public void SineOfHalfAngleBetweenLines_RightAngleAntiClockwise_half()
{
Vector2 line1 = new Vector2(4.0, 0.0);
Vector2 line2 = new Vector2(0.0, 3.0);
double sineHalfTheta = Lines2D.SineOfHalfAngleBetween(line1, line2);
Assert.IsTrue(sineHalfTheta == Math.Sin(Math.PI / 4));
}
public void SineOfAngleBetweenLines_180degreesParallel_0()
{
Vector2 line1 = new Vector2(4.0, 4.0);
Vector2 line2 = new Vector2(-4.0, -4.0);
double sineTheta = Lines2D.SineOfAngleBetween(line1, line2);
Assert.IsTrue(sineTheta == 0);
}
public void SineOfAngleBetweenLines_RightAngleClockwise_minus1()
{
Vector2 line1 = new Vector2(4.0, 0.0);
Vector2 line2 = new Vector2(0.0, -3.0);
double sineTheta = Lines2D.SineOfAngleBetween(line1, line2);
Assert.IsTrue(sineTheta == -1);
}
public void SineOfAngleBetweenLines_45degreesNonOrigin_half()
{
Vector2 l1Start = new Vector2(1.0, 0.0);
Vector2 l1End = new Vector2(6.0, 0.0);
Vector2 l2Start = new Vector2(0.0, 1.0);
Vector2 l2End = new Vector2(6.0, 4.0);
double sineTheta = Lines2D.SineOfAngleBetween(l1Start, l1End, l2Start, l2End);
Assert.IsTrue(sineTheta == 0.5);
}
public void TempTest()
{
Vector2 line1 = new Vector2(8.0, 0.0);
Vector2 line2 = new Vector2(0.0, 8.0);
double distSq = 50.0;
double expectedResult = 5.0;
double epsilon = 0.000005;
var cross = Lines2D.SineOfAngleBetween(line1, line2);
var h = Math.Sqrt(distSq) / (2 * Math.Sin(0.5 * Math.Asin(cross)));
Assert.IsTrue(h >= (expectedResult - epsilon) && h <= (expectedResult + epsilon));
}
