public bool RotateHeadingToFacePosition(Vector2D target)
{
Vector2D delta = target - Position;
Vector2D toTarget = Vector2D.Vec2DNormalize(delta);
double dot = _heading.GetDotProduct(toTarget);
//some compilers lose acurracy so the value is clamped to ensure it
//remains valid for the acos
if (dot < -1)
{
dot = -1;
}
else if (dot > 1)
{
dot = 1;
}
//first determine the angle between the heading vector and the target
double angle = Math.Acos(dot);
//return true if the player is facing the target
if (angle < .00001)
{
return(true);
}
//clamp the amount to turn to the max turn rate
if (angle > _maxTurnRate)
{
angle = _maxTurnRate;
}
//The next few lines use a rotation matrix to rotate the player's heading
//vector accordingly
Matrix2D rotationMatrix = new Matrix2D();
//notice how the direction of rotation has to be determined when creating
//the rotation matrix
rotationMatrix.Rotate(angle * _heading.Sign(toTarget));
rotationMatrix.TransformVector2Ds(_heading);
rotationMatrix.TransformVector2Ds(_velocity);
//finally recreate m_vSide
_side = _heading.Perp;
return(false);
}