1 #include "compat.h"
2
3 struct hsv {
4 float h, s, v;
5 };
6
7 struct rgb {
8 float r, g, b;
9 };
10
11 struct gradient {
12 int start, len, chompends;
13 struct hsv startcolour, endcolour;
14 };
15
16 float min2(float x, float y);
17 float max2(float x, float y);
18 void convertHSVtoRGB(struct hsv *hsv, struct rgb *rgb);
19 int showusage(void);
20 int readscript(char *fn);
21
22 struct gradient ramps[256];
23 int nramps = 0;
24
main(int argc,char ** argv)25 int main(int argc, char **argv)
26 {
27 struct hsv palette[256], lerpstep, lerped;
28 struct rgb rgbidx;
29 unsigned char rgbout[3];
30 int idx, step, rampnum;
31 FILE* fh;
32 char const * outfile = "palette.dat";
33
34 memset(palette,0,sizeof(palette));
35
36 if (argc < 2) return showusage();
37 if (readscript(argv[1])) return 1;
38 if (argc >= 3) outfile = argv[2];
39
40 for (rampnum = 0; rampnum < nramps; rampnum++) {
41 idx = ramps[rampnum].start;
42 step = ramps[rampnum].len;
43 if (ramps[rampnum].chompends & 1) step++;
44 if (ramps[rampnum].chompends & 2) step++;
45 lerpstep.h = (ramps[rampnum].endcolour.h - ramps[rampnum].startcolour.h) / (float)step;
46 lerpstep.s = (ramps[rampnum].endcolour.s - ramps[rampnum].startcolour.s) / (float)step;
47 lerpstep.v = (ramps[rampnum].endcolour.v - ramps[rampnum].startcolour.v) / (float)step;
48 lerped = ramps[rampnum].startcolour;
49 if (ramps[rampnum].chompends & 1) {
50 step--;
51 lerped.h += lerpstep.h;
52 lerped.s += lerpstep.s;
53 lerped.v += lerpstep.v;
54 }
55 if (ramps[rampnum].chompends & 2) step--;
56
57 for (; step > 0; step--,idx++) {
58 palette[idx].h = lerped.h;
59 palette[idx].s = lerped.s;
60 palette[idx].v = lerped.v;
61 lerped.h += lerpstep.h;
62 lerped.s += lerpstep.s;
63 lerped.v += lerpstep.v;
64 }
65 }
66
67 fh = fopen(outfile,"wb");
68 if (!fh) return 1;
69
70 for (idx=0; idx<256; idx++) {
71 convertHSVtoRGB(&palette[idx], &rgbidx);
72 //printf("Index %d: r=%g g=%g b=%g\n",idx,rgbidx.r,rgbidx.g,rgbidx.b);
73 rgbout[0] = (unsigned char)min2(255,max2(0,(int)(rgbidx.r * 255.0))) >> 2;
74 rgbout[1] = (unsigned char)min2(255,max2(0,(int)(rgbidx.g * 255.0))) >> 2;
75 rgbout[2] = (unsigned char)min2(255,max2(0,(int)(rgbidx.b * 255.0))) >> 2;
76 fwrite(rgbout,3,1,fh);
77 }
78
79 fclose(fh);
80
81 return 0;
82 }
83
min2(float x,float y)84 float min2(float x, float y)
85 {
86 return x < y ? x : y;
87 }
88
max2(float x,float y)89 float max2(float x, float y)
90 {
91 return x > y ? x : y;
92 }
93
94 // http://www.cs.rit.edu/~ncs/color/t_convert.html
convertHSVtoRGB(struct hsv * hsv,struct rgb * rgb)95 void convertHSVtoRGB(struct hsv *hsv, struct rgb *rgb)
96 {
97 int i;
98 float f, p, q, t;
99 if( hsv->s == 0 ) {
100 // achromatic (grey)
101 rgb->r = rgb->g = rgb->b = hsv->v;
102 return;
103 }
104 hsv->h /= 60; // sector 0 to 5
105 i = floor( hsv->h );
106 f = hsv->h - i; // factorial part of h
107 p = hsv->v * ( 1 - hsv->s );
108 q = hsv->v * ( 1 - hsv->s * f );
109 t = hsv->v * ( 1 - hsv->s * ( 1 - f ) );
110 switch( i ) {
111 case 0:
112 rgb->r = hsv->v;
113 rgb->g = t;
114 rgb->b = p;
115 break;
116 case 1:
117 rgb->r = q;
118 rgb->g = hsv->v;
119 rgb->b = p;
120 break;
121 case 2:
122 rgb->r = p;
123 rgb->g = hsv->v;
124 rgb->b = t;
125 break;
126 case 3:
127 rgb->r = p;
128 rgb->g = q;
129 rgb->b = hsv->v;
130 break;
131 case 4:
132 rgb->r = t;
133 rgb->g = p;
134 rgb->b = hsv->v;
135 break;
136 default: // case 5:
137 rgb->r = hsv->v;
138 rgb->g = p;
139 rgb->b = q;
140 break;
141 }
142 }
143
showusage(void)144 int showusage(void)
145 {
146 puts("mkpalette <palettescript.txt> [outputfile]");
147 puts("If outputfile is not given, palette.dat is assumed");
148
149 puts("\nPalette script format:\n"
150 " A line beginning with # is a comment, otherwise each line contains none\n"
151 "values separated by spaces defining the gradient:\n"
152 "\n"
153 " startindex rangesize skip starthue startsat startval endhue endsat endval\n"
154 "\n"
155 "Any text after the end of a gradient description is ignored, so may use it\n"
156 "to describe the colour.\n"
157 "\n"
158 "* 'startindex' specifies the first palette index to write to\n"
159 "* 'rangesize' specifies the length of the gradient\n"
160 "* 'skip' specifies whether the first and/or last elements of the range should\n"
161 " be ignored and with 'rangesize' elements interpolated between. This is so\n"
162 " you can have a gradient starting at (potentially) pure black and ending at\n"
163 " (potentially) pure white but without wasting a palette index on those colours\n"
164 " if they already exist, eg. in a grey ramp.\n"
165 " Legal values are 0 (no skipping), 1 (skip start), 2 (skip end),\n"
166 " or 3 (skip start and end).\n"
167 "* 'starthue', 'startsat', 'startval' are integers specifying the beginning\n"
168 " colour in Hue-Saturation-Value format.\n"
169 " 'starthue' should be in the range 0-360 indicating a degrees value\n"
170 " 'startsat' should be in the range 0-100 indicating a saturation percentage\n"
171 " 'startval' should be in the range 0-100 indicating an intensity percentage\n"
172 "* 'endhue', 'endsat', 'endval' specify the ending colour."
173 );
174 return 0;
175 }
176
readscript(char * fn)177 int readscript(char *fn)
178 {
179 int start, len, skip, shue, ssat, sval, ehue, esat, eval;
180 FILE *fp;
181 char line[1024];
182
183 fp = fopen(fn,"rt");
184 if (!fp) {
185 puts("Error opening palette script");
186 return 1;
187 }
188
189 while (fgets(line,sizeof(line),fp)) {
190 {
191 // test for comment
192 char *p = line;
193 while (*p && (*p == ' ' || *p == '\t')) p++;
194 if (*p == '#') continue;
195 }
196
197 if (sscanf(line, "%d %d %d %d %d %d %d %d %d", &start,&len,&skip,&shue,&ssat,&sval,&ehue,&esat,&eval) < 9)
198 continue;
199
200 if (start < 0 || start > 255) {
201 printf("start index of %d is out of range 0-255\n", start);
202 continue;
203 }
204 if (len < 1 || len > 255) {
205 printf("length %d is out of range 1-255\n", len);
206 continue;
207 }
208 if (skip != (skip&3)) {
209 printf("skip value of %d is out of range 0-3\n", skip);
210 continue;
211 }
212 if (shue < 0 || shue > 360) {
213 printf("start hue %d is out of range 0-360\n", shue);
214 continue;
215 }
216 if (ssat < 0 || ssat > 100) {
217 printf("start saturation %d is out of range 0-100\n", ssat);
218 continue;
219 }
220 if (sval < 0 || sval > 100) {
221 printf("start value %d is out of range 0-100\n", sval);
222 continue;
223 }
224 if (ehue < 0 || ehue > 360) {
225 printf("end hue %d is out of range 0-360\n", shue);
226 continue;
227 }
228 if (esat < 0 || esat > 100) {
229 printf("end saturation %d is out of range 0-100\n", ssat);
230 continue;
231 }
232 if (eval < 0 || eval > 100) {
233 printf("end value %d is out of range 0-100\n", sval);
234 continue;
235 }
236
237 ramps[nramps].start = start;
238 ramps[nramps].len = len;
239 ramps[nramps].chompends = skip;
240 ramps[nramps].startcolour.h = (float)shue;
241 ramps[nramps].startcolour.s = (float)ssat / 100.0;
242 ramps[nramps].startcolour.v = (float)sval / 100.0;
243 ramps[nramps].endcolour.h = (float)ehue;
244 ramps[nramps].endcolour.s = (float)esat / 100.0;
245 ramps[nramps].endcolour.v = (float)eval / 100.0;
246 nramps++;
247 }
248
249 fclose(fp);
250 return 0;
251 }
252