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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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* Integer operations on COLR scanlines |
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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 <math.h> |
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#include "color.h" |
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|
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#define NULL 0 |
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|
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extern char *bmalloc(); |
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|
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#define MAXGSHIFT 31 /* maximum shift for gamma table */ |
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|
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static BYTE *g_mant = NULL, *g_nexp = NULL; |
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|
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static BYTE (*g_bval)[256] = NULL; |
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|
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|
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int |
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setcolrcor(f, a2) /* set brightness correction */ |
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double (*f)(); |
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double a2; |
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{ |
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double mult; |
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register int i, j; |
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/* allocate tables */ |
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if (g_bval == NULL && (g_bval = |
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(BYTE (*)[256])bmalloc((MAXGSHIFT+1)*256)) == NULL) |
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return(-1); |
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/* compute colr -> gamb mapping */ |
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mult = 1.0/256.0; |
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for (i = 0; i <= MAXGSHIFT; i++) { |
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for (j = 0; j < 256; j++) |
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g_bval[i][j] = 256.0 * (*f)((j+.5)*mult, a2); |
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mult *= 0.5; |
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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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setcolrinv(f, a2) /* set inverse brightness correction */ |
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double (*f)(); |
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double a2; |
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{ |
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double mult; |
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register int i, j; |
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/* allocate tables */ |
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if (g_mant == NULL && (g_mant = (BYTE *)bmalloc(256)) == NULL) |
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return(-1); |
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if (g_nexp == NULL && (g_nexp = (BYTE *)bmalloc(256)) == NULL) |
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return(-1); |
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/* compute gamb -> colr mapping */ |
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i = 0; |
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mult = 256.0; |
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for (j = 256; j--; ) { |
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while ((g_mant[j] = mult * (*f)((j+.5)/256.0, a2)) < 128) { |
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i++; |
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mult *= 2.0; |
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} |
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g_nexp[j] = i; |
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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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setcolrgam(g) /* set gamma conversion */ |
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double g; |
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{ |
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if (setcolrcor(pow, 1.0/g) < 0) |
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return(-1); |
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return(setcolrinv(pow, g)); |
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} |
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|
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|
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int |
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colrs_gambs(scan, len) /* convert scanline of colrs to gamma bytes */ |
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register COLR *scan; |
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int len; |
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{ |
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register int i, expo; |
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|
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if (g_bval == NULL) |
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return(-1); |
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while (len-- > 0) { |
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expo = scan[0][EXP] - COLXS; |
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if (expo < -MAXGSHIFT) { |
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if (expo < -MAXGSHIFT-8) { |
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scan[0][RED] = |
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scan[0][GRN] = |
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scan[0][BLU] = 0; |
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} else { |
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i = (-MAXGSHIFT-1) - expo; |
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scan[0][RED] = |
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g_bval[MAXGSHIFT][((scan[0][RED]>>i)+1)>>1]; |
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scan[0][GRN] = |
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g_bval[MAXGSHIFT][((scan[0][GRN]>>i)+1)>>1]; |
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scan[0][BLU] = |
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g_bval[MAXGSHIFT][((scan[0][BLU]>>i)+1)>>1]; |
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} |
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} else if (expo > 0) { |
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if (expo > 8) { |
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scan[0][RED] = |
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scan[0][GRN] = |
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scan[0][BLU] = 255; |
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} else { |
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i = (scan[0][RED]<<1 | 1) << (expo-1); |
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scan[0][RED] = i > 255 ? 255 : g_bval[0][i]; |
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i = (scan[0][GRN]<<1 | 1) << (expo-1); |
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scan[0][GRN] = i > 255 ? 255 : g_bval[0][i]; |
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i = (scan[0][BLU]<<1 | 1) << (expo-1); |
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scan[0][BLU] = i > 255 ? 255 : g_bval[0][i]; |
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} |
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} else { |
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scan[0][RED] = g_bval[-expo][scan[0][RED]]; |
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scan[0][GRN] = g_bval[-expo][scan[0][GRN]]; |
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scan[0][BLU] = g_bval[-expo][scan[0][BLU]]; |
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} |
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scan[0][EXP] = COLXS; |
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scan++; |
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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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gambs_colrs(scan, len) /* convert gamma bytes to colr scanline */ |
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register COLR *scan; |
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int len; |
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{ |
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register int nexpo; |
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|
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if (g_mant == NULL | g_nexp == NULL) |
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return(-1); |
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while (len-- > 0) { |
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nexpo = g_nexp[scan[0][RED]]; |
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if (g_nexp[scan[0][GRN]] < nexpo) |
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nexpo = g_nexp[scan[0][GRN]]; |
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if (g_nexp[scan[0][BLU]] < nexpo) |
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nexpo = g_nexp[scan[0][BLU]]; |
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if (nexpo < g_nexp[scan[0][RED]]) |
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scan[0][RED] = g_mant[scan[0][RED]] |
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>> (g_nexp[scan[0][RED]]-nexpo); |
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else |
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scan[0][RED] = g_mant[scan[0][RED]]; |
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if (nexpo < g_nexp[scan[0][GRN]]) |
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scan[0][GRN] = g_mant[scan[0][GRN]] |
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>> (g_nexp[scan[0][GRN]]-nexpo); |
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else |
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scan[0][GRN] = g_mant[scan[0][GRN]]; |
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if (nexpo < g_nexp[scan[0][BLU]]) |
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scan[0][BLU] = g_mant[scan[0][BLU]] |
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>> (g_nexp[scan[0][BLU]]-nexpo); |
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else |
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scan[0][BLU] = g_mant[scan[0][BLU]]; |
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scan[0][EXP] = COLXS - nexpo; |
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scan++; |
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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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shiftcolrs(scan, len, adjust) /* shift a scanline of colors by 2^adjust */ |
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register COLR *scan; |
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register int len; |
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register int adjust; |
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{ |
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int minexp; |
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|
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if (adjust == 0) |
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return; |
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minexp = adjust < 0 ? -adjust : 0; |
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while (len-- > 0) { |
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if (scan[0][EXP] <= minexp) |
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scan[0][RED] = scan[0][GRN] = scan[0][BLU] = |
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scan[0][EXP] = 0; |
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else |
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scan[0][EXP] += adjust; |
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scan++; |
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} |
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} |
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|
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|
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void |
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normcolrs(scan, len, adjust) /* normalize a scanline of colrs */ |
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register COLR *scan; |
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int len; |
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int adjust; |
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{ |
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register int c; |
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register int shift; |
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|
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while (len-- > 0) { |
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shift = scan[0][EXP] + adjust - COLXS; |
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if (shift > 0) { |
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if (shift > 8) { |
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scan[0][RED] = |
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scan[0][GRN] = |
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scan[0][BLU] = 255; |
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} else { |
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shift--; |
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c = (scan[0][RED]<<1 | 1) << shift; |
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scan[0][RED] = c > 255 ? 255 : c; |
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c = (scan[0][GRN]<<1 | 1) << shift; |
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scan[0][GRN] = c > 255 ? 255 : c; |
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c = (scan[0][BLU]<<1 | 1) << shift; |
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scan[0][BLU] = c > 255 ? 255 : c; |
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} |
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} else if (shift < 0) { |
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if (shift < -8) { |
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scan[0][RED] = |
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scan[0][GRN] = |
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scan[0][BLU] = 0; |
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} else { |
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shift = -1-shift; |
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scan[0][RED] = ((scan[0][RED]>>shift)+1)>>1; |
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scan[0][GRN] = ((scan[0][GRN]>>shift)+1)>>1; |
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scan[0][BLU] = ((scan[0][BLU]>>shift)+1)>>1; |
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} |
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} |
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scan[0][EXP] = COLXS - adjust; |
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scan++; |
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} |
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} |