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#ifndef lint |
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static const char RCSid[] = "$Id$"; |
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#endif |
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/* |
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* color.c - routines for color calculations. |
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* |
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* Externals declared in color.h |
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*/ |
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|
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/* ==================================================================== |
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* The Radiance Software License, Version 1.0 |
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* |
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* Copyright (c) 1990 - 2002 The Regents of the University of California, |
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* through Lawrence Berkeley National Laboratory. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* |
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* 3. The end-user documentation included with the redistribution, |
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* if any, must include the following acknowledgment: |
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* "This product includes Radiance software |
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* (http://radsite.lbl.gov/) |
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* developed by the Lawrence Berkeley National Laboratory |
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* (http://www.lbl.gov/)." |
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* Alternately, this acknowledgment may appear in the software itself, |
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* if and wherever such third-party acknowledgments normally appear. |
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* |
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* 4. The names "Radiance," "Lawrence Berkeley National Laboratory" |
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* and "The Regents of the University of California" must |
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* not be used to endorse or promote products derived from this |
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* software without prior written permission. For written |
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* permission, please contact [email protected]. |
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* |
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* 5. Products derived from this software may not be called "Radiance", |
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* nor may "Radiance" appear in their name, without prior written |
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* permission of Lawrence Berkeley National Laboratory. |
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* |
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR |
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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* ==================================================================== |
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* |
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* This software consists of voluntary contributions made by many |
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* individuals on behalf of Lawrence Berkeley National Laboratory. For more |
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* information on Lawrence Berkeley National Laboratory, please see |
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* <http://www.lbl.gov/>. |
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*/ |
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|
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#include <stdio.h> |
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|
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#include <stdlib.h> |
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|
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#include <math.h> |
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|
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#include "color.h" |
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|
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#define MINELEN 8 /* minimum scanline length for encoding */ |
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#define MAXELEN 0x7fff /* maximum scanline length for encoding */ |
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#define MINRUN 4 /* minimum run length */ |
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|
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|
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char * |
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tempbuffer(len) /* get a temporary buffer */ |
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unsigned int len; |
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{ |
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static char *tempbuf = NULL; |
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static unsigned tempbuflen = 0; |
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|
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if (len > tempbuflen) { |
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if (tempbuflen > 0) |
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tempbuf = (char *)realloc(tempbuf, len); |
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else |
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tempbuf = (char *)malloc(len); |
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tempbuflen = tempbuf==NULL ? 0 : len; |
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} |
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return(tempbuf); |
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} |
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|
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|
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int |
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fwritecolrs(scanline, len, fp) /* write out a colr scanline */ |
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register COLR *scanline; |
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int len; |
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register FILE *fp; |
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{ |
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register int i, j, beg, cnt = 1; |
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int c2; |
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|
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if (len < MINELEN | len > MAXELEN) /* OOBs, write out flat */ |
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return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len); |
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/* put magic header */ |
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putc(2, fp); |
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putc(2, fp); |
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putc(len>>8, fp); |
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putc(len&255, fp); |
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/* put components seperately */ |
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for (i = 0; i < 4; i++) { |
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for (j = 0; j < len; j += cnt) { /* find next run */ |
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for (beg = j; beg < len; beg += cnt) { |
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for (cnt = 1; cnt < 127 && beg+cnt < len && |
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scanline[beg+cnt][i] == scanline[beg][i]; cnt++) |
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; |
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if (cnt >= MINRUN) |
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break; /* long enough */ |
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} |
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if (beg-j > 1 && beg-j < MINRUN) { |
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c2 = j+1; |
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while (scanline[c2++][i] == scanline[j][i]) |
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if (c2 == beg) { /* short run */ |
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putc(128+beg-j, fp); |
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putc(scanline[j][i], fp); |
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j = beg; |
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break; |
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} |
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} |
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while (j < beg) { /* write out non-run */ |
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if ((c2 = beg-j) > 128) c2 = 128; |
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putc(c2, fp); |
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while (c2--) |
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putc(scanline[j++][i], fp); |
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} |
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if (cnt >= MINRUN) { /* write out run */ |
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putc(128+cnt, fp); |
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putc(scanline[beg][i], fp); |
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} else |
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cnt = 0; |
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} |
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} |
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return(ferror(fp) ? -1 : 0); |
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} |
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|
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|
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static int |
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oldreadcolrs(scanline, len, fp) /* read in an old colr scanline */ |
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register COLR *scanline; |
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int len; |
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register FILE *fp; |
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{ |
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int rshift; |
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register int i; |
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|
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rshift = 0; |
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|
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while (len > 0) { |
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scanline[0][RED] = getc(fp); |
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scanline[0][GRN] = getc(fp); |
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scanline[0][BLU] = getc(fp); |
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scanline[0][EXP] = getc(fp); |
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if (feof(fp) || ferror(fp)) |
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return(-1); |
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if (scanline[0][RED] == 1 && |
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scanline[0][GRN] == 1 && |
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scanline[0][BLU] == 1) { |
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for (i = scanline[0][EXP] << rshift; i > 0; i--) { |
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copycolr(scanline[0], scanline[-1]); |
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scanline++; |
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len--; |
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} |
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rshift += 8; |
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} else { |
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scanline++; |
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len--; |
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rshift = 0; |
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} |
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} |
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return(0); |
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} |
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|
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|
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int |
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freadcolrs(scanline, len, fp) /* read in an encoded colr scanline */ |
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register COLR *scanline; |
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int len; |
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register FILE *fp; |
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{ |
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register int i, j; |
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int code, val; |
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/* determine scanline type */ |
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if (len < MINELEN | len > MAXELEN) |
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return(oldreadcolrs(scanline, len, fp)); |
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if ((i = getc(fp)) == EOF) |
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return(-1); |
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if (i != 2) { |
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ungetc(i, fp); |
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return(oldreadcolrs(scanline, len, fp)); |
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} |
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scanline[0][GRN] = getc(fp); |
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scanline[0][BLU] = getc(fp); |
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if ((i = getc(fp)) == EOF) |
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return(-1); |
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if (scanline[0][GRN] != 2 || scanline[0][BLU] & 128) { |
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scanline[0][RED] = 2; |
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scanline[0][EXP] = i; |
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return(oldreadcolrs(scanline+1, len-1, fp)); |
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} |
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if ((scanline[0][BLU]<<8 | i) != len) |
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return(-1); /* length mismatch! */ |
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/* read each component */ |
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for (i = 0; i < 4; i++) |
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for (j = 0; j < len; ) { |
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if ((code = getc(fp)) == EOF) |
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return(-1); |
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if (code > 128) { /* run */ |
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code &= 127; |
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if ((val = getc(fp)) == EOF) |
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return -1; |
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while (code--) |
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scanline[j++][i] = val; |
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} else /* non-run */ |
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while (code--) { |
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if ((val = getc(fp)) == EOF) |
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return -1; |
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scanline[j++][i] = val; |
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} |
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} |
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return(0); |
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} |
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|
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|
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int |
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fwritescan(scanline, len, fp) /* write out a scanline */ |
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register COLOR *scanline; |
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int len; |
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FILE *fp; |
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{ |
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COLR *clrscan; |
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int n; |
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register COLR *sp; |
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/* get scanline buffer */ |
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if ((sp = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL) |
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return(-1); |
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clrscan = sp; |
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/* convert scanline */ |
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n = len; |
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while (n-- > 0) { |
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setcolr(sp[0], scanline[0][RED], |
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scanline[0][GRN], |
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scanline[0][BLU]); |
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scanline++; |
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sp++; |
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} |
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return(fwritecolrs(clrscan, len, fp)); |
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} |
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|
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|
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int |
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freadscan(scanline, len, fp) /* read in a scanline */ |
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register COLOR *scanline; |
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int len; |
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FILE *fp; |
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{ |
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register COLR *clrscan; |
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|
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if ((clrscan = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL) |
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return(-1); |
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if (freadcolrs(clrscan, len, fp) < 0) |
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return(-1); |
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/* convert scanline */ |
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colr_color(scanline[0], clrscan[0]); |
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while (--len > 0) { |
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scanline++; clrscan++; |
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if (clrscan[0][RED] == clrscan[-1][RED] && |
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clrscan[0][GRN] == clrscan[-1][GRN] && |
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clrscan[0][BLU] == clrscan[-1][BLU] && |
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clrscan[0][EXP] == clrscan[-1][EXP]) |
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copycolor(scanline[0], scanline[-1]); |
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else |
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colr_color(scanline[0], clrscan[0]); |
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} |
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return(0); |
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} |
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|
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|
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void |
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setcolr(clr, r, g, b) /* assign a short color value */ |
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register COLR clr; |
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double r, g, b; |
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{ |
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double d; |
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int e; |
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|
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d = r > g ? r : g; |
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if (b > d) d = b; |
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|
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if (d <= 1e-32) { |
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clr[RED] = clr[GRN] = clr[BLU] = 0; |
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clr[EXP] = 0; |
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return; |
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} |
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|
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d = frexp(d, &e) * 255.9999 / d; |
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|
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clr[RED] = r * d; |
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clr[GRN] = g * d; |
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clr[BLU] = b * d; |
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clr[EXP] = e + COLXS; |
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} |
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|
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|
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void |
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colr_color(col, clr) /* convert short to float color */ |
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register COLOR col; |
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register COLR clr; |
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{ |
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double f; |
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|
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if (clr[EXP] == 0) |
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col[RED] = col[GRN] = col[BLU] = 0.0; |
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else { |
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f = ldexp(1.0, (int)clr[EXP]-(COLXS+8)); |
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col[RED] = (clr[RED] + 0.5)*f; |
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col[GRN] = (clr[GRN] + 0.5)*f; |
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col[BLU] = (clr[BLU] + 0.5)*f; |
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} |
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} |
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|
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|
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int |
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bigdiff(c1, c2, md) /* c1 delta c2 > md? */ |
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register COLOR c1, c2; |
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double md; |
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{ |
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register int i; |
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|
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for (i = 0; i < 3; i++) |
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if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) || |
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colval(c2,i)-colval(c1,i) > md*colval(c1,i)) |
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return(1); |
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return(0); |
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} |