private float Angle(Vector vec1, Vector vec2)
{
float angle = (float)Math.Atan2(vec1.X * vec2.Y - vec2.X * vec1.Y, vec1.X * vec2.X + vec1.Y * vec2.Y);
return angle % (2 * (float)Math.PI);
}
public override ToolState UpdatePointerSequence(PointerEventInfo info, ILevelGeometry viewport)
{
Vector vecCenter = new Vector(InitialPosition.X, InitialPosition.Y);
Vector vec1 = new Vector(InitialLocation.X, InitialLocation.Y) - vecCenter;
Vector vec2 = new Vector((float)info.X, (float)info.Y) - vecCenter;
Vector imgCenter = new Vector(InitialCenter.X, InitialCenter.Y);
Vector originWorking = new Vector(InitialPosition.X, InitialPosition.Y) - imgCenter;
float angle = Angle(vec1, vec2);
float s = (float)Math.Sin(angle);
float c = (float)Math.Cos(angle);
Vector originPrime = new Vector(
originWorking.X * c - originWorking.Y * s,
originWorking.X * s + originWorking.Y * c);
originPrime += imgCenter;
HitObject.Position = new Point((int)originPrime.X, (int)originPrime.Y);
HitObject.Rotation = InitialAngle + angle;
return this;
}
public static float DistanceSquared(Vector v1, Vector v2)
{
float x = v1.X - v2.X;
float y = v1.Y - v2.Y;
return (x * x + y * y);
}
public static float Angle(Vector vec1, Vector vec2)
{
float dot = Vector.Dot(vec1, vec2);
dot = dot / (vec1.Length * vec2.Length);
return (float)Math.Acos(dot);
}
public bool Equals(Vector other)
{
return this.X == other.X && this.Y == other.Y;
}
public static float Dot(Vector v1, Vector v2)
{
return (v1.X * v2.X) + (v1.Y * v2.Y);
}