time for a snapshot

workshop/steps/04-aabb/aabb.ts

@@ -0,0 +1,18 @@
+export type Vec = { x: number; y: number };
+
+/** Axis-aligned box: (x,y) is the top-left corner, w/h are width/height. */
+export type AABB = { x: number; y: number; w: number; h: number };
+
+/** Is the point inside (or on the edge of) the box? */
+export function pointInAABB(p: Vec, box: AABB): boolean {
+	return (
+		p.x >= box.x && p.x <= box.x + box.w && p.y >= box.y && p.y <= box.y + box.h
+	);
+}
+
+/** Do the two boxes overlap right now? (discrete test) */
+export function aabbOverlap(a: AABB, b: AABB): boolean {
+	return (
+		a.x < b.x + b.w && b.x < a.x + a.w && a.y < b.y + b.h && b.y < a.y + a.h
+	);
+}