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#include <u.h>
#include <libc.h>
#include <draw.h>
enum { SEC = 1000 };
enum {
Cred,
Cgrn,
Cblu,
Cgx,
Cgy,
Cend
};
Image *col[Cend];
int dx, dy;
void *
emalloc(ulong n)
{
void *p;
p = malloc(n);
if(p == nil)
sysfatal("malloc: %r");
memset(p, 0, n);
setmalloctag(p, getcallerpc(&n));
return p;
}
Image *
eallocimage(Display *d, Rectangle r, ulong chan, int repl, ulong col)
{
Image *i;
i = allocimage(d, r, chan, repl, col);
if(i == nil)
sysfatal("allocimage: %r");
return i;
}
void
usage(void)
{
fprint(2, "usage: colgrad\n");
exits("usage");
}
void
main(int argc, char *argv[])
{
int i;
uchar *gx, *gy;
ARGBEGIN{
default: usage();
}ARGEND;
if(initdraw(nil, nil, "colgrad") < 0)
sysfatal("initdraw: %r");
dx = Dx(screen->r), dy = Dy(screen->r);
col[Cred] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DRed);
col[Cgrn] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DGreen);
col[Cblu] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DBlue);
col[Cgx] = eallocimage(display, Rect(0, 0, dx, 1), GREY8, 1, DNofill);
col[Cgy] = eallocimage(display, Rect(0, 0, 1, dy), GREY8, 1, DNofill);
gx = emalloc(dx);
gy = emalloc(dy);
for(i = 0; i < dx; i++)
gx[i] = 255.0 * i/(dx-1);
for(i = 0; i < dy; i++)
gy[i] = 255.0 * i/(dy-1);
loadimage(col[Cgx], col[Cgx]->r, gx, dx);
loadimage(col[Cgy], col[Cgy]->r, gy, dy);
draw(screen, screen->r, col[Cred], nil, ZP);
draw(screen, screen->r, col[Cgrn], col[Cgx], ZP);
draw(screen, screen->r, col[Cblu], col[Cgy], ZP);
flushimage(display, 1);
sleep(5*SEC);
exits(0);
}
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