/// <summary>
/// Check whether a certain percentage of the stroke is within the lasso
/// </summary>
/// <param name="lassoPoints"></param>
/// <param name="percentageWithinLasso"></param>
/// <returns></returns>
public bool HitTest(IEnumerable<Point> lassoPoints, int percentageWithinLasso)
{
if (lassoPoints == null)
{
throw new System.ArgumentNullException("lassoPoints");
}
if ((percentageWithinLasso < 0) || (percentageWithinLasso > 100))
{
throw new System.ArgumentOutOfRangeException("percentageWithinLasso");
}
if (percentageWithinLasso == 0)
{
return true;
}
StrokeInfo strokeInfo = null;
try
{
strokeInfo = new StrokeInfo(this);
StylusPointCollection stylusPoints = strokeInfo.StylusPoints;
double target = strokeInfo.TotalWeight * percentageWithinLasso / 100.0f - PercentageTolerance;
Lasso lasso = new SingleLoopLasso();
lasso.AddPoints(lassoPoints);
for (int i = 0; i < stylusPoints.Count; i++)
{
if (true == lasso.Contains((Point)stylusPoints[i]))
{
target -= strokeInfo.GetPointWeight(i);
if (DoubleUtil.LessThan(target, 0f))
{
return true;
}
}
}
return false;
}
finally
{
if (strokeInfo != null)
{
//detach from event handlers, or else we leak.
strokeInfo.Detach();
}
}
}
/// <summary>
/// C-tor.
/// </summary>
/// <param name="strokes">strokes to hit-test</param>
/// <param name="percentageWithinLasso">a hit-testing parameter that defines the minimal
/// percent of nodes of a stroke to be inside the lasso to consider the stroke hit</param>
internal IncrementalLassoHitTester(StrokeCollection strokes, int percentageWithinLasso)
: base(strokes)
{
System.Diagnostics.Debug.Assert((percentageWithinLasso >= 0) && (percentageWithinLasso <= 100));
_lasso = new SingleLoopLasso();
_percentIntersect = percentageWithinLasso;
}
/// <summary>
/// Erase with lasso points.
/// </summary>
/// <param name="lassoPoints">Lasso points to erase with</param>
/// <returns>The after-erasing strokes</returns>
public StrokeCollection GetEraseResult(IEnumerable<Point> lassoPoints)
{
// Check the input parameters
if (lassoPoints == null)
{
throw new System.ArgumentNullException("lassoPoints");
}
if (IEnumerablePointHelper.GetCount(lassoPoints) == 0)
{
throw new ArgumentException(SR.Get(SRID.EmptyArray));
}
Lasso lasso = new SingleLoopLasso();
lasso.AddPoints(lassoPoints);
return this.Erase(this.HitTest(lasso));
}