public static bool TestLineSegmentWithConvexPolygon(Vector2 startPoint, Vector2 endPoint, Polygon polygon, IEnumerable <Vector2> axes, out Contact?contact)
{
Vector2[] intersections = polygon.Intersects(new Line(startPoint, endPoint));
// no intersections, no contact
if (intersections.Length == 0)
{
contact = null;
return(false);
}
Contact leastPenetrationContact = new Contact {
Position = intersections[0],
PenetrationDepth = float.PositiveInfinity
};
// calculate line-segment first contact point position
float closestIntersectionDist = Math.DistanceSquared(startPoint, intersections[0]);
for (int i = 1; i < intersections.Length; i++)
{
float d = Math.DistanceSquared(startPoint, intersections[i]);
if (d < closestIntersectionDist)
{
leastPenetrationContact.Position = intersections[i];
closestIntersectionDist = d;
}
}
foreach (Vector2 axis in axes)
{
Range projectionA = axis.Projection(startPoint, endPoint),
projectionB = polygon.Projection(axis);
if (!projectionA.Overlaps(projectionB, out float penetrationDepth))
{
contact = null;
return(false);
}
if (penetrationDepth < leastPenetrationContact.PenetrationDepth)
{
leastPenetrationContact.PenetrationDepth = penetrationDepth;
leastPenetrationContact.Normal = projectionA.Min > projectionB.Min ? -axis : axis;
}
}
contact = leastPenetrationContact;
return(true);
}
public bool Intersects(Polygon polygon)
{
foreach (Vector2 vertex in polygon)
{
if (ContainsInclusive(vertex))
{
return(true);
}
}
foreach (Line edge in Edges())
{
if (polygon.Intersects(edge).Length > 0 || polygon.IsInside(edge.PointA))
{
return(true);
}
}
return(false);
}
