/// <summary>
/// determines if the points in the list, all lie on the same side of the dividing plane.
/// Points on the plane are disregarded
/// </summary>
/// <param name="plane"></param>
/// <returns></returns>
public static bool AllPointsAreOnTheSameSideOf(this List<Point> pointList, Plane plane)
{
int index = 0;
//find a reference point
for (int i = 0; i < pointList.Count; i++)
{
if (!plane.Contains(pointList[i]))
{
index = i;
break;
}
}
Point referencePoint = pointList[index];
//Now check the remaining points
for (int i = index + 1; i < pointList.Count; i++)
{
if (!plane.Contains(pointList[i]) && !plane.PointIsOnSameSideAs(pointList[i], referencePoint))
{
return false;
}
}
return true;
}
public void Plane_PointOnSameSideAs()
{
Point testPoint = Point.MakePointWithInches(1, 3, -1);
Point testPoint2 = Point.MakePointWithInches(-1, -2, 5);
Point testPoint3 = Point.MakePointWithInches(0, 1, 0);
Point referencePoint = Point.MakePointWithInches(1, 2, 1);
Point referencePoint2 = Point.MakePointWithInches(0, 2, 1);
Vector testNormalVector = new Vector(Point.MakePointWithInches(1, 0, 0));
Plane testPlane = new Plane(testNormalVector);
testPlane.PointIsOnSameSideAs(testPoint, referencePoint).Should().BeTrue(); //test one on the same side
testPlane.PointIsOnSameSideAs(testPoint2, referencePoint).Should().BeFalse(); //test one on the opposite side
testPlane.PointIsOnSameSideAs(testPoint3, referencePoint).Should().BeFalse(); //test one on the plane
testPlane.PointIsOnSameSideAs(testPoint, referencePoint2).Should().BeFalse(); //test a reference point on the plane
Point testPointOffOrigin = Point.MakePointWithInches(5, 4, 0);
Point testPointOffOrigin2 = Point.MakePointWithInches(5, -2, 0);
Point referencePointOffOrigin = Point.MakePointWithInches(1, 2, 3);
Point planeBase = Point.MakePointWithInches(1, -4, 2);
Vector testNormalVectorOffOrigin = new Vector(Point.MakePointWithInches(-1, 2, 1));
Plane testPlaneOffOrigin = new Plane(testNormalVectorOffOrigin.Direction, planeBase);
testPlaneOffOrigin.PointIsOnSameSideAs(testPointOffOrigin, referencePointOffOrigin).Should().BeTrue();
testPlaneOffOrigin.PointIsOnSameSideAs(testPointOffOrigin2, referencePointOffOrigin).Should().BeFalse();
testPlaneOffOrigin.PointIsOnSameSideAs(planeBase, referencePointOffOrigin).Should().BeFalse();
}