Did a lot of work off-repo, basically init

ui/util.go

@@ -0,0 +1,23 @@
+package ui
+
+// Max returns the larger integer.
+func Max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+// Min returns the smaller integer.
+func Min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+// Clamp keeps `v` within `a` and `b` numerically. `a` must be smaller than `b`.
+// Returns clamped `v`.
+func Clamp(v, a, b int) int {
+	return Max(a, Min(v, b))
+}