Initial import.
diff --git a/src/libdraw/writesubfont.c b/src/libdraw/writesubfont.c
new file mode 100644
index 0000000..1ea985f
--- /dev/null
+++ b/src/libdraw/writesubfont.c
@@ -0,0 +1,45 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+
+static
+void
+packinfo(Fontchar *fc, uchar *p, int n)
+{
+ int j;
+
+ for(j=0; j<=n; j++){
+ p[0] = fc->x;
+ p[1] = fc->x>>8;
+ p[2] = fc->top;
+ p[3] = fc->bottom;
+ p[4] = fc->left;
+ p[5] = fc->width;
+ fc++;
+ p += 6;
+ }
+}
+
+int
+writesubfont(int fd, Subfont *f)
+{
+ char hdr[3*12+1];
+ uchar *data;
+ int nb;
+
+ sprint(hdr, "%11d %11d %11d ", f->n, f->height, f->ascent);
+ if(write(fd, hdr, 3*12) != 3*12){
+ Err:
+ werrstr("writesubfont: bad write: %r");
+ return -1;
+ }
+ nb = 6*(f->n+1);
+ data = malloc(nb);
+ if(data == nil)
+ return -1;
+ packinfo(f->info, data, f->n);
+ if(write(fd, data, nb) != nb)
+ goto Err;
+ free(data);
+ return 0;
+}
