public static Vector2 ChangeDirection(GameTime gameTime, Vector2 dir, Vector2 pos, Vector2 followedPos, double degreeChange)
{
double radians = RadiansFromDir(dir);
double radianChange = degreeChange * (Math.PI / 180);
Vector2 dirToFollowed = new Vector2(followedPos.X - pos.X, followedPos.Y - pos.Y);
dirToFollowed = MathFunctions.ScaleDirection(dirToFollowed);
double dirFolRadians;
if (dirToFollowed.Y > 0)
{
dirFolRadians = Math.Acos(dirToFollowed.X);
}
else
{
dirFolRadians = 2 * Math.PI - (Math.Acos(dirToFollowed.X));
}
if (dirFolRadians > 2 * Math.PI)
{
dirFolRadians -= 2 * Math.PI;
}
double deltaRadians = MathFunctions.DeltaRadians(radians, dirFolRadians);
// If target angle is closer to current than the given delta angle, assign target angle
if (Math.Abs(deltaRadians) < Math.Abs(radianChange))
{
radians = dirFolRadians;
}
// If not, increment current angle by given delta angle
else
{
var fpsCompensatedRadianChange = radianChange * MathFunctions.FPSSyncFactor(gameTime);
if (deltaRadians > 0 && deltaRadians <= 180)
{
radians += fpsCompensatedRadianChange;
}
else if (deltaRadians < 0 && deltaRadians <= 180)
{
radians -= fpsCompensatedRadianChange;
}
else if (deltaRadians > 0 && deltaRadians > 180)
{
radians -= fpsCompensatedRadianChange;
}
else //(dirFolRadians < Radians && (dirFolRadians - Radians) > 180)
{
radians += fpsCompensatedRadianChange;
}
}
Vector2 newDir = Vector2.Zero;
newDir.X = (float)(Math.Cos(radians));
newDir.Y = (float)(Math.Sin(radians));
return(newDir);
}