237 |
greg |
2.5 |
wt = 1./sqrt( mymat[0][i]*mymat[0][i] + |
238 |
greg |
2.2 |
mymat[1][i]*mymat[1][i] + |
239 |
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mymat[2][i]*mymat[2][i] ); |
240 |
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for (j = 3; j--; ) |
241 |
greg |
2.5 |
mymat[j][i] *= wt; |
242 |
greg |
2.2 |
} |
243 |
greg |
2.5 |
if (!invmat4(inmat, mymat)) /* need inverse as well */ |
244 |
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error(INTERNAL, "cannot invert BSDF transform"); |
245 |
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newdist(nalt*nazi); /* resample distribution */ |
246 |
greg |
2.4 |
for (i = b->ninc; i--; ) { |
247 |
greg |
2.5 |
getBSDF_incvec(dv, b, i); /* compute incident irrad. */ |
248 |
greg |
2.2 |
multv3(dv, dv, mymat); |
249 |
greg |
2.5 |
if (dv[2] < 0.0) dv[2] = -dv[2]; |
250 |
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wt = getBSDF_incrad(b, i); |
251 |
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wt *= wt*PI * dv[2]; /* solid_angle*cosine(theta) */ |
252 |
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cp = &idist[3*i]; |
253 |
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copycolor(cinc, cp); |
254 |
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scalecolor(cinc, wt); |
255 |
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for (k = nalt; k--; ) /* loop over distribution */ |
256 |
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for (j = nazi; j--; ) { |
257 |
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flatdir(dv, (k + .5)/nalt, (double)j/nazi); |
258 |
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multv3(dv, dv, inmat); |
259 |
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/* evaluate BSDF @ outgoing */ |
260 |
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wt = BSDF_visible(b, i, getBSDF_outndx(b, dv)); |
261 |
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copycolor(col, cinc); |
262 |
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scalecolor(col, wt); |
263 |
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csum = &distarr[3*(k*nazi + j)]; |
264 |
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addcolor(csum, col); /* sum into distribution */ |
265 |
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} |
266 |
greg |
2.2 |
} |
267 |
greg |
2.5 |
free(idist); /* free temp space */ |
268 |
greg |
2.2 |
} |