1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4
5 /*
6 * int getcmap(int id, char *file, unsigned char *buf)
7 * Read a colormap from the given file into the buffer.
8 * Returns 1 on success, 0 otherwise.
9 * Goes to unglaublich length to figure out what the file name means:
10 * If the name is "screen" or "display" or "vga", reads the colormap from /dev/draw/id/colormap.
11 * If the name is "gamma",returns gamma=2.3 colormap
12 * If the name is "gamma###", returns gamma=#### colormap
13 * Ditto for rgamma, for reverse video.
14 * Looks for the file in a list of directories (given below).
15 */
16
17 char *cmapdir[] = {
18 "",
19 "/lib/cmap/",
20 0
21 };
22
23 int
getcmap(int id,char * f,unsigned char * buf)24 getcmap(int id, char *f, unsigned char *buf)
25 {
26 char name[512];
27 char *s, *lines[256], *fields[4];
28 int cmap, i, j, n, v, rev;
29 double gamma;
30
31 cmap = -1;
32 for(i=0; cmapdir[i]!=nil ;i++){
33 snprint(name, sizeof name, "%s%s", cmapdir[i], f);
34 if((cmap = open(name, OREAD)) >= 0)
35 break;
36 }
37
38 if(cmap == -1){
39 if(strcmp(name, "screen")==0 || strcmp(name, "display")==0 || strcmp(name, "vga")==0){
40 snprint(name, sizeof name, "/dev/draw/%d/colormap", id);
41 cmap = open(name, OREAD);
42 if(cmap < 0)
43 return 0;
44 }
45 }
46
47 if(cmap==-1){ /* could be gamma or gamma<number> or fb */
48 if(strncmp(f, "gamma", 5)==0){
49 rev=0;
50 f+=5;
51 }else if(strncmp(f, "rgamma", 6)==0){
52 rev = 1;
53 f+=6;
54 }else
55 return 0;
56 if(*f == '\0')
57 gamma=2.3;
58 else{
59 if(strspn(f, "0123456789.") != strlen(f))
60 return 0;
61 gamma = atof(f);
62 }
63 for(i=0; i!=256; i++){
64 v=255.*pow(i/255., 1./gamma);
65 if(rev)
66 v=255-v;
67 buf[0] = buf[1] = buf[2] = v;
68 buf += 3;
69 }
70 return 1;
71 }
72
73 s = malloc(20000);
74 n = readn(cmap, s, 20000-1);
75 if(n <= 0)
76 return 0;
77 s[n] = '\0';
78 if(getfields(s, lines, 256, 0, "\n") != 256)
79 return 0;
80 for(i=0; i<256; i++){
81 if(getfields(lines[i], fields, 4, 1, " \t") != 4)
82 return 0;
83 if(atoi(fields[0]) != i)
84 return 0;
85 for(j=0; j<3; j++)
86 buf[3*i+j] = atoi(fields[j+1]);
87 }
88 return 1;
89 }
90
91 /* replicate (from top) value in v (n bits) until it fills a ulong */
92 ulong
rep(ulong v,int n)93 rep(ulong v, int n)
94 {
95 int o;
96 ulong rv;
97
98 rv = 0;
99 for(o=32-n; o>=0; o-=n)
100 rv |= v<<o;
101 if(o != -n)
102 rv |= v>>-o;
103 return rv;
104 }
105
106 void
putcmap(int id,uchar cmap[256* 3])107 putcmap(int id, uchar cmap[256*3])
108 {
109 char *s, *t;
110 int i, fd;
111 char name[64];
112
113 snprint(name, sizeof name, "/dev/draw/%d/colormap", id);
114 fd = open(name, OWRITE);
115 if(fd < 0)
116 sysfatal("can't open colormap file: %r");
117 s = malloc(20000);
118 t = s;
119 for(i = 0; i<256; i++)
120 t += sprint(t, "%d %d %d %d\n", i, cmap[3*i+0], cmap[3*i+1], cmap[3*i+2]);
121 if(write(fd, s, t-s) != t-s)
122 sysfatal("writing color map: %r");
123 close(fd);
124 }
125
126 void
main(int argc,char * argv[])127 main(int argc, char *argv[])
128 {
129 uchar cmapbuf[256*3];
130 char *map, buf[12*12+1];
131 int fd, id;
132
133 if(argc>2){
134 fprint(2, "Usage: %s colormap\n", argv[0]);
135 exits("usage");
136 }
137 map = "rgbv";
138 if(argc > 1)
139 map = argv[1];
140
141 fd = open("/dev/draw/new", OREAD);
142 if(fd < 0 || read(fd, buf, sizeof buf) != 12*12)
143 sysfatal("can't connect to display: %r");
144 id = atoi(buf+0*12);
145 if(strncmp(buf+2*12, " m8 ", 12) != 0)
146 sysfatal("can't set colormap except on CMAP8 (m8) displays; this one is %.12s", buf+2*12);
147
148 if(getcmap(id, map, cmapbuf) == 0){
149 fprint(2, "%s: can't find %s\n", argv[0], map);
150 exits("not found");
151 }
152
153 putcmap(id, cmapbuf);
154 exits(0);
155 }
156