public virtual void UpdateVelocity(CCPoint point)
{
// Calculate distance and angle from the center.
float dx = point.X - PositionX;
float dy = point.Y - PositionY;
dycache = dy;
float dSq = dx * dx + dy * dy;
if (dSq <= DeadRadiusSq)
{
Velocity = CCPoint.Zero;
Degrees = 0.0f;
StickPosition = Center;
return;
}
float angle = (float)Math.Atan2(dy, dx); // in radians
if (angle < 0)
{
angle += CCMathHelper.TwoPi;
}
float cosAngle;
float sinAngle;
if (isDPad)
{
float anglePerSector = 360.0f / CCMathHelper.ToRadians(NumberOfDirections); // NumberOfDirections * ((float)Math.PI / 180.0f);
angle = (float)Math.Round(angle / anglePerSector) * anglePerSector;
}
cosAngle = CCMathHelper.Cos(angle);
sinAngle = CCMathHelper.Sin(angle);
// NOTE: Velocity goes from -1.0 to 1.0.
if (dSq > JoystickRadiusSq || isDPad)
{
dx = cosAngle * joystickRadius;
dy = sinAngle * joystickRadius;
}
Velocity = new CCPoint(dx / joystickRadius, dy / joystickRadius);
Degrees = CCMathHelper.ToDegrees(angle);
// Update the thumb's position
var newLoc = new CCPoint(dx + ContentSize.Width / 2, dy + ContentSize.Height / 2);
StickPosition = newLoc;
}