public static bool ArcCircleCollides(Vector2F arcCenter, Vector2F arcDirection, float arcRadius, float arcLength, Circle circle)
{
Vector2F arcDelta = arcDirection - arcCenter;
Vector2F circleDelta = circle.Center - arcCenter;
if (arcDelta == circleDelta)
return true;
if (arcDelta.Angle(circleDelta) < arcLength / 2f)
return Vector2F.Distance(arcCenter, circle.Center) <= arcRadius + circle.Radius;
else
return false;
}
public static bool MovingCircleCollides(Circle mover, Vector2F velocity, Circle target)
{
Vector2F closest = ClosestPointOnLineSegment(target.Center,
mover.Center,
mover.Center + velocity);
float distanceSq = (float)(Math.Pow(closest.X - target.Center.X, 2) + Math.Pow(closest.Y - target.Center.Y, 2));
return distanceSq <= (float)Math.Pow(mover.Radius + target.Radius, 2);
}
private void _CheckCollisions()
{
if (OnCollision == null) return;
// check if we collided with anything since last update
float radius = this.ActorData.Cylinder.Ax2;
Circle startCircle = new Circle(_prevUpdatePosition.X, _prevUpdatePosition.Y, radius);
// make a velocity representing the change to the current position
Vector2F velocity = PowerMath.VectorWithoutZ(this.Position - _prevUpdatePosition);
Actor hit = null;
TargetList targets = this.Context.GetEnemiesInRadius(this.Position, radius + 25f);
if (CollisionFilter != null)
targets.Actors.RemoveAll(actor => !CollisionFilter(actor));
targets.SortByDistanceFrom(_prevUpdatePosition);
foreach (Actor target in targets.Actors)
{
float targetRadius = 1.5f; // TODO: use target.ActorData.Cylinder.Ax2 ?
if (PowerMath.MovingCircleCollides(startCircle, velocity, new Circle(target.Position.X, target.Position.Y, targetRadius)))
{
hit = target;
break;
}
}
if (hit != null)
OnCollision(hit);
}
public static bool CircleInBeam(Circle circle, Vector3D beamStart, Vector3D beamEnd, float beamThickness)
{
// NOTE: right now this does everything in 2d, ignoring Z
// offset start beam position by beam thickness
beamStart = TranslateDirection2D(beamStart, beamEnd, beamStart, beamThickness);
return MovingCircleCollides(new Circle(beamStart.X, beamStart.Y, beamThickness),
VectorWithoutZ(beamEnd - beamStart),
circle);
}
private void _CheckCollisions()
{
if (OnCollision == null) return;
// check if we collided with anything since last update
float radius = this.ActorData.Cylinder.Ax2;
Circle startCircle = new Circle(_prevUpdatePosition.X, _prevUpdatePosition.Y, radius);
// make a velocity representing the change to the current position
Vector2F velocity = PowerMath.VectorWithoutZ(this.Position - _prevUpdatePosition);
Actor hit = null;
foreach (Actor target in this.Context.GetEnemiesInRadius(this.Position, radius + 25f)
.OrderBy(t => PowerMath.Distance2D(_prevUpdatePosition, t.Position)))
{
float targetRadius = 1.5f; // target.ActorData.Cylinder.Ax2;
if (PowerMath.MovingCircleCollides(startCircle, velocity, new Circle(target.Position.X, target.Position.Y, targetRadius)))
{
hit = target;
break;
}
}
if (hit != null)
OnCollision(hit);
}
