Document HitTestBezierContext

[terryspitz]

Document HitTestBezierContext

[wieslawsoltes]

It's used for hit-testing shapes.

Example usage:

SpiroNet/src/SpiroNet.Editor/Editor/SpiroEditor.cs

Lines 593 to 624 in c5f4eff

	private static bool HitTestForShape(IList<SpiroShape> shapes, double x, double y, double treshold, out SpiroShape hitShape, out int hitShapePointIndex)
	{
	for (int i = 0; i < shapes.Count; i++)
	{
	var bc = new HitTestBezierContext(x, y);
	var shape = shapes[i];
	int knontIndex;
	try
	{
	if (!TryToRunSpiro(shape, bc))
	continue;
	}
	catch (Exception ex)
	{
	Debug.WriteLine(ex.Message);
	Debug.WriteLine(ex.StackTrace);
	continue;
	}
	if (bc.Report(out knontIndex) < treshold)
	{
	hitShape = shape;
	hitShapePointIndex = knontIndex;
	return true;
	}
	}
	hitShape = null;
	hitShapePointIndex = -1;
	return false;
	}

[wieslawsoltes]

@terryspitz Please note this code is ported to C# from https://github.com/fontforge/libspiro and is licensed under the GPL-3.0.

[terryspitz]

OK, it looks like it's for finding the closest knot (or curve segment) on the curve to a given point. Thanks.