| 1 |
greg |
1.1 |
/* Copyright (c) 1986 Regents of the University of California */
|
| 2 |
|
|
|
| 3 |
|
|
#ifndef lint
|
| 4 |
|
|
static char SCCSid[] = "$SunId$ LBL";
|
| 5 |
|
|
#endif
|
| 6 |
|
|
|
| 7 |
|
|
/*
|
| 8 |
|
|
* pf2.c - routines used by pfilt.
|
| 9 |
|
|
*
|
| 10 |
|
|
* 10/3/85
|
| 11 |
|
|
*/
|
| 12 |
|
|
|
| 13 |
|
|
#include <stdio.h>
|
| 14 |
|
|
|
| 15 |
|
|
#include "random.h"
|
| 16 |
|
|
|
| 17 |
|
|
#include "color.h"
|
| 18 |
|
|
|
| 19 |
|
|
#define PI 3.14159265359
|
| 20 |
|
|
|
| 21 |
|
|
#define FTINY (1e-6)
|
| 22 |
|
|
|
| 23 |
|
|
extern int nrows, ncols; /* number of rows and columns for output */
|
| 24 |
|
|
|
| 25 |
|
|
extern int xres, yres; /* x and y resolution */
|
| 26 |
|
|
|
| 27 |
|
|
extern int avghot; /* true means average in avgbrt spots */
|
| 28 |
|
|
|
| 29 |
|
|
extern double hotlvl; /* brightness considered "hot" */
|
| 30 |
|
|
|
| 31 |
|
|
extern int npts; /* # of points for stars */
|
| 32 |
|
|
|
| 33 |
|
|
extern double spread; /* spread for star points */
|
| 34 |
|
|
|
| 35 |
|
|
extern char *progname;
|
| 36 |
|
|
|
| 37 |
|
|
extern COLOR exposure; /* exposure for frame */
|
| 38 |
|
|
|
| 39 |
|
|
#define AVGLVL 0.5 /* target mean brightness */
|
| 40 |
|
|
|
| 41 |
|
|
double avgbrt; /* average picture brightness */
|
| 42 |
|
|
|
| 43 |
|
|
typedef struct hotpix { /* structure for avgbrt pixels */
|
| 44 |
|
|
struct hotpix *next; /* next in list */
|
| 45 |
|
|
COLOR val; /* pixel color */
|
| 46 |
|
|
short x, y; /* pixel position */
|
| 47 |
|
|
float slope; /* random slope for diffraction */
|
| 48 |
|
|
} HOTPIX;
|
| 49 |
|
|
|
| 50 |
|
|
HOTPIX *head; /* head of avgbrt pixel list */
|
| 51 |
|
|
|
| 52 |
|
|
double sprdfact; /* computed spread factor */
|
| 53 |
|
|
|
| 54 |
|
|
|
| 55 |
|
|
pass1init() /* prepare for first pass */
|
| 56 |
|
|
{
|
| 57 |
|
|
avgbrt = 0.0;
|
| 58 |
|
|
head = NULL;
|
| 59 |
|
|
}
|
| 60 |
|
|
|
| 61 |
|
|
|
| 62 |
|
|
pass1default() /* for single pass */
|
| 63 |
|
|
{
|
| 64 |
|
|
avgbrt = AVGLVL * xres * yres;
|
| 65 |
|
|
head = NULL;
|
| 66 |
|
|
}
|
| 67 |
|
|
|
| 68 |
|
|
|
| 69 |
|
|
pass1scan(scan, y) /* process first pass scanline */
|
| 70 |
|
|
register COLOR *scan;
|
| 71 |
|
|
int y;
|
| 72 |
|
|
{
|
| 73 |
|
|
extern char *malloc();
|
| 74 |
|
|
extern double tan(), sqrt();
|
| 75 |
|
|
double cbrt;
|
| 76 |
|
|
register int x;
|
| 77 |
|
|
register HOTPIX *hp;
|
| 78 |
|
|
|
| 79 |
|
|
for (x = 0; x < xres; x++) {
|
| 80 |
|
|
|
| 81 |
|
|
cbrt = bright(scan[x]);
|
| 82 |
|
|
|
| 83 |
|
|
if (avghot || cbrt < hotlvl)
|
| 84 |
|
|
avgbrt += cbrt;
|
| 85 |
|
|
|
| 86 |
|
|
if (npts && cbrt >= hotlvl) {
|
| 87 |
|
|
hp = (HOTPIX *)malloc(sizeof(HOTPIX));
|
| 88 |
|
|
if (hp == NULL) {
|
| 89 |
|
|
fprintf(stderr, "%s: out of memory\n",
|
| 90 |
|
|
progname);
|
| 91 |
|
|
quit(1);
|
| 92 |
|
|
}
|
| 93 |
|
|
copycolor(hp->val, scan[x]);
|
| 94 |
|
|
hp->x = x;
|
| 95 |
|
|
hp->y = y;
|
| 96 |
|
|
hp->slope = tan(PI*(0.5-(random()%npts+0.5)/npts));
|
| 97 |
|
|
hp->next = head;
|
| 98 |
|
|
head = hp;
|
| 99 |
|
|
}
|
| 100 |
|
|
}
|
| 101 |
|
|
}
|
| 102 |
|
|
|
| 103 |
|
|
|
| 104 |
|
|
pass2init() /* prepare for final pass */
|
| 105 |
|
|
{
|
| 106 |
|
|
avgbrt /= (double)xres * yres;
|
| 107 |
|
|
|
| 108 |
|
|
if (avgbrt <= FTINY) {
|
| 109 |
|
|
fprintf(stderr, "%s: picture too dark\n", progname);
|
| 110 |
|
|
quit(1);
|
| 111 |
|
|
}
|
| 112 |
|
|
|
| 113 |
|
|
scalecolor(exposure, AVGLVL/avgbrt);
|
| 114 |
|
|
|
| 115 |
|
|
sprdfact = spread / (hotlvl * bright(exposure))
|
| 116 |
|
|
* ((double)xres*xres + (double)yres*yres) / 4.0;
|
| 117 |
|
|
}
|
| 118 |
|
|
|
| 119 |
|
|
|
| 120 |
|
|
pass2scan(scan, y) /* process final pass scanline */
|
| 121 |
|
|
register COLOR *scan;
|
| 122 |
|
|
int y;
|
| 123 |
|
|
{
|
| 124 |
|
|
int xmin, xmax;
|
| 125 |
|
|
register int x;
|
| 126 |
|
|
register HOTPIX *hp;
|
| 127 |
|
|
|
| 128 |
|
|
for (hp = head; hp != NULL; hp = hp->next) {
|
| 129 |
|
|
if (hp->slope > FTINY) {
|
| 130 |
|
|
xmin = (y - hp->y - 0.5)/hp->slope + hp->x;
|
| 131 |
|
|
xmax = (y - hp->y + 0.5)/hp->slope + hp->x;
|
| 132 |
|
|
} else if (hp->slope < -FTINY) {
|
| 133 |
|
|
xmin = (y - hp->y + 0.5)/hp->slope + hp->x;
|
| 134 |
|
|
xmax = (y - hp->y - 0.5)/hp->slope + hp->x;
|
| 135 |
|
|
} else if (y == hp->y) {
|
| 136 |
|
|
xmin = 0;
|
| 137 |
|
|
xmax = xres-1;
|
| 138 |
|
|
} else {
|
| 139 |
|
|
xmin = 1;
|
| 140 |
|
|
xmax = 0;
|
| 141 |
|
|
}
|
| 142 |
|
|
if (xmin < 0)
|
| 143 |
|
|
xmin = 0;
|
| 144 |
|
|
if (xmax >= xres)
|
| 145 |
|
|
xmax = xres-1;
|
| 146 |
|
|
for (x = xmin; x <= xmax; x++)
|
| 147 |
|
|
starpoint(scan[x], x, y, hp);
|
| 148 |
|
|
}
|
| 149 |
|
|
for (x = 0; x < xres; x++)
|
| 150 |
|
|
multcolor(scan[x], exposure);
|
| 151 |
|
|
}
|
| 152 |
|
|
|
| 153 |
|
|
|
| 154 |
|
|
starpoint(fcol, x, y, hp) /* pixel is on the star's point */
|
| 155 |
|
|
COLOR fcol;
|
| 156 |
|
|
int x, y;
|
| 157 |
|
|
register HOTPIX *hp;
|
| 158 |
|
|
{
|
| 159 |
|
|
COLOR ctmp;
|
| 160 |
|
|
double d2;
|
| 161 |
|
|
|
| 162 |
|
|
d2 = (double)(x - hp->x)*(x - hp->x) + (double)(y - hp->y)*(y - hp->y);
|
| 163 |
|
|
if (d2 > sprdfact) {
|
| 164 |
|
|
d2 = sprdfact / d2;
|
| 165 |
|
|
if (d2 < FTINY)
|
| 166 |
|
|
return;
|
| 167 |
|
|
copycolor(ctmp, hp->val);
|
| 168 |
|
|
scalecolor(ctmp, d2);
|
| 169 |
|
|
addcolor(fcol, ctmp);
|
| 170 |
|
|
} else if (d2 > FTINY) {
|
| 171 |
|
|
addcolor(fcol, hp->val);
|
| 172 |
|
|
}
|
| 173 |
|
|
}
|
