public RayCollisionInfo getRayCollisionInfo(Vector rayStart, Vector rayDir)
{
VectorSet set = calculateTrans();
Vector? pClosest = null;
Edge eClosest = null;
if (rayDir.Length > 0)
{
float distance = float.MaxValue;
set.forEachEdge(edge =>
{
float x = rayStart.X * edge.Unit.Y - rayStart.Y * edge.Unit.X - edge.V1.X * edge.Unit.Y + edge.V1.Y * edge.Unit.X;
x /= rayDir.Y * edge.Unit.X - rayDir.X * edge.Unit.Y;
float y = rayStart.X * rayDir.Y - rayStart.Y * rayDir.X + rayDir.X * edge.V1.Y - rayDir.Y * edge.V1.X;
y /= rayDir.Y * edge.Unit.X - rayDir.X * edge.Unit.Y;
if (x > 0 && y > 0 && y < edge.Length)
{
Vector p = edge.V1 + y * edge.Unit;
float testDistance = (p - rayStart).Length;
if (testDistance < distance)
{
distance = testDistance;
pClosest = p;
eClosest = edge;
}
}
});
}
if (pClosest.HasValue)
{
return(new RayCollisionInfo(rayStart, rayDir, eClosest.Normal, pClosest.Value));
}
else
{
return(null);
}
}
/// <summary>
/// Run an SAT test against the other convex object
/// </summary>
/// <param name="conv"></param>
/// <returns></returns>
public CollisionInfo getCollisionInfo(Convex conv)
{
List <Vector> axisSet = new List <Vector>();
VectorSet aSet = calculateTrans();
VectorSet bSet = conv.calculateTrans();
Vector mtv = Vector.One * 10000;
bool colliding = true;
aSet.forEachEdge(e => axisSet.Add(e.Normal));
bSet.forEachEdge(e => axisSet.Add(e.Normal));
foreach (Vector a in axisSet)
{
//create the axis
Vector axis = a.Unit;
float aMin = float.MaxValue, aMax = float.MinValue;
float bMin = float.MaxValue, bMax = float.MinValue;
//project conv, a, onto axis
aSet.forEachVector(v =>
{
float p = (v).dot(axis);
if (p < aMin)
{
aMin = p;
}
if (p > aMax)
{
aMax = p;
}
});
//project conv, b, onto axis
bSet.forEachVector(v =>
{
float p = (v).dot(axis);
if (p < bMin)
{
bMin = p;
}
if (p > bMax)
{
bMax = p;
}
});
//are a and b overlapping?
if ((aMin > bMin && aMin < bMax) ||
(aMax > bMin && aMax < bMax) ||
(bMin > aMin && bMin < aMax) ||
(bMax > aMin && bMax < aMax)
)
{
//they are overlapping
//calculate overlap vector
float overlap = Math.Min(aMax, bMax) - Math.Max(aMin, bMin);
if (aMax < bMax)
{
overlap *= -1;
}
if (Math.Abs(overlap) < mtv.Length)
{
mtv = axis * overlap;
}
}
else
{
//they are not overlapping. no collision can be occuring.
colliding = false;
break;
}
}
CollisionInfo collInfo = new CollisionInfo(mtv);
if (!colliding)
{
return(null);
}
else
{
return(collInfo);
}
}