1 files changed, 55 insertions, 0 deletions
diff --git a/src/main/scala/sims/collision/AABB.scala b/src/main/scala/sims/collision/AABB.scala
new file mode 100644
index 0000000..68782d1
--- /dev/null
+++ b/src/main/scala/sims/collision/AABB.scala
@@ -0,0 +1,55 @@
+/*    _____ _ __  ________    ___                                      *\
+**   / ___/(_)  |/  / ___/   |__ \  Simple Mechanics Simulator 2       **
+**   \__ \/ / /|_/ /\__ \    __/ /  copyright (c) 2011 Jakob Odersky   **
+**  ___/ / / /  / /___/ /   / __/                                      **
+** /____/_/_/  /_//____/   /____/                                      **
+\*                                                                     */
+
+package sims.collision
+
+import sims.math._
+
+/* 
+ * y
+ * ^
+ * |
+ * |  +-------+
+ * |  |    max|
+ * |  |       |
+ * |  |min    |
+ * |  +-------+
+ * |
+ * 0-------------->x
+ * 
+ */
+
+/** Axis Aligned Bounding Boxes (AABBs) are rectangles that frame a shape.
+  * Their X-axis and Y-axis orientation makes it easy to test two AABBs for overlap.
+  * @param minVertex Position vector of the bottom-left vertex
+  * @param maxVertex Position vector of the upper-right vertex */
+case class AABB(val minVertex: Vector2D,
+                val maxVertex: Vector2D) {
+	
+	/** Diagonal vector from `minVertex` to `maxVertex`. */
+	def diagonal = maxVertex - minVertex
+	
+	/** Width of this AABB. */
+	def width = maxVertex.x - minVertex.x
+	
+	/** Height of this AABB. */
+	def height = maxVertex.y - minVertex.y
+	
+	/** Checks if the given point is located within this AABB. */
+	def contains(point: Vector2D): Boolean = minVertex.x <= point.x && point.x <= maxVertex.x && minVertex.y <= point.y && point.y <= maxVertex.y
+	
+	/** Checks if the given AABB is located within this AABB. */
+	def contains(box: AABB): Boolean = contains(box.minVertex) && contains(box.maxVertex)
+	
+  /** Checks this AABB with <code>box</code> for overlap.
+    * @param box AABB with which to check for overlap */
+  def overlaps(box: AABB): Boolean = {
+    val d1 = box.minVertex - maxVertex
+    val d2 = minVertex - box.maxVertex
+    !(d1.x > 0 || d1.y > 0 || d2.x > 0 || d2.y > 0)
+  }
+}