reduce array allocations when doing collision

src/Marble.hx

@@ -260,7 +260,8 @@ class Marble extends GameObject {
 
 	public var contacts:Array<CollisionInfo> = [];
 	public var bestContact:CollisionInfo;
-	public var contactEntities:Array<CollisionEntity> = [];
+
+	static var contactScratch:Array<CollisionEntity> = [];
 
 	var queuedContacts:Array<CollisionInfo> = [];
 	var appliedImpulses:Array<{impulse:Vector, contactImpulse:Bool}> = [];
@@ -700,9 +701,7 @@ class Marble extends GameObject {
 	function findContacts(collisiomWorld:CollisionWorld, timeState:TimeState) {
 		this.contacts = queuedContacts;
 		CollisionPool.clear();
-		var c = collisiomWorld.sphereIntersection(this.collider, timeState);
+		collisiomWorld.sphereIntersection(this.collider, timeState, this.contacts);
-		this.contactEntities = c.foundEntities;
-		contacts = contacts.concat(c.contacts);
 	}
 
 	public function queueCollision(collisionInfo:CollisionInfo) {
@@ -1274,7 +1273,10 @@ class Marble extends GameObject {
 		searchbox.addSpherePos(position.x, position.y, position.z, _radius);
 		searchbox.addSpherePos(position.x + velocity.x * deltaT, position.y + velocity.y * deltaT, position.z + velocity.z * deltaT, _radius);
 
-		var foundObjs = this.collisionWorld.boundingSearch(searchbox);
+		contactScratch.resize(0);
+		this.collisionWorld.boundingSearch(searchbox, contactScratch);
+
+		var foundObjs = contactScratch;
 
 		var finalT = deltaT;
 		var found = false;
@@ -1904,7 +1906,7 @@ class Marble extends GameObject {
 			}
 			// }
 		}
-		this.queuedContacts = [];
+		this.queuedContacts.resize(0);
 
 		newPos = this.collider.transform.getPosition(); // this.getAbsPos().getPosition().clone();
 
@@ -1983,7 +1985,9 @@ class Marble extends GameObject {
 		// marbleHitbox.offset(end.x, end.y, end.z);
 
 		// spherebounds.addSpherePos(gjkCapsule.p2.x, gjkCapsule.p2.y, gjkCapsule.p2.z, gjkCapsule.radius);
-		var contacts = this.collisionWorld.boundingSearch(box);
+		contactScratch.resize(0);
+		this.collisionWorld.boundingSearch(box, contactScratch);
+		var contacts = contactScratch;
 		// var contacts = marble.contactEntities;
 		var inside = [];
 
@@ -2036,7 +2040,9 @@ class Marble extends GameObject {
 				var checkSphereRadius = checkBounds.getMax().sub(checkBoundsCenter).length();
 				var checkSphere = new Bounds();
 				checkSphere.addSpherePos(checkBoundsCenter.x, checkBoundsCenter.y, checkBoundsCenter.z, checkSphereRadius);
-				var endpadBB = this.collisionWorld.boundingSearch(checkSphere, false);
+				contactScratch.resize(0);
+				this.collisionWorld.boundingSearch(checkSphere, contactScratch, false);
+				var endpadBB = contactScratch;
 				var found = false;
 				for (collider in endpadBB) {
 					if (collider.go == @:privateAccess this.level.endPad) {
@@ -2820,7 +2826,6 @@ class Marble extends GameObject {
 		this.megaMarbleUseTick = 0;
 		this.netFlags = MarbleNetFlags.DoBlast | MarbleNetFlags.DoMega | MarbleNetFlags.DoHelicopter | MarbleNetFlags.DoShockAbsorber | MarbleNetFlags.DoSuperBounce | MarbleNetFlags.PickupPowerup | MarbleNetFlags.GravityChange | MarbleNetFlags.UsePowerup;
 		this.lastContactNormal = new Vector(0, 0, 1);
-		this.contactEntities = [];
 		this.cloak = false;
 		this._firstTick = true;
 		this.lastRespawnTick = -100000;

src/collision/BoxCollisionEntity.hx

@@ -56,7 +56,5 @@ class BoxCollisionEntity extends CollisionEntity implements IBVHObject {
 		return Math.POSITIVE_INFINITY;
 	}
 
-	public override function sphereIntersection(collisionEntity:SphereCollisionEntity, timeState:TimeState) {
+	public override function sphereIntersection(collisionEntity:SphereCollisionEntity, timeState:TimeState, contacts:Array<CollisionInfo>) {}
-		return [];
-	}
 }

src/collision/CollisionEntity.hx

@@ -200,7 +200,7 @@ class CollisionEntity implements IOctreeObject implements IBVHObject {
 		this.priority = priority;
 	}
 
-	public function sphereIntersection(collisionEntity:SphereCollisionEntity, timeState:TimeState) {
+	public function sphereIntersection(collisionEntity:SphereCollisionEntity, timeState:TimeState, contacts:Array<CollisionInfo>) {
 		var position = collisionEntity.transform.getPosition();
 		var radius = collisionEntity.radius + 0.001;
 
@@ -227,8 +227,6 @@ class CollisionEntity implements IOctreeObject implements IBVHObject {
 			invtform.load(Matrix.I());
 		}
 
-		var contacts = [];
-
 		for (obj in surfaces) {
 			var surface:CollisionSurface = cast obj;
 
@@ -301,7 +299,5 @@ class CollisionEntity implements IOctreeObject implements IBVHObject {
 			// if (surfaceBestContact != null)
 			// contacts.push(surfaceBestContact);
 		}
-
-		return contacts;
 	}
 }

src/collision/CollisionHull.hx

@@ -18,7 +18,7 @@ class CollisionHull extends CollisionEntity {
 		super(go);
 	}
 
-	public override function sphereIntersection(collisionEntity:SphereCollisionEntity, timeState:TimeState):Array<CollisionInfo> {
+	public override function sphereIntersection(collisionEntity:SphereCollisionEntity, timeState:TimeState, contacts:Array<CollisionInfo>) {
 		var bbox = this.boundingBox;
 		var box = new Bounds();
 		var pos = collisionEntity.transform.getPosition();
@@ -51,10 +51,9 @@ class CollisionHull extends CollisionEntity {
 				cinfo.friction = friction;
 				cinfo.force = force;
 				this.go.onMarbleContact(collisionEntity.marble, timeState, cinfo);
-				return [cinfo];
+				contacts.push(cinfo);
 			}
 		}
-		return [];
 	}
 
 	public override function addSurface(surface:CollisionSurface) {

src/collision/CollisionWorld.hx

@@ -38,11 +38,12 @@ class CollisionWorld {
 		this.dynamicGrid.build();
 	}
 
-	public function sphereIntersection(spherecollision:SphereCollisionEntity, timeState:TimeState):SphereIntersectionResult {
+	var contactList:Array<CollisionInfo> = [];
+	var intersectionList:Array<CollisionEntity> = [];
+
+	public function sphereIntersection(spherecollision:SphereCollisionEntity, timeState:TimeState, contacts:Array<CollisionInfo>) {
 		var position = spherecollision.transform.getPosition();
 		var radius = spherecollision.radius;
-		// var velocity = spherecollision.velocity;
-		// var intersections = this.octree.radiusSearch(position, searchdist);
 
 		var box = new Bounds();
 		box.addSpherePos(0, 0, 0, radius);
@@ -50,60 +51,24 @@ class CollisionWorld {
 		box.transform(rotQuat.toMatrix());
 		box.offset(position.x, position.y, position.z);
 		// box.addSpherePos(position.x + velocity.x * timeState.dt, position.y + velocity.y * timeState.dt, position.z + velocity.z * timeState.dt, radius);
-		var intersections = this.grid.boundingSearch(box);
+		this.intersectionList.resize(0);
+		this.grid.boundingSearch(box, this.intersectionList);
+		dynamicGrid.boundingSearch(box, this.intersectionList);
 
-		// var intersections = this.rtree.search([box.xMin, box.yMax, box.zMin], [box.xSize, box.ySize, box.zSize]);
+		for (obj in this.intersectionList) {
-
-		var contacts = [];
-		var foundEntities = [];
-
-		for (obj in intersections) {
-			var entity:CollisionEntity = cast obj;
-
-			foundEntities.push(entity);
-			if (entity.go.isCollideable) {
-				contacts = contacts.concat(entity.sphereIntersection(spherecollision, timeState));
-			}
-		}
-
-		// if (marbleEntities.length > 1) {
-		// 	marbleSap.recompute();
-		// 	var sapCollisions = marbleSap.getIntersections(spherecollision);
-		// 	for (obj in sapCollisions) {
-		// 		if (obj.go.isCollideable) {
-		// 			contacts = contacts.concat(obj.sphereIntersection(spherecollision, timeState));
-		// 		}
-		// 	}
-		// }
-
-		// contacts = contacts.concat(this.staticWorld.sphereIntersection(spherecollision, timeState));
-
-		var dynSearch = dynamicGrid.boundingSearch(box);
-		for (obj in dynSearch) {
 			if (obj != spherecollision) {
-				var col = cast(obj, CollisionEntity);
+				var entity = obj;
-				if (col.boundingBox.collide(box) && col.go.isCollideable)
+
-					contacts = contacts.concat(col.sphereIntersection(spherecollision, timeState));
+				if (obj.boundingBox.collide(box) && entity.go.isCollideable) {
+					entity.sphereIntersection(spherecollision, timeState, contacts);
+				}
 			}
 		}
-
-		// for (marb in marbleEntities) {
-		// 	if (marb != spherecollision) {
-		// 		if (spherecollision.go.isCollideable) {
-		// 			var isecs = marb.sphereIntersection(spherecollision, timeState);
-		// 			if (isecs.length > 0)
-		// 				foundEntities.push(marb);
-		// 			contacts = contacts.concat(isecs);
-		// 		}
-		// 	}
-		// }
-		return {foundEntities: foundEntities, contacts: contacts};
 	}
 
-	public function boundingSearch(bounds:Bounds, useCache:Bool = true) {
+	public function boundingSearch(bounds:Bounds, contacts:Array<CollisionEntity>, useCache:Bool = true) {
-		var contacts = this.grid.boundingSearch(bounds).map(x -> cast(x, CollisionEntity));
+		this.grid.boundingSearch(bounds, contacts);
-		contacts = contacts.concat(dynamicGrid.boundingSearch(bounds).map(x -> cast(x, CollisionEntity)));
+		dynamicGrid.boundingSearch(bounds, contacts);
-		return contacts;
 	}
 
 	public function rayCast(rayStart:Vector, rayDirection:Vector, rayLength:Float) {
@@ -116,19 +81,17 @@ class CollisionWorld {
 			+ rayDirection.x * rayLength, rayStart.y
 			+ rayDirection.y * rayLength, rayStart.z
 			+ rayDirection.z * rayLength);
-		var objs = this.grid.boundingSearch(bounds);
+		this.intersectionList.splice(0, this.intersectionList.length);
-		var dynObjs = dynamicGrid.boundingSearch(bounds);
+
+		this.grid.boundingSearch(bounds, this.intersectionList);
+		dynamicGrid.boundingSearch(bounds, this.intersectionList);
+
 		var results = [];
-		for (obj in objs) {
+		for (obj in this.intersectionList) {
-			var oo = cast(obj, CollisionEntity);
+			var oo = obj;
 			oo.rayCast(rayStart, rayDirection, results, rayLength);
 		}
 
-		for (obj in dynObjs) {
-			var oo = cast(obj, CollisionEntity);
-			oo.rayCast(rayStart, rayDirection, results, rayLength);
-		}
-		// results = results.concat(this.staticWorld.rayCast(rayStart, rayDirection));
 		return results;
 	}
 

src/collision/GridBroadphase.hx

@@ -221,7 +221,7 @@ class GridBroadphase {
 	}
 
 	// searchbox should be in LOCAL coordinates
-	public function boundingSearch(searchbox:Bounds) {
+	public function boundingSearch(searchbox:Bounds, foundSurfaces:Array<CollisionEntity>) {
 		var queryMinX = Math.max(searchbox.xMin, bounds.xMin);
 		var queryMinY = Math.max(searchbox.yMin, bounds.yMin);
 		var queryMaxX = Math.min(searchbox.xMax, bounds.xMax);
@@ -240,8 +240,6 @@ class GridBroadphase {
 		if (yEnd > CELL_SIZE)
 			yEnd = CELL_SIZE;
 
-		var foundSurfaces = [];
-
 		searchKey++;
 
 		// Insert the surface references from [xStart, yStart, zStart] to [xEnd, yEnd, zEnd] into the map

src/collision/SphereCollisionEntity.hx

@@ -75,10 +75,9 @@ class SphereCollisionEntity extends CollisionEntity {
 		return Math.POSITIVE_INFINITY;
 	}
 
-	public override function sphereIntersection(collisionEntity:SphereCollisionEntity, timeState:TimeState) {
+	public override function sphereIntersection(collisionEntity:SphereCollisionEntity, timeState:TimeState, contacts:Array<CollisionInfo>) {
 		if (ignore)
-			return [];
+			return;
-		var contacts = [];
 		var thispos = transform.getPosition();
 		var position = collisionEntity.transform.getPosition();
 		var velocity = collisionEntity.velocity;
@@ -113,6 +112,5 @@ class SphereCollisionEntity extends CollisionEntity {
 			// othercontact.penetration = this.radius - (thispos.sub(othercontact.point).dot(othercontact.normal));
 			// this.marble.queueCollision(othercontact);
 		}
-		return contacts;
 	}
 }