1 |
greg |
1.1 |
#ifndef lint |
2 |
greg |
2.9 |
static const char RCSid[] = "$Id$"; |
3 |
greg |
1.1 |
#endif |
4 |
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/* |
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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 |
8 |
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*/ |
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10 |
greg |
2.10 |
#include "copyright.h" |
11 |
greg |
1.1 |
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12 |
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#include <stdio.h> |
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greg |
2.9 |
#include <stdlib.h> |
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greg |
2.7 |
#include <math.h> |
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18 |
greg |
1.1 |
#include "color.h" |
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20 |
greg |
1.14 |
#define MINELEN 8 /* minimum scanline length for encoding */ |
21 |
greg |
2.6 |
#define MAXELEN 0x7fff /* maximum scanline length for encoding */ |
22 |
greg |
1.14 |
#define MINRUN 4 /* minimum run length */ |
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24 |
greg |
2.4 |
|
25 |
greg |
1.14 |
char * |
26 |
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tempbuffer(len) /* get a temporary buffer */ |
27 |
greg |
2.9 |
unsigned int len; |
28 |
greg |
1.14 |
{ |
29 |
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static char *tempbuf = NULL; |
30 |
greg |
2.5 |
static unsigned tempbuflen = 0; |
31 |
greg |
1.14 |
|
32 |
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if (len > tempbuflen) { |
33 |
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if (tempbuflen > 0) |
34 |
greg |
2.9 |
tempbuf = (char *)realloc(tempbuf, len); |
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greg |
1.14 |
else |
36 |
greg |
2.9 |
tempbuf = (char *)malloc(len); |
37 |
greg |
1.14 |
tempbuflen = tempbuf==NULL ? 0 : len; |
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} |
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return(tempbuf); |
40 |
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} |
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42 |
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43 |
greg |
2.9 |
int |
44 |
greg |
1.1 |
fwritecolrs(scanline, len, fp) /* write out a colr scanline */ |
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register COLR *scanline; |
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greg |
2.9 |
int len; |
47 |
greg |
1.1 |
register FILE *fp; |
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{ |
49 |
greg |
2.9 |
register int i, j, beg, cnt = 1; |
50 |
greg |
1.14 |
int c2; |
51 |
greg |
1.1 |
|
52 |
greg |
2.5 |
if (len < MINELEN | len > MAXELEN) /* OOBs, write out flat */ |
53 |
greg |
1.14 |
return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len); |
54 |
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) { |
63 |
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for (cnt = 1; cnt < 127 && beg+cnt < len && |
64 |
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scanline[beg+cnt][i] == scanline[beg][i]; cnt++) |
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; |
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if (cnt >= MINRUN) |
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break; /* long enough */ |
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greg |
1.1 |
} |
69 |
greg |
1.15 |
if (beg-j > 1 && beg-j < MINRUN) { |
70 |
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c2 = j+1; |
71 |
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while (scanline[c2++][i] == scanline[j][i]) |
72 |
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if (c2 == beg) { /* short run */ |
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putc(128+beg-j, fp); |
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putc(scanline[j][i], fp); |
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j = beg; |
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break; |
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} |
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} |
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while (j < beg) { /* write out non-run */ |
80 |
greg |
1.14 |
if ((c2 = beg-j) > 128) c2 = 128; |
81 |
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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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greg |
2.9 |
static int |
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oldreadcolrs(scanline, len, fp) /* read in an old colr scanline */ |
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register COLR *scanline; |
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int len; |
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register FILE *fp; |
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{ |
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int rshift; |
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register int i; |
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rshift = 0; |
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107 |
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while (len > 0) { |
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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); |
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scanline[0][EXP] = getc(fp); |
112 |
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if (feof(fp) || ferror(fp)) |
113 |
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return(-1); |
114 |
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if (scanline[0][RED] == 1 && |
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scanline[0][GRN] == 1 && |
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scanline[0][BLU] == 1) { |
117 |
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for (i = scanline[0][EXP] << rshift; i > 0; i--) { |
118 |
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copycolr(scanline[0], scanline[-1]); |
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scanline++; |
120 |
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len--; |
121 |
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} |
122 |
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rshift += 8; |
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} else { |
124 |
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scanline++; |
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len--; |
126 |
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rshift = 0; |
127 |
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} |
128 |
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} |
129 |
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return(0); |
130 |
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} |
131 |
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132 |
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int |
134 |
greg |
1.14 |
freadcolrs(scanline, len, fp) /* read in an encoded colr scanline */ |
135 |
greg |
1.1 |
register COLR *scanline; |
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int len; |
137 |
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register FILE *fp; |
138 |
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{ |
139 |
greg |
1.14 |
register int i, j; |
140 |
greg |
2.6 |
int code, val; |
141 |
greg |
1.14 |
/* determine scanline type */ |
142 |
greg |
2.5 |
if (len < MINELEN | len > MAXELEN) |
143 |
greg |
1.14 |
return(oldreadcolrs(scanline, len, fp)); |
144 |
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if ((i = getc(fp)) == EOF) |
145 |
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return(-1); |
146 |
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if (i != 2) { |
147 |
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ungetc(i, fp); |
148 |
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return(oldreadcolrs(scanline, len, fp)); |
149 |
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} |
150 |
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scanline[0][GRN] = getc(fp); |
151 |
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scanline[0][BLU] = getc(fp); |
152 |
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if ((i = getc(fp)) == EOF) |
153 |
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return(-1); |
154 |
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if (scanline[0][GRN] != 2 || scanline[0][BLU] & 128) { |
155 |
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scanline[0][RED] = 2; |
156 |
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scanline[0][EXP] = i; |
157 |
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return(oldreadcolrs(scanline+1, len-1, fp)); |
158 |
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} |
159 |
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if ((scanline[0][BLU]<<8 | i) != len) |
160 |
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return(-1); /* length mismatch! */ |
161 |
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/* read each component */ |
162 |
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for (i = 0; i < 4; i++) |
163 |
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for (j = 0; j < len; ) { |
164 |
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if ((code = getc(fp)) == EOF) |
165 |
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return(-1); |
166 |
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if (code > 128) { /* run */ |
167 |
greg |
2.6 |
code &= 127; |
168 |
greg |
2.9 |
if ((val = getc(fp)) == EOF) |
169 |
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return -1; |
170 |
greg |
2.6 |
while (code--) |
171 |
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scanline[j++][i] = val; |
172 |
greg |
1.14 |
} else /* non-run */ |
173 |
greg |
2.9 |
while (code--) { |
174 |
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if ((val = getc(fp)) == EOF) |
175 |
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return -1; |
176 |
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scanline[j++][i] = val; |
177 |
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} |
178 |
greg |
1.14 |
} |
179 |
greg |
1.1 |
return(0); |
180 |
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} |
181 |
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182 |
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183 |
greg |
2.9 |
int |
184 |
greg |
1.1 |
fwritescan(scanline, len, fp) /* write out a scanline */ |
185 |
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register COLOR *scanline; |
186 |
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int len; |
187 |
greg |
1.14 |
FILE *fp; |
188 |
greg |
1.1 |
{ |
189 |
greg |
1.14 |
COLR *clrscan; |
190 |
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int n; |
191 |
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register COLR *sp; |
192 |
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/* get scanline buffer */ |
193 |
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if ((sp = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL) |
194 |
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return(-1); |
195 |
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clrscan = sp; |
196 |
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/* convert scanline */ |
197 |
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n = len; |
198 |
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while (n-- > 0) { |
199 |
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setcolr(sp[0], scanline[0][RED], |
200 |
greg |
1.1 |
scanline[0][GRN], |
201 |
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scanline[0][BLU]); |
202 |
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scanline++; |
203 |
greg |
1.14 |
sp++; |
204 |
greg |
1.1 |
} |
205 |
greg |
1.14 |
return(fwritecolrs(clrscan, len, fp)); |
206 |
greg |
1.1 |
} |
207 |
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208 |
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209 |
greg |
2.9 |
int |
210 |
greg |
1.1 |
freadscan(scanline, len, fp) /* read in a scanline */ |
211 |
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register COLOR *scanline; |
212 |
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int len; |
213 |
greg |
1.14 |
FILE *fp; |
214 |
greg |
1.1 |
{ |
215 |
greg |
1.14 |
register COLR *clrscan; |
216 |
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217 |
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if ((clrscan = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL) |
218 |
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return(-1); |
219 |
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if (freadcolrs(clrscan, len, fp) < 0) |
220 |
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return(-1); |
221 |
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/* convert scanline */ |
222 |
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colr_color(scanline[0], clrscan[0]); |
223 |
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while (--len > 0) { |
224 |
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scanline++; clrscan++; |
225 |
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if (clrscan[0][RED] == clrscan[-1][RED] && |
226 |
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clrscan[0][GRN] == clrscan[-1][GRN] && |
227 |
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clrscan[0][BLU] == clrscan[-1][BLU] && |
228 |
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clrscan[0][EXP] == clrscan[-1][EXP]) |
229 |
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copycolor(scanline[0], scanline[-1]); |
230 |
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else |
231 |
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colr_color(scanline[0], clrscan[0]); |
232 |
greg |
1.1 |
} |
233 |
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return(0); |
234 |
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} |
235 |
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236 |
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237 |
greg |
2.9 |
void |
238 |
greg |
1.1 |
setcolr(clr, r, g, b) /* assign a short color value */ |
239 |
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register COLR clr; |
240 |
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double r, g, b; |
241 |
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{ |
242 |
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double d; |
243 |
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int e; |
244 |
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245 |
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d = r > g ? r : g; |
246 |
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if (b > d) d = b; |
247 |
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|
248 |
greg |
1.4 |
if (d <= 1e-32) { |
249 |
greg |
1.1 |
clr[RED] = clr[GRN] = clr[BLU] = 0; |
250 |
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clr[EXP] = 0; |
251 |
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return; |
252 |
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} |
253 |
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|
254 |
greg |
2.8 |
d = frexp(d, &e) * 255.9999 / d; |
255 |
greg |
1.1 |
|
256 |
greg |
2.11 |
if (r > 0.0) |
257 |
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clr[RED] = r * d; |
258 |
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else |
259 |
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clr[RED] = 0; |
260 |
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if (g > 0.0) |
261 |
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clr[GRN] = g * d; |
262 |
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else |
263 |
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clr[GRN] = 0; |
264 |
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if (b > 0.0) |
265 |
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clr[BLU] = b * d; |
266 |
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else |
267 |
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clr[BLU] = 0; |
268 |
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269 |
greg |
1.1 |
clr[EXP] = e + COLXS; |
270 |
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} |
271 |
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272 |
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|
273 |
greg |
2.9 |
void |
274 |
greg |
1.1 |
colr_color(col, clr) /* convert short to float color */ |
275 |
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register COLOR col; |
276 |
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register COLR clr; |
277 |
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{ |
278 |
greg |
1.6 |
double f; |
279 |
greg |
1.1 |
|
280 |
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if (clr[EXP] == 0) |
281 |
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col[RED] = col[GRN] = col[BLU] = 0.0; |
282 |
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else { |
283 |
greg |
1.2 |
f = ldexp(1.0, (int)clr[EXP]-(COLXS+8)); |
284 |
greg |
1.1 |
col[RED] = (clr[RED] + 0.5)*f; |
285 |
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col[GRN] = (clr[GRN] + 0.5)*f; |
286 |
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col[BLU] = (clr[BLU] + 0.5)*f; |
287 |
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} |
288 |
greg |
1.6 |
} |
289 |
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290 |
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291 |
greg |
2.9 |
int |
292 |
greg |
1.7 |
bigdiff(c1, c2, md) /* c1 delta c2 > md? */ |
293 |
|
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register COLOR c1, c2; |
294 |
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double md; |
295 |
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{ |
296 |
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register int i; |
297 |
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298 |
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for (i = 0; i < 3; i++) |
299 |
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if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) || |
300 |
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colval(c2,i)-colval(c1,i) > md*colval(c1,i)) |
301 |
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return(1); |
302 |
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return(0); |
303 |
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} |