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/* Copyright (c) 1986 Regents of the University of California */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
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|
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/* |
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* image.c - routines for image generation. |
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* |
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* 10/17/85 |
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*/ |
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|
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#include <ctype.h> |
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|
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#include "standard.h" |
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|
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#include "view.h" |
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|
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VIEW stdview = STDVIEW(512); /* default view parameters */ |
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|
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|
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char * |
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sskip(s) /* skip a word */ |
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register char *s; |
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{ |
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while (isspace(*s)) s++; |
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while (*s && !isspace(*s)) s++; |
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return(s); |
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} |
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|
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|
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char * |
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setview(v) /* set vhinc and vvinc, return message on error */ |
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register VIEW *v; |
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{ |
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double tan(), dt; |
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|
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if (normalize(v->vdir) == 0.0) /* normalize direction */ |
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return("zero view direction"); |
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|
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fcross(v->vhinc, v->vdir, v->vup); /* compute horiz dir */ |
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|
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if (normalize(v->vhinc) == 0.0) |
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return("illegal view up vector"); |
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|
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fcross(v->vvinc, v->vhinc, v->vdir); /* compute vert dir */ |
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|
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if (v->type == VT_PAR) |
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dt = v->horiz; |
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else if (v->type == VT_PER) |
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dt = 2.0 * tan(v->horiz*(PI/180.0/2.0)); |
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else |
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return("unknown view type"); |
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|
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if (dt <= FTINY || dt >= FHUGE) |
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return("illegal horizontal view size"); |
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|
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if (v->hresolu <= 0) |
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return("illegal horizontal resolution"); |
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|
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dt /= (double)v->hresolu; |
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v->vhinc[0] *= dt; |
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v->vhinc[1] *= dt; |
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v->vhinc[2] *= dt; |
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|
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if (v->type == VT_PAR) |
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dt = v->vert; |
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else |
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dt = 2.0 * tan(v->vert*(PI/180.0/2.0)); |
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|
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if (dt <= FTINY || dt >= FHUGE) |
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return("illegal vertical view size"); |
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|
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if (v->vresolu <= 0) |
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return("illegal vertical resolution"); |
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|
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dt /= (double)v->vresolu; |
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v->vvinc[0] *= dt; |
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v->vvinc[1] *= dt; |
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v->vvinc[2] *= dt; |
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|
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v->vhn2 = DOT(v->vhinc,v->vhinc); |
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v->vvn2 = DOT(v->vvinc,v->vvinc); |
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|
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return(NULL); |
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} |
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|
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|
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rayview(orig, direc, v, x, y) /* compute ray origin and direction */ |
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FVECT orig, direc; |
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register VIEW *v; |
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double x, y; |
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{ |
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x -= 0.5 * v->hresolu; |
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y -= 0.5 * v->vresolu; |
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|
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if (v->type == VT_PAR) { /* parallel view */ |
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orig[0] = v->vp[0] + x*v->vhinc[0] + y*v->vvinc[0]; |
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orig[1] = v->vp[1] + x*v->vhinc[1] + y*v->vvinc[1]; |
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orig[2] = v->vp[2] + x*v->vhinc[2] + y*v->vvinc[2]; |
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VCOPY(direc, v->vdir); |
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} else { /* perspective view */ |
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VCOPY(orig, v->vp); |
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direc[0] = v->vdir[0] + x*v->vhinc[0] + y*v->vvinc[0]; |
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direc[1] = v->vdir[1] + x*v->vhinc[1] + y*v->vvinc[1]; |
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direc[2] = v->vdir[2] + x*v->vhinc[2] + y*v->vvinc[2]; |
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normalize(direc); |
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} |
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} |
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|
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|
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pixelview(xp, yp, zp, v, p) /* find image location for point */ |
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double *xp, *yp, *zp; |
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register VIEW *v; |
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FVECT p; |
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{ |
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extern double sqrt(); |
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double d; |
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FVECT disp; |
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|
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disp[0] = p[0] - v->vp[0]; |
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disp[1] = p[1] - v->vp[1]; |
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disp[2] = p[2] - v->vp[2]; |
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|
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if (v->type == VT_PAR) { /* parallel view */ |
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if (zp != NULL) |
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*zp = DOT(disp,v->vdir); |
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} else { /* perspective view */ |
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d = 1.0/DOT(disp,v->vdir); |
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if (zp != NULL) { |
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*zp = sqrt(DOT(disp,disp)); |
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if (d < 0.0) |
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*zp = -*zp; |
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} |
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disp[0] *= d; |
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disp[1] *= d; |
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disp[2] *= d; |
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} |
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*xp = DOT(disp,v->vhinc)/v->vhn2 + 0.5*v->hresolu; |
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*yp = DOT(disp,v->vvinc)/v->vvn2 + 0.5*v->vresolu; |
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} |
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|
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|
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sscanview(vp, s) /* get view parameters */ |
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register VIEW *vp; |
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register char *s; |
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{ |
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for ( ; ; ) |
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switch (*s++) { |
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case '\0': |
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case '\n': |
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return(0); |
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case '-': |
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switch (*s++) { |
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case '\0': |
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return(-1); |
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case 'x': |
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if (sscanf(s, "%d", &vp->hresolu) != 1) |
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return(-1); |
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s = sskip(s); |
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continue; |
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case 'y': |
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if (sscanf(s, "%d", &vp->vresolu) != 1) |
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return(-1); |
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s = sskip(s); |
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continue; |
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case 'v': |
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switch (*s++) { |
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case '\0': |
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return(-1); |
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case 't': |
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vp->type = *s++; |
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continue; |
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case 'p': |
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if (sscanf(s, "%lf %lf %lf", |
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&vp->vp[0], |
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&vp->vp[1], |
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&vp->vp[2]) != 3) |
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return(-1); |
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s = sskip(sskip(sskip(s))); |
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continue; |
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case 'd': |
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if (sscanf(s, "%lf %lf %lf", |
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&vp->vdir[0], |
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&vp->vdir[1], |
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&vp->vdir[2]) != 3) |
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return(-1); |
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s = sskip(sskip(sskip(s))); |
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continue; |
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case 'u': |
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if (sscanf(s, "%lf %lf %lf", |
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&vp->vup[0], |
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&vp->vup[1], |
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&vp->vup[2]) != 3) |
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return(-1); |
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s = sskip(sskip(sskip(s))); |
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continue; |
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case 'h': |
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if (sscanf(s, "%lf", |
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&vp->horiz) != 1) |
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return(-1); |
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s = sskip(s); |
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continue; |
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case 'v': |
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if (sscanf(s, "%lf", |
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&vp->vert) != 1) |
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return(-1); |
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s = sskip(s); |
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continue; |
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} |
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continue; |
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} |
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continue; |
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} |
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} |
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|
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|
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fprintview(vp, fp) /* write out view parameters */ |
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register VIEW *vp; |
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FILE *fp; |
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{ |
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fprintf(fp, " -vt%c", vp->type); |
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fprintf(fp, " -vp %.6g %.6g %.6g", vp->vp[0], vp->vp[1], vp->vp[2]); |
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fprintf(fp, " -vd %.6g %.6g %.6g", vp->vdir[0], vp->vdir[1], vp->vdir[2]); |
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fprintf(fp, " -vu %.6g %.6g %.6g", vp->vup[0], vp->vup[1], vp->vup[2]); |
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fprintf(fp, " -vh %.6g -vv %.6g", vp->horiz, vp->vert); |
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fprintf(fp, " -x %d -y %d", vp->hresolu, vp->vresolu); |
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} |
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|
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|
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static VIEW *hview; /* view from header */ |
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static int gothview; /* success indicator */ |
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static char *altname[] = {NULL,"rpict","rview","pinterp",VIEWSTR,NULL}; |
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|
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|
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static |
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gethview(s) /* get view from header */ |
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char *s; |
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{ |
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register char **an; |
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|
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for (an = altname; *an != NULL; an++) |
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if (!strncmp(*an, s, strlen(*an))) { |
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if (sscanview(hview, s+strlen(*an)) == 0) |
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gothview++; |
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return; |
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} |
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} |
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|
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|
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int |
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viewfile(fname, vp) /* get view from file */ |
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char *fname; |
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VIEW *vp; |
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{ |
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extern char *progname; |
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FILE *fp; |
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|
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if ((fp = fopen(fname, "r")) == NULL) |
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return(-1); |
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|
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altname[0] = progname; |
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hview = vp; |
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gothview = 0; |
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|
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getheader(fp, gethview); |
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|
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fclose(fp); |
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|
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return(gothview); |
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} |
