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/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ SGI"; |
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#endif |
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|
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/* |
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* Routines for handling OpenGL light sources |
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*/ |
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|
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#include "radogl.h" |
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|
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double expval = 0.; /* global exposure value */ |
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|
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COLOR ambval = {0.2, 0.2, 0.2}; /* global ambient value */ |
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|
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int dolights = MAXLIGHTS; /* do how many more light sources? */ |
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|
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static int lightid[MAXLIGHTS] = {GL_LIGHT0, GL_LIGHT1, GL_LIGHT2, |
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GL_LIGHT3, GL_LIGHT4, GL_LIGHT5, GL_LIGHT6, GL_LIGHT7}; |
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|
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static int lightlist; /* light list id */ |
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|
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/* source types */ |
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#define L_NONE 0 |
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#define L_SOURCE 1 |
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#define L_FLAT 2 |
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#define L_SPHERE 3 |
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|
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static struct { |
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int type; /* light type (0 if none) */ |
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MATREC *m; /* light material */ |
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FVECT pos; /* light position (or direction) */ |
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FVECT norm; /* flat source normal */ |
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double area; /* source area (or solid angle) */ |
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} lightrec[MAXLIGHTS]; /* light source list */ |
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|
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static int nlights; /* number of defined lights */ |
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|
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static int l_flatsrc(), l_spheresrc(), l_source(); |
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|
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|
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lightinit() /* initialize lighting */ |
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{ |
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GLfloat ambv[4]; |
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register int i; |
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|
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if (!dolights) |
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return; |
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glPushAttrib(GL_LIGHTING_BIT); |
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if (expval <= FTINY && bright(ambval) > FTINY) |
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expval = 0.2/bright(ambval); |
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ambv[0] = expval*colval(ambval,RED); |
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ambv[1] = expval*colval(ambval,GRN); |
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ambv[2] = expval*colval(ambval,BLU); |
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ambv[3] = 1.; |
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glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambv); |
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glCallList(lightlist = newglist()); |
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rgl_checkerr("in lightinit"); |
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nlights = 0; |
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} |
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|
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|
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lightclean() /* clean up light source commands */ |
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{ |
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if ((dolights += nlights) <= 0) |
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return; |
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glPopAttrib(); |
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} |
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|
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|
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lightdefs() /* define light source list */ |
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{ |
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register int i; |
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|
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if (!nlights) |
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return; |
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glNewList(lightlist, GL_COMPILE); |
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while (nlights--) { |
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switch (lightrec[nlights].type) { |
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case L_FLAT: |
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l_flatsrc(nlights); |
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break; |
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case L_SPHERE: |
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l_sphsrc(nlights); |
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break; |
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case L_SOURCE: |
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l_source(nlights); |
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break; |
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default: |
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error(CONSISTENCY, "botched light type in lightdefs"); |
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} |
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freemtl(lightrec[nlights].m); |
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lightrec[nlights].type = L_NONE; |
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} |
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glEndList(); |
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rgl_checkerr("defining lights"); |
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} |
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|
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|
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o_source(o) /* record a distant source */ |
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register OBJREC *o; |
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{ |
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if (!dolights || !issrcmat((MATREC *)o->os)) |
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return(0); |
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if (o->oargs.nfargs != 4) |
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objerror(o, USER, "bad # real arguments"); |
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/* record type & material */ |
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lightrec[nlights].type = L_SOURCE; |
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(lightrec[nlights].m = (MATREC *)o->os)->nlinks++; |
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/* assign direction */ |
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VCOPY(lightrec[nlights].pos, o->oargs.farg); |
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/* compute solid angle */ |
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if (o->oargs.farg[3] <= FTINY) |
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objerror(o, USER, "zero size"); |
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lightrec[nlights].area = 2.*PI*(1. - cos(PI/180./2.*o->oargs.farg[3])); |
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nlights++; dolights--; |
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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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doflatsrc(m, pos, norm, area) /* record a flat source */ |
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MATREC *m; |
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FVECT pos, norm; |
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double area; |
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{ |
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if (!dolights || !issrcmat(m) || area <= FTINY) |
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return(0); |
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/* record type & material */ |
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lightrec[nlights].type = L_FLAT; |
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(lightrec[nlights].m = m)->nlinks++; |
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/* assign geometry */ |
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VCOPY(lightrec[nlights].pos, pos); |
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VCOPY(lightrec[nlights].norm, norm); |
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lightrec[nlights].area = area; |
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nlights++; dolights--; |
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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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dosphsrc(m, pos, area) /* record a spherical source */ |
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register MATREC *m; |
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FVECT pos; |
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double area; |
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{ |
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if (!dolights || !issrcmat(m) || area <= FTINY) |
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return(0); |
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/* record type & material */ |
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lightrec[nlights].type = L_SPHERE; |
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(lightrec[nlights].m = m)->nlinks++; |
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/* assign geometry */ |
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VCOPY(lightrec[nlights].pos, pos); |
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lightrec[nlights].area = area; |
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nlights++; dolights--; |
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return(1); |
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} |
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|
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|
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static |
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l_source(n) /* convert a distant source */ |
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register int n; |
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{ |
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register MATREC *m = lightrec[n].m; |
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int thislight = lightid[n]; |
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GLfloat vec[4]; |
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/* assign direction */ |
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VCOPY(vec, lightrec[n].pos); |
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vec[3] = 0.; |
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glLightfv(thislight, GL_POSITION, vec); |
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/* assign color */ |
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vec[0] = expval*lightrec[n].area*colval(m->u.l.emission,RED); |
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vec[1] = expval*lightrec[n].area*colval(m->u.l.emission,GRN); |
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vec[2] = expval*lightrec[n].area*colval(m->u.l.emission,BLU); |
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vec[3] = 1.; |
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glLightfv(thislight, GL_SPECULAR, vec); |
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glLightfv(thislight, GL_DIFFUSE, vec); |
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vec[0] = vec[1] = vec[2] = 0.; vec[3] = 1.; |
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glLightfv(thislight, GL_AMBIENT, vec); |
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glEnable(thislight); |
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} |
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|
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|
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static |
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l_flatsrc(n) /* convert a flat source */ |
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register int n; |
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{ |
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GLfloat vec[4]; |
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register MATREC *m = lightrec[n].m; |
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int thislight = lightid[n]; |
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/* assign position */ |
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VCOPY(vec, lightrec[n].pos); vec[3] = 1.; |
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glLightfv(thislight, GL_POSITION, vec); |
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/* assign color */ |
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vec[0] = expval*lightrec[n].area*colval(m->u.l.emission,RED); |
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vec[1] = expval*lightrec[n].area*colval(m->u.l.emission,GRN); |
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vec[2] = expval*lightrec[n].area*colval(m->u.l.emission,BLU); |
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vec[3] = 1.; |
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glLightfv(thislight, GL_SPECULAR, vec); |
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glLightfv(thislight, GL_DIFFUSE, vec); |
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vec[0] = vec[1] = vec[2] = 0.; vec[3] = 1.; |
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glLightfv(thislight, GL_AMBIENT, vec); |
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glLightf(thislight, GL_SPOT_EXPONENT, 1.); |
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glLightf(thislight, GL_CONSTANT_ATTENUATION, 0.); |
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glLightf(thislight, GL_LINEAR_ATTENUATION, 0.); |
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glLightf(thislight, GL_QUADRATIC_ATTENUATION, 1.); |
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if (m->type == MAT_SPOT && m->u.l.spotang < 90.) { |
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glLightf(thislight, GL_SPOT_CUTOFF, m->u.l.spotang); |
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glLightfv(thislight, GL_SPOT_DIRECTION, m->u.l.spotdir); |
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} else { |
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glLightf(thislight, GL_SPOT_CUTOFF, 90.); |
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VCOPY(vec, lightrec[n].norm); |
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glLightfv(thislight, GL_SPOT_DIRECTION, vec); |
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} |
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glEnable(thislight); |
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} |
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|
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|
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static |
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l_sphsrc(n) /* convert a spherical source */ |
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register int n; |
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{ |
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GLfloat vec[4]; |
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register MATREC *m = lightrec[n].m; |
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int thislight = lightid[n]; |
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/* assign position */ |
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VCOPY(vec, lightrec[n].pos); vec[3] = 1.; |
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glLightfv(thislight, GL_POSITION, vec); |
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/* assign color */ |
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vec[0] = expval*lightrec[n].area*colval(m->u.l.emission,RED); |
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vec[1] = expval*lightrec[n].area*colval(m->u.l.emission,GRN); |
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vec[2] = expval*lightrec[n].area*colval(m->u.l.emission,BLU); |
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vec[3] = 1.; |
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glLightfv(thislight, GL_SPECULAR, vec); |
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glLightfv(thislight, GL_DIFFUSE, vec); |
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vec[0] = vec[1] = vec[2] = 0.; vec[3] = 1.; |
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glLightfv(thislight, GL_AMBIENT, vec); |
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glLightf(thislight, GL_SPOT_EXPONENT, 0.); |
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glLightf(thislight, GL_CONSTANT_ATTENUATION, 0.); |
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glLightf(thislight, GL_LINEAR_ATTENUATION, 0.); |
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glLightf(thislight, GL_QUADRATIC_ATTENUATION, 1.); |
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if (m->type == MAT_SPOT && m->u.l.spotang <= 90.) { |
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glLightf(thislight, GL_SPOT_CUTOFF, m->u.l.spotang); |
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glLightfv(thislight, GL_SPOT_DIRECTION, m->u.l.spotdir); |
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} else |
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glLightf(thislight, GL_SPOT_CUTOFF, 180.); |
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glEnable(thislight); |
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} |
