public Direction2D To2D(Direction direction)
{
var result = Direction2D.Create(direction.DotProduct(XAxis), direction.DotProduct(YAxis));
if (direction != To3D(result))
{
throw new ArgumentException("The direction does not lie within the embedded space.");
}
return(result);
}
public static void ThirtyDegreesFromDirection2DTest()
{
// This can be relaxed slightly if needed.
var precision = Math.Pow(2, -53);
var direction = Direction2D.Create(Math.Sqrt(3), 1);
var thirtyDegrees = direction.AngleFromPositiveX();
thirtyDegrees.CosineOfAngle.Should().BeApproximately(Math.Sqrt(3) / 2, precision);
thirtyDegrees.SineOfAngle.Should().BeApproximately(0.5, precision);
thirtyDegrees.ToProperAngle().Should().Be(30 * Unit.Degrees);
thirtyDegrees.ToSignedAngle().Should().Be(30 * Unit.Degrees);
var negativeThirtyDegrees = thirtyDegrees.Negate();
negativeThirtyDegrees.CosineOfAngle.Should().BeApproximately(Math.Sqrt(3) / 2, precision);
negativeThirtyDegrees.SineOfAngle.Should().BeApproximately(-0.5, precision);
negativeThirtyDegrees.ToProperAngle().Should().Be(330 * Unit.Degrees);
negativeThirtyDegrees.ToSignedAngle().Should().Be(-30 * Unit.Degrees);
}
public Direction2D ProjectTo2D(Direction direction) => Direction2D.Create(direction.DotProduct(XAxis), direction.DotProduct(YAxis));