1 files changed, 34 insertions, 0 deletions
diff --git a/src/main/scala/sims/dynamics/Circle.scala b/src/main/scala/sims/dynamics/Circle.scala
new file mode 100644
index 0000000..d6db07d
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+++ b/src/main/scala/sims/dynamics/Circle.scala
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+/*
+ * Simple Mechanics Simulator (SiMS)
+ * copyright (c) 2009 Jakob Odersky
+ * made available under the MIT License
+*/
+
+package sims.dynamics
+
+import sims.geometry._
+import sims.collision._
+
+/**
+ * A circle.
+ * @param radius radius of this circle
+ * @param density density of this circle
+ */
+case class Circle(radius: Double, density: Double) extends Shape{
+  
+  val volume = math.Pi * radius * radius
+  
+  val I = mass * radius * radius / 2
+  
+  def AABB = new AABB(pos - Vector2D(radius,radius),
+                      pos + Vector2D(radius,radius))
+  
+  def project(axis: Vector2D) = if (axis.x != 0) Projection(axis,
+                                                            (pos.project(axis).x / axis.x) - radius,
+                                                            (pos.project(axis).x / axis.x) + radius)
+                                else Projection(axis,
+                                                (pos.project(axis).y / axis.y) - radius,
+                                                (pos.project(axis).y / axis.y) + radius)
+  
+  def contains(point: Vector2D) = (point - pos).length <= radius
+}