From 452c5f4e6f258ab0ff86c25c48d6a36b401e5651 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@habraun.net>
Date: Wed, 4 Mar 2009 11:27:19 +0100
Subject: [PATCH] Physics: Added support for applying impulses to Body.

---
 src/net/habraun/kong/physics/Body.scala      | 22 +++++++++++++
 test/net/habraun/kong/physics/BodyTest.scala | 46 ++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/src/net/habraun/kong/physics/Body.scala b/src/net/habraun/kong/physics/Body.scala
index 55eb3cb..1d0ee85 100644
--- a/src/net/habraun/kong/physics/Body.scala
+++ b/src/net/habraun/kong/physics/Body.scala
@@ -132,6 +132,28 @@ class Body {
 
 
 	/**
+	 * Applies an impulse to the body.
+	 * The effect of the impulse is computed when the world simulation is stepped.
+	 * Valling this method several times between steps will simply add the applied impulses up. When the
+	 * simulation is stepped, the sum of all the impulses is applied.
+	 * An impulse must never be null.
+	 */
+
+	private[this] var _appliedImpulse = Vec2D(0, 0)
+
+	def appliedImpulse = _appliedImpulse
+
+	def applyImpulse(impulse: Vec2D) {
+		_appliedImpulse += impulse
+	}
+
+	def resetImpulse {
+		_appliedImpulse = Vec2D(0, 0)
+	}
+
+
+
+	/**
 	 * Sets the maximum velocity for this body.
 	 * After creation, a body has a maximum velocity of Double.PositiveInfinity.
 	 * The maximum velocity must never be negative.
diff --git a/test/net/habraun/kong/physics/BodyTest.scala b/test/net/habraun/kong/physics/BodyTest.scala
index 3079805..1232a0c 100644
--- a/test/net/habraun/kong/physics/BodyTest.scala
+++ b/test/net/habraun/kong/physics/BodyTest.scala
@@ -188,6 +188,52 @@ class BodyTest {
 
 
 
+	@Test
+	def checkInitialAppliedImpulse {
+		val body = new Body
+		assertEquals(Vec2D(0, 0), body.appliedImpulse)
+	}
+
+
+
+	@Test
+	def applyImpulse {
+		val body = new Body
+		val impulse = Vec2D(10, 10)
+		body.applyImpulse(impulse)
+		assertEquals(impulse, body.appliedImpulse)
+	}
+
+
+
+	@Test
+	def applyTwoImpulses {
+		val body = new Body
+		body.applyImpulse(Vec2D(2, 1))
+		body.applyImpulse(Vec2D(1, 2))
+		assertEquals(Vec2D(3, 3), body.appliedImpulse)
+	}
+
+
+
+	@Test { val expected = classOf[NullPointerException] }
+	def applyNullImpulse {
+		val body = new Body
+		body.applyImpulse(null)
+	}
+
+
+
+	@Test
+	def applyAndResetImpulse {
+		val body = new Body
+		body.applyImpulse(Vec2D(10, 10))
+		body.resetImpulse
+		assertEquals(Vec2D(0, 0), body.appliedImpulse)
+	}
+
+
+
 	@Test { val expected = classOf[NullPointerException] }
 	def applyNullForceExpectException {
 		val body = new Body
-- 
2.11.4.GIT