basic collision detection

1 files changed, 28 insertions, 0 deletions

diff --git a/assets/javascripts/rectangles/models/room.js b/assets/javascripts/rectangles/models/room.js
index 3ccf1fb..c760174 100644
--- a/assets/javascripts/rectangles/models/room.js
+++ b/assets/javascripts/rectangles/models/room.js
@@ -40,7 +40,35 @@ window.room = (function(){
 		}
 		this.regions = regions
 	}
+	
+	room.prototype.collides = function(x,y){
+		var collision = 0
+		this.regions.forEach(function(r){
+			if (! r.sides) return
+
+			if ((r.sides & FRONT) && y < r.y.a && r.x.contains(x)) {
+				collision |= FRONT
+			}
+			if ((r.sides & BACK) && r.y.b < y && r.x.contains(x)) {
+				collision |= BACK
+			}
+			if ((r.sides & LEFT) && x < r.x.a && r.y.contains(y)) {
+				collision |= LEFT
+			}
+			if ((r.sides & RIGHT) && r.x.b < x && r.y.contains(y)) {
+				collision |= RIGHT
+			}
+		})
+		return collision
+	}
 
 	return room
 
 })()
+
+function bitcount(v) {
+  v = v - ((v >>> 1) & 0x55555555);
+  v = (v & 0x33333333) + ((v >>> 2) & 0x33333333);
+  return ((v + (v >>> 4) & 0xF0F0F0F) * 0x1010101) >>> 24;
+}
+