src/common/colrops.c

#ifndef lint
static const char       RCSid[] = "$Id$";
#endif
/*
 * Integer operations on COLR scanlines
 */

/* ====================================================================
 * 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 [email protected].
 *
 * 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,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * 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
 * <http://www.lbl.gov/>.
 */

#include <math.h>
#include "color.h"

#define NULL            0

extern char     *bmalloc();

#define MAXGSHIFT       31              /* maximum shift for gamma table */

static BYTE     *g_mant = NULL, *g_nexp = NULL;

static BYTE     (*g_bval)[256] = NULL;


int
setcolrcor(f, a2)               /* set brightness correction */
double  (*f)();
double  a2;
{
        double  mult;
        register int    i, j;
                                        /* allocate tables */
        if (g_bval == NULL && (g_bval =
                        (BYTE (*)[256])bmalloc((MAXGSHIFT+1)*256)) == NULL)
                return(-1);
                                        /* compute colr -> gamb mapping */
        mult = 1.0/256.0;
        for (i = 0; i <= MAXGSHIFT; i++) {
                for (j = 0; j < 256; j++)
                        g_bval[i][j] = 256.0 * (*f)((j+.5)*mult, a2);
                mult *= 0.5;
        }
        return(0);
}


int
setcolrinv(f, a2)               /* set inverse brightness correction */
double  (*f)();
double  a2;
{
        double  mult;
        register int    i, j;
                                        /* allocate tables */
        if (g_mant == NULL && (g_mant = (BYTE *)bmalloc(256)) == NULL)
                return(-1);
        if (g_nexp == NULL && (g_nexp = (BYTE *)bmalloc(256)) == NULL)
                return(-1);
                                        /* compute gamb -> colr mapping */
        i = 0;
        mult = 256.0;
        for (j = 256; j--; ) {
                while ((g_mant[j] = mult * (*f)((j+.5)/256.0, a2)) < 128) {
                        i++;
                        mult *= 2.0;
                }
                g_nexp[j] = i;
        }
        return(0);
}


int
setcolrgam(g)                   /* set gamma conversion */
double  g;
{
        if (setcolrcor(pow, 1.0/g) < 0)
                return(-1);
        return(setcolrinv(pow, g));
}


int
colrs_gambs(scan, len)          /* convert scanline of colrs to gamma bytes */
register COLR   *scan;
int     len;
{
        register int    i, expo;

        if (g_bval == NULL)
                return(-1);
        while (len-- > 0) {
                expo = scan[0][EXP] - COLXS;
                if (expo < -MAXGSHIFT) {
                        if (expo < -MAXGSHIFT-8) {
                                scan[0][RED] =
                                scan[0][GRN] =
                                scan[0][BLU] = 0;
                        } else {
                                i = (-MAXGSHIFT-1) - expo;
                                scan[0][RED] = 
                                g_bval[MAXGSHIFT][((scan[0][RED]>>i)+1)>>1];
                                scan[0][GRN] =
                                g_bval[MAXGSHIFT][((scan[0][GRN]>>i)+1)>>1];
                                scan[0][BLU] =
                                g_bval[MAXGSHIFT][((scan[0][BLU]>>i)+1)>>1];
                        }
                } else if (expo > 0) {
                        if (expo > 8) {
                                scan[0][RED] =
                                scan[0][GRN] =
                                scan[0][BLU] = 255;
                        } else {
                                i = (scan[0][RED]<<1 | 1) << (expo-1);
                                scan[0][RED] = i > 255 ? 255 : g_bval[0][i];
                                i = (scan[0][GRN]<<1 | 1) << (expo-1);
                                scan[0][GRN] = i > 255 ? 255 : g_bval[0][i];
                                i = (scan[0][BLU]<<1 | 1) << (expo-1);
                                scan[0][BLU] = i > 255 ? 255 : g_bval[0][i];
                        }
                } else {
                        scan[0][RED] = g_bval[-expo][scan[0][RED]];
                        scan[0][GRN] = g_bval[-expo][scan[0][GRN]];
                        scan[0][BLU] = g_bval[-expo][scan[0][BLU]];
                }
                scan[0][EXP] = COLXS;
                scan++;
        }
        return(0);
}


int
gambs_colrs(scan, len)          /* convert gamma bytes to colr scanline */
register COLR   *scan;
int     len;
{
        register int    nexpo;

        if (g_mant == NULL | g_nexp == NULL)
                return(-1);
        while (len-- > 0) {
                nexpo = g_nexp[scan[0][RED]];
                if (g_nexp[scan[0][GRN]] < nexpo)
                        nexpo = g_nexp[scan[0][GRN]];
                if (g_nexp[scan[0][BLU]] < nexpo)
                        nexpo = g_nexp[scan[0][BLU]];
                if (nexpo < g_nexp[scan[0][RED]])
                        scan[0][RED] = g_mant[scan[0][RED]]
                                        >> (g_nexp[scan[0][RED]]-nexpo);
                else
                        scan[0][RED] = g_mant[scan[0][RED]];
                if (nexpo < g_nexp[scan[0][GRN]])
                        scan[0][GRN] = g_mant[scan[0][GRN]]
                                        >> (g_nexp[scan[0][GRN]]-nexpo);
                else
                        scan[0][GRN] = g_mant[scan[0][GRN]];
                if (nexpo < g_nexp[scan[0][BLU]])
                        scan[0][BLU] = g_mant[scan[0][BLU]]
                                        >> (g_nexp[scan[0][BLU]]-nexpo);
                else
                        scan[0][BLU] = g_mant[scan[0][BLU]];
                scan[0][EXP] = COLXS - nexpo;
                scan++;
        }
        return(0);
}


void
shiftcolrs(scan, len, adjust)   /* shift a scanline of colors by 2^adjust */
register COLR   *scan;
register int    len;
register int    adjust;
{
        int     minexp;

        if (adjust == 0)
                return;
        minexp = adjust < 0 ? -adjust : 0;
        while (len-- > 0) {
                if (scan[0][EXP] <= minexp)
                        scan[0][RED] = scan[0][GRN] = scan[0][BLU] =
                        scan[0][EXP] = 0;
                else
                        scan[0][EXP] += adjust;
                scan++;
        }
}


void
normcolrs(scan, len, adjust)    /* normalize a scanline of colrs */
register COLR  *scan;
int  len;
int  adjust;
{
        register int  c;
        register int  shift;

        while (len-- > 0) {
                shift = scan[0][EXP] + adjust - COLXS;
                if (shift > 0) {
                        if (shift > 8) {
                                scan[0][RED] =
                                scan[0][GRN] =
                                scan[0][BLU] = 255;
                        } else {
                                shift--;
                                c = (scan[0][RED]<<1 | 1) << shift;
                                scan[0][RED] = c > 255 ? 255 : c;
                                c = (scan[0][GRN]<<1 | 1) << shift;
                                scan[0][GRN] = c > 255 ? 255 : c;
                                c = (scan[0][BLU]<<1 | 1) << shift;
                                scan[0][BLU] = c > 255 ? 255 : c;
                        }
                } else if (shift < 0) {
                        if (shift < -8) {
                                scan[0][RED] =
                                scan[0][GRN] =
                                scan[0][BLU] = 0;
                        } else {
                                shift = -1-shift;
                                scan[0][RED] = ((scan[0][RED]>>shift)+1)>>1;
                                scan[0][GRN] = ((scan[0][GRN]>>shift)+1)>>1;
                                scan[0][BLU] = ((scan[0][BLU]>>shift)+1)>>1;
                        }
                }
                scan[0][EXP] = COLXS - adjust;
                scan++;
        }
}
Revision:	2.6
Committed:	Sat Feb 22 02:07:22 2003 UTC (22 years, 8 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.5:	+66 -8 lines
Log Message:	Changes and check-in for 3.5 release Includes new source files and modifications not recorded for many years See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.6	static const char RCSid[] = "$Id$";
3	greg	1.1	#endif
4			/*
5			* Integer operations on COLR scanlines
6			*/
7
8	greg	2.6	/* ====================================================================
9			* The Radiance Software License, Version 1.0
10			*
11			* Copyright (c) 1990 - 2002 The Regents of the University of California,
12			* through Lawrence Berkeley National Laboratory. All rights reserved.
13			*
14			* Redistribution and use in source and binary forms, with or without
15			* modification, are permitted provided that the following conditions
16			* are met:
17			*
18			* 1. Redistributions of source code must retain the above copyright
19			* notice, this list of conditions and the following disclaimer.
20			*
21			* 2. Redistributions in binary form must reproduce the above copyright
22			* notice, this list of conditions and the following disclaimer in
23			* the documentation and/or other materials provided with the
24			* distribution.
25			*
26			* 3. The end-user documentation included with the redistribution,
27			* if any, must include the following acknowledgment:
28			* "This product includes Radiance software
29			* (http://radsite.lbl.gov/)
30			* developed by the Lawrence Berkeley National Laboratory
31			* (http://www.lbl.gov/)."
32			* Alternately, this acknowledgment may appear in the software itself,
33			* if and wherever such third-party acknowledgments normally appear.
34			*
35			* 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
36			* and "The Regents of the University of California" must
37			* not be used to endorse or promote products derived from this
38			* software without prior written permission. For written
39			* permission, please contact [email protected].
40			*
41			* 5. Products derived from this software may not be called "Radiance",
42			* nor may "Radiance" appear in their name, without prior written
43			* permission of Lawrence Berkeley National Laboratory.
44			*
45			* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
46			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
47			* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
48			* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
49			* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
50			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
51			* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
52			* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
53			* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
54			* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
55			* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56			* SUCH DAMAGE.
57			* ====================================================================
58			*
59			* This software consists of voluntary contributions made by many
60			* individuals on behalf of Lawrence Berkeley National Laboratory. For more
61			* information on Lawrence Berkeley National Laboratory, please see
62			* <http://www.lbl.gov/>.
63			*/
64
65			#include <math.h>
66	greg	1.1	#include "color.h"
67
68	greg	2.3	#define NULL 0
69	greg	1.1
70	greg	2.3	extern char *bmalloc();
71	greg	1.1
72	greg	2.3	#define MAXGSHIFT 31 /* maximum shift for gamma table */
73	greg	1.1
74	greg	2.3	static BYTE g_mant = NULL, g_nexp = NULL;
75	greg	1.1
76	greg	2.3	static BYTE (*g_bval)[256] = NULL;
77
78
79	greg	2.6	int
80	greg	2.3	setcolrcor(f, a2) /* set brightness correction */
81			double (*f)();
82			double a2;
83	greg	1.1	{
84			double mult;
85			register int i, j;
86	greg	2.3	/* allocate tables */
87			if (g_bval == NULL && (g_bval =
88			(BYTE ()[256])bmalloc((MAXGSHIFT+1)256)) == NULL)
89			return(-1);
90	greg	1.1	/* compute colr -> gamb mapping */
91	greg	2.3	mult = 1.0/256.0;
92	greg	1.1	for (i = 0; i <= MAXGSHIFT; i++) {
93			for (j = 0; j < 256; j++)
94	greg	2.3	g_bval[i][j] = 256.0 * (f)((j+.5)mult, a2);
95			mult *= 0.5;
96	greg	1.1	}
97	greg	2.3	return(0);
98			}
99
100
101	greg	2.6	int
102	greg	2.3	setcolrinv(f, a2) /* set inverse brightness correction */
103			double (*f)();
104			double a2;
105			{
106			double mult;
107			register int i, j;
108			/* allocate tables */
109			if (g_mant == NULL && (g_mant = (BYTE *)bmalloc(256)) == NULL)
110			return(-1);
111			if (g_nexp == NULL && (g_nexp = (BYTE *)bmalloc(256)) == NULL)
112			return(-1);
113	greg	1.1	/* compute gamb -> colr mapping */
114			i = 0;
115			mult = 256.0;
116	gregl	2.5	for (j = 256; j--; ) {
117			while ((g_mant[j] = mult * (*f)((j+.5)/256.0, a2)) < 128) {
118	greg	1.1	i++;
119			mult *= 2.0;
120			}
121			g_nexp[j] = i;
122			}
123	greg	2.3	return(0);
124	greg	1.1	}
125
126
127	greg	2.6	int
128	greg	2.3	setcolrgam(g) /* set gamma conversion */
129			double g;
130			{
131			if (setcolrcor(pow, 1.0/g) < 0)
132			return(-1);
133			return(setcolrinv(pow, g));
134			}
135
136
137	greg	2.6	int
138	greg	1.1	colrs_gambs(scan, len) /* convert scanline of colrs to gamma bytes */
139			register COLR *scan;
140			int len;
141			{
142			register int i, expo;
143
144	greg	2.3	if (g_bval == NULL)
145			return(-1);
146	greg	1.1	while (len-- > 0) {
147			expo = scan[0][EXP] - COLXS;
148			if (expo < -MAXGSHIFT) {
149			if (expo < -MAXGSHIFT-8) {
150			scan[0][RED] =
151			scan[0][GRN] =
152			scan[0][BLU] = 0;
153			} else {
154			i = (-MAXGSHIFT-1) - expo;
155			scan[0][RED] =
156			g_bval[MAXGSHIFT][((scan[0][RED]>>i)+1)>>1];
157			scan[0][GRN] =
158			g_bval[MAXGSHIFT][((scan[0][GRN]>>i)+1)>>1];
159			scan[0][BLU] =
160			g_bval[MAXGSHIFT][((scan[0][BLU]>>i)+1)>>1];
161			}
162			} else if (expo > 0) {
163			if (expo > 8) {
164			scan[0][RED] =
165			scan[0][GRN] =
166			scan[0][BLU] = 255;
167			} else {
168			i = (scan[0][RED]<<1 \| 1) << (expo-1);
169			scan[0][RED] = i > 255 ? 255 : g_bval[0][i];
170			i = (scan[0][GRN]<<1 \| 1) << (expo-1);
171			scan[0][GRN] = i > 255 ? 255 : g_bval[0][i];
172			i = (scan[0][BLU]<<1 \| 1) << (expo-1);
173			scan[0][BLU] = i > 255 ? 255 : g_bval[0][i];
174			}
175			} else {
176			scan[0][RED] = g_bval[-expo][scan[0][RED]];
177			scan[0][GRN] = g_bval[-expo][scan[0][GRN]];
178			scan[0][BLU] = g_bval[-expo][scan[0][BLU]];
179			}
180			scan[0][EXP] = COLXS;
181			scan++;
182			}
183	greg	2.3	return(0);
184	greg	1.1	}
185
186
187	greg	2.6	int
188	greg	1.1	gambs_colrs(scan, len) /* convert gamma bytes to colr scanline */
189			register COLR *scan;
190			int len;
191			{
192			register int nexpo;
193
194	greg	2.3	if (g_mant == NULL \| g_nexp == NULL)
195			return(-1);
196	greg	1.1	while (len-- > 0) {
197			nexpo = g_nexp[scan[0][RED]];
198			if (g_nexp[scan[0][GRN]] < nexpo)
199			nexpo = g_nexp[scan[0][GRN]];
200			if (g_nexp[scan[0][BLU]] < nexpo)
201			nexpo = g_nexp[scan[0][BLU]];
202			if (nexpo < g_nexp[scan[0][RED]])
203			scan[0][RED] = g_mant[scan[0][RED]]
204			>> (g_nexp[scan[0][RED]]-nexpo);
205			else
206			scan[0][RED] = g_mant[scan[0][RED]];
207			if (nexpo < g_nexp[scan[0][GRN]])
208			scan[0][GRN] = g_mant[scan[0][GRN]]
209			>> (g_nexp[scan[0][GRN]]-nexpo);
210			else
211			scan[0][GRN] = g_mant[scan[0][GRN]];
212			if (nexpo < g_nexp[scan[0][BLU]])
213			scan[0][BLU] = g_mant[scan[0][BLU]]
214			>> (g_nexp[scan[0][BLU]]-nexpo);
215			else
216			scan[0][BLU] = g_mant[scan[0][BLU]];
217			scan[0][EXP] = COLXS - nexpo;
218			scan++;
219			}
220	greg	2.3	return(0);
221	greg	1.1	}
222
223
224	greg	2.6	void
225	greg	1.1	shiftcolrs(scan, len, adjust) /* shift a scanline of colors by 2^adjust */
226			register COLR *scan;
227			register int len;
228			register int adjust;
229			{
230	greg	2.2	int minexp;
231
232			if (adjust == 0)
233			return;
234			minexp = adjust < 0 ? -adjust : 0;
235	greg	1.1	while (len-- > 0) {
236	greg	2.2	if (scan[0][EXP] <= minexp)
237			scan[0][RED] = scan[0][GRN] = scan[0][BLU] =
238			scan[0][EXP] = 0;
239			else
240			scan[0][EXP] += adjust;
241	greg	1.1	scan++;
242			}
243			}
244
245
246	greg	2.6	void
247	greg	1.1	normcolrs(scan, len, adjust) /* normalize a scanline of colrs */
248			register COLR *scan;
249			int len;
250			int adjust;
251			{
252			register int c;
253			register int shift;
254
255			while (len-- > 0) {
256			shift = scan[0][EXP] + adjust - COLXS;
257			if (shift > 0) {
258			if (shift > 8) {
259			scan[0][RED] =
260			scan[0][GRN] =
261			scan[0][BLU] = 255;
262			} else {
263			shift--;
264			c = (scan[0][RED]<<1 \| 1) << shift;
265			scan[0][RED] = c > 255 ? 255 : c;
266			c = (scan[0][GRN]<<1 \| 1) << shift;
267			scan[0][GRN] = c > 255 ? 255 : c;
268			c = (scan[0][BLU]<<1 \| 1) << shift;
269			scan[0][BLU] = c > 255 ? 255 : c;
270			}
271			} else if (shift < 0) {
272			if (shift < -8) {
273			scan[0][RED] =
274			scan[0][GRN] =
275			scan[0][BLU] = 0;
276			} else {
277			shift = -1-shift;
278			scan[0][RED] = ((scan[0][RED]>>shift)+1)>>1;
279			scan[0][GRN] = ((scan[0][GRN]>>shift)+1)>>1;
280			scan[0][BLU] = ((scan[0][BLU]>>shift)+1)>>1;
281			}
282			}
283			scan[0][EXP] = COLXS - adjust;
284			scan++;
285			}
286			}