Adding tests for forces and impulses.

Author: slembcke

UnitTests/CCPhysicsTests.m

@@ -770,6 +770,156 @@ -(void)testBodyEachCollisionPair
 	[physicsNode onExit];
 }
 
+-(void)testApplyImpulse
+{
+	CCPhysicsNode *physics = [CCPhysicsNode node];
+	[physics onEnter];
+	
+	{
+		CCNode *node = [CCNode node];
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		node.physicsBody.velocity = ccp(10, 10);
+		[node.physicsBody applyImpulse:ccp(5, 5)];
+		XCTAssert(ccpDistance(ccp(11, 11), node.physicsBody.velocity) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.rotation = 90;
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		node.physicsBody.velocity = ccp(10, 10);
+		[node.physicsBody applyImpulse:ccp(5, 5)];
+		XCTAssert(ccpDistance(ccp(11, 11), node.physicsBody.velocity) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.position = ccp(20, 20);
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		node.physicsBody.velocity = ccp(10, 10);
+		[node.physicsBody applyImpulse:ccp(5, 5) atWorldPoint:node.position];
+		XCTAssert(ccpDistance(ccp(11, 11), node.physicsBody.velocity) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.position = ccp(20, 20);
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		node.physicsBody.velocity = ccp(10, 10);
+		[node.physicsBody applyImpulse:ccp(5, 5) atLocalPoint:ccp(0, 0)];
+		XCTAssert(ccpDistance(ccp(11, 11), node.physicsBody.velocity) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.position = ccp(20, 20);
+		node.rotation = 90;
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		node.physicsBody.velocity = ccp(10, 10);
+		[node.physicsBody applyImpulse:ccp(5, 0) atLocalPoint:ccp(0, 0)];
+		XCTAssert(ccpDistance(ccp(10, 9), node.physicsBody.velocity) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.position = ccp(20, 20);
+		node.rotation = 180;
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		node.physicsBody.velocity = ccp(10, 10);
+		[node.physicsBody applyImpulse:ccp(5, 0) atLocalPoint:ccp(0, 1)];
+		XCTAssert(ccpDistance(ccp(9, 10), node.physicsBody.velocity) < 1e-5, @"");
+		XCTAssertEqualWithAccuracy(node.physicsBody.angularVelocity, -2, 1e-5, @"");
+	}
+	
+	[physics onExit];
+}
+
+-(void)testApplyForce
+{
+	CCPhysicsNode *physics = [CCPhysicsNode node];
+	[physics onEnter];
+	
+	{
+		CCNode *node = [CCNode node];
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		[node.physicsBody applyForce:ccp(5, 5)];
+		XCTAssert(ccpDistance(ccp(5, 5), node.physicsBody.force) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.rotation = 90;
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		[node.physicsBody applyForce:ccp(5, 5)];
+		XCTAssert(ccpDistance(ccp(5, 5), node.physicsBody.force) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.position = ccp(20, 20);
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		[node.physicsBody applyForce:ccp(5, 5) atWorldPoint:node.position];
+		XCTAssert(ccpDistance(ccp(5, 5), node.physicsBody.force) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.position = ccp(20, 20);
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		[node.physicsBody applyForce:ccp(5, 5) atLocalPoint:ccp(0, 0)];
+		XCTAssert(ccpDistance(ccp(5, 5), node.physicsBody.force) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.position = ccp(20, 20);
+		node.rotation = 90;
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		[node.physicsBody applyForce:ccp(5, 0) atLocalPoint:ccp(0, 0)];
+		XCTAssert(ccpDistance(ccp(0, -5), node.physicsBody.force) < 1e-5, @"");
+	}{
+		CCNode *node = [CCNode node];
+		node.position = ccp(20, 20);
+		node.rotation = 180;
+		[physics addChild:node];
+		
+		node.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:1 andCenter:CGPointZero];
+		node.physicsBody.mass = 5;
+		
+		[node.physicsBody applyForce:ccp(5, 0) atLocalPoint:ccp(0, 1)];
+		XCTAssert(ccpDistance(ccp(-5, 0), node.physicsBody.force) < 1e-5, @"");
+		XCTAssertEqualWithAccuracy(node.physicsBody.torque, -5, 1e-5, @"");
+	}
+	
+	[physics onExit];
+}
+
 // TODO
 // * Check that body and shape settings are preserved through multiple add/remove cycles and are actually applied to the cpBody.
 // * Check that changing properties before and after adding to an active physics node updates the properties correctly.

cocos2d/CCPhysicsBody.m

@@ -314,14 +314,12 @@ -(void)applyImpulse:(CGPoint)impulse {_body.velocity = cpvadd(_body.velocity, cp
 
 -(void)applyForce:(CGPoint)force atLocalPoint:(CGPoint)point
 {
-	cpVect f = cpTransformVect(_body.transform, CCP_TO_CPV(force));
-	[_body applyForce:f atLocalPoint:CCP_TO_CPV(point)];
+	[_body applyForce:CCP_TO_CPV(force) atLocalPoint:CCP_TO_CPV(point)];
 }
 
 -(void)applyImpulse:(CGPoint)impulse atLocalPoint:(CGPoint)point
 {
-	cpVect j = cpTransformVect(_body.transform, CCP_TO_CPV(impulse));
-	[_body applyImpulse:j atLocalPoint:CCP_TO_CPV(point)];
+	[_body applyImpulse:CCP_TO_CPV(impulse) atLocalPoint:CCP_TO_CPV(point)];
 }
 
 -(void)applyForce:(CGPoint)force atWorldPoint:(CGPoint)point {[_body applyForce:CCP_TO_CPV(force) atWorldPoint:CCP_TO_CPV(point)];}