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#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: mkillum4.c,v 2.5 2007/12/05 20:07:34 greg Exp $"; |
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#endif |
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/* |
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* Routines for handling BSDF data within mkillum |
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*/ |
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|
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#include "mkillum.h" |
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#include "paths.h" |
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#include "ezxml.h" |
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|
| 12 |
#define MAXLATS 46 /* maximum number of latitudes */ |
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|
| 14 |
/* BSDF angle specification (terminate with nphi = -1) */ |
| 15 |
typedef struct { |
| 16 |
char name[32]; /* basis name */ |
| 17 |
int nangles; /* total number of directions */ |
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struct { |
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float tmin; /* starting theta */ |
| 20 |
short nphis; /* number of phis (0 term) */ |
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} lat[MAXLATS+1]; /* latitudes */ |
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} ANGLE_BASIS; |
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|
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#define NABASES 3 /* number of predefined bases */ |
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|
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ANGLE_BASIS abase_list[NABASES] = { |
| 27 |
{ |
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"LBNL/Klems Full", 145, |
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{ {-5., 1}, |
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{5., 8}, |
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{15., 16}, |
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{25., 20}, |
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{35., 24}, |
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{45., 24}, |
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{55., 24}, |
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{65., 16}, |
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{75., 12}, |
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{90., 0} } |
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}, { |
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"LBNL/Klems Half", 73, |
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{ {-6.5, 1}, |
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{6.5, 8}, |
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{19.5, 12}, |
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{32.5, 16}, |
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{46.5, 20}, |
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{61.5, 12}, |
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{76.5, 4}, |
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{90., 0} } |
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}, { |
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"LBNL/Klems Quarter", 41, |
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{ {-9., 1}, |
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{9., 8}, |
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{27., 12}, |
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{46., 12}, |
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{66., 8}, |
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{90., 0} } |
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} |
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}; |
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|
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|
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static int |
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ab_getvec( /* get vector for this angle basis index */ |
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FVECT v, |
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int ndx, |
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void *p |
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) |
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{ |
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ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
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int li; |
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double alt, azi, d; |
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|
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if ((ndx < 0) | (ndx >= ab->nangles)) |
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return(0); |
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for (li = 0; ndx >= ab->lat[li].nphis; li++) |
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ndx -= ab->lat[li].nphis; |
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alt = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin); |
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azi = 2.*PI*ndx/ab->lat[li].nphis; |
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d = sin(alt); |
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v[0] = cos(azi)*d; |
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v[1] = sin(azi)*d; |
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v[2] = cos(alt); |
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return(1); |
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} |
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|
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|
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static int |
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ab_getndx( /* get index corresponding to the given vector */ |
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FVECT v, |
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void *p |
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) |
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{ |
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ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
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int li, ndx; |
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double alt, azi, d; |
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|
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if ((v[2] < 0.0) | (v[2] > 1.0)) |
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return(-1); |
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alt = 180.0/PI*acos(v[2]); |
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azi = 180.0/PI*atan2(v[1], v[0]); |
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if (azi < 0.0) azi += 360.0; |
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for (li = 1; ab->lat[li].tmin <= alt; li++) |
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if (!ab->lat[li].nphis) |
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return(-1); |
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--li; |
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ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5); |
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if (ndx >= ab->lat[li].nphis) ndx = 0; |
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while (li--) |
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ndx += ab->lat[li].nphis; |
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return(ndx); |
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} |
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|
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|
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static double |
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ab_getohm( /* get solid angle for this angle basis index */ |
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int ndx, |
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void *p |
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) |
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{ |
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ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
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int li; |
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double tdia, pdia; |
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|
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if ((ndx < 0) | (ndx >= ab->nangles)) |
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return(0); |
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for (li = 0; ndx >= ab->lat[li].nphis; li++) |
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ndx -= ab->lat[li].nphis; |
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tdia = PI/180.*(ab->lat[li+1].tmin - ab->lat[li].tmin); |
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pdia = 2.*PI/ab->lat[li].nphis; |
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return(tdia*pdia); |
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} |
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|
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|
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static int |
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ab_getvecR( /* get reverse vector for this angle basis index */ |
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FVECT v, |
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int ndx, |
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void *p |
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) |
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{ |
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if (!ab_getvec(v, ndx, p)) |
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return(0); |
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|
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v[0] = -v[0]; |
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v[1] = -v[1]; |
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|
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return(1); |
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} |
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|
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|
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static int |
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ab_getndxR( /* get index corresponding to the reverse vector */ |
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FVECT v, |
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void *p |
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) |
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{ |
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FVECT v2; |
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|
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v2[0] = -v[0]; |
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v2[1] = -v[1]; |
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v2[2] = v[2]; |
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|
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return ab_getndx(v2, p); |
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} |
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|
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static void |
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load_bsdf_data( /* load BSDF distribution for this wavelength */ |
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struct BSDF_data *dp, |
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ezxml_t wdb |
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) |
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{ |
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const char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
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const char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
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int i; |
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|
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for (i = NABASES; i--; ) |
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if (!strcmp(cbasis, abase_list[i].name)) { |
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dp->ninc = abase_list[i].nangles; |
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dp->ib_priv = (void *)&abase_list[i]; |
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dp->ib_vec = ab_getvec; |
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dp->ib_ndx = ab_getndx; |
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dp->ib_ohm = ab_getohm; |
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break; |
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} |
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if (i < 0) { |
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sprintf(errmsg, "unsupported incident basis '%s'", cbasis); |
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error(INTERNAL, errmsg); |
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} |
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for (i = NABASES; i--; ) |
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if (!strcmp(rbasis, abase_list[i].name)) { |
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dp->nout = abase_list[i].nangles; |
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dp->ob_priv = (void *)&abase_list[i]; |
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dp->ob_vec = ab_getvecR; |
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dp->ob_ndx = ab_getndxR; |
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dp->ob_ohm = ab_getohm; |
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break; |
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} |
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if (i < 0) { |
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sprintf(errmsg, "unsupported exitant basis '%s'", cbasis); |
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error(INTERNAL, errmsg); |
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} |
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} |
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|
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|
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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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ezxml_t fl, wld, wdb; |
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struct BSDF_data *dp; |
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|
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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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fl = ezxml_parse_file(path); |
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if (fl == NULL) { |
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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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if (ezxml_error(fl)[0]) { |
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sprintf(errmsg, "BSDF \"%s\": %s", path, ezxml_error(fl)); |
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error(WARNING, errmsg); |
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ezxml_free(fl); |
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return(NULL); |
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} |
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dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data)); |
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for (wld = ezxml_child(fl, "WavelengthData"); |
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fl != NULL; fl = fl->next) { |
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if (strcmp(ezxml_txt(ezxml_child(wld,"Wavelength")), "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_txt(ezxml_child(wdb,"WavelengthDataDirection")), |
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"Transmission Front")) |
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continue; |
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load_bsdf_data(dp, wdb); /* load front BTDF */ |
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break; /* ignore the rest */ |
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} |
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ezxml_free(fl); /* done with XML file */ |
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if (dp->bsdf == NULL) { |
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sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path); |
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error(WARNING, errmsg); |
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free_BSDF(dp); |
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dp = NULL; |
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} |
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return(dp); |
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} |
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|
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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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if (b->bsdf != NULL) |
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free(b->bsdf); |
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free(b); |
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} |
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|
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|
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int |
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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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|
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if (!getBSDF_incvec(v, b, i)) |
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return(0); |
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rad = sqrt(getBSDF_incohm(b, i) / PI); |
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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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return(1); |
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} |
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|
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|
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int |
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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; |
| 305 |
int j; |
| 306 |
|
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if (!getBSDF_outvec(v, b, o)) |
| 308 |
return(0); |
| 309 |
rad = sqrt(getBSDF_outohm(b, o) / PI); |
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multisamp(pert, 3, rv); |
| 311 |
for (j = 0; j < 3; j++) |
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v[j] += rad*(2.*pert[j] - 1.); |
| 313 |
if (xm != NULL) |
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multv3(v, v, xm); |
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normalize(v); |
| 316 |
return(1); |
| 317 |
} |
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|
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|
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#define FEQ(a,b) ((a)-(b) <= 1e-7 && (b)-(a) <= 1e-7) |
| 321 |
|
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static int |
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addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */ |
| 324 |
char *xfarg[], |
| 325 |
FVECT xp, |
| 326 |
FVECT yp, |
| 327 |
FVECT zp |
| 328 |
) |
| 329 |
{ |
| 330 |
static char bufs[3][16]; |
| 331 |
int bn = 0; |
| 332 |
char **xfp = xfarg; |
| 333 |
double theta; |
| 334 |
|
| 335 |
theta = atan2(yp[2], zp[2]); |
| 336 |
if (!FEQ(theta,0.0)) { |
| 337 |
*xfp++ = "-rx"; |
| 338 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
| 339 |
*xfp++ = bufs[bn++]; |
| 340 |
} |
| 341 |
theta = asin(-xp[2]); |
| 342 |
if (!FEQ(theta,0.0)) { |
| 343 |
*xfp++ = "-ry"; |
| 344 |
sprintf(bufs[bn], " %f", theta*(180./PI)); |
| 345 |
*xfp++ = bufs[bn++]; |
| 346 |
} |
| 347 |
theta = atan2(xp[1], xp[0]); |
| 348 |
if (!FEQ(theta,0.0)) { |
| 349 |
*xfp++ = "-rz"; |
| 350 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
| 351 |
*xfp++ = bufs[bn++]; |
| 352 |
} |
| 353 |
*xfp = NULL; |
| 354 |
return(xfp - xfarg); |
| 355 |
} |
| 356 |
|
| 357 |
|
| 358 |
int |
| 359 |
getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */ |
| 360 |
MAT4 xm, |
| 361 |
FVECT nrm, |
| 362 |
UpDir ud |
| 363 |
) |
| 364 |
{ |
| 365 |
char *xfargs[7]; |
| 366 |
XF myxf; |
| 367 |
FVECT updir, xdest, ydest; |
| 368 |
|
| 369 |
updir[0] = updir[1] = updir[2] = 0.; |
| 370 |
switch (ud) { |
| 371 |
case UDzneg: |
| 372 |
updir[2] = -1.; |
| 373 |
break; |
| 374 |
case UDyneg: |
| 375 |
updir[1] = -1.; |
| 376 |
break; |
| 377 |
case UDxneg: |
| 378 |
updir[0] = -1.; |
| 379 |
break; |
| 380 |
case UDxpos: |
| 381 |
updir[0] = 1.; |
| 382 |
break; |
| 383 |
case UDypos: |
| 384 |
updir[1] = 1.; |
| 385 |
break; |
| 386 |
case UDzpos: |
| 387 |
updir[2] = 1.; |
| 388 |
break; |
| 389 |
case UDunknown: |
| 390 |
error(WARNING, "unspecified up direction"); |
| 391 |
return(0); |
| 392 |
} |
| 393 |
fcross(xdest, updir, nrm); |
| 394 |
if (normalize(xdest) == 0.0) |
| 395 |
return(0); |
| 396 |
fcross(ydest, nrm, xdest); |
| 397 |
xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs); |
| 398 |
copymat4(xm, myxf.xfm); |
| 399 |
return(1); |
| 400 |
} |
| 401 |
|
| 402 |
|
| 403 |
void |
| 404 |
redistribute( /* pass distarr ray sums through BSDF */ |
| 405 |
struct BSDF_data *b, |
| 406 |
int nalt, |
| 407 |
int nazi, |
| 408 |
FVECT u, |
| 409 |
FVECT v, |
| 410 |
FVECT w, |
| 411 |
MAT4 xm |
| 412 |
) |
| 413 |
{ |
| 414 |
int nout = 0; |
| 415 |
MAT4 mymat, inmat; |
| 416 |
COLORV *idist; |
| 417 |
COLORV *cp, *csum; |
| 418 |
FVECT dv; |
| 419 |
double wt; |
| 420 |
int i, j, k, o; |
| 421 |
COLOR col, cinc; |
| 422 |
/* copy incoming distribution */ |
| 423 |
if (b->ninc != distsiz) |
| 424 |
error(INTERNAL, "error 1 in redistribute"); |
| 425 |
idist = (COLORV *)malloc(sizeof(COLOR)*distsiz); |
| 426 |
if (idist == NULL) |
| 427 |
error(SYSTEM, "out of memory in redistribute"); |
| 428 |
memcpy(idist, distarr, sizeof(COLOR)*distsiz); |
| 429 |
/* compose direction transform */ |
| 430 |
for (i = 3; i--; ) { |
| 431 |
mymat[i][0] = u[i]; |
| 432 |
mymat[i][1] = v[i]; |
| 433 |
mymat[i][2] = w[i]; |
| 434 |
mymat[i][3] = 0.; |
| 435 |
} |
| 436 |
mymat[3][0] = mymat[3][1] = mymat[3][2] = 0.; |
| 437 |
mymat[3][3] = 1.; |
| 438 |
if (xm != NULL) |
| 439 |
multmat4(mymat, xm, mymat); |
| 440 |
for (i = 3; i--; ) { /* make sure it's normalized */ |
| 441 |
wt = 1./sqrt( mymat[0][i]*mymat[0][i] + |
| 442 |
mymat[1][i]*mymat[1][i] + |
| 443 |
mymat[2][i]*mymat[2][i] ); |
| 444 |
for (j = 3; j--; ) |
| 445 |
mymat[j][i] *= wt; |
| 446 |
} |
| 447 |
if (!invmat4(inmat, mymat)) /* need inverse as well */ |
| 448 |
error(INTERNAL, "cannot invert BSDF transform"); |
| 449 |
newdist(nalt*nazi); /* resample distribution */ |
| 450 |
for (i = b->ninc; i--; ) { |
| 451 |
getBSDF_incvec(dv, b, i); /* compute incident irrad. */ |
| 452 |
multv3(dv, dv, mymat); |
| 453 |
if (dv[2] < 0.0) dv[2] = -dv[2]; |
| 454 |
wt = getBSDF_incohm(b, i); |
| 455 |
wt *= dv[2]; /* solid_angle*cosine(theta) */ |
| 456 |
cp = &idist[3*i]; |
| 457 |
copycolor(cinc, cp); |
| 458 |
scalecolor(cinc, wt); |
| 459 |
for (k = nalt; k--; ) /* loop over distribution */ |
| 460 |
for (j = nazi; j--; ) { |
| 461 |
flatdir(dv, (k + .5)/nalt, (double)j/nazi); |
| 462 |
multv3(dv, dv, inmat); |
| 463 |
/* evaluate BSDF @ outgoing */ |
| 464 |
o = getBSDF_outndx(b, dv); |
| 465 |
if (o < 0) { |
| 466 |
nout++; |
| 467 |
continue; |
| 468 |
} |
| 469 |
wt = BSDF_visible(b, i, o); |
| 470 |
copycolor(col, cinc); |
| 471 |
scalecolor(col, wt); |
| 472 |
csum = &distarr[3*(k*nazi + j)]; |
| 473 |
addcolor(csum, col); /* sum into distribution */ |
| 474 |
} |
| 475 |
} |
| 476 |
free(idist); /* free temp space */ |
| 477 |
if (nout) { |
| 478 |
sprintf(errmsg, "missing %.1f%% of BSDF directions", |
| 479 |
100.*nout/(b->ninc*nalt*nazi)); |
| 480 |
error(WARNING, errmsg); |
| 481 |
} |
| 482 |
} |
