1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4
5 static
6 int
unitsperline(Rectangle r,int d,int bitsperunit)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
wordsperline(Rectangle r,int d)25 wordsperline(Rectangle r, int d)
26 {
27 return unitsperline(r, d, 8*sizeof(ulong));
28 }
29
30 int
bytesperline(Rectangle r,int d)31 bytesperline(Rectangle r, int d)
32 {
33 return unitsperline(r, d, 8);
34 }
35