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

#ifndef lint
static char SCCSid[] = "@(#)color.c 2.1 11/12/91 LBL";
#endif

/*
 *  color.c - routines for color calculations.
 *
 *     10/10/85
 */

#include  <stdio.h>

#include  "color.h"

#define  MINELEN	8	/* minimum scanline length for encoding */
#define  MINRUN		4	/* minimum run length */


char *tempbuffer(len)			/* get a temporary buffer */
unsigned  len;
{
	extern char  *malloc(), *realloc();
	static char  *tempbuf = NULL;
	static int  tempbuflen = 0;

	if (len > tempbuflen) {
		if (tempbuflen > 0)
			tempbuf = realloc(tempbuf, len);
		else
			tempbuf = malloc(len);
		tempbuflen = tempbuf==NULL ? 0 : len;
	}
	return(tempbuf);
}


int fwritecolrs(scanline, len, fp)		/* write out a colr scanline */
register COLR  *scanline;
int  len;
register FILE  *fp;
{
	register int  i, j, beg, cnt;
	int  c2;
	
	if (len < MINELEN)		/* too small to encode */
		return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len);
	if (len > 32767)		/* too big! */
		return(-1);
	putc(2, fp);			/* put magic header */
	putc(2, fp);
	putc(len>>8, fp);
	putc(len&255, fp);
					/* put components seperately */
	for (i = 0; i < 4; i++) {
	    for (j = 0; j < len; j += cnt) {	/* find next run */
		for (beg = j; beg < len; beg += cnt) {
		    for (cnt = 1; cnt < 127 && beg+cnt < len &&
			    scanline[beg+cnt][i] == scanline[beg][i]; cnt++)
			;
		    if (cnt >= MINRUN)
			break;			/* long enough */
		}
		if (beg-j > 1 && beg-j < MINRUN) {
		    c2 = j+1;
		    while (scanline[c2++][i] == scanline[j][i])
			if (c2 == beg) {	/* short run */
			    putc(128+beg-j, fp);
			    putc(scanline[j][i], fp);
			    j = beg;
			    break;
			}
		}
		while (j < beg) {		/* write out non-run */
		    if ((c2 = beg-j) > 128) c2 = 128;
		    putc(c2, fp);
		    while (c2--)
			putc(scanline[j++][i], fp);
		}
		if (cnt >= MINRUN) {		/* write out run */
		    putc(128+cnt, fp);
		    putc(scanline[beg][i], fp);
		} else
		    cnt = 0;
	    }
	}
	return(ferror(fp) ? -1 : 0);
}

int fwritescan(scanline, len, fp)		/* write out a scanline */
register COLOR  *scanline;
int  len;
FILE  *fp;
{
	COLR  *clrscan;
	int  n;
	register COLR  *sp;
					/* get scanline buffer */
	if ((sp = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
		return(-1);
	clrscan = sp;
					/* convert scanline */
	n = len;
	while (n-- > 0) {
		setcolr(sp[0], scanline[0][RED],
				  scanline[0][GRN],
				  scanline[0][BLU]);
		scanline++;
		sp++;
	}
	return(fwritecolrs(clrscan, len, fp));
}

int setcolr(clr, r, g, b)		/* assign a short color value */
register COLR  clr;
double  r, g, b;
{
	double  frexp();
	double  d;
	int  e;
	
	d = r > g ? r : g;
	if (b > d) d = b;

	if (d <= 1e-32) {
		clr[RED] = clr[GRN] = clr[BLU] = 0;
		clr[EXP] = 0;
		return;
	}

	d = frexp(d, &e) * 256.0 / d;

	clr[RED] = r * d;
	clr[GRN] = g * d;
	clr[BLU] = b * d;
	clr[EXP] = e + COLXS;
}
/* Copyright (c) 1991 Regents of the University of California */

/*
 *  header.c - routines for reading and writing information headers.
 *
 *	8/19/88
 *
 *  printargs(ac,av,fp)	print an argument list to fp, followed by '\n'
 *  isformat(s)		returns true if s is of the form "FORMAT=*"
 *  formatval(r,s)	copy the format value in s to r
 *  fputformat(s,fp)	write "FORMAT=%s" to fp
 *  getheader(fp,f,p)	read header from fp, calling f(s,p) on each line
 *  checkheader(i,p,o)	check header format from i against p and copy to o
 *
 *  To copy header from input to output, use getheader(fin, fputs, fout)
 */

#include  <stdio.h>
#include  <ctype.h>

#define  MAXLINE	512

char  FMTSTR[] = "FORMAT=";
int  FMTSTRL = 7;


int fputformat(s, fp)		/* put out a format value */
char  *s;
FILE  *fp;
{
	fputs(FMTSTR, fp);
	fputs(s, fp);
	putc('\n', fp);
}