1 files changed, 20 insertions, 0 deletions
diff --git a/vec.go b/vec.go
new file mode 100644
index 0000000..08422c6
--- /dev/null
+++ b/vec.go
@@ -0,0 +1,20 @@
+package mt
+
+// A Vec is a 3D vector in units of 0.1 nodes.
+type Vec [3]float32
+
+// Add returns v+w.
+func (v Vec) Add(w Vec) Vec {
+	for i := range v {
+		v[i] += w[i]
+	}
+	return v
+}
+
+// Sub returns v-w.
+func (v Vec) Sub(w Vec) Vec {
+	for i := range v {
+		v[i] -= w[i]
+	}
+	return v
+}