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root/radiance/ray/src/cv/mgf2meta.c
Revision: 2.4
Committed: Thu May 4 13:55:30 1995 UTC (28 years, 11 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.3: +53 -9 lines
Log Message:
decreased number of lines by checking for overdraw and
throwing out small segments on a random basis

File Contents

# User Rev Content
1 greg 2.1 /* Copyright (c) 1995 Regents of the University of California */
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ LBL";
5     #endif
6    
7     /*
8 greg 2.2 * Convert MGF (Materials and Geometry Format) to Metafile 2-d graphics
9 greg 2.1 */
10    
11     #include <stdio.h>
12     #include <math.h>
13 greg 2.4 #include "random.h"
14 greg 2.1 #include "mgflib/parser.h"
15    
16 greg 2.2 #define MX(v) (int)(((1<<14)-1)*(v)[(proj_axis+1)%3])
17     #define MY(v) (int)(((1<<14)-1)*(v)[(proj_axis+2)%3])
18 greg 2.1
19     int r_face();
20     int proj_axis;
21     double limit[3][2];
22 greg 2.3 int layer;
23 greg 2.1
24     extern int mg_nqcdivs;
25    
26    
27     main(argc, argv) /* convert files to stdout */
28     int argc;
29     char *argv[];
30     {
31     int i;
32     /* initialize dispatch table */
33     mg_ehand[MG_E_FACE] = r_face;
34     mg_ehand[MG_E_POINT] = c_hvertex;
35     mg_ehand[MG_E_VERTEX] = c_hvertex;
36     mg_ehand[MG_E_XF] = xf_handler;
37     mg_nqcdivs = 3; /* reduce object subdivision */
38     mg_init(); /* initialize the parser */
39     /* get arguments */
40     if (argc < 8 || (proj_axis = argv[1][0]-'x') < 0 || proj_axis > 2)
41     goto userr;
42     limit[0][0] = atof(argv[2]); limit[0][1] = atof(argv[3]);
43     limit[1][0] = atof(argv[4]); limit[1][1] = atof(argv[5]);
44     limit[2][0] = atof(argv[6]); limit[2][1] = atof(argv[7]);
45    
46     if (argc == 8) { /* convert stdin */
47     if (mg_load(NULL) != MG_OK)
48     exit(1);
49     } else /* convert each file */
50 greg 2.2 for (i = 8; i < argc; i++) {
51 greg 2.1 if (mg_load(argv[i]) != MG_OK)
52     exit(1);
53 greg 2.4 newlayer();
54 greg 2.2 }
55 greg 2.3 mendpage(); /* print page */
56 greg 2.2 mdone(); /* close output */
57 greg 2.1 exit(0);
58     userr:
59     fprintf(stderr, "Usage: %s {x|y|z} xmin xmax ymin ymax zmin zmax [file.mgf] ..\n",
60     argv[0]);
61     exit(1);
62     }
63    
64    
65     int
66     r_face(ac, av) /* convert a face */
67     int ac;
68     char **av;
69     {
70     static FVECT bbmin = {0,0,0}, bbmax = {1,1,1};
71     register int i, j;
72     register C_VERTEX *cv;
73     FVECT v1, v2, vo;
74    
75     if (ac < 4)
76     return(MG_EARGC);
77     /* connect to last point */
78     if ((cv = c_getvert(av[ac-1])) == NULL)
79     return(MG_EUNDEF);
80     xf_xfmpoint(vo, cv->p);
81     for (j = 0; j < 3; j++)
82     vo[j] = (vo[j] - limit[j][0])/(limit[j][1]-limit[j][0]);
83     for (i = 1; i < ac; i++) { /* go around face */
84     if ((cv = c_getvert(av[i])) == NULL)
85     return(MG_EUNDEF);
86     xf_xfmpoint(v2, cv->p);
87     for (j = 0; j < 3; j++)
88     v2[j] = (v2[j] - limit[j][0])/(limit[j][1]-limit[j][0]);
89     VCOPY(v1, vo);
90     VCOPY(vo, v2);
91 greg 2.4 if (clip(v1, v2, bbmin, bbmax))
92     doline(MX(v1), MY(v1), MX(v2), MY(v2));
93 greg 2.1 }
94     return(MG_OK);
95 greg 2.4 }
96    
97    
98     #define HTBLSIZ 16381 /* prime hash table size */
99    
100     short hshtab[HTBLSIZ][4]; /* done line segments */
101    
102     #define hash(mx1,my1,mx2,my2) ((long)(mx1)<<15 ^ (long)(my1)<<10 ^ \
103     (long)(mx2)<<5 ^ (long)(my2))
104    
105     #define RANDMASK ((1L<<14)-1)
106    
107    
108     newlayer() /* start a new layer */
109     {
110     #ifdef BSD
111     bzero((char *)hshtab, sizeof(hshtab));
112     #else
113     (void)memset((char *)hshtab, 0, sizeof(hshtab));
114     #endif
115     if (++layer >= 16) {
116     mendpage();
117     layer = 0;
118     }
119     }
120    
121    
122     int
123     doline(v1x, v1y, v2x, v2y) /* draw line conditionally */
124     int v1x, v1y, v2x, v2y;
125     {
126     register int h;
127    
128     if (v1x > v2x || (v1x == v2x && v1y > v2y)) { /* sort endpoints */
129     h=v1x; v1x=v2x; v2x=h;
130     h=v1y; v1y=v2y; v2y=h;
131     }
132     h = hash(v1x, v1y, v2x, v2y) % HTBLSIZ;
133     if (hshtab[h][0] == v1x && hshtab[h][1] == v1y &&
134     hshtab[h][2] == v2x && hshtab[h][3] == v2y)
135     return(0);
136     hshtab[h][0] = v1x; hshtab[h][1] = v1y;
137     hshtab[h][2] = v2x; hshtab[h][3] = v2y;
138     if ((long)(v2x-v1x)*(v2x-v1x) + (long)(v2y-v1y)*(v2y-v1y)
139     <= (random()&RANDMASK))
140     return(0);
141     mline(v1x, v1y, layer/4, 0, layer%4);
142     mdraw(v2x, v2y);
143     return(1);
144 greg 2.1 }