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/* Copyright (c) 1986 Regents of the University of California */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
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|
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/* |
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* color.c - routines for color calculations. |
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* |
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* 10/10/85 |
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*/ |
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|
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#include <stdio.h> |
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|
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#include "color.h" |
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|
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|
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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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COLR lastcolr; |
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int rept; |
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|
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lastcolr[RED] = lastcolr[GRN] = lastcolr[BLU] = 1; |
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lastcolr[EXP] = 0; |
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rept = 0; |
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|
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while (len > 0) { |
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if (scanline[0][EXP] == lastcolr[EXP] && |
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scanline[0][RED] == lastcolr[RED] && |
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scanline[0][GRN] == lastcolr[GRN] && |
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scanline[0][BLU] == lastcolr[BLU]) |
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rept++; |
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else { |
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while (rept) { /* write out count */ |
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putc(1, fp); |
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putc(1, fp); |
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putc(1, fp); |
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putc(rept & 255, fp); |
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rept >>= 8; |
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} |
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putc(scanline[0][RED], fp); /* new color */ |
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putc(scanline[0][GRN], fp); |
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putc(scanline[0][BLU], fp); |
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putc(scanline[0][EXP], fp); |
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copycolr(lastcolr, scanline[0]); |
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rept = 0; |
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} |
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scanline++; |
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len--; |
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} |
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while (rept) { /* write out count */ |
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putc(1, fp); |
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putc(1, fp); |
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putc(1, fp); |
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putc(rept & 255, fp); |
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rept >>= 8; |
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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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freadcolrs(scanline, len, fp) /* read in 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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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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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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register FILE *fp; |
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{ |
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COLR lastcolr, thiscolr; |
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int rept; |
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|
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lastcolr[RED] = lastcolr[GRN] = lastcolr[BLU] = 1; |
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lastcolr[EXP] = 0; |
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rept = 0; |
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|
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while (len > 0) { |
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setcolr(thiscolr, scanline[0][RED], |
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scanline[0][GRN], |
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scanline[0][BLU]); |
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if (thiscolr[EXP] == lastcolr[EXP] && |
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thiscolr[RED] == lastcolr[RED] && |
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thiscolr[GRN] == lastcolr[GRN] && |
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thiscolr[BLU] == lastcolr[BLU]) |
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rept++; |
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else { |
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while (rept) { /* write out count */ |
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putc(1, fp); |
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putc(1, fp); |
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putc(1, fp); |
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putc(rept & 255, fp); |
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rept >>= 8; |
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} |
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putc(thiscolr[RED], fp); /* new color */ |
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putc(thiscolr[GRN], fp); |
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putc(thiscolr[BLU], fp); |
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putc(thiscolr[EXP], fp); |
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copycolr(lastcolr, thiscolr); |
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rept = 0; |
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} |
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scanline++; |
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len--; |
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} |
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while (rept) { /* write out count */ |
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putc(1, fp); |
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putc(1, fp); |
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putc(1, fp); |
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putc(rept & 255, fp); |
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rept >>= 8; |
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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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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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register FILE *fp; |
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{ |
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COLR thiscolr; |
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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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thiscolr[RED] = getc(fp); |
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thiscolr[GRN] = getc(fp); |
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thiscolr[BLU] = getc(fp); |
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thiscolr[EXP] = getc(fp); |
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if (feof(fp) || ferror(fp)) |
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return(-1); |
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if (thiscolr[RED] == 1 && |
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thiscolr[GRN] == 1 && |
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thiscolr[BLU] == 1) { |
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for (i = thiscolr[EXP] << rshift; i > 0; i--) { |
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copycolor(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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colr_color(scanline[0], thiscolr); |
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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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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 frexp(); |
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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) * 256.0 / 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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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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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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} |
