src/px/pcomb.c

/* Copyright (c) 1992 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>

#ifdef MSDOS
#include <fcntl.h>
#endif

#include <math.h>

#include <errno.h>

#include "color.h"

#include "resolu.h"

#include "calcomp.h"

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

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    Command[] = "<Command>";
char    vcolin[3][4] = {"ri", "gi", "bi"};
char    vcolout[3][4] = {"ro", "go", "bo"};
char    vbrtin[] = "li";
char    vbrtout[] = "lo";
char    vcolexp[3][4] = {"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();

extern char     *emalloc();


main(argc, argv)
int     argc;
char    *argv[];
{
        int     original;
        double  f;
        int     a, i;
#ifdef MSDOS
        extern int  _fmode;
        _fmode = O_BINARY;
        setmode(fileno(stdin), O_BINARY);
        setmode(fileno(stdout), O_BINARY);
#endif
                                                /* 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++;
                                continue;
                        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 {
                        if (argv[a][0] == '!') {
                                input[nfiles].name = Command;
                                input[nfiles].fp = popen(argv[a]+1, "r");
                        } else {
                                input[nfiles].name = argv[a];
                                input[nfiles].fp = 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':
                                varset(vxres, ':', eval(argv[++a]));
                                continue;
                        case 'y':
                                varset(vyres, ':', eval(argv[++a]));
                                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');
        fprtresolu(xres, yres, stdout);
                                                /* combine pictures */
        combine();
        quit(0);
usage:
        eputs("Usage: ");
        eputs(argv[0]);
        eputs(
" [-w][-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) < 0) {
                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);
                        }
                        if (fabs(colval(input[i].coef,RED)-1.0) > 1e-3 ||
                                fabs(colval(input[i].coef,GRN)-1.0) > 1e-3 ||
                                fabs(colval(input[i].coef,BLU)-1.0) > 1e-3)
                                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)              /* exit gracefully */
int  code;
{
        register int  i;
                                /* close input files */
        for (i = 0; i < nfiles; i++)
                if (input[i].name == Command)
                        pclose(input[i].fp);
                else
                        fclose(input[i].fp);
        exit(code);
}
Revision:	2.8
Committed:	Fri Oct 2 16:22:51 1992 UTC (31 years, 7 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.7:	+3 -2 lines
Log Message:	Removed problematic math function declarations
#	User	Rev	Content
1	greg	2.6	/* Copyright (c) 1992 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	greg	2.7	#ifdef MSDOS
16			#include <fcntl.h>
17			#endif
18
19	greg	2.8	#include <math.h>
20
21	greg	1.1	#include <errno.h>
22
23			#include "color.h"
24
25	greg	2.8	#include "resolu.h"
26	greg	1.23
27	greg	1.1	#include "calcomp.h"
28
29	greg	1.6	#define MAXINP 32 /* maximum number of input files */
30	greg	1.14	#define WINSIZ 9 /* scanline window size */
31			#define MIDSCN 4 /* current scan position */
32	greg	1.1
33			struct {
34	greg	1.19	char name; / file or command name */
35	greg	1.1	FILE fp; / stream pointer */
36	greg	1.14	COLOR scan[WINSIZ]; / input scanline window */
37	greg	1.3	COLOR coef; /* coefficient */
38	greg	1.17	COLOR expos; /* recorded exposure */
39	greg	1.1	} input[MAXINP]; /* input pictures */
40
41			int nfiles; /* number of input files */
42
43	greg	2.6	char Command[] = "<Command>";
44	greg	1.21	char vcolin[3][4] = {"ri", "gi", "bi"};
45			char vcolout[3][4] = {"ro", "go", "bo"};
46	greg	1.15	char vbrtin[] = "li";
47			char vbrtout[] = "lo";
48	greg	1.21	char vcolexp[3][4] = {"re", "ge", "be"};
49	greg	1.17	char vbrtexp[] = "le";
50	greg	1.1
51	greg	1.18	char vnfiles[] = "nfiles";
52			char vxmax[] = "xmax";
53			char vymax[] = "ymax";
54			char vxres[] = "xres";
55			char vyres[] = "yres";
56			char vxpos[] = "x";
57			char vypos[] = "y";
58	greg	1.1
59			int nowarn = 0; /* no warning messages? */
60
61	greg	1.18	int xmax = 0, ymax = 0; /* input resolution */
62	greg	1.9
63	greg	1.18	int xscan, yscan; /* input position */
64	greg	1.1
65	greg	1.18	int xres, yres; /* output resolution */
66	greg	1.1
67	greg	1.18	int xpos, ypos; /* output position */
68
69	greg	1.10	int wrongformat = 0;
70	greg	1.1
71	greg	1.19	FILE *popen();
72	greg	1.10
73	greg	2.7	extern char *emalloc();
74	greg	1.19
75	greg	2.7
76	greg	1.1	main(argc, argv)
77			int argc;
78			char *argv[];
79			{
80	greg	1.18	int original;
81	greg	1.3	double f;
82	greg	1.14	int a, i;
83	greg	2.7	#ifdef MSDOS
84			extern int _fmode;
85			_fmode = O_BINARY;
86			setmode(fileno(stdin), O_BINARY);
87			setmode(fileno(stdout), O_BINARY);
88			#endif
89	greg	1.15	/* scan options */
90			for (a = 1; a < argc; a++) {
91	greg	1.1	if (argv[a][0] == '-')
92			switch (argv[a][1]) {
93			case 'x':
94			case 'y':
95	greg	1.18	a++;
96	greg	1.15	continue;
97	greg	1.1	case 'w':
98			nowarn = !nowarn;
99	greg	1.15	continue;
100	greg	1.1	case 'f':
101			case 'e':
102	greg	1.16	a++;
103	greg	1.15	continue;
104	greg	1.1	}
105	greg	1.15	break;
106			}
107			/* process files */
108	greg	1.17	for (nfiles = 0; nfiles < MAXINP; nfiles++) {
109	greg	1.3	setcolor(input[nfiles].coef, 1.0, 1.0, 1.0);
110	greg	1.17	setcolor(input[nfiles].expos, 1.0, 1.0, 1.0);
111			}
112	greg	1.1	nfiles = 0;
113	greg	1.18	original = 0;
114	greg	1.1	for ( ; a < argc; a++) {
115			if (nfiles >= MAXINP) {
116			eputs(argv[0]);
117			eputs(": too many picture files\n");
118			quit(1);
119			}
120	greg	1.3	if (argv[a][0] == '-')
121			switch (argv[a][1]) {
122			case '\0':
123			input[nfiles].name = "<stdin>";
124			input[nfiles].fp = stdin;
125			break;
126	greg	1.17	case 'o':
127			original++;
128	greg	1.22	continue;
129	greg	1.3	case 's':
130			f = atof(argv[++a]);
131			scalecolor(input[nfiles].coef, f);
132			continue;
133			case 'c':
134			colval(input[nfiles].coef,RED)*=atof(argv[++a]);
135			colval(input[nfiles].coef,GRN)*=atof(argv[++a]);
136			colval(input[nfiles].coef,BLU)*=atof(argv[++a]);
137			continue;
138			default:
139			goto usage;
140			}
141			else {
142	greg	2.2	if (argv[a][0] == '!') {
143	greg	2.6	input[nfiles].name = Command;
144	greg	2.2	input[nfiles].fp = popen(argv[a]+1, "r");
145			} else {
146			input[nfiles].name = argv[a];
147			input[nfiles].fp = fopen(argv[a], "r");
148			}
149	greg	1.1	if (input[nfiles].fp == NULL) {
150	greg	1.6	perror(argv[a]);
151	greg	1.1	quit(1);
152			}
153			}
154	greg	1.16	checkfile();
155	greg	1.18	if (original) {
156			colval(input[nfiles].coef,RED) /=
157			colval(input[nfiles].expos,RED);
158			colval(input[nfiles].coef,GRN) /=
159			colval(input[nfiles].expos,GRN);
160			colval(input[nfiles].coef,BLU) /=
161			colval(input[nfiles].expos,BLU);
162			}
163			nfiles++;
164	greg	1.17	original = 0;
165	greg	1.15	}
166	greg	1.18	init(); /* set constants */
167	greg	1.15	/* go back and get expressions */
168			for (a = 1; a < argc; a++) {
169			if (argv[a][0] == '-')
170			switch (argv[a][1]) {
171			case 'x':
172	greg	1.21	varset(vxres, ':', eval(argv[++a]));
173	greg	1.18	continue;
174	greg	1.15	case 'y':
175	greg	1.21	varset(vyres, ':', eval(argv[++a]));
176	greg	1.16	continue;
177	greg	1.15	case 'w':
178			continue;
179			case 'f':
180			fcompile(argv[++a]);
181			continue;
182			case 'e':
183			scompile(argv[++a], NULL, 0);
184			continue;
185			}
186			break;
187			}
188	greg	1.18	/* set/get output resolution */
189			if (!vardefined(vxres))
190			varset(vxres, ':', (double)xmax);
191			if (!vardefined(vyres))
192			varset(vyres, ':', (double)ymax);
193			xres = varvalue(vxres) + .5;
194			yres = varvalue(vyres) + .5;
195			if (xres <= 0 \|\| yres <= 0) {
196			eputs(argv[0]);
197			eputs(": illegal output resolution\n");
198			quit(1);
199			}
200	greg	1.15	/* complete header */
201			printargs(argc, argv, stdout);
202			fputformat(COLRFMT, stdout);
203			putchar('\n');
204	greg	1.23	fprtresolu(xres, yres, stdout);
205	greg	1.15	/* combine pictures */
206			combine();
207			quit(0);
208			usage:
209			eputs("Usage: ");
210			eputs(argv[0]);
211			eputs(
212	greg	1.20	" [-w][-x xr][-y yr][-e expr][-f file] [ [-s f][-c r g b] pic ..]\n");
213	greg	1.15	quit(1);
214			}
215
216
217			tputs(s) /* put out string preceded by a tab */
218			char *s;
219			{
220			char fmt[32];
221			double d;
222			COLOR ctmp;
223
224			if (isformat(s)) { /* check format */
225			formatval(fmt, s);
226			wrongformat = strcmp(fmt, COLRFMT);
227	greg	1.17	return; /* don't echo */
228			}
229			if (isexpos(s)) { /* exposure */
230			d = exposval(s);
231			scalecolor(input[nfiles].expos, d);
232			} else if (iscolcor(s)) { /* color correction */
233	greg	1.15	colcorval(ctmp, s);
234	greg	1.17	multcolor(input[nfiles].expos, ctmp);
235	greg	1.15	}
236	greg	1.17	/* echo line */
237			putchar('\t');
238			fputs(s, stdout);
239	greg	1.16	}
240	greg	1.15
241	greg	1.16
242			checkfile() /* ready a file */
243			{
244	greg	1.18	int xinp, yinp;
245	greg	1.16	register int i;
246			/* process header */
247			fputs(input[nfiles].name, stdout);
248			fputs(":\n", stdout);
249			getheader(input[nfiles].fp, tputs, NULL);
250			if (wrongformat) {
251			eputs(input[nfiles].name);
252			eputs(": not in Radiance picture format\n");
253			quit(1);
254			}
255	greg	1.23	if (fgetresolu(&xinp, &yinp, input[nfiles].fp) < 0) {
256	greg	1.16	eputs(input[nfiles].name);
257			eputs(": bad picture size\n");
258			quit(1);
259			}
260	greg	1.18	if (xmax == 0 && ymax == 0) {
261			xmax = xinp;
262			ymax = yinp;
263			} else if (xinp != xmax \|\| yinp != ymax) {
264	greg	1.16	eputs(input[nfiles].name);
265			eputs(": resolution mismatch\n");
266			quit(1);
267			}
268			/* allocate scanlines */
269			for (i = 0; i < WINSIZ; i++)
270	greg	1.18	input[nfiles].scan[i] = (COLOR )emalloc(xmaxsizeof(COLOR));
271	greg	1.15	}
272
273
274	greg	1.18	init() /* perform final setup */
275	greg	1.15	{
276	greg	1.17	double l_colin(), l_expos();
277	greg	1.16	register int i;
278	greg	1.15	/* define constants */
279			varset(vnfiles, ':', (double)nfiles);
280	greg	1.18	varset(vxmax, ':', (double)xmax);
281			varset(vymax, ':', (double)ymax);
282	greg	1.15	/* set functions */
283			for (i = 0; i < 3; i++) {
284	greg	1.17	funset(vcolexp[i], 1, ':', l_expos);
285	greg	1.15	funset(vcolin[i], 1, '=', l_colin);
286			}
287	greg	1.17	funset(vbrtexp, 1, ':', l_expos);
288	greg	1.15	funset(vbrtin, 1, '=', l_colin);
289	greg	1.1	}
290
291
292			combine() /* combine pictures */
293			{
294	greg	1.8	EPNODE coldef[3], brtdef;
295	greg	1.1	COLOR *scanout;
296	greg	1.8	double d;
297	greg	1.1	register int i, j;
298			/* check defined variables */
299	greg	1.4	for (j = 0; j < 3; j++) {
300			if (vardefined(vcolout[j]))
301			coldef[j] = eparse(vcolout[j]);
302			else
303			coldef[j] = NULL;
304			}
305	greg	1.8	if (vardefined(vbrtout))
306			brtdef = eparse(vbrtout);
307			else
308			brtdef = NULL;
309	greg	1.1	/* allocate scanline */
310			scanout = (COLOR )emalloc(xressizeof(COLOR));
311	greg	1.18	/* set input position */
312			yscan = ymax+MIDSCN;
313	greg	1.1	/* combine files */
314			for (ypos = yres-1; ypos >= 0; ypos--) {
315	greg	1.14	advance();
316	greg	1.11	varset(vypos, '=', (double)ypos);
317	greg	1.8	for (xpos = 0; xpos < xres; xpos++) {
318	greg	1.18	xscan = (long)xpos*xmax/xres;
319	greg	1.11	varset(vxpos, '=', (double)xpos);
320	greg	1.8	eclock++;
321			if (brtdef != NULL) {
322			d = evalue(brtdef);
323			if (d < 0.0)
324			d = 0.0;
325			setcolor(scanout[xpos], d, d, d);
326			} else {
327			for (j = 0; j < 3; j++) {
328			if (coldef[j] != NULL) {
329	greg	1.13	d = evalue(coldef[j]);
330	greg	1.8	} else {
331	greg	1.13	d = 0.0;
332	greg	1.8	for (i = 0; i < nfiles; i++)
333	greg	1.18	d += colval(input[i].scan[MIDSCN][xscan],j);
334	greg	1.1	}
335	greg	1.13	if (d < 0.0)
336			d = 0.0;
337			colval(scanout[xpos],j) = d;
338	greg	1.8	}
339	greg	1.1	}
340	greg	1.8	}
341			if (fwritescan(scanout, xres, stdout) < 0) {
342			perror("write error");
343			quit(1);
344			}
345	greg	1.1	}
346			efree(scanout);
347			}
348
349
350	greg	1.18	advance() /* read in data for next scanline */
351	greg	1.14	{
352	greg	1.18	int ytarget;
353	greg	1.14	register COLOR *st;
354			register int i, j;
355
356	greg	1.18	for (ytarget = (long)ypos*ymax/yres; yscan > ytarget; yscan--)
357			for (i = 0; i < nfiles; i++) {
358			st = input[i].scan[WINSIZ-1];
359			for (j = WINSIZ-1; j > 0; j--) /* rotate window */
360			input[i].scan[j] = input[i].scan[j-1];
361			input[i].scan[0] = st;
362			if (yscan <= MIDSCN) /* hit bottom? */
363			continue;
364	greg	2.4	if (freadscan(st, xmax, input[i].fp) < 0) { /* read */
365	greg	1.18	eputs(input[i].name);
366			eputs(": read error\n");
367			quit(1);
368			}
369	greg	2.4	if (fabs(colval(input[i].coef,RED)-1.0) > 1e-3 \|\|
370			fabs(colval(input[i].coef,GRN)-1.0) > 1e-3 \|\|
371			fabs(colval(input[i].coef,BLU)-1.0) > 1e-3)
372			for (j = 0; j < xmax; j++) /* adjust color */
373			multcolor(st[j], input[i].coef);
374	greg	1.14	}
375			}
376
377
378	greg	1.1	double
379	greg	1.17	l_expos(nam) /* return picture exposure */
380	greg	1.15	register char *nam;
381	greg	1.1	{
382	greg	1.15	register int fn, n;
383	greg	1.14
384	greg	1.18	fn = argument(1) - .5;
385			if (fn < 0 \|\| fn >= nfiles)
386			return(1.0);
387	greg	1.17	if (nam == vbrtexp)
388			return(bright(input[fn].expos));
389	greg	1.15	n = 3;
390			while (n--)
391	greg	1.17	if (nam == vcolexp[n])
392			return(colval(input[fn].expos,n));
393			eputs("Bad call to l_expos()!\n");
394	greg	1.15	quit(1);
395			}
396
397
398			double
399			l_colin(nam) /* return color value for picture */
400			register char *nam;
401			{
402			int fn;
403			register int n, xoff, yoff;
404			double d;
405
406	greg	1.16	d = argument(1);
407			if (d > -.5 && d < .5)
408			return((double)nfiles);
409			fn = d - .5;
410			if (fn < 0 \|\| fn >= nfiles) {
411	greg	1.15	errno = EDOM;
412			return(0.0);
413			}
414	greg	1.14	xoff = yoff = 0;
415			n = nargum();
416			if (n >= 2) {
417			d = argument(2);
418			if (d < 0.0) {
419			xoff = d-.5;
420	greg	1.18	if (xscan+xoff < 0)
421			xoff = -xscan;
422	greg	1.14	} else {
423			xoff = d+.5;
424	greg	1.18	if (xscan+xoff >= xmax)
425			xoff = xmax-1-xscan;
426	greg	1.14	}
427			}
428			if (n >= 3) {
429			d = argument(3);
430			if (d < 0.0) {
431			yoff = d-.5;
432			if (yoff+MIDSCN < 0)
433			yoff = -MIDSCN;
434	greg	1.18	if (yscan+yoff < 0)
435			yoff = -yscan;
436	greg	1.14	} else {
437			yoff = d+.5;
438			if (yoff+MIDSCN >= WINSIZ)
439			yoff = WINSIZ-1-MIDSCN;
440	greg	1.18	if (yscan+yoff >= ymax)
441			yoff = ymax-1-yscan;
442	greg	1.14	}
443			}
444	greg	1.15	if (nam == vbrtin)
445	greg	1.18	return(bright(input[fn].scan[MIDSCN+yoff][xscan+xoff]));
446	greg	1.15	n = 3;
447			while (n--)
448			if (nam == vcolin[n])
449	greg	1.18	return(colval(input[fn].scan[MIDSCN+yoff][xscan+xoff],n));
450	greg	1.15	eputs("Bad call to l_colin()!\n");
451			quit(1);
452	greg	1.1	}
453
454
455			wputs(msg)
456			char *msg;
457			{
458			if (!nowarn)
459			eputs(msg);
460			}
461
462
463			eputs(msg)
464			char *msg;
465			{
466			fputs(msg, stderr);
467			}
468
469
470	greg	2.4	quit(code) /* exit gracefully */
471			int code;
472			{
473	greg	2.5	register int i;
474			/* close input files */
475			for (i = 0; i < nfiles; i++)
476	greg	2.6	if (input[i].name == Command)
477			pclose(input[i].fp);
478			else
479			fclose(input[i].fp);
480	greg	1.1	exit(code);
481			}