src/common/colrops.c

#ifndef lint
static const char       RCSid[] = "$Id: colrops.c,v 2.7 2003/02/25 02:47:21 greg Exp $";
#endif
/*
 * Integer operations on COLR scanlines
 */

#include "copyright.h"

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

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:	2.8
Committed:	Mon Mar 10 17:13:29 2003 UTC (21 years, 1 month ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R5
Changes since 2.7:	+1 -3 lines
Log Message:	Compile error fixes for Linux and other improvements
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.8	static const char RCSid[] = "$Id: colrops.c,v 2.7 2003/02/25 02:47:21 greg Exp $";
3	greg	1.1	#endif
4			/*
5			* Integer operations on COLR scanlines
6			*/
7
8	greg	2.7	#include "copyright.h"
9	greg	2.6
10			#include <math.h>
11	greg	1.1	#include "color.h"
12
13	greg	2.3	extern char *bmalloc();
14	greg	1.1
15	greg	2.3	#define MAXGSHIFT 31 /* maximum shift for gamma table */
16	greg	1.1
17	greg	2.3	static BYTE g_mant = NULL, g_nexp = NULL;
18	greg	1.1
19	greg	2.3	static BYTE (*g_bval)[256] = NULL;
20
21
22	greg	2.6	int
23	greg	2.3	setcolrcor(f, a2) /* set brightness correction */
24			double (*f)();
25			double a2;
26	greg	1.1	{
27			double mult;
28			register int i, j;
29	greg	2.3	/* allocate tables */
30			if (g_bval == NULL && (g_bval =
31			(BYTE ()[256])bmalloc((MAXGSHIFT+1)256)) == NULL)
32			return(-1);
33	greg	1.1	/* compute colr -> gamb mapping */
34	greg	2.3	mult = 1.0/256.0;
35	greg	1.1	for (i = 0; i <= MAXGSHIFT; i++) {
36			for (j = 0; j < 256; j++)
37	greg	2.3	g_bval[i][j] = 256.0 * (f)((j+.5)mult, a2);
38			mult *= 0.5;
39	greg	1.1	}
40	greg	2.3	return(0);
41			}
42
43
44	greg	2.6	int
45	greg	2.3	setcolrinv(f, a2) /* set inverse brightness correction */
46			double (*f)();
47			double a2;
48			{
49			double mult;
50			register int i, j;
51			/* allocate tables */
52			if (g_mant == NULL && (g_mant = (BYTE *)bmalloc(256)) == NULL)
53			return(-1);
54			if (g_nexp == NULL && (g_nexp = (BYTE *)bmalloc(256)) == NULL)
55			return(-1);
56	greg	1.1	/* compute gamb -> colr mapping */
57			i = 0;
58			mult = 256.0;
59	gregl	2.5	for (j = 256; j--; ) {
60			while ((g_mant[j] = mult * (*f)((j+.5)/256.0, a2)) < 128) {
61	greg	1.1	i++;
62			mult *= 2.0;
63			}
64			g_nexp[j] = i;
65			}
66	greg	2.3	return(0);
67	greg	1.1	}
68
69
70	greg	2.6	int
71	greg	2.3	setcolrgam(g) /* set gamma conversion */
72			double g;
73			{
74			if (setcolrcor(pow, 1.0/g) < 0)
75			return(-1);
76			return(setcolrinv(pow, g));
77			}
78
79
80	greg	2.6	int
81	greg	1.1	colrs_gambs(scan, len) /* convert scanline of colrs to gamma bytes */
82			register COLR *scan;
83			int len;
84			{
85			register int i, expo;
86
87	greg	2.3	if (g_bval == NULL)
88			return(-1);
89	greg	1.1	while (len-- > 0) {
90			expo = scan[0][EXP] - COLXS;
91			if (expo < -MAXGSHIFT) {
92			if (expo < -MAXGSHIFT-8) {
93			scan[0][RED] =
94			scan[0][GRN] =
95			scan[0][BLU] = 0;
96			} else {
97			i = (-MAXGSHIFT-1) - expo;
98			scan[0][RED] =
99			g_bval[MAXGSHIFT][((scan[0][RED]>>i)+1)>>1];
100			scan[0][GRN] =
101			g_bval[MAXGSHIFT][((scan[0][GRN]>>i)+1)>>1];
102			scan[0][BLU] =
103			g_bval[MAXGSHIFT][((scan[0][BLU]>>i)+1)>>1];
104			}
105			} else if (expo > 0) {
106			if (expo > 8) {
107			scan[0][RED] =
108			scan[0][GRN] =
109			scan[0][BLU] = 255;
110			} else {
111			i = (scan[0][RED]<<1 \| 1) << (expo-1);
112			scan[0][RED] = i > 255 ? 255 : g_bval[0][i];
113			i = (scan[0][GRN]<<1 \| 1) << (expo-1);
114			scan[0][GRN] = i > 255 ? 255 : g_bval[0][i];
115			i = (scan[0][BLU]<<1 \| 1) << (expo-1);
116			scan[0][BLU] = i > 255 ? 255 : g_bval[0][i];
117			}
118			} else {
119			scan[0][RED] = g_bval[-expo][scan[0][RED]];
120			scan[0][GRN] = g_bval[-expo][scan[0][GRN]];
121			scan[0][BLU] = g_bval[-expo][scan[0][BLU]];
122			}
123			scan[0][EXP] = COLXS;
124			scan++;
125			}
126	greg	2.3	return(0);
127	greg	1.1	}
128
129
130	greg	2.6	int
131	greg	1.1	gambs_colrs(scan, len) /* convert gamma bytes to colr scanline */
132			register COLR *scan;
133			int len;
134			{
135			register int nexpo;
136
137	greg	2.3	if (g_mant == NULL \| g_nexp == NULL)
138			return(-1);
139	greg	1.1	while (len-- > 0) {
140			nexpo = g_nexp[scan[0][RED]];
141			if (g_nexp[scan[0][GRN]] < nexpo)
142			nexpo = g_nexp[scan[0][GRN]];
143			if (g_nexp[scan[0][BLU]] < nexpo)
144			nexpo = g_nexp[scan[0][BLU]];
145			if (nexpo < g_nexp[scan[0][RED]])
146			scan[0][RED] = g_mant[scan[0][RED]]
147			>> (g_nexp[scan[0][RED]]-nexpo);
148			else
149			scan[0][RED] = g_mant[scan[0][RED]];
150			if (nexpo < g_nexp[scan[0][GRN]])
151			scan[0][GRN] = g_mant[scan[0][GRN]]
152			>> (g_nexp[scan[0][GRN]]-nexpo);
153			else
154			scan[0][GRN] = g_mant[scan[0][GRN]];
155			if (nexpo < g_nexp[scan[0][BLU]])
156			scan[0][BLU] = g_mant[scan[0][BLU]]
157			>> (g_nexp[scan[0][BLU]]-nexpo);
158			else
159			scan[0][BLU] = g_mant[scan[0][BLU]];
160			scan[0][EXP] = COLXS - nexpo;
161			scan++;
162			}
163	greg	2.3	return(0);
164	greg	1.1	}
165
166
167	greg	2.6	void
168	greg	1.1	shiftcolrs(scan, len, adjust) /* shift a scanline of colors by 2^adjust */
169			register COLR *scan;
170			register int len;
171			register int adjust;
172			{
173	greg	2.2	int minexp;
174
175			if (adjust == 0)
176			return;
177			minexp = adjust < 0 ? -adjust : 0;
178	greg	1.1	while (len-- > 0) {
179	greg	2.2	if (scan[0][EXP] <= minexp)
180			scan[0][RED] = scan[0][GRN] = scan[0][BLU] =
181			scan[0][EXP] = 0;
182			else
183			scan[0][EXP] += adjust;
184	greg	1.1	scan++;
185			}
186			}
187
188
189	greg	2.6	void
190	greg	1.1	normcolrs(scan, len, adjust) /* normalize a scanline of colrs */
191			register COLR *scan;
192			int len;
193			int adjust;
194			{
195			register int c;
196			register int shift;
197
198			while (len-- > 0) {
199			shift = scan[0][EXP] + adjust - COLXS;
200			if (shift > 0) {
201			if (shift > 8) {
202			scan[0][RED] =
203			scan[0][GRN] =
204			scan[0][BLU] = 255;
205			} else {
206			shift--;
207			c = (scan[0][RED]<<1 \| 1) << shift;
208			scan[0][RED] = c > 255 ? 255 : c;
209			c = (scan[0][GRN]<<1 \| 1) << shift;
210			scan[0][GRN] = c > 255 ? 255 : c;
211			c = (scan[0][BLU]<<1 \| 1) << shift;
212			scan[0][BLU] = c > 255 ? 255 : c;
213			}
214			} else if (shift < 0) {
215			if (shift < -8) {
216			scan[0][RED] =
217			scan[0][GRN] =
218			scan[0][BLU] = 0;
219			} else {
220			shift = -1-shift;
221			scan[0][RED] = ((scan[0][RED]>>shift)+1)>>1;
222			scan[0][GRN] = ((scan[0][GRN]>>shift)+1)>>1;
223			scan[0][BLU] = ((scan[0][BLU]>>shift)+1)>>1;
224			}
225			}
226			scan[0][EXP] = COLXS - adjust;
227			scan++;
228			}
229			}