public static TraceGroup ToTraceGroup(this Ink ink)
{
var traceGroup = new TraceGroup();
foreach(var stroke in ink.Strokes)
{
var trace = new Trace();
foreach(var point in stroke.GetPoints())
{
var penPoint = new PenPoint {X = point.X, Y = point.Y};
trace.Points.Add(penPoint);
}
traceGroup.Traces.Add(trace);
}
return traceGroup;
}
public Trace ResampleTrace(Trace inTrace, int resamplePoints)
{
var outTrace = new Trace();
var xSum = 0f;
var ySum = 0f;
var x = 0f;
var y = 0f;
var numTracePoints = inTrace.Points.Count;
var xDiff = 0f;
var yDiff = 0f;
var pointDistance = 0f;
var unitLength = 0f;
var distanceVec = new List<float>();
var balanceDistance = 0f; // distance between the last resampled point and
// the next raw sample point
var measuredDistance = 0f;
var m1 = 0f;
var m2 = 0f;
var ptIndex = 0;
var currentPointIndex = 0;
var xVec = inTrace.ChannelX;
var yVec = inTrace.ChannelY;
var xTemp = 0f;
var yTemp = 0f;
if(resamplePoints==1)
{
xSum = inTrace.GetSumX();
ySum = inTrace.GetSumY();
x = xSum/numTracePoints;
y = ySum/numTracePoints;
var penPoint = new PenPoint {X = x, Y = y};
outTrace.Points.Add(penPoint);
}else
{
for(var i=0;i<(numTracePoints-1);++i)
{
xDiff = inTrace.ChannelX[i] - inTrace.ChannelX[i + 1];
yDiff = inTrace.ChannelY[i] - inTrace.ChannelY[i + 1];
pointDistance = (float) Math.Sqrt(xDiff*xDiff + yDiff*yDiff);
unitLength += pointDistance;
distanceVec.Add(pointDistance);
}
unitLength /= (resamplePoints - 1);
x = inTrace.ChannelX[0];
y = inTrace.ChannelY[0];
outTrace.Points.Add(new PenPoint{X=x, Y=y});
for(var i=1; i<(resamplePoints-1); ++i)
{
measuredDistance = balanceDistance;
while(measuredDistance<unitLength)
{
measuredDistance += distanceVec[ptIndex++];
if (ptIndex == 1) currentPointIndex = 1;
else currentPointIndex++;
}
if (ptIndex < 1) ptIndex = 1;
m2 = measuredDistance - unitLength;
m1 = distanceVec[ptIndex - 1] - m2;
if(Math.Abs(m1+m2)>_eps)
{
xTemp = (m1*xVec[currentPointIndex] + m2*xVec[currentPointIndex - 1])/(m1 + m2);
yTemp = (m1*yVec[currentPointIndex] + m2*yVec[currentPointIndex - 1])/(m1 + m2);
}else
{
xTemp = xVec[currentPointIndex];
yTemp = yVec[currentPointIndex];
}
outTrace.Points.Add(new PenPoint{X=xTemp, Y=yTemp});
balanceDistance = m2;
}
x = xVec[xVec.Count - 1]; //adding x of last point
y = yVec[yVec.Count - 1]; //adding y of last point
outTrace.Points.Add(new PenPoint{X=x, Y=y});
}
return outTrace;
}