From 9d20024aa35cd7f923ebfc1ed9a2ffbf2731da70 Mon Sep 17 00:00:00 2001
From: Jakob Odersky <jodersky@gmail.com>
Date: Thu, 5 Nov 2009 21:02:40 +0000
Subject: Initial import.

---
 src/sims/dynamics/joints/SpringJoint.scala | 60 ++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 src/sims/dynamics/joints/SpringJoint.scala

(limited to 'src/sims/dynamics/joints/SpringJoint.scala')

diff --git a/src/sims/dynamics/joints/SpringJoint.scala b/src/sims/dynamics/joints/SpringJoint.scala
new file mode 100644
index 0000000..f03b35d
--- /dev/null
+++ b/src/sims/dynamics/joints/SpringJoint.scala
@@ -0,0 +1,60 @@
+/*
+ * Simple Mechanics Simulator (SiMS)
+ * copyright (c) 2009 Jakob Odersky
+ * made available under the MIT License
+*/
+
+package sims.dynamics.joints
+
+import sims.geometry._
+
+/**Eine Hooksche Feder.
+ * @param node1 erster Koerper der Verbindung
+ * @param anchor1 Bindungspunkt auf Koerper eins
+ * @param node2 zweiter Koerper der Verbindung
+ * @param anchor2 Bindungspunkt auf Koerper zwei
+ * @param springConstant Federkonstante
+ * @param initialLength Initiallaenge
+ */
+case class SpringJoint(node1: Body, anchor1: Vector2D, node2: Body, anchor2: Vector2D, springConstant: Double, initialLength: Double) extends Joint with ForceJoint{
+  
+  def this(node1: Body, anchor1: Vector2D, node2: Body, anchor2: Vector2D, springConstant: Double) = {
+    this(node1: Body, anchor1, node2: Body, anchor2, springConstant: Double, (anchor2 - anchor1).length)
+  }
+  
+  def this(node1: Body, node2: Body, springConstant: Double, initialLength: Double) = {
+    this(node1: Body, node1.pos, node2: Body, node2.pos, springConstant: Double, initialLength: Double)
+  }
+  def this(node1: Body, node2: Body, springConstant: Double) = {
+    this(node1: Body, node1.pos, node2: Body, node2.pos, springConstant: Double, (node2.pos - node1.pos).length)
+  }
+  
+  private val a1 = anchor1 - node1.pos
+  private val a2 = anchor2 - node2.pos
+  private val initRotation1 = node1.rotation
+  private val initRotation2 = node2.rotation
+  
+  /**Ergibt den Bindungspunkt auf Koerper eins.*/
+  def connection1 = (a1 rotate (node1.rotation - initRotation1)) + node1.pos
+  
+  /**Ergibt den Bindungspunkt auf Koerper zwei.*/
+  def connection2 = (a2 rotate (node2.rotation - initRotation2)) + node2.pos
+  
+  /**Daempfung.*/
+  var damping = 0.0
+  
+  /**Relative Position der Bindungspunkte.*/
+  def x = connection2 - connection1
+  
+  /**Ergibt die Federkraft nach dem Hookschen Gesetz.*/
+  def force = (x.length - initialLength) * springConstant
+  
+  /**Uebt die Federkraft auf die Bindungspunkte aus.*/
+  def applyForce() = {
+    node1.applyForce(x.unit * force - ((node1 velocityOfPoint connection1) * damping) project x, connection1)
+    node2.applyForce(-x.unit * force - ((node2 velocityOfPoint connection2) * damping) project x, connection2)
+  }
+  
+  def correctPosition(h: Double) = ()
+  def correctVelocity(h: Double) = ()
+}
\ No newline at end of file
-- 
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