prova.collision.intersects source code

1 module prova.collision.intersects;
2 
3 import prova.collision,
4        prova.math,
5        std.math;
6 
7 bool pointIntersectsPoint(PointCollider pointA, PointCollider pointB)
8 {
9   return pointA.getPosition() == pointB.getPosition();
10 }
11 
12 bool pointIntersectsCircle(PointCollider point, CircleCollider circle)
13 {
14   const float distance = point.getPosition().distanceTo(circle.getPosition());
15   
16   return distance <= circle.radius;
17 }
18 
19 bool pointIntersectsRect(PointCollider point, RectCollider rect)
20 {
21   Vector2 position = point.getPosition();
22   Rect bounds = rect.getBounds();
23 
24   return position.x > bounds.left && position.x < bounds.left + bounds.width &&
25         position.y < bounds.top && position.y > bounds.top - bounds.height;
26 }
27 
28 bool circleIntersectsCircle(CircleCollider circleA, CircleCollider circleB)
29 {
30   const float distance = circleA.getPosition().distanceTo(circleB.getPosition());
31 
32   return distance < circleA.radius + circleB.radius;
33 }
34 
35 bool circleIntersectsRect(CircleCollider circle, RectCollider rect)
36 {
37   // Following answer provided by e.James https://stackoverflow.com/users/33686/e-james
38   // https://stackoverflow.com/questions/401847/circle-rectangle-collision-detection-intersection
39 
40   const Vector2 circlePosition = circle.getPosition();
41   const Vector2 rectPosition = rect.getPosition();
42 
43   const Vector2 distance = Vector2(
44     abs(circlePosition.x - rectPosition.x),
45     abs(circlePosition.y - rectPosition.y)
46   );
47 
48   if(distance.x >= rect.width / 2 + circle.radius)
49     return false;
50   if(distance.y >= rect.height / 2 + circle.radius)
51     return false;
52 
53   if(distance.x < rect.width / 2)
54     return true;
55   if(distance.y < rect.height / 2)
56     return true;
57 
58   const float cornerDistSquared = (distance.x - rect.width / 2) ^^ 2 +
59                                   (distance.y - rect.height / 2) ^^ 2;
60 
61   return cornerDistSquared < circle.radius ^^ 2;
62 }
63 
64 bool rectIntersectsRect(RectCollider rectA, RectCollider rectB)
65 {
66   Rect boundsA = rectA.getBounds();
67   Rect boundsB = rectB.getBounds();
68 
69   return boundsA.left < boundsB.right &&
70           boundsA.right > boundsB.left &&
71           boundsA.top > boundsB.bottom &&
72           boundsA.bottom < boundsB.top;
73 }