initial public release.HEADfront

1 files changed, 29 insertions, 0 deletions

diff --git a/util.c b/util.c
new file mode 100644
index 0000000..bd865df
--- /dev/null
+++ b/util.c
@@ -0,0 +1,29 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include "dat.h"
+#include "fns.h"
+
+double
+round(double n)
+{
+	return floor(n + 0.5);
+}
+
+Point
+rotatept(Point p, double θ, Point c)
+{
+	Point r;
+
+	p = subpt(p, c);
+	r.x = round(p.x*cos(θ) - p.y*sin(θ));
+	r.y = round(p.x*sin(θ) + p.y*cos(θ));
+	r = addpt(r, c);
+	return r;
+}
+
+double
+hypot3(double x, double y, double z)
+{
+	return hypot(x, hypot(y, z));
+}