Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <draw.h>

/*
 * int getcmap(int id, char *file, unsigned char *buf)
 *      Read a colormap from the given file into the buffer.
 *      Returns 1 on success, 0 otherwise.
 *      Goes to unglaublich length to figure out what the file name means:
 *      If the name is "screen" or "display" or "vga", reads the colormap from /dev/draw/id/colormap.
 *      If the name is "gamma",returns gamma=2.3 colormap
 *      If the name is "gamma###", returns gamma=#### colormap
 *      Ditto for rgamma, for reverse video.
 *      Looks for the file in a list of directories (given below).
 */

char *cmapdir[] = {
        "",
        "/lib/cmap/",
        0
};

int
getcmap(int id, char *f, unsigned char *buf)
{
        char name[512];
        char *s, *lines[256], *fields[4];
        int cmap, i, j, n, v, rev;
        double gamma;

        cmap = -1;
        for(i=0; cmapdir[i]!=nil ;i++){
                snprint(name, sizeof name, "%s%s", cmapdir[i], f);
                if((cmap = open(name, OREAD)) >= 0)
                        break;
        }

        if(cmap == -1){
                if(strcmp(name, "screen")==0 || strcmp(name, "display")==0 || strcmp(name, "vga")==0){
                        snprint(name, sizeof name, "/dev/draw/%d/colormap", id);
                        cmap = open(name, OREAD);
                        if(cmap < 0)
                                return 0;
                }
        }

        if(cmap==-1){ /* could be gamma or gamma<number> or fb */
                if(strncmp(f, "gamma", 5)==0){
                        rev=0;
                        f+=5;
                }else if(strncmp(f, "rgamma", 6)==0){
                        rev = 1;
                        f+=6;
                }else
                        return 0;
                if(*f == '\0')
                        gamma=2.3;
                else{
                        if(strspn(f, "0123456789.") != strlen(f))
                                return 0;
                        gamma = atof(f);
                }
                for(i=0; i!=256; i++){
                        v=255.*pow(i/255., 1./gamma);
                        if(rev)
                                v=255-v;
                        buf[0] = buf[1] = buf[2] = v;
                        buf += 3;
                }
                return 1;
        }

        s = malloc(20000);
        n = readn(cmap, s, 20000-1);
        if(n <= 0)
                return 0;
        s[n] = '\0';
        if(getfields(s, lines, 256, 0, "\n") != 256)
                return 0;
        for(i=0; i<256; i++){
                if(getfields(lines[i], fields, 4, 1, " \t") != 4)
                        return 0;
                if(atoi(fields[0]) != i)
                        return 0;
                for(j=0; j<3; j++)
                        buf[3*i+j] = atoi(fields[j+1]);
        }
        return 1;
}

/* replicate (from top) value in v (n bits) until it fills a ulong */
ulong
rep(ulong v, int n)
{
        int o;
        ulong rv;

        rv = 0;
        for(o=32-n; o>=0; o-=n)
                rv |= v<<o;
        if(o != -n)
                rv |= v>>-o;
        return rv;
}

void
putcmap(int id, uchar cmap[256*3])
{
        char *s, *t;
        int i, fd;
        char name[64];

        snprint(name, sizeof name, "/dev/draw/%d/colormap", id);
        fd = open(name, OWRITE);
        if(fd < 0)
                sysfatal("can't open colormap file: %r");
        s = malloc(20000);
        t = s;
        for(i = 0; i<256; i++)
                t += sprint(t, "%d %d %d %d\n", i, cmap[3*i+0], cmap[3*i+1], cmap[3*i+2]);
        if(write(fd, s, t-s) != t-s)
                sysfatal("writing color map: %r");
        close(fd);
}

void
main(int argc, char *argv[])
{
        uchar cmapbuf[256*3];
        char *map, buf[12*12+1];
        int fd, id;

        if(argc>2){
                fprint(2, "Usage: %s colormap\n", argv[0]);
                exits("usage");
        }
        map = "rgbv";
        if(argc > 1)
                map = argv[1];

        fd = open("/dev/draw/new", OREAD);
        if(fd < 0 || read(fd, buf, sizeof buf) != 12*12)
                sysfatal("can't connect to display: %r");
        id = atoi(buf+0*12);
        if(strncmp(buf+2*12, "         m8 ", 12) != 0)
                sysfatal("can't set colormap except on CMAP8 (m8) displays; this one is %.12s", buf+2*12);

        if(getcmap(id, map, cmapbuf) == 0){
                fprint(2, "%s: can't find %s\n", argv[0], map);
                exits("not found");
        }

        putcmap(id, cmapbuf);
        exits(0);
}