| 1 |
/* Copyright (c) 1986 Regents of the University of California */
|
| 2 |
|
| 3 |
#ifndef lint
|
| 4 |
static char SCCSid[] = "$SunId$ LBL";
|
| 5 |
#endif
|
| 6 |
|
| 7 |
/*
|
| 8 |
* image.c - routines for image generation.
|
| 9 |
*
|
| 10 |
* 10/17/85
|
| 11 |
*/
|
| 12 |
|
| 13 |
#include "standard.h"
|
| 14 |
|
| 15 |
#include "view.h"
|
| 16 |
|
| 17 |
VIEW stdview = STDVIEW; /* default view parameters */
|
| 18 |
|
| 19 |
|
| 20 |
char *
|
| 21 |
setview(v) /* set hvec and vvec, return message on error */
|
| 22 |
register VIEW *v;
|
| 23 |
{
|
| 24 |
extern double tan(), normalize();
|
| 25 |
|
| 26 |
if (normalize(v->vdir) == 0.0) /* normalize direction */
|
| 27 |
return("zero view direction");
|
| 28 |
|
| 29 |
fcross(v->hvec, v->vdir, v->vup); /* compute horiz dir */
|
| 30 |
|
| 31 |
if (normalize(v->hvec) == 0.0)
|
| 32 |
return("illegal view up vector");
|
| 33 |
|
| 34 |
fcross(v->vvec, v->hvec, v->vdir); /* compute vert dir */
|
| 35 |
|
| 36 |
if (v->type == VT_PAR)
|
| 37 |
v->hn2 = v->horiz;
|
| 38 |
else if (v->type == VT_PER)
|
| 39 |
v->hn2 = 2.0 * tan(v->horiz*(PI/180.0/2.0));
|
| 40 |
else
|
| 41 |
return("unknown view type");
|
| 42 |
|
| 43 |
if (v->hn2 <= FTINY || v->hn2 >= FHUGE)
|
| 44 |
return("illegal horizontal view size");
|
| 45 |
|
| 46 |
v->hvec[0] *= v->hn2;
|
| 47 |
v->hvec[1] *= v->hn2;
|
| 48 |
v->hvec[2] *= v->hn2;
|
| 49 |
v->hn2 *= v->hn2;
|
| 50 |
|
| 51 |
if (v->type == VT_PAR)
|
| 52 |
v->vn2 = v->vert;
|
| 53 |
else
|
| 54 |
v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
|
| 55 |
|
| 56 |
if (v->vn2 <= FTINY || v->vn2 >= FHUGE)
|
| 57 |
return("illegal vertical view size");
|
| 58 |
|
| 59 |
v->vvec[0] *= v->vn2;
|
| 60 |
v->vvec[1] *= v->vn2;
|
| 61 |
v->vvec[2] *= v->vn2;
|
| 62 |
v->vn2 *= v->vn2;
|
| 63 |
|
| 64 |
return(NULL);
|
| 65 |
}
|
| 66 |
|
| 67 |
|
| 68 |
normaspect(va, ap, xp, yp) /* fix pixel aspect or resolution */
|
| 69 |
double va; /* view aspect ratio */
|
| 70 |
double *ap; /* pixel aspect in (or out if 0) */
|
| 71 |
int *xp, *yp; /* x and y resolution in (or out if *ap!=0) */
|
| 72 |
{
|
| 73 |
if (*ap <= FTINY)
|
| 74 |
*ap = va * *xp / *yp; /* compute pixel aspect */
|
| 75 |
else if (va * *xp > *ap * *yp)
|
| 76 |
*xp = *yp / va * *ap; /* reduce x resolution */
|
| 77 |
else
|
| 78 |
*yp = *xp * va / *ap; /* reduce y resolution */
|
| 79 |
}
|
| 80 |
|
| 81 |
|
| 82 |
viewray(orig, direc, v, x, y) /* compute ray origin and direction */
|
| 83 |
FVECT orig, direc;
|
| 84 |
register VIEW *v;
|
| 85 |
double x, y;
|
| 86 |
{
|
| 87 |
x += v->hoff - 0.5;
|
| 88 |
y += v->voff - 0.5;
|
| 89 |
|
| 90 |
if (v->type == VT_PAR) { /* parallel view */
|
| 91 |
orig[0] = v->vp[0] + x*v->hvec[0] + y*v->vvec[0];
|
| 92 |
orig[1] = v->vp[1] + x*v->hvec[1] + y*v->vvec[1];
|
| 93 |
orig[2] = v->vp[2] + x*v->hvec[2] + y*v->vvec[2];
|
| 94 |
VCOPY(direc, v->vdir);
|
| 95 |
} else { /* perspective view */
|
| 96 |
VCOPY(orig, v->vp);
|
| 97 |
direc[0] = v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
|
| 98 |
direc[1] = v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
|
| 99 |
direc[2] = v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
|
| 100 |
normalize(direc);
|
| 101 |
}
|
| 102 |
}
|
| 103 |
|
| 104 |
|
| 105 |
viewpixel(xp, yp, zp, v, p) /* find image location for point */
|
| 106 |
double *xp, *yp, *zp;
|
| 107 |
register VIEW *v;
|
| 108 |
FVECT p;
|
| 109 |
{
|
| 110 |
extern double sqrt();
|
| 111 |
double d;
|
| 112 |
FVECT disp;
|
| 113 |
|
| 114 |
disp[0] = p[0] - v->vp[0];
|
| 115 |
disp[1] = p[1] - v->vp[1];
|
| 116 |
disp[2] = p[2] - v->vp[2];
|
| 117 |
|
| 118 |
if (v->type == VT_PAR) { /* parallel view */
|
| 119 |
if (zp != NULL)
|
| 120 |
*zp = DOT(disp,v->vdir);
|
| 121 |
} else { /* perspective view */
|
| 122 |
d = 1.0/DOT(disp,v->vdir);
|
| 123 |
if (zp != NULL) {
|
| 124 |
*zp = sqrt(DOT(disp,disp));
|
| 125 |
if (d < 0.0)
|
| 126 |
*zp = -*zp;
|
| 127 |
}
|
| 128 |
disp[0] *= d;
|
| 129 |
disp[1] *= d;
|
| 130 |
disp[2] *= d;
|
| 131 |
}
|
| 132 |
*xp = DOT(disp,v->hvec)/v->hn2 + 0.5 - v->hoff;
|
| 133 |
*yp = DOT(disp,v->vvec)/v->vn2 + 0.5 - v->voff;
|
| 134 |
}
|
| 135 |
|
| 136 |
|
| 137 |
int
|
| 138 |
getviewopt(v, ac, av) /* process view argument */
|
| 139 |
register VIEW *v;
|
| 140 |
int ac;
|
| 141 |
register char *av[];
|
| 142 |
{
|
| 143 |
#define check(c,n) if ((av[0][c]&&av[0][c]!=' ') || n>=ac) return(-1)
|
| 144 |
extern double atof();
|
| 145 |
|
| 146 |
if (av[0][0] != '-' || av[0][1] != 'v')
|
| 147 |
return(-1);
|
| 148 |
switch (av[0][2]) {
|
| 149 |
case 't': /* type */
|
| 150 |
if (!av[0][3] || av[0][3]==' ')
|
| 151 |
return(-1);
|
| 152 |
check(4,0);
|
| 153 |
v->type = av[0][3];
|
| 154 |
return(0);
|
| 155 |
case 'p': /* point */
|
| 156 |
check(3,3);
|
| 157 |
v->vp[0] = atof(av[1]);
|
| 158 |
v->vp[1] = atof(av[2]);
|
| 159 |
v->vp[2] = atof(av[3]);
|
| 160 |
return(3);
|
| 161 |
case 'd': /* direction */
|
| 162 |
check(3,3);
|
| 163 |
v->vdir[0] = atof(av[1]);
|
| 164 |
v->vdir[1] = atof(av[2]);
|
| 165 |
v->vdir[2] = atof(av[3]);
|
| 166 |
return(3);
|
| 167 |
case 'u': /* up */
|
| 168 |
check(3,3);
|
| 169 |
v->vup[0] = atof(av[1]);
|
| 170 |
v->vup[1] = atof(av[2]);
|
| 171 |
v->vup[2] = atof(av[3]);
|
| 172 |
return(3);
|
| 173 |
case 'h': /* horizontal size */
|
| 174 |
check(3,1);
|
| 175 |
v->horiz = atof(av[1]);
|
| 176 |
return(1);
|
| 177 |
case 'v': /* vertical size */
|
| 178 |
check(3,1);
|
| 179 |
v->vert = atof(av[1]);
|
| 180 |
return(1);
|
| 181 |
case 's': /* shift */
|
| 182 |
check(3,1);
|
| 183 |
v->hoff = atof(av[1]);
|
| 184 |
return(1);
|
| 185 |
case 'l': /* lift */
|
| 186 |
check(3,1);
|
| 187 |
v->voff = atof(av[1]);
|
| 188 |
return(1);
|
| 189 |
default:
|
| 190 |
return(-1);
|
| 191 |
}
|
| 192 |
#undef check
|
| 193 |
}
|
| 194 |
|
| 195 |
|
| 196 |
int
|
| 197 |
sscanview(vp, s) /* get view parameters from string */
|
| 198 |
VIEW *vp;
|
| 199 |
register char *s;
|
| 200 |
{
|
| 201 |
int ac;
|
| 202 |
char *av[4];
|
| 203 |
int na;
|
| 204 |
int nvopts = 0;
|
| 205 |
|
| 206 |
while (*s == ' ')
|
| 207 |
s++;
|
| 208 |
do {
|
| 209 |
ac = 0;
|
| 210 |
do {
|
| 211 |
av[ac++] = s;
|
| 212 |
while (*s && *s != ' ')
|
| 213 |
s++;
|
| 214 |
while (*s == ' ')
|
| 215 |
s++;
|
| 216 |
} while (*s && ac < 4);
|
| 217 |
if ((na = getviewopt(vp, ac, av)) >= 0) {
|
| 218 |
if (na+1 < ac)
|
| 219 |
s = av[na+1];
|
| 220 |
nvopts++;
|
| 221 |
}
|
| 222 |
} while (*s);
|
| 223 |
return(nvopts);
|
| 224 |
}
|
| 225 |
|
| 226 |
|
| 227 |
fprintview(vp, fp) /* write out view parameters */
|
| 228 |
register VIEW *vp;
|
| 229 |
FILE *fp;
|
| 230 |
{
|
| 231 |
fprintf(fp, " -vt%c", vp->type);
|
| 232 |
fprintf(fp, " -vp %.6g %.6g %.6g", vp->vp[0], vp->vp[1], vp->vp[2]);
|
| 233 |
fprintf(fp, " -vd %.6g %.6g %.6g", vp->vdir[0], vp->vdir[1], vp->vdir[2]);
|
| 234 |
fprintf(fp, " -vu %.6g %.6g %.6g", vp->vup[0], vp->vup[1], vp->vup[2]);
|
| 235 |
fprintf(fp, " -vh %.6g -vv %.6g", vp->horiz, vp->vert);
|
| 236 |
fprintf(fp, " -vs %d -vl %d", vp->hoff, vp->voff);
|
| 237 |
}
|
| 238 |
|
| 239 |
|
| 240 |
static VIEW *hview; /* view from header */
|
| 241 |
static int gothview; /* success indicator */
|
| 242 |
static char *altname[] = {NULL,"rpict","rview","pinterp",VIEWSTR,NULL};
|
| 243 |
|
| 244 |
|
| 245 |
static
|
| 246 |
gethview(s) /* get view from header */
|
| 247 |
char *s;
|
| 248 |
{
|
| 249 |
register char **an;
|
| 250 |
|
| 251 |
for (an = altname; *an != NULL; an++)
|
| 252 |
if (!strncmp(*an, s, strlen(*an))) {
|
| 253 |
if (sscanview(hview, s+strlen(*an)) > 0)
|
| 254 |
gothview++;
|
| 255 |
return;
|
| 256 |
}
|
| 257 |
}
|
| 258 |
|
| 259 |
|
| 260 |
int
|
| 261 |
viewfile(fname, vp, xp, yp) /* get view from file */
|
| 262 |
char *fname;
|
| 263 |
VIEW *vp;
|
| 264 |
int *xp, *yp;
|
| 265 |
{
|
| 266 |
extern char *progname;
|
| 267 |
FILE *fp;
|
| 268 |
|
| 269 |
if ((fp = fopen(fname, "r")) == NULL)
|
| 270 |
return(-1);
|
| 271 |
|
| 272 |
altname[0] = progname;
|
| 273 |
hview = vp;
|
| 274 |
gothview = 0;
|
| 275 |
|
| 276 |
getheader(fp, gethview);
|
| 277 |
|
| 278 |
if (xp != NULL && yp != NULL
|
| 279 |
&& fgetresolu(xp, yp, fp) == -1)
|
| 280 |
gothview = 0;
|
| 281 |
|
| 282 |
fclose(fp);
|
| 283 |
|
| 284 |
return(gothview);
|
| 285 |
}
|
