src/common/color.c

#ifndef lint
static const char       RCSid[] = "$Id: color.c,v 2.13 2003/07/27 22:12:01 schorsch Exp $";
#endif
/*
 *  color.c - routines for color calculations.
 *
 *  Externals declared in color.h
 */

#include "copyright.h"

#include  <stdio.h>

#include  <stdlib.h>

#include  <math.h>

#include  "color.h"

#ifdef getc_unlocked            /* avoid horrendous overhead of flockfile */
#define getc    getc_unlocked
#define putc    putc_unlocked
#endif

#define  MINELEN        8       /* minimum scanline length for encoding */
#define  MAXELEN        0x7fff  /* maximum scanline length for encoding */
#define  MINRUN         4       /* minimum run length */


char *
tempbuffer(len)                 /* get a temporary buffer */
unsigned int  len;
{
        static char  *tempbuf = NULL;
        static unsigned  tempbuflen = 0;

        if (len > tempbuflen) {
                if (tempbuflen > 0)
                        tempbuf = (char *)realloc((void *)tempbuf, len);
                else
                        tempbuf = (char *)malloc(len);
                tempbuflen = tempbuf==NULL ? 0 : len;
        }
        return(tempbuf);
}


int
fwritecolrs(scanline, len, fp)          /* write out a colr scanline */
register COLR  *scanline;
int  len;
register FILE  *fp;
{
        register int  i, j, beg, cnt = 1;
        int  c2;
        
        if ((len < MINELEN) | (len > MAXELEN))  /* OOBs, write out flat */
                return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len);
                                        /* put magic header */
        putc(2, fp);
        putc(2, fp);
        putc(len>>8, fp);
        putc(len&255, fp);
                                        /* put components seperately */
        for (i = 0; i < 4; i++) {
            for (j = 0; j < len; j += cnt) {    /* find next run */
                for (beg = j; beg < len; beg += cnt) {
                    for (cnt = 1; cnt < 127 && beg+cnt < len &&
                            scanline[beg+cnt][i] == scanline[beg][i]; cnt++)
                        ;
                    if (cnt >= MINRUN)
                        break;                  /* long enough */
                }
                if (beg-j > 1 && beg-j < MINRUN) {
                    c2 = j+1;
                    while (scanline[c2++][i] == scanline[j][i])
                        if (c2 == beg) {        /* short run */
                            putc(128+beg-j, fp);
                            putc(scanline[j][i], fp);
                            j = beg;
                            break;
                        }
                }
                while (j < beg) {               /* write out non-run */
                    if ((c2 = beg-j) > 128) c2 = 128;
                    putc(c2, fp);
                    while (c2--)
                        putc(scanline[j++][i], fp);
                }
                if (cnt >= MINRUN) {            /* write out run */
                    putc(128+cnt, fp);
                    putc(scanline[beg][i], fp);
                } else
                    cnt = 0;
            }
        }
        return(ferror(fp) ? -1 : 0);
}


static int
oldreadcolrs(scanline, len, fp)         /* read in an old colr scanline */
register COLR  *scanline;
int  len;
register FILE  *fp;
{
        int  rshift;
        register int  i;
        
        rshift = 0;
        
        while (len > 0) {
                scanline[0][RED] = getc(fp);
                scanline[0][GRN] = getc(fp);
                scanline[0][BLU] = getc(fp);
                scanline[0][EXP] = getc(fp);
                if (feof(fp) || ferror(fp))
                        return(-1);
                if (scanline[0][RED] == 1 &&
                                scanline[0][GRN] == 1 &&
                                scanline[0][BLU] == 1) {
                        for (i = scanline[0][EXP] << rshift; i > 0; i--) {
                                copycolr(scanline[0], scanline[-1]);
                                scanline++;
                                len--;
                        }
                        rshift += 8;
                } else {
                        scanline++;
                        len--;
                        rshift = 0;
                }
        }
        return(0);
}


int
freadcolrs(scanline, len, fp)           /* read in an encoded colr scanline */
register COLR  *scanline;
int  len;
register FILE  *fp;
{
        register int  i, j;
        int  code, val;
                                        /* determine scanline type */
        if ((len < MINELEN) | (len > MAXELEN))
                return(oldreadcolrs(scanline, len, fp));
        if ((i = getc(fp)) == EOF)
                return(-1);
        if (i != 2) {
                ungetc(i, fp);
                return(oldreadcolrs(scanline, len, fp));
        }
        scanline[0][GRN] = getc(fp);
        scanline[0][BLU] = getc(fp);
        if ((i = getc(fp)) == EOF)
                return(-1);
        if (scanline[0][GRN] != 2 || scanline[0][BLU] & 128) {
                scanline[0][RED] = 2;
                scanline[0][EXP] = i;
                return(oldreadcolrs(scanline+1, len-1, fp));
        }
        if ((scanline[0][BLU]<<8 | i) != len)
                return(-1);             /* length mismatch! */
                                        /* read each component */
        for (i = 0; i < 4; i++)
            for (j = 0; j < len; ) {
                if ((code = getc(fp)) == EOF)
                    return(-1);
                if (code > 128) {       /* run */
                    code &= 127;
                    if ((val = getc(fp)) == EOF)
                        return -1;
                    while (code--)
                        scanline[j++][i] = val;
                } else                  /* non-run */
                    while (code--) {
                        if ((val = getc(fp)) == EOF)
                            return -1;
                        scanline[j++][i] = val;
                    }
            }
        return(0);
}


int
fwritescan(scanline, len, fp)           /* write out a scanline */
register COLOR  *scanline;
int  len;
FILE  *fp;
{
        COLR  *clrscan;
        int  n;
        register COLR  *sp;
                                        /* get scanline buffer */
        if ((sp = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
                return(-1);
        clrscan = sp;
                                        /* convert scanline */
        n = len;
        while (n-- > 0) {
                setcolr(sp[0], scanline[0][RED],
                                  scanline[0][GRN],
                                  scanline[0][BLU]);
                scanline++;
                sp++;
        }
        return(fwritecolrs(clrscan, len, fp));
}


int
freadscan(scanline, len, fp)            /* read in a scanline */
register COLOR  *scanline;
int  len;
FILE  *fp;
{
        register COLR  *clrscan;

        if ((clrscan = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
                return(-1);
        if (freadcolrs(clrscan, len, fp) < 0)
                return(-1);
                                        /* convert scanline */
        colr_color(scanline[0], clrscan[0]);
        while (--len > 0) {
                scanline++; clrscan++;
                if (clrscan[0][RED] == clrscan[-1][RED] &&
                            clrscan[0][GRN] == clrscan[-1][GRN] &&
                            clrscan[0][BLU] == clrscan[-1][BLU] &&
                            clrscan[0][EXP] == clrscan[-1][EXP])
                        copycolor(scanline[0], scanline[-1]);
                else
                        colr_color(scanline[0], clrscan[0]);
        }
        return(0);
}


void
setcolr(clr, r, g, b)           /* assign a short color value */
register COLR  clr;
double  r, g, b;
{
        double  d;
        int  e;
        
        d = r > g ? r : g;
        if (b > d) d = b;

        if (d <= 1e-32) {
                clr[RED] = clr[GRN] = clr[BLU] = 0;
                clr[EXP] = 0;
                return;
        }

        d = frexp(d, &e) * 255.9999 / d;

        if (r > 0.0)
                clr[RED] = r * d;
        else
                clr[RED] = 0;
        if (g > 0.0)
                clr[GRN] = g * d;
        else
                clr[GRN] = 0;
        if (b > 0.0)
                clr[BLU] = b * d;
        else
                clr[BLU] = 0;

        clr[EXP] = e + COLXS;
}


void
colr_color(col, clr)            /* convert short to float color */
register COLOR  col;
register COLR  clr;
{
        double  f;
        
        if (clr[EXP] == 0)
                col[RED] = col[GRN] = col[BLU] = 0.0;
        else {
                f = ldexp(1.0, (int)clr[EXP]-(COLXS+8));
                col[RED] = (clr[RED] + 0.5)*f;
                col[GRN] = (clr[GRN] + 0.5)*f;
                col[BLU] = (clr[BLU] + 0.5)*f;
        }
}


int
bigdiff(c1, c2, md)                     /* c1 delta c2 > md? */
register COLOR  c1, c2;
double  md;
{
        register int  i;

        for (i = 0; i < 3; i++)
                if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) ||
                        colval(c2,i)-colval(c1,i) > md*colval(c1,i))
                        return(1);
        return(0);
}
Revision:	2.14
Committed:	Tue Dec 9 15:51:42 2003 UTC (20 years, 4 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.13:	+6 -1 lines
Log Message:	Added redirection for getc() and putc() on threaded C library
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.14	static const char RCSid[] = "$Id: color.c,v 2.13 2003/07/27 22:12:01 schorsch Exp $";
3	greg	1.1	#endif
4			/*
5			* color.c - routines for color calculations.
6			*
7	greg	2.9	* Externals declared in color.h
8			*/
9
10	greg	2.10	#include "copyright.h"
11	greg	1.1
12			#include <stdio.h>
13
14	greg	2.9	#include <stdlib.h>
15
16	greg	2.7	#include <math.h>
17
18	greg	1.1	#include "color.h"
19	greg	2.14
20			#ifdef getc_unlocked /* avoid horrendous overhead of flockfile */
21			#define getc getc_unlocked
22			#define putc putc_unlocked
23			#endif
24	greg	1.1
25	greg	1.14	#define MINELEN 8 /* minimum scanline length for encoding */
26	greg	2.6	#define MAXELEN 0x7fff /* maximum scanline length for encoding */
27	greg	1.14	#define MINRUN 4 /* minimum run length */
28
29	greg	2.4
30	greg	1.14	char *
31			tempbuffer(len) /* get a temporary buffer */
32	greg	2.9	unsigned int len;
33	greg	1.14	{
34			static char *tempbuf = NULL;
35	greg	2.5	static unsigned tempbuflen = 0;
36	greg	1.14
37			if (len > tempbuflen) {
38			if (tempbuflen > 0)
39	greg	2.12	tempbuf = (char )realloc((void )tempbuf, len);
40	greg	1.14	else
41	greg	2.9	tempbuf = (char *)malloc(len);
42	greg	1.14	tempbuflen = tempbuf==NULL ? 0 : len;
43			}
44			return(tempbuf);
45			}
46
47
48	greg	2.9	int
49	greg	1.1	fwritecolrs(scanline, len, fp) /* write out a colr scanline */
50			register COLR *scanline;
51	greg	2.9	int len;
52	greg	1.1	register FILE *fp;
53			{
54	greg	2.9	register int i, j, beg, cnt = 1;
55	greg	1.14	int c2;
56	greg	1.1
57	schorsch	2.13	if ((len < MINELEN) \| (len > MAXELEN)) /* OOBs, write out flat */
58	greg	1.14	return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len);
59	greg	2.2	/* put magic header */
60			putc(2, fp);
61	greg	1.14	putc(2, fp);
62			putc(len>>8, fp);
63			putc(len&255, fp);
64			/* put components seperately */
65			for (i = 0; i < 4; i++) {
66			for (j = 0; j < len; j += cnt) { /* find next run */
67			for (beg = j; beg < len; beg += cnt) {
68			for (cnt = 1; cnt < 127 && beg+cnt < len &&
69			scanline[beg+cnt][i] == scanline[beg][i]; cnt++)
70			;
71			if (cnt >= MINRUN)
72			break; /* long enough */
73	greg	1.1	}
74	greg	1.15	if (beg-j > 1 && beg-j < MINRUN) {
75			c2 = j+1;
76			while (scanline[c2++][i] == scanline[j][i])
77			if (c2 == beg) { /* short run */
78			putc(128+beg-j, fp);
79			putc(scanline[j][i], fp);
80			j = beg;
81			break;
82			}
83			}
84			while (j < beg) { /* write out non-run */
85	greg	1.14	if ((c2 = beg-j) > 128) c2 = 128;
86			putc(c2, fp);
87			while (c2--)
88			putc(scanline[j++][i], fp);
89			}
90			if (cnt >= MINRUN) { /* write out run */
91			putc(128+cnt, fp);
92			putc(scanline[beg][i], fp);
93			} else
94			cnt = 0;
95			}
96	greg	1.1	}
97			return(ferror(fp) ? -1 : 0);
98			}
99
100
101	greg	2.9	static int
102			oldreadcolrs(scanline, len, fp) /* read in an old colr scanline */
103			register COLR *scanline;
104			int len;
105			register FILE *fp;
106			{
107			int rshift;
108			register int i;
109
110			rshift = 0;
111
112			while (len > 0) {
113			scanline[0][RED] = getc(fp);
114			scanline[0][GRN] = getc(fp);
115			scanline[0][BLU] = getc(fp);
116			scanline[0][EXP] = getc(fp);
117			if (feof(fp) \|\| ferror(fp))
118			return(-1);
119			if (scanline[0][RED] == 1 &&
120			scanline[0][GRN] == 1 &&
121			scanline[0][BLU] == 1) {
122			for (i = scanline[0][EXP] << rshift; i > 0; i--) {
123			copycolr(scanline[0], scanline[-1]);
124			scanline++;
125			len--;
126			}
127			rshift += 8;
128			} else {
129			scanline++;
130			len--;
131			rshift = 0;
132			}
133			}
134			return(0);
135			}
136
137
138			int
139	greg	1.14	freadcolrs(scanline, len, fp) /* read in an encoded colr scanline */
140	greg	1.1	register COLR *scanline;
141			int len;
142			register FILE *fp;
143			{
144	greg	1.14	register int i, j;
145	greg	2.6	int code, val;
146	greg	1.14	/* determine scanline type */
147	schorsch	2.13	if ((len < MINELEN) \| (len > MAXELEN))
148	greg	1.14	return(oldreadcolrs(scanline, len, fp));
149			if ((i = getc(fp)) == EOF)
150			return(-1);
151			if (i != 2) {
152			ungetc(i, fp);
153			return(oldreadcolrs(scanline, len, fp));
154			}
155			scanline[0][GRN] = getc(fp);
156			scanline[0][BLU] = getc(fp);
157			if ((i = getc(fp)) == EOF)
158			return(-1);
159			if (scanline[0][GRN] != 2 \|\| scanline[0][BLU] & 128) {
160			scanline[0][RED] = 2;
161			scanline[0][EXP] = i;
162			return(oldreadcolrs(scanline+1, len-1, fp));
163			}
164			if ((scanline[0][BLU]<<8 \| i) != len)
165			return(-1); /* length mismatch! */
166			/* read each component */
167			for (i = 0; i < 4; i++)
168			for (j = 0; j < len; ) {
169			if ((code = getc(fp)) == EOF)
170			return(-1);
171			if (code > 128) { /* run */
172	greg	2.6	code &= 127;
173	greg	2.9	if ((val = getc(fp)) == EOF)
174			return -1;
175	greg	2.6	while (code--)
176			scanline[j++][i] = val;
177	greg	1.14	} else /* non-run */
178	greg	2.9	while (code--) {
179			if ((val = getc(fp)) == EOF)
180			return -1;
181			scanline[j++][i] = val;
182			}
183	greg	1.14	}
184	greg	1.1	return(0);
185			}
186
187
188	greg	2.9	int
189	greg	1.1	fwritescan(scanline, len, fp) /* write out a scanline */
190			register COLOR *scanline;
191			int len;
192	greg	1.14	FILE *fp;
193	greg	1.1	{
194	greg	1.14	COLR *clrscan;
195			int n;
196			register COLR *sp;
197			/* get scanline buffer */
198			if ((sp = (COLR )tempbuffer(lensizeof(COLR))) == NULL)
199			return(-1);
200			clrscan = sp;
201			/* convert scanline */
202			n = len;
203			while (n-- > 0) {
204			setcolr(sp[0], scanline[0][RED],
205	greg	1.1	scanline[0][GRN],
206			scanline[0][BLU]);
207			scanline++;
208	greg	1.14	sp++;
209	greg	1.1	}
210	greg	1.14	return(fwritecolrs(clrscan, len, fp));
211	greg	1.1	}
212
213
214	greg	2.9	int
215	greg	1.1	freadscan(scanline, len, fp) /* read in a scanline */
216			register COLOR *scanline;
217			int len;
218	greg	1.14	FILE *fp;
219	greg	1.1	{
220	greg	1.14	register COLR *clrscan;
221
222			if ((clrscan = (COLR )tempbuffer(lensizeof(COLR))) == NULL)
223			return(-1);
224			if (freadcolrs(clrscan, len, fp) < 0)
225			return(-1);
226			/* convert scanline */
227			colr_color(scanline[0], clrscan[0]);
228			while (--len > 0) {
229			scanline++; clrscan++;
230			if (clrscan[0][RED] == clrscan[-1][RED] &&
231			clrscan[0][GRN] == clrscan[-1][GRN] &&
232			clrscan[0][BLU] == clrscan[-1][BLU] &&
233			clrscan[0][EXP] == clrscan[-1][EXP])
234			copycolor(scanline[0], scanline[-1]);
235			else
236			colr_color(scanline[0], clrscan[0]);
237	greg	1.1	}
238			return(0);
239			}
240
241
242	greg	2.9	void
243	greg	1.1	setcolr(clr, r, g, b) /* assign a short color value */
244			register COLR clr;
245			double r, g, b;
246			{
247			double d;
248			int e;
249
250			d = r > g ? r : g;
251			if (b > d) d = b;
252
253	greg	1.4	if (d <= 1e-32) {
254	greg	1.1	clr[RED] = clr[GRN] = clr[BLU] = 0;
255			clr[EXP] = 0;
256			return;
257			}
258
259	greg	2.8	d = frexp(d, &e) * 255.9999 / d;
260	greg	1.1
261	greg	2.11	if (r > 0.0)
262			clr[RED] = r * d;
263			else
264			clr[RED] = 0;
265			if (g > 0.0)
266			clr[GRN] = g * d;
267			else
268			clr[GRN] = 0;
269			if (b > 0.0)
270			clr[BLU] = b * d;
271			else
272			clr[BLU] = 0;
273
274	greg	1.1	clr[EXP] = e + COLXS;
275			}
276
277
278	greg	2.9	void
279	greg	1.1	colr_color(col, clr) /* convert short to float color */
280			register COLOR col;
281			register COLR clr;
282			{
283	greg	1.6	double f;
284	greg	1.1
285			if (clr[EXP] == 0)
286			col[RED] = col[GRN] = col[BLU] = 0.0;
287			else {
288	greg	1.2	f = ldexp(1.0, (int)clr[EXP]-(COLXS+8));
289	greg	1.1	col[RED] = (clr[RED] + 0.5)*f;
290			col[GRN] = (clr[GRN] + 0.5)*f;
291			col[BLU] = (clr[BLU] + 0.5)*f;
292			}
293	greg	1.6	}
294
295
296	greg	2.9	int
297	greg	1.7	bigdiff(c1, c2, md) /* c1 delta c2 > md? */
298			register COLOR c1, c2;
299			double md;
300			{
301			register int i;
302
303			for (i = 0; i < 3; i++)
304			if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) \|\|
305			colval(c2,i)-colval(c1,i) > md*colval(c1,i))
306			return(1);
307			return(0);
308			}