git release.HEADmaster

1 files changed, 54 insertions, 0 deletions

diff --git a/vector.c b/vector.c
new file mode 100644
index 0000000..21a3711
--- /dev/null
+++ b/vector.c
@@ -0,0 +1,54 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include "dat.h"
+#include "fns.h"
+
+Vector
+Vec(double x, double y)
+{
+	return (Vector){x, y};
+}
+
+Vector
+Vpt(Point p)
+{
+	return (Vector){p.x, p.y};
+}
+
+Vector
+addvec(Vector v, Vector u)
+{
+	return (Vector){v.x+u.x, v.y+u.y};
+}
+
+Vector
+subvec(Vector v, Vector u)
+{
+	return (Vector){v.x-u.x, v.y-u.y};
+}
+
+Vector
+mulvec(Vector v, double s)
+{
+	return (Vector){v.x*s, v.y*s};
+}
+
+double
+dotvec(Vector v, Vector u)
+{
+	return v.x*u.x + v.y*u.y;
+}
+
+Vector
+normvec(Vector v)
+{
+	double len;
+
+	len = hypot(v.x, v.y);
+	if(len == 0)
+		return (Vector){0, 0};
+	v.x /= len;
+	v.y /= len;
+	return v;
+}