// Updates our supported state to true with the new given normal.
// Also updates our velocity to keep the same perpendicular speed
// we had relative to our last support if we can move on this slope
private void TransferSupport(Vector2 newSupportNormal, Vector2 netForce, bool allowWallRunning)
{
Vector2 forceDirection = netForce.normalized;
Vector2 oldSupport = -forceDirection;
if (supported)
{
oldSupport = supportNormal;
}
bool wasSliding = Sliding();
UpdateNormal(newSupportNormal, forceDirection, allowWallRunning, false);
if (!supported || (!allowWallRunning && (sliding || wasSliding)))
{
// Remove movement in the direction of our normal vector
float velocityIntoNormal = Vector2.Dot(velocity, newSupportNormal);
if (velocityIntoNormal < 0.0f)
{
velocity -= velocityIntoNormal * newSupportNormal;
}
}
else
{
// Move perpendicular to our normal in the same way we were moving
// perpendicular to our last normal.
float perpSpeed = Vector2.Dot(velocity, Vector2.Perpendicular(oldSupport));
Vector2 targetPerp = Vector2.Perpendicular(newSupportNormal);
float velocityTowardsTransferDirection = Vector2.Dot(velocity, targetPerp);
bool flipped = false;
if (Mathf.Abs(velocityTowardsTransferDirection) > Mathf.Epsilon && Mathf.Sign(velocityTowardsTransferDirection) != Mathf.Sign(perpSpeed))
{
targetPerp *= -1;
flipped = true;
}
velocity = perpSpeed * targetPerp;
data.MarkMomentumTransfer(oldSupport, supportNormal, perpSpeed * Vector2.Perpendicular(oldSupport), perpSpeed * targetPerp, flipped, velocityTowardsTransferDirection * Vector2.Perpendicular(newSupportNormal));
}
}
