private static bool IsLine(SketchStroke stroke, int i1, int i2)
{
SketchPoint p1 = stroke.Points[i1];
SketchPoint p2 = stroke.Points[i2];
return(MathHelpers.EuclideanDistance(p1, p2) / SketchStrokeFeatureExtraction.PathLength(stroke, i1, i2) > LineValidationThreshold);
}
public static SketchStroke ResampleStroke(SketchStroke stroke, int n)
{
SketchStroke resampledStroke = new SketchStroke();
List <SketchPoint> points = new List <SketchPoint>();
List <long> timeStamp = new List <long>();
// Copies the points and timeStamps list of the initial stroke
foreach (SketchPoint p in stroke.Points)
{
points.Add(p);
}
foreach (long t in stroke.TimeStamp)
{
timeStamp.Add(t);
}
double totalLength = SketchStrokeFeatureExtraction.PathLength(stroke);
double increment = totalLength / (n - 1);
double dist = 0;
resampledStroke.AppendPoint(points[0]);
for (int i = 1; i < points.Count; i++)
{
SketchPoint cur = points[i];
SketchPoint pre = points[i - 1];
double d = MathHelpers.EuclideanDistance(cur, pre);
if (dist + d >= increment)
{
double qx = pre.X + ((increment - dist) / d) * (cur.X - pre.X);
double qy = pre.Y + ((increment - dist) / d) * (cur.Y - pre.Y);
SketchPoint q = new SketchPoint(qx, qy);
resampledStroke.AppendPoint(q);
points.Insert(i, q);
dist = 0.0;
}
else
{
dist = dist + d;
}
}
int oldTimeCount = timeStamp.Count;
int newTimeCount = resampledStroke.Points.Count;
for (int j = 0; j < newTimeCount; ++j)
{
int index = (int)((double)j / newTimeCount * oldTimeCount);
resampledStroke.AppendTime(timeStamp[index]);
}
return(resampledStroke);
}
private static SketchStroke ResampleForCornerFinding(SketchStroke stroke)
{
BoundingBox bb = new BoundingBox(stroke);
double resamplingDistance = bb.Diagonal / DiagonalDividedFactor;
double strokeLength = SketchStrokeFeatureExtraction.PathLength(stroke);
int numOfSampledPoints = (int)(strokeLength / resamplingDistance + 1);
SketchStroke resampledStroke = SketchStrokePreprocessing.ResampleStroke(stroke, numOfSampledPoints);
return(resampledStroke);
}
public static List <SketchStroke> Resample(List <SketchStroke> strokes, int n)
{
double totalLength = 0;
foreach (SketchStroke stroke in strokes)
{
totalLength += SketchStrokeFeatureExtraction.PathLength(stroke);
}
double I = totalLength / (n - 1);
double D = 0.0;
List <SketchStroke> newStrokes = new List <SketchStroke>();
// Iterates through each stroke points in a list of strokes
int pointCount = 0;
foreach (SketchStroke stroke in strokes)
{
//Resamples point locations
List <SketchPoint> points = stroke.Points;
List <SketchPoint> newPoints = new List <SketchPoint>();
newPoints.Add(new SketchPoint(points[0].X, points[0].Y));
++pointCount;
bool isDone = false;
for (int i = 1; i < points.Count; ++i)
{
double d = MathHelpers.EuclideanDistance(points[i - 1], points[i]);
if (D + d >= I)
{
double qx = points[i - 1].X + ((I - D) / d) * (points[i].X - points[i - 1].X);
double qy = points[i - 1].Y + ((I - D) / d) * (points[i].Y - points[i - 1].Y);
if (pointCount < n - 1)
{
newPoints.Add(new SketchPoint(qx, qy));
++pointCount;
points.Insert(i, new SketchPoint(qx, qy));
D = 0.0;
}
else
{
isDone = true;
}
}
else
{
D += d;
}
if (isDone)
{
break;
}
}
D = 0.0;
// Resamples time stamps
List <long> timeStamp = stroke.TimeStamp;
List <long> newTimeStamp = new List <long>();
int oldCount = timeStamp.Count;
int newCount = newPoints.Count;
for (int j = 0; j < newCount; ++j)
{
int index = (int)((double)j / newCount * oldCount);
newTimeStamp.Add(timeStamp[index]);
}
SketchStroke newStroke = new SketchStroke(newPoints, newTimeStamp);
newStrokes.Add(newStroke);
}
return(newStrokes);
}