Collision data shape ordering (second attempt)

echo/Shape.hx

@@ -206,11 +206,11 @@ class Shape #if cog implements cog.IComponent #end {
 
  public function collides(s:Shape):Null<CollisionData> return null;
 
- function collide_rect(r:Rect):Null<CollisionData> return null;
+ function collide_rect(r:Rect, flip:Bool = false):Null<CollisionData> return null;
 
- function collide_circle(c:Circle):Null<CollisionData> return null;
+ function collide_circle(c:Circle, flip:Bool = false):Null<CollisionData> return null;
 
- function collide_polygon(p:Polygon):Null<CollisionData> return null;
+ function collide_polygon(p:Polygon, flip:Bool = false):Null<CollisionData> return null;
 
  function toString() {
  var s = switch (type) {

echo/shape/Circle.hx

@@ -87,13 +87,13 @@ class Circle extends Shape implements Poolable {
  return false;
  }
 
- override inline function collides(s:Shape):Null<CollisionData> return s.collide_circle(this);
+ override inline function collides(s:Shape):Null<CollisionData> return s.collide_circle(this, true);
 
- override inline function collide_rect(r:Rect):Null<CollisionData> return r.rect_and_circle(this, true);
+ override inline function collide_rect(r:Rect, flip:Bool = false):Null<CollisionData> return r.rect_and_circle(this, !flip);
 
- override inline function collide_circle(c:Circle):Null<CollisionData> return c.circle_and_circle(this);
+ override inline function collide_circle(c:Circle, flip:Bool = false):Null<CollisionData> return c.circle_and_circle(this, !flip);
 
- override inline function collide_polygon(p:Polygon):Null<CollisionData> return this.circle_and_polygon(p, true);
+ override inline function collide_polygon(p:Polygon, flip:Bool = false):Null<CollisionData> return this.circle_and_polygon(p, flip);
 
  // getters
  inline function get_radius():Float return local_radius * scale_x;

echo/shape/Polygon.hx

@@ -197,13 +197,13 @@ class Polygon extends Shape implements Poolable {
  return false;
  }
 
- override inline function collides(s:Shape):Null<CollisionData> return s.collide_polygon(this);
+ override inline function collides(s:Shape):Null<CollisionData> return s.collide_polygon(this, true);
 
- override inline function collide_rect(r:Rect):Null<CollisionData> return r.rect_and_polygon(this, true);
+ override inline function collide_rect(r:Rect, flip:Bool = false):Null<CollisionData> return r.rect_and_polygon(this, !flip);
 
- override inline function collide_circle(c:Circle):Null<CollisionData> return c.circle_and_polygon(this);
+ override inline function collide_circle(c:Circle, flip:Bool = false):Null<CollisionData> return c.circle_and_polygon(this, !flip);
 
- override inline function collide_polygon(p:Polygon):Null<CollisionData> return p.polygon_and_polygon(this, true);
+ override inline function collide_polygon(p:Polygon, flip:Bool = false):Null<CollisionData> return this.polygon_and_polygon(p, flip);
 
  override inline function get_top():Float {
  if (count == 0 || vertices[0] == null) return y;

echo/shape/Rect.hx

@@ -174,13 +174,13 @@ class Rect extends Shape implements Poolable {
  return false;
  }
 
- override inline function collides(s:Shape):Null<CollisionData> return s.collide_rect(this);
+ override inline function collides(s:Shape):Null<CollisionData> return s.collide_rect(this, true);
 
- override inline function collide_rect(r:Rect):Null<CollisionData> return r.rect_and_rect(this);
+ override inline function collide_rect(r:Rect, flip:Bool = false):Null<CollisionData> return this.rect_and_rect(r, flip);
 
- override inline function collide_circle(c:Circle):Null<CollisionData> return this.rect_and_circle(c);
+ override inline function collide_circle(c:Circle, flip:Bool = false):Null<CollisionData> return this.rect_and_circle(c, flip);
 
- override inline function collide_polygon(p:Polygon):Null<CollisionData> return this.rect_and_polygon(p);
+ override inline function collide_polygon(p:Polygon, flip:Bool = false):Null<CollisionData> return this.rect_and_polygon(p, flip);
 
  override function set_parent(?body:Body) {
  super.set_parent(body);

echo/util/SAT.hx

@@ -190,17 +190,17 @@ class SAT {
  var col:CollisionData = null;
  if (rect1.rotation != 0 || rect2.rotation != 0) {
  if (rect1.transformed_rect != null) {
- col = rect_and_polygon(rect2, rect1.transformed_rect, flip);
+ col = rect_and_polygon(rect2, rect1.transformed_rect, !flip);
 
  if (col == null) return null;
 
- if (flip) col.sa = rect1;
+ if (flip) col.sa = rect2;
  else col.sb = rect1;
 
  return col;
  }
  if (rect2.transformed_rect != null) {
- col = rect_and_polygon(rect1, rect2.transformed_rect, !flip);
+ col = rect_and_polygon(rect1, rect2.transformed_rect, flip);
 
  if (col == null) return null;
 
@@ -318,6 +318,7 @@ class SAT {
  data1.put();
  return data2;
  }
+
  /**
  * Test a Rect and a Circle for a Collision.
  * @param r
@@ -327,19 +328,24 @@ class SAT {
  */
  public static function rect_and_circle(r:Rect, c:Circle, flip:Bool = false):Null<CollisionData> {
  if (r.transformed_rect != null && r.rotation != 0) {
- var col = circle_and_polygon(c, r.transformed_rect, flip);
+ var col = circle_and_polygon(c, r.transformed_rect, !flip);
 
  if (col == null) return null;
 
- if (flip) col.sa = r;
- else col.sb = r;
+ // collisions used the transformed rect, set the collision data's shape back
+ // to the original rect
+ if (!flip) {
+ col.sa = r;
+ } else {
+ col.sb = r;
+ }
 
  return col;
  }
 
  // Vector from A to B
- var nx = flip ? c.x - r.x : r.x - c.x;
- var ny = flip ? c.y - r.y : r.y - c.y;
+ var nx = flip ? r.x - c.x : c.x - r.x;
+ var ny = flip ? r.y - c.y : c.y - r.y;
  // Closest point on A to center of B
  var cx = nx;
  var cy = ny;
@@ -407,8 +413,13 @@ class SAT {
 
  if (col == null) return null;
 
- if (flip) col.sb = r;
- else col.sa = r;
+ // collisions were done with a polygon derrived from the provided rect
+ // so we need to set our collision data shape back to the original rectangle
+ if (flip) {
+ col.sb = r;
+ } else {
+ col.sa = r;
+ }
 
  return col;
  }
@@ -495,7 +506,7 @@ class SAT {
  test1 = min1 - max2;
  test2 = min2 - max1;
 
- // Preform another test
+ // Preform another test // TODO: What is this test doing, exactly?
  if (test1 > 0 || test2 > 0) {
  col.put();
  return null;
@@ -579,7 +590,9 @@ class SAT {
  col.sa = flip ? polygon2 : polygon1;
  col.sb = flip ? polygon1 : polygon2;
 
- if (flip) {
+ // collision normal is calculated as resolution for poly2, so we need to
+ // negate the normal if we are not flipping the collision check.
+ if (!flip) {
  col.normal.negate();
  }
 

sample/Main.hx

@@ -46,7 +46,7 @@ class Main extends BaseApp {
 
  // Set up our Sample States
  sample_states = [
- PolygonState, StackingState, MultiShapeState, ShapesState, GroupsState, StaticState, LinecastState, Linecast2State, TileMapState, TileMapState2,
+ OverlappingSpawnState, ListenerState, PolygonState, StackingState, MultiShapeState, ShapesState, GroupsState, StaticState, LinecastState, Linecast2State, TileMapState, TileMapState2,
  BezierState, VerletState
  ];
  index = 0;

sample/state/ListenerState.hx

@@ -0,0 +1,82 @@
+package state;
+
+import echo.data.Options.ListenerOptions;
+import echo.Material;
+import echo.Body;
+import echo.World;
+import util.Random;
+
+class ListenerState extends BaseState {
+
+ override public function enter(world:World) {
+ Main.instance.state_text.text = "Sample: Collision Listener";
+
+ // Create a material for all the shapes to share
+ var material:Material = {elasticity: 0.7};
+
+ var bodyA = new Body({
+ x: Random.range(60, world.width - 60),
+ y: Random.range(0, world.height / 2),
+ // rotation: Random.range(0, 360),
+ material: material,
+ shapes: [
+ {
+ type: POLYGON,
+ radius: Random.range(16, 32),
+ width: Random.range(16, 48),
+ height: Random.range(16, 48),
+ sides: Random.range_int(3, 8),
+ offset_y: -10,
+ },
+ {
+ type: POLYGON,
+ radius: Random.range(16, 32),
+ width: Random.range(16, 48),
+ height: Random.range(16, 48),
+ sides: Random.range_int(3, 8),
+ offset_y: 10,
+ }
+ ]
+ });
+ world.add(bodyA);
+
+ // Add a Physics body at the bottom of the screen for the other Physics Bodies to stack on top of
+ // This body has a mass of 0, so it acts as an immovable object
+ var bodyB = new Body({
+ mass: STATIC,
+ x: world.width / 5,
+ y: world.height - 40,
+ material: material,
+ rotation: 5,
+ shape: {
+ type: RECT,
+ width: world.width,
+ height: 20
+ }
+ });
+ world.add(bodyB);
+
+ var dbgOpts:ListenerOptions = {
+ enter: (a, b, data) -> {
+ trace('bodyA == listener `a`: ${bodyA == a}');
+ // the second shape is our 'bottom' shape that is making the collision
+ trace('bodyA owns data `shape a`: ${bodyA.shapes.contains(data[0].sa)}');
+ trace('bodyB == listener `b`: ${bodyB == b}');
+ trace('bodyB owns `shape b`: ${bodyB.shapes.contains(data[0].sb)}');
+ },
+ };
+
+ // Create a listener for collisions between the Physics Bodies
+ world.listen(bodyA, bodyB, dbgOpts);
+ }
+
+ override function step(world:World, dt:Float) {
+ // Reset any off-screen Bodies
+ world.for_each((member) -> {
+ if (offscreen(member, world)) {
+ member.velocity.set(0, 0);
+ member.set_position(Random.range(0, world.width), 0);
+ }
+ });
+ }
+}

sample/state/OverlappingSpawnState.hx

@@ -0,0 +1,72 @@
+package state;
+
+import echo.data.Options.ListenerOptions;
+import echo.Material;
+import echo.Body;
+import echo.World;
+import util.Random;
+
+class OverlappingSpawnState extends BaseState {
+
+ override public function enter(world:World) {
+ Main.instance.state_text.text = "Sample: Collision Listener";
+
+ // Create a material for all the shapes to share
+ var material:Material = {elasticity: 0.7};
+
+ var body = new Body({
+ x: 200,
+ y: 50,
+ rotation: 0,
+ material: material,
+ shape: {
+ type: CIRCLE,
+ radius: 16,
+ offset_y: 0,
+ }
+ });
+ world.add(body);
+
+ // body = new Body({
+ // x: 200,
+ // y: 53,
+ // rotation: 0,
+ // material: material,
+ // shape: {
+ // type: CIRCLE,
+ // radius: 12,
+ // offset_y: 0,
+ // }
+ // });
+ // world.add(body);
+
+ // Add a Physics body at the bottom of the screen for the other Physics Bodies to stack on top of
+ // This body has a mass of 0, so it acts as an immovable object
+ var floor = new Body({
+ mass: STATIC,
+ x: world.width / 5,
+ y: world.height - 40,
+ material: material,
+ // rotation: 5,
+ shape: {
+ type: RECT,
+ width: world.width,
+ height: 20
+ }
+ });
+ world.add(floor);
+
+ // Create a listener for collisions between the Physics Bodies
+ world.listen();
+ }
+
+ override function step(world:World, dt:Float) {
+ // Reset any off-screen Bodies
+ world.for_each((member) -> {
+ if (offscreen(member, world)) {
+ member.velocity.set(0, 0);
+ member.set_position(Random.range(0, world.width), 0);
+ }
+ });
+ }
+}

sample/state/PolygonState.hx

@@ -21,7 +21,7 @@ class PolygonState extends BaseState {
  var b = new Body({
  x: Random.range(60, world.width - 60),
  y: Random.range(0, world.height / 2),
- rotation: Random.range(0, 360),
+ rotation: 0,
  material: material,
  shape: {
  type: POLYGON,

sample/state/StaticState.hx

@@ -33,6 +33,8 @@ class StaticState extends BaseState {
  shape: {
  type: CIRCLE,
  radius: Random.range(2, 4),
+ width: Random.range(2, 4),
+ height: Random.range(2, 4)
  }
  });
  world.add(b);