src/px/pcomb.c

/* Copyright (c) 1991 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 *  Combine picture files according to calcomp functions.
 *
 *      1/4/89
 */

#include <stdio.h>

#include <errno.h>

#include "color.h"

#include "calcomp.h"

#define MAXINP          32              /* maximum number of input files */
#define WINSIZ          9               /* scanline window size */
#define MIDSCN          4               /* current scan position */

#define BRT             (-1)            /* special index for brightness */

struct {
        char    *name;          /* file or command name */
        FILE    *fp;            /* stream pointer */
        COLOR   *scan[WINSIZ];  /* input scanline window */
        COLOR   coef;           /* coefficient */
        COLOR   expos;          /* recorded exposure */
}       input[MAXINP];                  /* input pictures */

int     nfiles;                         /* number of input files */

char    *vcolin[3] = {"ri", "gi", "bi"};
char    *vcolout[3] = {"ro", "go", "bo"};
char    vbrtin[] = "li";
char    vbrtout[] = "lo";
char    *vcolexp[3] = {"re", "ge", "be"};
char    vbrtexp[] = "le";

char    vnfiles[] = "nfiles";
char    vxmax[] = "xmax";
char    vymax[] = "ymax";
char    vxres[] = "xres";
char    vyres[] = "yres";
char    vxpos[] = "x";
char    vypos[] = "y";

int     nowarn = 0;                     /* no warning messages? */

int     xmax = 0, ymax = 0;             /* input resolution */

int     xscan, yscan;                   /* input position */

int     xres, yres;                     /* output resolution */

int     xpos, ypos;                     /* output position */

int     wrongformat = 0;

FILE    *popen();


main(argc, argv)
int     argc;
char    *argv[];
{
        char    buf[128];
        int     original;
        double  f;
        int     a, i;
                                                /* scan options */
        for (a = 1; a < argc; a++) {
                if (argv[a][0] == '-')
                        switch (argv[a][1]) {
                        case 'x':
                        case 'y':
                                a++;
                                continue;
                        case 'w':
                                nowarn = !nowarn;
                                continue;
                        case 'f':
                        case 'e':
                                a++;
                                continue;
                        }
                break;
        }
                                        /* process files */
        for (nfiles = 0; nfiles < MAXINP; nfiles++) {
                setcolor(input[nfiles].coef, 1.0, 1.0, 1.0);
                setcolor(input[nfiles].expos, 1.0, 1.0, 1.0);
        }
        nfiles = 0;
        original = 0;
        for ( ; a < argc; a++) {
                if (nfiles >= MAXINP) {
                        eputs(argv[0]);
                        eputs(": too many picture files\n");
                        quit(1);
                }
                if (argv[a][0] == '-')
                        switch (argv[a][1]) {
                        case '\0':
                                input[nfiles].name = "<stdin>";
                                input[nfiles].fp = stdin;
                                break;
                        case 'o':
                                original++;
                                break;
                        case 's':
                                f = atof(argv[++a]);
                                scalecolor(input[nfiles].coef, f);
                                continue;
                        case 'c':
                                colval(input[nfiles].coef,RED)*=atof(argv[++a]);
                                colval(input[nfiles].coef,GRN)*=atof(argv[++a]);
                                colval(input[nfiles].coef,BLU)*=atof(argv[++a]);
                                continue;
                        default:
                                goto usage;
                        }
                else {
                        input[nfiles].name = argv[a];
                        input[nfiles].fp = argv[a][0]=='!' ?
                                        popen(argv[a]+1, "r") :
                                        fopen(argv[a], "r");
                        if (input[nfiles].fp == NULL) {
                                perror(argv[a]);
                                quit(1);
                        }
                }
                checkfile();
                if (original) {
                        colval(input[nfiles].coef,RED) /=
                                        colval(input[nfiles].expos,RED);
                        colval(input[nfiles].coef,GRN) /=
                                        colval(input[nfiles].expos,GRN);
                        colval(input[nfiles].coef,BLU) /=
                                        colval(input[nfiles].expos,BLU);
                }
                nfiles++;
                original = 0;
        }
        init();                         /* set constants */
                                        /* go back and get expressions */
        for (a = 1; a < argc; a++) {
                if (argv[a][0] == '-')
                        switch (argv[a][1]) {
                        case 'x':
                                strcpy(buf, vxres);
                                strcat(buf, ":");
                                strcat(buf, argv[++a]);
                                scompile(buf, NULL, 0);
                                continue;
                        case 'y':
                                strcpy(buf, vyres);
                                strcat(buf, ":");
                                strcat(buf, argv[++a]);
                                scompile(buf, NULL, 0);
                                continue;
                        case 'w':
                                continue;
                        case 'f':
                                fcompile(argv[++a]);
                                continue;
                        case 'e':
                                scompile(argv[++a], NULL, 0);
                                continue;
                        }
                break;
        }
                                                /* set/get output resolution */
        if (!vardefined(vxres))
                varset(vxres, ':', (double)xmax);
        if (!vardefined(vyres))
                varset(vyres, ':', (double)ymax);
        xres = varvalue(vxres) + .5;
        yres = varvalue(vyres) + .5;
        if (xres <= 0 || yres <= 0) {
                eputs(argv[0]);
                eputs(": illegal output resolution\n");
                quit(1);
        }
                                                /* complete header */
        printargs(argc, argv, stdout);
        fputformat(COLRFMT, stdout);
        putchar('\n');
        fputresolu(YMAJOR|YDECR, xres, yres, stdout);
                                                /* combine pictures */
        combine();
        quit(0);
usage:
        eputs("Usage: ");
        eputs(argv[0]);
        eputs(
" [-w][-h][-x xr][-y yr][-e expr][-f file] [ [-s f][-c r g b] pic ..]\n");
        quit(1);
}


tputs(s)                        /* put out string preceded by a tab */
char    *s;
{
        char    fmt[32];
        double  d;
        COLOR   ctmp;

        if (isformat(s)) {                      /* check format */
                formatval(fmt, s);
                wrongformat = strcmp(fmt, COLRFMT);
                return;         /* don't echo */
        }
        if (isexpos(s)) {                       /* exposure */
                d = exposval(s);
                scalecolor(input[nfiles].expos, d);
        } else if (iscolcor(s)) {               /* color correction */
                colcorval(ctmp, s);
                multcolor(input[nfiles].expos, ctmp);
        }
                                                /* echo line */
        putchar('\t');
        fputs(s, stdout);
}


checkfile()                     /* ready a file */
{
        int     xinp, yinp;
        register int    i;
                                        /* process header */
        fputs(input[nfiles].name, stdout);
        fputs(":\n", stdout);
        getheader(input[nfiles].fp, tputs, NULL);
        if (wrongformat) {
                eputs(input[nfiles].name);
                eputs(": not in Radiance picture format\n");
                quit(1);
        }
        if (fgetresolu(&xinp, &yinp, input[nfiles].fp) != (YMAJOR|YDECR)) {
                eputs(input[nfiles].name);
                eputs(": bad picture size\n");
                quit(1);
        }
        if (xmax == 0 && ymax == 0) {
                xmax = xinp;
                ymax = yinp;
        } else if (xinp != xmax || yinp != ymax) {
                eputs(input[nfiles].name);
                eputs(": resolution mismatch\n");
                quit(1);
        }
                                        /* allocate scanlines */
        for (i = 0; i < WINSIZ; i++)
                input[nfiles].scan[i] = (COLOR *)emalloc(xmax*sizeof(COLOR));
}


init()                                  /* perform final setup */
{
        double  l_colin(), l_expos();
        register int    i;
                                                /* define constants */
        varset(vnfiles, ':', (double)nfiles);
        varset(vxmax, ':', (double)xmax);
        varset(vymax, ':', (double)ymax);
                                                /* set functions */
        for (i = 0; i < 3; i++) {
                funset(vcolexp[i], 1, ':', l_expos);
                funset(vcolin[i], 1, '=', l_colin);
        }
        funset(vbrtexp, 1, ':', l_expos);
        funset(vbrtin, 1, '=', l_colin);
}


combine()                       /* combine pictures */
{
        EPNODE  *coldef[3], *brtdef;
        COLOR   *scanout;
        double  d;
        register int    i, j;
                                                /* check defined variables */
        for (j = 0; j < 3; j++) {
                if (vardefined(vcolout[j]))
                        coldef[j] = eparse(vcolout[j]);
                else
                        coldef[j] = NULL;
        }
        if (vardefined(vbrtout))
                brtdef = eparse(vbrtout);
        else
                brtdef = NULL;
                                                /* allocate scanline */
        scanout = (COLOR *)emalloc(xres*sizeof(COLOR));
                                                /* set input position */
        yscan = ymax+MIDSCN;
                                                /* combine files */
        for (ypos = yres-1; ypos >= 0; ypos--) {
            advance();
            varset(vypos, '=', (double)ypos);
            for (xpos = 0; xpos < xres; xpos++) {
                xscan = (long)xpos*xmax/xres;
                varset(vxpos, '=', (double)xpos);
                eclock++;
                if (brtdef != NULL) {
                    d = evalue(brtdef);
                    if (d < 0.0)
                        d = 0.0;
                    setcolor(scanout[xpos], d, d, d);
                } else {
                    for (j = 0; j < 3; j++) {
                        if (coldef[j] != NULL) {
                                d = evalue(coldef[j]);
                        } else {
                            d = 0.0;
                            for (i = 0; i < nfiles; i++)
                                d += colval(input[i].scan[MIDSCN][xscan],j);
                        }
                        if (d < 0.0)
                            d = 0.0;
                        colval(scanout[xpos],j) = d;
                    }
                }
            }
            if (fwritescan(scanout, xres, stdout) < 0) {
                    perror("write error");
                    quit(1);
            }
        }
        efree(scanout);
}


advance()                       /* read in data for next scanline */
{
        int     ytarget;
        register COLOR  *st;
        register int    i, j;

        for (ytarget = (long)ypos*ymax/yres; yscan > ytarget; yscan--)
                for (i = 0; i < nfiles; i++) {
                        st = input[i].scan[WINSIZ-1];
                        for (j = WINSIZ-1; j > 0; j--)  /* rotate window */
                                input[i].scan[j] = input[i].scan[j-1];
                        input[i].scan[0] = st;
                        if (yscan <= MIDSCN)            /* hit bottom? */
                                continue;
                        if (freadscan(st, xmax, input[i].fp) < 0) {     /* read */
                                eputs(input[i].name);
                                eputs(": read error\n");
                                quit(1);
                        }
                        for (j = 0; j < xmax; j++)      /* adjust color */
                                multcolor(st[j], input[i].coef);
                }
}


double
l_expos(nam)                    /* return picture exposure */
register char   *nam;
{
        register int    fn, n;

        fn = argument(1) - .5;
        if (fn < 0 || fn >= nfiles)
                return(1.0);
        if (nam == vbrtexp)
                return(bright(input[fn].expos));
        n = 3;
        while (n--)
                if (nam == vcolexp[n])
                        return(colval(input[fn].expos,n));
        eputs("Bad call to l_expos()!\n");
        quit(1);
}


double
l_colin(nam)                    /* return color value for picture */
register char   *nam;
{
        int     fn;
        register int    n, xoff, yoff;
        double  d;

        d = argument(1);
        if (d > -.5 && d < .5)
                return((double)nfiles);
        fn = d - .5;
        if (fn < 0 || fn >= nfiles) {
                errno = EDOM;
                return(0.0);
        }
        xoff = yoff = 0;
        n = nargum();
        if (n >= 2) {
                d = argument(2);
                if (d < 0.0) {
                        xoff = d-.5;
                        if (xscan+xoff < 0)
                                xoff = -xscan;
                } else {
                        xoff = d+.5;
                        if (xscan+xoff >= xmax)
                                xoff = xmax-1-xscan;
                }
        }
        if (n >= 3) {
                d = argument(3);
                if (d < 0.0) {
                        yoff = d-.5;
                        if (yoff+MIDSCN < 0)
                                yoff = -MIDSCN;
                        if (yscan+yoff < 0)
                                yoff = -yscan;
                } else {
                        yoff = d+.5;
                        if (yoff+MIDSCN >= WINSIZ)
                                yoff = WINSIZ-1-MIDSCN;
                        if (yscan+yoff >= ymax)
                                yoff = ymax-1-yscan;
                }
        }
        if (nam == vbrtin)
                return(bright(input[fn].scan[MIDSCN+yoff][xscan+xoff]));
        n = 3;
        while (n--)
            if (nam == vcolin[n])
                return(colval(input[fn].scan[MIDSCN+yoff][xscan+xoff],n));
        eputs("Bad call to l_colin()!\n");
        quit(1);
}


wputs(msg)
char    *msg;
{
        if (!nowarn)
                eputs(msg);
}


eputs(msg)
char    *msg;
{
        fputs(msg, stderr);
}


quit(code)
int     code;
{
        exit(code);
}
Revision:	1.19
Committed:	Thu May 30 09:47:14 1991 UTC (34 years, 5 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.18:	+6 -2 lines
Log Message:	added ability to open commands as well as files
#	User	Rev	Content
1	greg	1.8	/* Copyright (c) 1991 Regents of the University of California */
2	greg	1.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* Combine picture files according to calcomp functions.
9			*
10			* 1/4/89
11			*/
12
13			#include <stdio.h>
14
15			#include <errno.h>
16
17			#include "color.h"
18
19			#include "calcomp.h"
20
21	greg	1.6	#define MAXINP 32 /* maximum number of input files */
22	greg	1.14	#define WINSIZ 9 /* scanline window size */
23			#define MIDSCN 4 /* current scan position */
24	greg	1.1
25	greg	1.14	#define BRT (-1) /* special index for brightness */
26
27	greg	1.1	struct {
28	greg	1.19	char name; / file or command name */
29	greg	1.1	FILE fp; / stream pointer */
30	greg	1.14	COLOR scan[WINSIZ]; / input scanline window */
31	greg	1.3	COLOR coef; /* coefficient */
32	greg	1.17	COLOR expos; /* recorded exposure */
33	greg	1.1	} input[MAXINP]; /* input pictures */
34
35			int nfiles; /* number of input files */
36
37			char *vcolin[3] = {"ri", "gi", "bi"};
38			char *vcolout[3] = {"ro", "go", "bo"};
39	greg	1.15	char vbrtin[] = "li";
40			char vbrtout[] = "lo";
41	greg	1.17	char *vcolexp[3] = {"re", "ge", "be"};
42			char vbrtexp[] = "le";
43	greg	1.1
44	greg	1.18	char vnfiles[] = "nfiles";
45			char vxmax[] = "xmax";
46			char vymax[] = "ymax";
47			char vxres[] = "xres";
48			char vyres[] = "yres";
49			char vxpos[] = "x";
50			char vypos[] = "y";
51	greg	1.1
52			int nowarn = 0; /* no warning messages? */
53
54	greg	1.18	int xmax = 0, ymax = 0; /* input resolution */
55	greg	1.9
56	greg	1.18	int xscan, yscan; /* input position */
57	greg	1.1
58	greg	1.18	int xres, yres; /* output resolution */
59	greg	1.1
60	greg	1.18	int xpos, ypos; /* output position */
61
62	greg	1.10	int wrongformat = 0;
63	greg	1.1
64	greg	1.19	FILE *popen();
65	greg	1.10
66	greg	1.19
67	greg	1.1	main(argc, argv)
68			int argc;
69			char *argv[];
70			{
71	greg	1.18	char buf[128];
72			int original;
73	greg	1.3	double f;
74	greg	1.14	int a, i;
75	greg	1.15	/* scan options */
76			for (a = 1; a < argc; a++) {
77	greg	1.1	if (argv[a][0] == '-')
78			switch (argv[a][1]) {
79			case 'x':
80			case 'y':
81	greg	1.18	a++;
82	greg	1.15	continue;
83	greg	1.1	case 'w':
84			nowarn = !nowarn;
85	greg	1.15	continue;
86	greg	1.1	case 'f':
87			case 'e':
88	greg	1.16	a++;
89	greg	1.15	continue;
90	greg	1.1	}
91	greg	1.15	break;
92			}
93			/* process files */
94	greg	1.17	for (nfiles = 0; nfiles < MAXINP; nfiles++) {
95	greg	1.3	setcolor(input[nfiles].coef, 1.0, 1.0, 1.0);
96	greg	1.17	setcolor(input[nfiles].expos, 1.0, 1.0, 1.0);
97			}
98	greg	1.1	nfiles = 0;
99	greg	1.18	original = 0;
100	greg	1.1	for ( ; a < argc; a++) {
101			if (nfiles >= MAXINP) {
102			eputs(argv[0]);
103			eputs(": too many picture files\n");
104			quit(1);
105			}
106	greg	1.3	if (argv[a][0] == '-')
107			switch (argv[a][1]) {
108			case '\0':
109			input[nfiles].name = "<stdin>";
110			input[nfiles].fp = stdin;
111			break;
112	greg	1.17	case 'o':
113			original++;
114			break;
115	greg	1.3	case 's':
116			f = atof(argv[++a]);
117			scalecolor(input[nfiles].coef, f);
118			continue;
119			case 'c':
120			colval(input[nfiles].coef,RED)*=atof(argv[++a]);
121			colval(input[nfiles].coef,GRN)*=atof(argv[++a]);
122			colval(input[nfiles].coef,BLU)*=atof(argv[++a]);
123			continue;
124			default:
125			goto usage;
126			}
127			else {
128	greg	1.1	input[nfiles].name = argv[a];
129	greg	1.19	input[nfiles].fp = argv[a][0]=='!' ?
130			popen(argv[a]+1, "r") :
131			fopen(argv[a], "r");
132	greg	1.1	if (input[nfiles].fp == NULL) {
133	greg	1.6	perror(argv[a]);
134	greg	1.1	quit(1);
135			}
136			}
137	greg	1.16	checkfile();
138	greg	1.18	if (original) {
139			colval(input[nfiles].coef,RED) /=
140			colval(input[nfiles].expos,RED);
141			colval(input[nfiles].coef,GRN) /=
142			colval(input[nfiles].expos,GRN);
143			colval(input[nfiles].coef,BLU) /=
144			colval(input[nfiles].expos,BLU);
145			}
146			nfiles++;
147	greg	1.17	original = 0;
148	greg	1.15	}
149	greg	1.18	init(); /* set constants */
150	greg	1.15	/* go back and get expressions */
151			for (a = 1; a < argc; a++) {
152			if (argv[a][0] == '-')
153			switch (argv[a][1]) {
154			case 'x':
155	greg	1.18	strcpy(buf, vxres);
156			strcat(buf, ":");
157			strcat(buf, argv[++a]);
158			scompile(buf, NULL, 0);
159			continue;
160	greg	1.15	case 'y':
161	greg	1.18	strcpy(buf, vyres);
162			strcat(buf, ":");
163			strcat(buf, argv[++a]);
164			scompile(buf, NULL, 0);
165	greg	1.16	continue;
166	greg	1.15	case 'w':
167			continue;
168			case 'f':
169			fcompile(argv[++a]);
170			continue;
171			case 'e':
172			scompile(argv[++a], NULL, 0);
173			continue;
174			}
175			break;
176			}
177	greg	1.18	/* set/get output resolution */
178			if (!vardefined(vxres))
179			varset(vxres, ':', (double)xmax);
180			if (!vardefined(vyres))
181			varset(vyres, ':', (double)ymax);
182			xres = varvalue(vxres) + .5;
183			yres = varvalue(vyres) + .5;
184			if (xres <= 0 \|\| yres <= 0) {
185			eputs(argv[0]);
186			eputs(": illegal output resolution\n");
187			quit(1);
188			}
189	greg	1.15	/* complete header */
190			printargs(argc, argv, stdout);
191			fputformat(COLRFMT, stdout);
192			putchar('\n');
193			fputresolu(YMAJOR\|YDECR, xres, yres, stdout);
194			/* combine pictures */
195			combine();
196			quit(0);
197			usage:
198			eputs("Usage: ");
199			eputs(argv[0]);
200			eputs(
201			" [-w][-h][-x xr][-y yr][-e expr][-f file] [ [-s f][-c r g b] pic ..]\n");
202			quit(1);
203			}
204
205
206			tputs(s) /* put out string preceded by a tab */
207			char *s;
208			{
209			char fmt[32];
210			double d;
211			COLOR ctmp;
212
213			if (isformat(s)) { /* check format */
214			formatval(fmt, s);
215			wrongformat = strcmp(fmt, COLRFMT);
216	greg	1.17	return; /* don't echo */
217			}
218			if (isexpos(s)) { /* exposure */
219			d = exposval(s);
220			scalecolor(input[nfiles].expos, d);
221			} else if (iscolcor(s)) { /* color correction */
222	greg	1.15	colcorval(ctmp, s);
223	greg	1.17	multcolor(input[nfiles].expos, ctmp);
224	greg	1.15	}
225	greg	1.17	/* echo line */
226			putchar('\t');
227			fputs(s, stdout);
228	greg	1.16	}
229	greg	1.15
230	greg	1.16
231			checkfile() /* ready a file */
232			{
233	greg	1.18	int xinp, yinp;
234	greg	1.16	register int i;
235			/* process header */
236			fputs(input[nfiles].name, stdout);
237			fputs(":\n", stdout);
238			getheader(input[nfiles].fp, tputs, NULL);
239			if (wrongformat) {
240			eputs(input[nfiles].name);
241			eputs(": not in Radiance picture format\n");
242			quit(1);
243			}
244	greg	1.18	if (fgetresolu(&xinp, &yinp, input[nfiles].fp) != (YMAJOR\|YDECR)) {
245	greg	1.16	eputs(input[nfiles].name);
246			eputs(": bad picture size\n");
247			quit(1);
248			}
249	greg	1.18	if (xmax == 0 && ymax == 0) {
250			xmax = xinp;
251			ymax = yinp;
252			} else if (xinp != xmax \|\| yinp != ymax) {
253	greg	1.16	eputs(input[nfiles].name);
254			eputs(": resolution mismatch\n");
255			quit(1);
256			}
257			/* allocate scanlines */
258			for (i = 0; i < WINSIZ; i++)
259	greg	1.18	input[nfiles].scan[i] = (COLOR )emalloc(xmaxsizeof(COLOR));
260	greg	1.15	}
261
262
263	greg	1.18	init() /* perform final setup */
264	greg	1.15	{
265	greg	1.17	double l_colin(), l_expos();
266	greg	1.16	register int i;
267	greg	1.15	/* define constants */
268			varset(vnfiles, ':', (double)nfiles);
269	greg	1.18	varset(vxmax, ':', (double)xmax);
270			varset(vymax, ':', (double)ymax);
271	greg	1.15	/* set functions */
272			for (i = 0; i < 3; i++) {
273	greg	1.17	funset(vcolexp[i], 1, ':', l_expos);
274	greg	1.15	funset(vcolin[i], 1, '=', l_colin);
275			}
276	greg	1.17	funset(vbrtexp, 1, ':', l_expos);
277	greg	1.15	funset(vbrtin, 1, '=', l_colin);
278	greg	1.1	}
279
280
281			combine() /* combine pictures */
282			{
283	greg	1.8	EPNODE coldef[3], brtdef;
284	greg	1.1	COLOR *scanout;
285	greg	1.8	double d;
286	greg	1.1	register int i, j;
287			/* check defined variables */
288	greg	1.4	for (j = 0; j < 3; j++) {
289			if (vardefined(vcolout[j]))
290			coldef[j] = eparse(vcolout[j]);
291			else
292			coldef[j] = NULL;
293			}
294	greg	1.8	if (vardefined(vbrtout))
295			brtdef = eparse(vbrtout);
296			else
297			brtdef = NULL;
298	greg	1.1	/* allocate scanline */
299			scanout = (COLOR )emalloc(xressizeof(COLOR));
300	greg	1.18	/* set input position */
301			yscan = ymax+MIDSCN;
302	greg	1.1	/* combine files */
303			for (ypos = yres-1; ypos >= 0; ypos--) {
304	greg	1.14	advance();
305	greg	1.11	varset(vypos, '=', (double)ypos);
306	greg	1.8	for (xpos = 0; xpos < xres; xpos++) {
307	greg	1.18	xscan = (long)xpos*xmax/xres;
308	greg	1.11	varset(vxpos, '=', (double)xpos);
309	greg	1.8	eclock++;
310			if (brtdef != NULL) {
311			d = evalue(brtdef);
312			if (d < 0.0)
313			d = 0.0;
314			setcolor(scanout[xpos], d, d, d);
315			} else {
316			for (j = 0; j < 3; j++) {
317			if (coldef[j] != NULL) {
318	greg	1.13	d = evalue(coldef[j]);
319	greg	1.8	} else {
320	greg	1.13	d = 0.0;
321	greg	1.8	for (i = 0; i < nfiles; i++)
322	greg	1.18	d += colval(input[i].scan[MIDSCN][xscan],j);
323	greg	1.1	}
324	greg	1.13	if (d < 0.0)
325			d = 0.0;
326			colval(scanout[xpos],j) = d;
327	greg	1.8	}
328	greg	1.1	}
329	greg	1.8	}
330			if (fwritescan(scanout, xres, stdout) < 0) {
331			perror("write error");
332			quit(1);
333			}
334	greg	1.1	}
335			efree(scanout);
336			}
337
338
339	greg	1.18	advance() /* read in data for next scanline */
340	greg	1.14	{
341	greg	1.18	int ytarget;
342	greg	1.14	register COLOR *st;
343			register int i, j;
344
345	greg	1.18	for (ytarget = (long)ypos*ymax/yres; yscan > ytarget; yscan--)
346			for (i = 0; i < nfiles; i++) {
347			st = input[i].scan[WINSIZ-1];
348			for (j = WINSIZ-1; j > 0; j--) /* rotate window */
349			input[i].scan[j] = input[i].scan[j-1];
350			input[i].scan[0] = st;
351			if (yscan <= MIDSCN) /* hit bottom? */
352			continue;
353			if (freadscan(st, xmax, input[i].fp) < 0) { /* read */
354			eputs(input[i].name);
355			eputs(": read error\n");
356			quit(1);
357			}
358			for (j = 0; j < xmax; j++) /* adjust color */
359			multcolor(st[j], input[i].coef);
360	greg	1.14	}
361			}
362
363
364	greg	1.1	double
365	greg	1.17	l_expos(nam) /* return picture exposure */
366	greg	1.15	register char *nam;
367	greg	1.1	{
368	greg	1.15	register int fn, n;
369	greg	1.14
370	greg	1.18	fn = argument(1) - .5;
371			if (fn < 0 \|\| fn >= nfiles)
372			return(1.0);
373	greg	1.17	if (nam == vbrtexp)
374			return(bright(input[fn].expos));
375	greg	1.15	n = 3;
376			while (n--)
377	greg	1.17	if (nam == vcolexp[n])
378			return(colval(input[fn].expos,n));
379			eputs("Bad call to l_expos()!\n");
380	greg	1.15	quit(1);
381			}
382
383
384			double
385			l_colin(nam) /* return color value for picture */
386			register char *nam;
387			{
388			int fn;
389			register int n, xoff, yoff;
390			double d;
391
392	greg	1.16	d = argument(1);
393			if (d > -.5 && d < .5)
394			return((double)nfiles);
395			fn = d - .5;
396			if (fn < 0 \|\| fn >= nfiles) {
397	greg	1.15	errno = EDOM;
398			return(0.0);
399			}
400	greg	1.14	xoff = yoff = 0;
401			n = nargum();
402			if (n >= 2) {
403			d = argument(2);
404			if (d < 0.0) {
405			xoff = d-.5;
406	greg	1.18	if (xscan+xoff < 0)
407			xoff = -xscan;
408	greg	1.14	} else {
409			xoff = d+.5;
410	greg	1.18	if (xscan+xoff >= xmax)
411			xoff = xmax-1-xscan;
412	greg	1.14	}
413			}
414			if (n >= 3) {
415			d = argument(3);
416			if (d < 0.0) {
417			yoff = d-.5;
418			if (yoff+MIDSCN < 0)
419			yoff = -MIDSCN;
420	greg	1.18	if (yscan+yoff < 0)
421			yoff = -yscan;
422	greg	1.14	} else {
423			yoff = d+.5;
424			if (yoff+MIDSCN >= WINSIZ)
425			yoff = WINSIZ-1-MIDSCN;
426	greg	1.18	if (yscan+yoff >= ymax)
427			yoff = ymax-1-yscan;
428	greg	1.14	}
429			}
430	greg	1.15	if (nam == vbrtin)
431	greg	1.18	return(bright(input[fn].scan[MIDSCN+yoff][xscan+xoff]));
432	greg	1.15	n = 3;
433			while (n--)
434			if (nam == vcolin[n])
435	greg	1.18	return(colval(input[fn].scan[MIDSCN+yoff][xscan+xoff],n));
436	greg	1.15	eputs("Bad call to l_colin()!\n");
437			quit(1);
438	greg	1.1	}
439
440
441			wputs(msg)
442			char *msg;
443			{
444			if (!nowarn)
445			eputs(msg);
446			}
447
448
449			eputs(msg)
450			char *msg;
451			{
452			fputs(msg, stderr);
453			}
454
455
456			quit(code)
457			int code;
458			{
459			exit(code);
460			}