Exemplo n.º 1
0
        public static bool CollideBoxBox(Box2D boxA, Vector2 velocityA, Box2D boxB, float interpenetrationCorrection,
                                         out float collisionTime, out Vector2 collisionNormal, out Vector2 collisionEdge)
        {
#if COLLIDE_VIA_3D_ON_X
            Box3D   boxA_3d      = new Box3D(new Vector3(0, boxA.Min.X, boxA.Min.Y), new Vector3(1, boxA.Max.X, boxA.Max.Y));
            Vector3 velocityA_3d = new Vector3(0, velocityA.X, velocityA.Y);
            Box3D   boxB_3d      = new Box3D(new Vector3(0, boxB.Min.X, boxB.Min.Y), new Vector3(1, boxB.Max.X, boxB.Max.Y));

            bool returnValue = Collision3D.CollideBoxBox(boxA_3d, velocityA_3d, boxB_3d, interpenetrationCorrection,
                                                         out collisionTime, out Vector3 collisionNormal_3d, out Vector3 collisionEdgeUp_3d, out Vector3 collisionEdgeSide_3d);

            collisionNormal = new Vector2(collisionNormal_3d.Y, collisionNormal_3d.Z);
            collisionEdge   = new Vector2(collisionEdgeUp_3d.Y, collisionEdgeUp_3d.X);
            return(returnValue);
#elif COLLIDE_VIA_3D_ON_Z
            Box3D   boxA_3d      = new Box3D(new Vector3(boxA.Min.X, boxA.Min.Y, 0), new Vector3(boxA.Max.X, boxA.Max.Y, 1));
            Vector3 velocityA_3d = new Vector3(velocityA.X, velocityA.Y, 0);
            Box3D   boxB_3d      = new Box3D(new Vector3(boxB.Min.X, boxB.Min.Y, 0), new Vector3(boxB.Max.X, boxB.Max.Y, 1));

            bool returnValue = Collision3D.CollideBoxBox(boxA_3d, velocityA_3d, boxB_3d, interpenetrationCorrection,
                                                         out collisionTime, out Vector3 collisionNormal_3d, out Vector3 collisionEdgeUp_3d, out Vector3 collisionEdgeSide_3d);

            collisionNormal = new Vector2(collisionNormal_3d.X, collisionNormal_3d.Y);
            collisionEdge   = new Vector2(collisionEdgeUp_3d.X, collisionEdgeUp_3d.Y);
            return(returnValue);
#else
            Box2D expandedBoxB = boxB.ExpandBy(boxA);

            Vector2 boxACenter       = boxA.Center;
            Vector2 velocityAInverse = new Vector2(1.0f / velocityA.X, 1.0f / velocityA.Y);

            float timeX1 = (expandedBoxB.Min.X - boxACenter.X) * velocityAInverse.X;
            float timeX2 = (expandedBoxB.Max.X - boxACenter.X) * velocityAInverse.X;
            float timeY1 = (expandedBoxB.Min.Y - boxACenter.Y) * velocityAInverse.Y;
            float timeY2 = (expandedBoxB.Max.Y - boxACenter.Y) * velocityAInverse.Y;

            float firstCollideTimeX = Math.Min(timeX1, timeX2);
            float lastCollideTimeX  = Math.Max(timeX1, timeX2);
            float firstCollideTimeY = Math.Min(timeY1, timeY2);
            float lastCollideTimeY  = Math.Max(timeY1, timeY2);
            float firstCollideTime  = Math.Max(firstCollideTimeX, firstCollideTimeY);
            float lastCollideTime   = Math.Min(lastCollideTimeX, lastCollideTimeY);

            collisionTime = firstCollideTime;
            if (firstCollideTime == timeX1)
            {
                collisionNormal = -Vector2.UnitX;
                collisionEdge   = Vector2.UnitY;
            }
            else if (firstCollideTime == timeX2)
            {
                collisionNormal = Vector2.UnitX;
                collisionEdge   = Vector2.UnitY;
            }
            else if (firstCollideTime == timeY1)
            {
                collisionNormal = -Vector2.UnitY;
                collisionEdge   = Vector2.UnitX;
            }
            else
            {
                collisionNormal = Vector2.UnitY;
                collisionEdge   = Vector2.UnitX;
            }

            if (firstCollideTime < 0 && firstCollideTime > -interpenetrationCorrection)
            {
                // This accounts for floating point imprecision where a box might be moved to meet another box
                // but now actually slightly interpenetrates the box because the true position cannot be represented.
                // If boxes are slightly interpenetrating this treats them as if they are just touching.
                firstCollideTime = 0;
            }

            return(lastCollideTime > Math.Max(firstCollideTime, 0.0f) && firstCollideTime >= 0 && firstCollideTime < 1.0f);
#endif
        }
Exemplo n.º 2
0
 public static bool CollideBoxBox(Box2D boxA, Vector2 velocityA, Box2D boxB, float interpenetrationCorrection, out float collisionTime)
 {
     return(Collision2D.CollideBoxBox(boxA, velocityA, boxB, interpenetrationCorrection,
                                      out collisionTime, out _, out _));
 }