#ifndef lint
static const char RCSid[] = "$Id: color.c,v 2.9 2003/02/22 02:07:22 greg Exp $";
#endif
/*
* color.c - routines for color calculations.
*
* Externals declared in color.h
*/
/* ====================================================================
* The Radiance Software License, Version 1.0
*
* Copyright (c) 1990 - 2002 The Regents of the University of California,
* through Lawrence Berkeley National Laboratory. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes Radiance software
* (http://radsite.lbl.gov/)
* developed by the Lawrence Berkeley National Laboratory
* (http://www.lbl.gov/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
* and "The Regents of the University of California" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact radiance@radsite.lbl.gov.
*
* 5. Products derived from this software may not be called "Radiance",
* nor may "Radiance" appear in their name, without prior written
* permission of Lawrence Berkeley National Laboratory.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of Lawrence Berkeley National Laboratory. For more
* information on Lawrence Berkeley National Laboratory, please see
* .
*/
#include
#include
#include
#include "color.h"
#define MINELEN 8 /* minimum scanline length for encoding */
#define MAXELEN 0x7fff /* maximum scanline length for encoding */
#define MINRUN 4 /* minimum run length */
char *
tempbuffer(len) /* get a temporary buffer */
unsigned int len;
{
static char *tempbuf = NULL;
static unsigned tempbuflen = 0;
if (len > tempbuflen) {
if (tempbuflen > 0)
tempbuf = (char *)realloc(tempbuf, len);
else
tempbuf = (char *)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 = 1;
int c2;
if (len < MINELEN | len > MAXELEN) /* OOBs, write out flat */
return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len);
/* put magic header */
putc(2, fp);
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);
}
static int
oldreadcolrs(scanline, len, fp) /* read in an old colr scanline */
register COLR *scanline;
int len;
register FILE *fp;
{
int rshift;
register int i;
rshift = 0;
while (len > 0) {
scanline[0][RED] = getc(fp);
scanline[0][GRN] = getc(fp);
scanline[0][BLU] = getc(fp);
scanline[0][EXP] = getc(fp);
if (feof(fp) || ferror(fp))
return(-1);
if (scanline[0][RED] == 1 &&
scanline[0][GRN] == 1 &&
scanline[0][BLU] == 1) {
for (i = scanline[0][EXP] << rshift; i > 0; i--) {
copycolr(scanline[0], scanline[-1]);
scanline++;
len--;
}
rshift += 8;
} else {
scanline++;
len--;
rshift = 0;
}
}
return(0);
}
int
freadcolrs(scanline, len, fp) /* read in an encoded colr scanline */
register COLR *scanline;
int len;
register FILE *fp;
{
register int i, j;
int code, val;
/* determine scanline type */
if (len < MINELEN | len > MAXELEN)
return(oldreadcolrs(scanline, len, fp));
if ((i = getc(fp)) == EOF)
return(-1);
if (i != 2) {
ungetc(i, fp);
return(oldreadcolrs(scanline, len, fp));
}
scanline[0][GRN] = getc(fp);
scanline[0][BLU] = getc(fp);
if ((i = getc(fp)) == EOF)
return(-1);
if (scanline[0][GRN] != 2 || scanline[0][BLU] & 128) {
scanline[0][RED] = 2;
scanline[0][EXP] = i;
return(oldreadcolrs(scanline+1, len-1, fp));
}
if ((scanline[0][BLU]<<8 | i) != len)
return(-1); /* length mismatch! */
/* read each component */
for (i = 0; i < 4; i++)
for (j = 0; j < len; ) {
if ((code = getc(fp)) == EOF)
return(-1);
if (code > 128) { /* run */
code &= 127;
if ((val = getc(fp)) == EOF)
return -1;
while (code--)
scanline[j++][i] = val;
} else /* non-run */
while (code--) {
if ((val = getc(fp)) == EOF)
return -1;
scanline[j++][i] = val;
}
}
return(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
freadscan(scanline, len, fp) /* read in a scanline */
register COLOR *scanline;
int len;
FILE *fp;
{
register COLR *clrscan;
if ((clrscan = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
return(-1);
if (freadcolrs(clrscan, len, fp) < 0)
return(-1);
/* convert scanline */
colr_color(scanline[0], clrscan[0]);
while (--len > 0) {
scanline++; clrscan++;
if (clrscan[0][RED] == clrscan[-1][RED] &&
clrscan[0][GRN] == clrscan[-1][GRN] &&
clrscan[0][BLU] == clrscan[-1][BLU] &&
clrscan[0][EXP] == clrscan[-1][EXP])
copycolor(scanline[0], scanline[-1]);
else
colr_color(scanline[0], clrscan[0]);
}
return(0);
}
void
setcolr(clr, r, g, b) /* assign a short color value */
register COLR clr;
double r, g, b;
{
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) * 255.9999 / d;
clr[RED] = r * d;
clr[GRN] = g * d;
clr[BLU] = b * d;
clr[EXP] = e + COLXS;
}
void
colr_color(col, clr) /* convert short to float color */
register COLOR col;
register COLR clr;
{
double f;
if (clr[EXP] == 0)
col[RED] = col[GRN] = col[BLU] = 0.0;
else {
f = ldexp(1.0, (int)clr[EXP]-(COLXS+8));
col[RED] = (clr[RED] + 0.5)*f;
col[GRN] = (clr[GRN] + 0.5)*f;
col[BLU] = (clr[BLU] + 0.5)*f;
}
}
int
bigdiff(c1, c2, md) /* c1 delta c2 > md? */
register COLOR c1, c2;
double md;
{
register int i;
for (i = 0; i < 3; i++)
if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) ||
colval(c2,i)-colval(c1,i) > md*colval(c1,i))
return(1);
return(0);
}