1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4 
5 static
6 int
7 unitsperline(Rectangle r, int d, int bitsperunit)
8 {
9 	ulong l, t;
10 
11 	if(d <= 0 || d > 32)	/* being called wrong.  d is image depth. */
12 		abort();
13 
14 	if(r.min.x >= 0){
15 		l = (r.max.x*d+bitsperunit-1)/bitsperunit;
16 		l -= (r.min.x*d)/bitsperunit;
17 	}else{			/* make positive before divide */
18 		t = (-r.min.x*d+bitsperunit-1)/bitsperunit;
19 		l = t+(r.max.x*d+bitsperunit-1)/bitsperunit;
20 	}
21 	return l;
22 }
23 
24 int
25 wordsperline(Rectangle r, int d)
26 {
27 	return unitsperline(r, d, 8*sizeof(u32int));
28 }
29 
30 int
31 bytesperline(Rectangle r, int d)
32 {
33 	return unitsperline(r, d, 8);
34 }