1 #include	<u.h>
2 #include	<libc.h>
3 #include	<bio.h>
4 #include	"sky.h"
5 
6 char	rad28[] = "0123456789abcdefghijklmnopqr";
7 
8 Picture*
9 image(Angle ra, Angle dec, Angle wid, Angle hig)
10 {
11 	Pix *p;
12 	uchar *b, *up;
13 	int i, j, sx, sy, x, y;
14 	char file[50];
15 	Picture *pic;
16 	Img* ip;
17 	int lowx, lowy, higx, higy;
18 	int slowx, slowy, shigx, shigy;
19 	Header *h;
20 	Angle d, bd;
21 	Plate *pp, *bp;
22 
23 	if(gam.gamma == 0)
24 		gam.gamma = -1;
25 	if(gam.max == gam.min) {
26 		gam.max = 17600;
27 		gam.min = 2500;
28 	}
29 	gam.absgamma = gam.gamma;
30 	gam.neg = 0;
31 	if(gam.absgamma < 0) {
32 		gam.absgamma = -gam.absgamma;
33 		gam.neg = 1;
34 	}
35 	gam.mult1 = 1. / (gam.max - gam.min);
36 	gam.mult2 = 255. * gam.mult1;
37 
38 	if(nplate == 0)
39 		getplates();
40 
41 	bp = 0;
42 	bd = 0;
43 	for(i=0; i<nplate; i++) {
44 		pp = &plate[i];
45 		d = dist(ra, dec, pp->ra, pp->dec);
46 		if(bp == 0 || d < bd) {
47 			bp = pp;
48 			bd = d;
49 		}
50 	}
51 
52 	if(debug)
53 		Bprint(&bout, "best plate: %s %s disk %d %s\n",
54 			hms(bp->ra), dms(bp->dec),
55 			bp->disk, bp->rgn);
56 
57 	h = getheader(bp->rgn);
58 	xypos(h, ra, dec, 0, 0);
59 	if(wid <= 0 || hig <= 0) {
60 		lowx = h->x;
61 		lowy = h->y;
62 		lowx = (lowx/500) * 500;
63 		lowy = (lowy/500) * 500;
64 		higx = lowx + 500;
65 		higy = lowy + 500;
66 	} else {
67 		lowx = h->x - wid*ARCSECONDS_PER_RADIAN*1000 /
68 			(h->param[Pxpixelsz]*h->param[Ppltscale]*2);
69 		lowy = h->y - hig*ARCSECONDS_PER_RADIAN*1000 /
70 			(h->param[Pypixelsz]*h->param[Ppltscale]*2);
71 		higx = h->x + wid*ARCSECONDS_PER_RADIAN*1000 /
72 			(h->param[Pxpixelsz]*h->param[Ppltscale]*2);
73 		higy = h->y + hig*ARCSECONDS_PER_RADIAN*1000 /
74 			(h->param[Pypixelsz]*h->param[Ppltscale]*2);
75 	}
76 	free(h);
77 
78 	if(lowx < 0) lowx = 0;
79 	if(higx < 0) higx = 0;
80 	if(lowy < 0) lowy = 0;
81 	if(higy < 0) higy = 0;
82 	if(lowx > 14000) lowx = 14000;
83 	if(higx > 14000) higx = 14000;
84 	if(lowy > 14000) lowy = 14000;
85 	if(higy > 14000) higy = 14000;
86 
87 	if(debug)
88 		Bprint(&bout, "xy on plate: %d,%d %d,%d\n",
89 			lowx,lowy, higx, higy);
90 
91 	if(lowx >= higx || lowy >=higy) {
92 		Bprint(&bout, "no image found\n");
93 		return 0;
94 	}
95 
96 	b = malloc((higx-lowx)*(higy-lowy)*sizeof(*b));
97 	if(b == 0) {
98  emalloc:
99 		fprint(2, "malloc error\n");
100 		return 0;
101 	}
102 	memset(b, 0, (higx-lowx)*(higy-lowy)*sizeof(*b));
103 
104 	slowx = lowx/500;
105 	shigx = (higx-1)/500;
106 	slowy = lowy/500;
107 	shigy = (higy-1)/500;
108 
109 	for(sx=slowx; sx<=shigx; sx++)
110 	for(sy=slowy; sy<=shigy; sy++) {
111 		if(sx < 0 || sx >= nelem(rad28) || sy < 0 || sy >= nelem(rad28)) {
112 			fprint(2, "bad subplate %d %d\n", sy, sx);
113 			free(b);
114 			return 0;
115 		}
116 		sprint(file, "%s/%s/%s.%c%c",
117 			dssmount(bp->disk),
118 			bp->rgn, bp->rgn,
119 			rad28[sy],
120 			rad28[sx]);
121 
122 		ip = dssread(file);
123 		if(ip == 0) {
124 			fprint(2, "can't read %s: %r\n", file);
125 			free(b);
126 			return 0;
127 		}
128 
129 		x = sx*500;
130 		y = sy*500;
131 		for(j=0; j<ip->ny; j++) {
132 			if(y+j < lowy || y+j >= higy)
133 				continue;
134 			p = &ip->a[j*ip->ny];
135 			up = b + (higy - (y+j+1))*(higx-lowx) + (x - lowx);
136 			for(i=0; i<ip->nx; i++) {
137 				if(x+i >= lowx && x+i < higx)
138 					*up = dogamma(*p);
139 				up++;
140 				p += 1;
141 			}
142 		}
143 		free(ip);
144 	}
145 
146 	pic = malloc(sizeof(Picture));
147 	if(pic == 0){
148 		free(b);
149 		goto emalloc;
150 	}
151 	pic->minx = lowx;
152 	pic->miny = lowy;
153 	pic->maxx = higx;
154 	pic->maxy = higy;
155 	pic->data = b;
156 	strcpy(pic->name, bp->rgn);
157 	return pic;
158 }