/// <summary>
/// Gets the angle this vector is at in relationship to another Vector.
/// Take note that 0 degrees increases clockwise.
/// </summary>
/// <param name="src"></param>
/// <returns></returns>
public double GetAngleFromClockwise(Vector2D src)
{
double angle = 0.0d;
// We are within 0° - 180°.
if (this.Y > src.Y)
{
// We are in Quadrant I (0° - 90°).
if (this.X > src.X)
{
angle = (double)(this.X - src.X) / (double)(this.Y - src.Y);
angle = Math.Atan(angle);
angle = 90 - Mathlib.ToDegrees(angle);
}
else if (this.X < src.X)
{
// We are in Quadrant II (91° - 180°).
angle = (double)(src.X - this.X) / (double)(this.Y - src.Y);
angle = Math.Atan(-angle);
angle = 90 - Mathlib.ToDegrees(angle);
}
else if (this.X == src.X)
{
// We are between Quadrant I and II (90°).
angle = 90;
}
}
else if (this.Y < src.Y)
{
// We are in Quadrant III (180° - 270°).
if (this.X < src.X)
{
angle = (double)(src.X - this.X) / (double)(src.Y - this.Y);
angle = Math.Atan(angle);
angle = 270 - Mathlib.ToDegrees(angle);
}
// We are in Quadrant IV (271° - 360°).
else if (this.X > src.X)
{
angle = (double)(this.X - src.X) / (double)(src.Y - this.Y);
angle = Math.Atan(-angle);
angle = 270 - Mathlib.ToDegrees(angle);
}
// We are between Quadrant III and IV (270°).
else if (this.X == src.X)
{
angle = 270;
}
}
else if (this.Y == src.Y)
{
// We are at 180°.
if (this.X < src.X)
{
angle = 180;
}
// We are at 0° or 360°.
else if (this.X > src.X)
{
angle = 0;
}
}
return(angle);
}
/// <summary>
/// Returns the current theta (facing) of this vector in Degrees.
/// </summary>
/// <returns></returns>
public double GetThetaAsDegree()
{
double angle = GetThetaAsRadian();
return(Mathlib.ToDegrees(angle));
}