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root/radiance/ray/src/common/color.c
Revision: 2.15
Committed: Tue Sep 14 02:53:50 2004 UTC (19 years, 6 months ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad3R6, rad3R6P1
Changes since 2.14: +3 -1 lines
Log Message:
Added #undef for getc/putc where they were being replaced

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: color.c,v 2.14 2003/12/09 15:51:42 greg Exp $";
3 #endif
4 /*
5 * color.c - routines for color calculations.
6 *
7 * Externals declared in color.h
8 */
9
10 #include "copyright.h"
11
12 #include <stdio.h>
13
14 #include <stdlib.h>
15
16 #include <math.h>
17
18 #include "color.h"
19
20 #ifdef getc_unlocked /* avoid horrendous overhead of flockfile */
21 #undef getc
22 #undef putc
23 #define getc getc_unlocked
24 #define putc putc_unlocked
25 #endif
26
27 #define MINELEN 8 /* minimum scanline length for encoding */
28 #define MAXELEN 0x7fff /* maximum scanline length for encoding */
29 #define MINRUN 4 /* minimum run length */
30
31
32 char *
33 tempbuffer(len) /* get a temporary buffer */
34 unsigned int len;
35 {
36 static char *tempbuf = NULL;
37 static unsigned tempbuflen = 0;
38
39 if (len > tempbuflen) {
40 if (tempbuflen > 0)
41 tempbuf = (char *)realloc((void *)tempbuf, len);
42 else
43 tempbuf = (char *)malloc(len);
44 tempbuflen = tempbuf==NULL ? 0 : len;
45 }
46 return(tempbuf);
47 }
48
49
50 int
51 fwritecolrs(scanline, len, fp) /* write out a colr scanline */
52 register COLR *scanline;
53 int len;
54 register FILE *fp;
55 {
56 register int i, j, beg, cnt = 1;
57 int c2;
58
59 if ((len < MINELEN) | (len > MAXELEN)) /* OOBs, write out flat */
60 return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len);
61 /* put magic header */
62 putc(2, fp);
63 putc(2, fp);
64 putc(len>>8, fp);
65 putc(len&255, fp);
66 /* put components seperately */
67 for (i = 0; i < 4; i++) {
68 for (j = 0; j < len; j += cnt) { /* find next run */
69 for (beg = j; beg < len; beg += cnt) {
70 for (cnt = 1; cnt < 127 && beg+cnt < len &&
71 scanline[beg+cnt][i] == scanline[beg][i]; cnt++)
72 ;
73 if (cnt >= MINRUN)
74 break; /* long enough */
75 }
76 if (beg-j > 1 && beg-j < MINRUN) {
77 c2 = j+1;
78 while (scanline[c2++][i] == scanline[j][i])
79 if (c2 == beg) { /* short run */
80 putc(128+beg-j, fp);
81 putc(scanline[j][i], fp);
82 j = beg;
83 break;
84 }
85 }
86 while (j < beg) { /* write out non-run */
87 if ((c2 = beg-j) > 128) c2 = 128;
88 putc(c2, fp);
89 while (c2--)
90 putc(scanline[j++][i], fp);
91 }
92 if (cnt >= MINRUN) { /* write out run */
93 putc(128+cnt, fp);
94 putc(scanline[beg][i], fp);
95 } else
96 cnt = 0;
97 }
98 }
99 return(ferror(fp) ? -1 : 0);
100 }
101
102
103 static int
104 oldreadcolrs(scanline, len, fp) /* read in an old colr scanline */
105 register COLR *scanline;
106 int len;
107 register FILE *fp;
108 {
109 int rshift;
110 register int i;
111
112 rshift = 0;
113
114 while (len > 0) {
115 scanline[0][RED] = getc(fp);
116 scanline[0][GRN] = getc(fp);
117 scanline[0][BLU] = getc(fp);
118 scanline[0][EXP] = getc(fp);
119 if (feof(fp) || ferror(fp))
120 return(-1);
121 if (scanline[0][RED] == 1 &&
122 scanline[0][GRN] == 1 &&
123 scanline[0][BLU] == 1) {
124 for (i = scanline[0][EXP] << rshift; i > 0; i--) {
125 copycolr(scanline[0], scanline[-1]);
126 scanline++;
127 len--;
128 }
129 rshift += 8;
130 } else {
131 scanline++;
132 len--;
133 rshift = 0;
134 }
135 }
136 return(0);
137 }
138
139
140 int
141 freadcolrs(scanline, len, fp) /* read in an encoded colr scanline */
142 register COLR *scanline;
143 int len;
144 register FILE *fp;
145 {
146 register int i, j;
147 int code, val;
148 /* determine scanline type */
149 if ((len < MINELEN) | (len > MAXELEN))
150 return(oldreadcolrs(scanline, len, fp));
151 if ((i = getc(fp)) == EOF)
152 return(-1);
153 if (i != 2) {
154 ungetc(i, fp);
155 return(oldreadcolrs(scanline, len, fp));
156 }
157 scanline[0][GRN] = getc(fp);
158 scanline[0][BLU] = getc(fp);
159 if ((i = getc(fp)) == EOF)
160 return(-1);
161 if (scanline[0][GRN] != 2 || scanline[0][BLU] & 128) {
162 scanline[0][RED] = 2;
163 scanline[0][EXP] = i;
164 return(oldreadcolrs(scanline+1, len-1, fp));
165 }
166 if ((scanline[0][BLU]<<8 | i) != len)
167 return(-1); /* length mismatch! */
168 /* read each component */
169 for (i = 0; i < 4; i++)
170 for (j = 0; j < len; ) {
171 if ((code = getc(fp)) == EOF)
172 return(-1);
173 if (code > 128) { /* run */
174 code &= 127;
175 if ((val = getc(fp)) == EOF)
176 return -1;
177 while (code--)
178 scanline[j++][i] = val;
179 } else /* non-run */
180 while (code--) {
181 if ((val = getc(fp)) == EOF)
182 return -1;
183 scanline[j++][i] = val;
184 }
185 }
186 return(0);
187 }
188
189
190 int
191 fwritescan(scanline, len, fp) /* write out a scanline */
192 register COLOR *scanline;
193 int len;
194 FILE *fp;
195 {
196 COLR *clrscan;
197 int n;
198 register COLR *sp;
199 /* get scanline buffer */
200 if ((sp = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
201 return(-1);
202 clrscan = sp;
203 /* convert scanline */
204 n = len;
205 while (n-- > 0) {
206 setcolr(sp[0], scanline[0][RED],
207 scanline[0][GRN],
208 scanline[0][BLU]);
209 scanline++;
210 sp++;
211 }
212 return(fwritecolrs(clrscan, len, fp));
213 }
214
215
216 int
217 freadscan(scanline, len, fp) /* read in a scanline */
218 register COLOR *scanline;
219 int len;
220 FILE *fp;
221 {
222 register COLR *clrscan;
223
224 if ((clrscan = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
225 return(-1);
226 if (freadcolrs(clrscan, len, fp) < 0)
227 return(-1);
228 /* convert scanline */
229 colr_color(scanline[0], clrscan[0]);
230 while (--len > 0) {
231 scanline++; clrscan++;
232 if (clrscan[0][RED] == clrscan[-1][RED] &&
233 clrscan[0][GRN] == clrscan[-1][GRN] &&
234 clrscan[0][BLU] == clrscan[-1][BLU] &&
235 clrscan[0][EXP] == clrscan[-1][EXP])
236 copycolor(scanline[0], scanline[-1]);
237 else
238 colr_color(scanline[0], clrscan[0]);
239 }
240 return(0);
241 }
242
243
244 void
245 setcolr(clr, r, g, b) /* assign a short color value */
246 register COLR clr;
247 double r, g, b;
248 {
249 double d;
250 int e;
251
252 d = r > g ? r : g;
253 if (b > d) d = b;
254
255 if (d <= 1e-32) {
256 clr[RED] = clr[GRN] = clr[BLU] = 0;
257 clr[EXP] = 0;
258 return;
259 }
260
261 d = frexp(d, &e) * 255.9999 / d;
262
263 if (r > 0.0)
264 clr[RED] = r * d;
265 else
266 clr[RED] = 0;
267 if (g > 0.0)
268 clr[GRN] = g * d;
269 else
270 clr[GRN] = 0;
271 if (b > 0.0)
272 clr[BLU] = b * d;
273 else
274 clr[BLU] = 0;
275
276 clr[EXP] = e + COLXS;
277 }
278
279
280 void
281 colr_color(col, clr) /* convert short to float color */
282 register COLOR col;
283 register COLR clr;
284 {
285 double f;
286
287 if (clr[EXP] == 0)
288 col[RED] = col[GRN] = col[BLU] = 0.0;
289 else {
290 f = ldexp(1.0, (int)clr[EXP]-(COLXS+8));
291 col[RED] = (clr[RED] + 0.5)*f;
292 col[GRN] = (clr[GRN] + 0.5)*f;
293 col[BLU] = (clr[BLU] + 0.5)*f;
294 }
295 }
296
297
298 int
299 bigdiff(c1, c2, md) /* c1 delta c2 > md? */
300 register COLOR c1, c2;
301 double md;
302 {
303 register int i;
304
305 for (i = 0; i < 3; i++)
306 if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) ||
307 colval(c2,i)-colval(c1,i) > md*colval(c1,i))
308 return(1);
309 return(0);
310 }