/// <summary>
/// Get the velocity of this point on the polygon. A sum of the translational and tangential velocities at the point.
/// </summary>
/// <param name="pointOnPolygon">The point of the local velocity.</param>
/// <returns>Returns the velocity at this point.</returns>
public Vector2 GetLocalVelocity(Vector2 pointOnPolygon)
{
Vector2 radiusVector = pointOnPolygon - CollisionPolygon.CenterPoint;
Vector2 tangentialVelocity = IntersectionEvent.CrossProduct(_angularVelocity, radiusVector);
return(tangentialVelocity + _translationalVelocity);
}
/// <summary>
/// Applies a force at the given application point on the polygon. Will calculate torque.
/// </summary>
/// <param name="forceVector">The value of the force.</param>
/// <param name="applicationPoint">The point on the polygon at which to apply the force.</param>
public void ApplyForce(Vector2 forceVector, Vector2 applicationPoint)
{
AddTranslationalVelocity(forceVector * IntersectionEvent.GetLimitedRecip(Mass), isMomentum: false);
Vector2 radiusVector = applicationPoint - CollisionPolygon.CenterPoint;
radiusVector.Normalize();
AddAngularVelocity(IntersectionEvent.GetLimitedRecip(Inertia) * IntersectionEvent.CrossProduct(radiusVector, forceVector), isMomentum: false);
}
public float GreatestSameSide(Vector2[] points, Vector2 samplePoint)
{
float greatestDepth = float.NaN;
Vector2 lineNormal = NormalizedNormal;
for (int i = 0; i < points.Length; i++)
{
if (SharesPointSide(points[i], samplePoint))
{
float penetrationDepth = Math.Abs(IntersectionEvent.DotProduct(containedPoint, lineNormal) - IntersectionEvent.DotProduct(points[i], lineNormal));
if (float.IsNaN(greatestDepth) || penetrationDepth > greatestDepth)
{
greatestDepth = penetrationDepth;
}
}
}
return(greatestDepth);
}
public static bool AreColliding(RigidBody rigidBody1, RigidBody rigidBody2, out IntersectionEvent intersectionEvent)
{
//Get side segments
RigidBody[] rigidBodies = new RigidBody[] { rigidBody1, rigidBody2 };
LineSegment[][] sideSegments = new LineSegment[rigidBodies.Length][];
for (int i = 0; i < sideSegments.Length; i++)
{
sideSegments[i] = rigidBodies[i].CollisionPolygon.SideSegments;
}
//Determine overlapping axes
LineSegment minimumOverlap = null;
RigidBody recipientRB = null;
int recipientRBIndex = 0;
LineSegment recipientSide = null;
for (int i = 0; i < sideSegments.Length; i++)
{
if (rigidBodies[i].CollisionPolygon.ContainsPoint(rigidBodies[(i + 1) % rigidBodies.Length].CollisionPolygon.Vertices))
{
for (int j = 0; j < sideSegments[i].Length; j++)
{
Line segmentNormal = sideSegments[i][j].NormalLine;
LineSegment[] bodyProjections = new LineSegment[rigidBodies.Length];
for (int k = 0; k < rigidBodies.Length; k++)
{
bodyProjections[k] = rigidBodies[(k + i) % rigidBodies.Length].CollisionPolygon.PolygonProjection(segmentNormal);
}
//Determine overlap
LineSegment projectionOverlap;
if (bodyProjections[0].IsOverlapping(bodyProjections[1], out projectionOverlap))
{
//Check for minimum
Vector2 intersectionPoint = new Vector2();
if (projectionOverlap.IntersectsSegment(sideSegments[i][j], ref intersectionPoint) && (minimumOverlap == null || minimumOverlap.Length > projectionOverlap.Length))
{
minimumOverlap = projectionOverlap;
recipientRB = rigidBodies[i];
recipientRBIndex = i;
recipientSide = sideSegments[i][j];
//intersectionRecipient = new IntersectionRecipient(rigidBodies[i], sideSegments[i][j]);
}
}
else
{
//No overlap, not colliding
intersectionEvent = null;
return(false);
}
}
}
}
if (minimumOverlap != null)
{
intersectionEvent = new IntersectionEvent(rigidBodies[(recipientRBIndex + 1) % 2], recipientRB, new IntersectionData(false, minimumOverlap, recipientSide, true));
return(true);
}
else
{
intersectionEvent = null;
return(false);
}
}