/// <summary>
/// Fills all the values of target spatial by interpolating values from the two given spatials with the given factor and spin.
/// </summary>
public static void Interpolate(this SpriterSpatial target, SpriterSpatial a, SpriterSpatial b, float factor, int spin)
{
target.Angle = MathHelper.AngleLinear(a.Angle, b.Angle, spin, factor);
target.X = MathHelper.Linear(a.X, b.X, factor);
target.Y = MathHelper.Linear(a.Y, b.Y, factor);
target.ScaleX = MathHelper.Linear(a.ScaleX, b.ScaleX, factor);
target.ScaleY = MathHelper.Linear(a.ScaleY, b.ScaleY, factor);
}
/// <summary>
/// Fills all the values of target spatial from the given source spatial.
/// </summary>
public static void FillFrom(this SpriterSpatial target, SpriterSpatial source)
{
target.Alpha = source.Alpha;
target.Angle = source.Angle;
target.ScaleX = source.ScaleX;
target.ScaleY = source.ScaleY;
target.X = source.X;
target.Y = source.Y;
}
/// <summary>
/// Applies parent transforms to the given child spatial.
/// </summary>
public static void ApplyParentTransform(this SpriterSpatial child, SpriterSpatial parent)
{
float px = parent.ScaleX * child.X;
float py = parent.ScaleY * child.Y;
double angleRad = parent.Angle * Math.PI / 180;
float s = (float)Math.Sin(angleRad);
float c = (float)Math.Cos(angleRad);
child.X = px * c - py * s + parent.X;
child.Y = px * s + py * c + parent.Y;
child.ScaleX *= parent.ScaleX;
child.ScaleY *= parent.ScaleY;
child.Angle = parent.Angle + Math.Sign(parent.ScaleX * parent.ScaleY) * child.Angle;
child.Angle %= 360.0f;
}
