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greg |
1.1 |
#ifndef lint |
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greg |
2.18 |
static const char RCSid[] = "$Id: color.c,v 2.17 2014/05/31 20:13:31 greg Exp $"; |
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greg |
1.1 |
#endif |
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/* |
5 |
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* color.c - routines for color calculations. |
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* |
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greg |
2.9 |
* Externals declared in color.h |
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*/ |
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10 |
greg |
2.10 |
#include "copyright.h" |
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greg |
1.1 |
|
12 |
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#include <stdio.h> |
13 |
greg |
2.9 |
#include <stdlib.h> |
14 |
greg |
2.7 |
#include <math.h> |
15 |
greg |
1.1 |
#include "color.h" |
16 |
greg |
2.14 |
|
17 |
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#ifdef getc_unlocked /* avoid horrendous overhead of flockfile */ |
18 |
greg |
2.15 |
#undef getc |
19 |
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#undef putc |
20 |
greg |
2.14 |
#define getc getc_unlocked |
21 |
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#define putc putc_unlocked |
22 |
greg |
2.18 |
#define ferror ferror_unlocked |
23 |
greg |
2.14 |
#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 */ |
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greg |
2.4 |
|
30 |
greg |
1.14 |
char * |
31 |
greg |
2.17 |
tempbuffer( /* get a temporary buffer */ |
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unsigned int len |
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) |
34 |
greg |
1.14 |
{ |
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static char *tempbuf = NULL; |
36 |
greg |
2.5 |
static unsigned tempbuflen = 0; |
37 |
greg |
1.14 |
|
38 |
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if (len > tempbuflen) { |
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if (tempbuflen > 0) |
40 |
greg |
2.12 |
tempbuf = (char *)realloc((void *)tempbuf, len); |
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greg |
1.14 |
else |
42 |
greg |
2.9 |
tempbuf = (char *)malloc(len); |
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greg |
1.14 |
tempbuflen = tempbuf==NULL ? 0 : len; |
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} |
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return(tempbuf); |
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} |
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49 |
greg |
2.9 |
int |
50 |
greg |
2.17 |
fwritecolrs( /* write out a colr scanline */ |
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COLR *scanline, |
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int len, |
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FILE *fp |
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) |
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greg |
1.1 |
{ |
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greg |
2.17 |
int i, j, beg, cnt = 1; |
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greg |
1.14 |
int c2; |
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greg |
1.1 |
|
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schorsch |
2.13 |
if ((len < MINELEN) | (len > MAXELEN)) /* OOBs, write out flat */ |
60 |
greg |
1.14 |
return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len); |
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greg |
2.2 |
/* put magic header */ |
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putc(2, fp); |
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greg |
1.14 |
putc(2, fp); |
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putc(len>>8, fp); |
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putc(len&255, fp); |
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/* put components seperately */ |
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for (i = 0; i < 4; i++) { |
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for (j = 0; j < len; j += cnt) { /* find next run */ |
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for (beg = j; beg < len; beg += cnt) { |
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for (cnt = 1; cnt < 127 && beg+cnt < len && |
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scanline[beg+cnt][i] == scanline[beg][i]; cnt++) |
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; |
73 |
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if (cnt >= MINRUN) |
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break; /* long enough */ |
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greg |
1.1 |
} |
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greg |
1.15 |
if (beg-j > 1 && beg-j < MINRUN) { |
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c2 = j+1; |
78 |
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while (scanline[c2++][i] == scanline[j][i]) |
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if (c2 == beg) { /* short run */ |
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putc(128+beg-j, fp); |
81 |
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putc(scanline[j][i], fp); |
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j = beg; |
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break; |
84 |
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} |
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} |
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while (j < beg) { /* write out non-run */ |
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greg |
1.14 |
if ((c2 = beg-j) > 128) c2 = 128; |
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putc(c2, fp); |
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while (c2--) |
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putc(scanline[j++][i], fp); |
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} |
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if (cnt >= MINRUN) { /* write out run */ |
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putc(128+cnt, fp); |
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putc(scanline[beg][i], fp); |
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} else |
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cnt = 0; |
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} |
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greg |
1.1 |
} |
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return(ferror(fp) ? -1 : 0); |
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} |
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102 |
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103 |
greg |
2.9 |
static int |
104 |
greg |
2.17 |
oldreadcolrs( /* read in an old colr scanline */ |
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COLR *scanline, |
106 |
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int len, |
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FILE *fp |
108 |
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) |
109 |
greg |
2.9 |
{ |
110 |
greg |
2.18 |
int rshift = 0; |
111 |
greg |
2.17 |
int i; |
112 |
greg |
2.9 |
|
113 |
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while (len > 0) { |
114 |
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scanline[0][RED] = getc(fp); |
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scanline[0][GRN] = getc(fp); |
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scanline[0][BLU] = getc(fp); |
117 |
greg |
2.18 |
scanline[0][EXP] = i = getc(fp); |
118 |
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if (i == EOF) |
119 |
greg |
2.9 |
return(-1); |
120 |
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if (scanline[0][RED] == 1 && |
121 |
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scanline[0][GRN] == 1 && |
122 |
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scanline[0][BLU] == 1) { |
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for (i = scanline[0][EXP] << rshift; i > 0; i--) { |
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copycolr(scanline[0], scanline[-1]); |
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scanline++; |
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len--; |
127 |
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} |
128 |
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rshift += 8; |
129 |
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} else { |
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scanline++; |
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len--; |
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rshift = 0; |
133 |
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} |
134 |
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} |
135 |
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return(0); |
136 |
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} |
137 |
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139 |
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int |
140 |
greg |
2.17 |
freadcolrs( /* read in an encoded colr scanline */ |
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COLR *scanline, |
142 |
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int len, |
143 |
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FILE *fp |
144 |
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) |
145 |
greg |
1.1 |
{ |
146 |
greg |
2.17 |
int i, j; |
147 |
greg |
2.6 |
int code, val; |
148 |
greg |
1.14 |
/* determine scanline type */ |
149 |
schorsch |
2.13 |
if ((len < MINELEN) | (len > MAXELEN)) |
150 |
greg |
1.14 |
return(oldreadcolrs(scanline, len, fp)); |
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if ((i = getc(fp)) == EOF) |
152 |
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return(-1); |
153 |
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if (i != 2) { |
154 |
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ungetc(i, fp); |
155 |
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return(oldreadcolrs(scanline, len, fp)); |
156 |
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} |
157 |
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scanline[0][GRN] = getc(fp); |
158 |
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scanline[0][BLU] = getc(fp); |
159 |
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if ((i = getc(fp)) == EOF) |
160 |
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return(-1); |
161 |
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if (scanline[0][GRN] != 2 || scanline[0][BLU] & 128) { |
162 |
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scanline[0][RED] = 2; |
163 |
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scanline[0][EXP] = i; |
164 |
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return(oldreadcolrs(scanline+1, len-1, fp)); |
165 |
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} |
166 |
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if ((scanline[0][BLU]<<8 | i) != len) |
167 |
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return(-1); /* length mismatch! */ |
168 |
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/* read each component */ |
169 |
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for (i = 0; i < 4; i++) |
170 |
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for (j = 0; j < len; ) { |
171 |
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if ((code = getc(fp)) == EOF) |
172 |
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return(-1); |
173 |
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if (code > 128) { /* run */ |
174 |
greg |
2.6 |
code &= 127; |
175 |
greg |
2.9 |
if ((val = getc(fp)) == EOF) |
176 |
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return -1; |
177 |
greg |
2.16 |
if (j + code > len) |
178 |
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return -1; /* overrun */ |
179 |
greg |
2.6 |
while (code--) |
180 |
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scanline[j++][i] = val; |
181 |
greg |
2.16 |
} else { /* non-run */ |
182 |
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if (j + code > len) |
183 |
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return -1; /* overrun */ |
184 |
greg |
2.9 |
while (code--) { |
185 |
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if ((val = getc(fp)) == EOF) |
186 |
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return -1; |
187 |
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scanline[j++][i] = val; |
188 |
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} |
189 |
greg |
2.16 |
} |
190 |
greg |
1.14 |
} |
191 |
greg |
1.1 |
return(0); |
192 |
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} |
193 |
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194 |
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195 |
greg |
2.9 |
int |
196 |
greg |
2.17 |
fwritescan( /* write out a scanline */ |
197 |
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COLOR *scanline, |
198 |
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int len, |
199 |
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FILE *fp |
200 |
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) |
201 |
greg |
1.1 |
{ |
202 |
greg |
1.14 |
COLR *clrscan; |
203 |
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int n; |
204 |
greg |
2.17 |
COLR *sp; |
205 |
greg |
1.14 |
/* get scanline buffer */ |
206 |
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if ((sp = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL) |
207 |
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return(-1); |
208 |
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clrscan = sp; |
209 |
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/* convert scanline */ |
210 |
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n = len; |
211 |
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while (n-- > 0) { |
212 |
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setcolr(sp[0], scanline[0][RED], |
213 |
greg |
1.1 |
scanline[0][GRN], |
214 |
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scanline[0][BLU]); |
215 |
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scanline++; |
216 |
greg |
1.14 |
sp++; |
217 |
greg |
1.1 |
} |
218 |
greg |
1.14 |
return(fwritecolrs(clrscan, len, fp)); |
219 |
greg |
1.1 |
} |
220 |
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221 |
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222 |
greg |
2.9 |
int |
223 |
greg |
2.17 |
freadscan( /* read in a scanline */ |
224 |
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COLOR *scanline, |
225 |
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int len, |
226 |
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FILE *fp |
227 |
|
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) |
228 |
greg |
1.1 |
{ |
229 |
greg |
2.17 |
COLR *clrscan; |
230 |
greg |
1.14 |
|
231 |
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if ((clrscan = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL) |
232 |
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return(-1); |
233 |
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if (freadcolrs(clrscan, len, fp) < 0) |
234 |
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return(-1); |
235 |
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/* convert scanline */ |
236 |
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colr_color(scanline[0], clrscan[0]); |
237 |
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while (--len > 0) { |
238 |
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scanline++; clrscan++; |
239 |
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if (clrscan[0][RED] == clrscan[-1][RED] && |
240 |
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clrscan[0][GRN] == clrscan[-1][GRN] && |
241 |
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clrscan[0][BLU] == clrscan[-1][BLU] && |
242 |
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clrscan[0][EXP] == clrscan[-1][EXP]) |
243 |
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copycolor(scanline[0], scanline[-1]); |
244 |
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else |
245 |
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colr_color(scanline[0], clrscan[0]); |
246 |
greg |
1.1 |
} |
247 |
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return(0); |
248 |
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} |
249 |
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|
250 |
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|
251 |
greg |
2.9 |
void |
252 |
greg |
2.17 |
setcolr( /* assign a short color value */ |
253 |
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COLR clr, |
254 |
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double r, |
255 |
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double g, |
256 |
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double b |
257 |
|
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) |
258 |
greg |
1.1 |
{ |
259 |
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double d; |
260 |
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int e; |
261 |
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|
262 |
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d = r > g ? r : g; |
263 |
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if (b > d) d = b; |
264 |
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|
265 |
greg |
1.4 |
if (d <= 1e-32) { |
266 |
greg |
1.1 |
clr[RED] = clr[GRN] = clr[BLU] = 0; |
267 |
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clr[EXP] = 0; |
268 |
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return; |
269 |
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} |
270 |
|
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|
271 |
greg |
2.8 |
d = frexp(d, &e) * 255.9999 / d; |
272 |
greg |
1.1 |
|
273 |
greg |
2.11 |
if (r > 0.0) |
274 |
|
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clr[RED] = r * d; |
275 |
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else |
276 |
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clr[RED] = 0; |
277 |
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if (g > 0.0) |
278 |
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clr[GRN] = g * d; |
279 |
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else |
280 |
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clr[GRN] = 0; |
281 |
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if (b > 0.0) |
282 |
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clr[BLU] = b * d; |
283 |
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else |
284 |
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clr[BLU] = 0; |
285 |
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|
286 |
greg |
1.1 |
clr[EXP] = e + COLXS; |
287 |
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} |
288 |
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289 |
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|
290 |
greg |
2.9 |
void |
291 |
greg |
2.17 |
colr_color( /* convert short to float color */ |
292 |
|
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COLOR col, |
293 |
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COLR clr |
294 |
|
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) |
295 |
greg |
1.1 |
{ |
296 |
greg |
1.6 |
double f; |
297 |
greg |
1.1 |
|
298 |
|
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if (clr[EXP] == 0) |
299 |
|
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col[RED] = col[GRN] = col[BLU] = 0.0; |
300 |
|
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else { |
301 |
greg |
1.2 |
f = ldexp(1.0, (int)clr[EXP]-(COLXS+8)); |
302 |
greg |
1.1 |
col[RED] = (clr[RED] + 0.5)*f; |
303 |
|
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col[GRN] = (clr[GRN] + 0.5)*f; |
304 |
|
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col[BLU] = (clr[BLU] + 0.5)*f; |
305 |
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} |
306 |
greg |
1.6 |
} |
307 |
|
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|
308 |
|
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|
309 |
greg |
2.9 |
int |
310 |
greg |
2.17 |
bigdiff( /* c1 delta c2 > md? */ |
311 |
|
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COLOR c1, |
312 |
|
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COLOR c2, |
313 |
|
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double md |
314 |
|
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) |
315 |
greg |
1.7 |
{ |
316 |
greg |
2.17 |
int i; |
317 |
greg |
1.7 |
|
318 |
|
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for (i = 0; i < 3; i++) |
319 |
|
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if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) || |
320 |
|
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colval(c2,i)-colval(c1,i) > md*colval(c1,i)) |
321 |
|
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return(1); |
322 |
|
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return(0); |
323 |
|
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} |