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);
}
/// <summary>
/// Concatenate two strokes s1, s2
/// </summary>
/// <param name="s1"></param>
/// <param name="s2"></param>
/// <returns>s1 + s2</returns>
public static SketchStroke ConcatenateStrokes(SketchStroke s1, SketchStroke s2)
{
SketchStroke result = new SketchStroke();
for (int i = 0; i < s1.PointsCount; i++)
{
result.AppendPoint(s1.Points[i]);
result.AppendTime(s1.TimeStamp[i]);
}
for (int i = 0; i < s2.PointsCount; i++)
{
result.AppendPoint(s2.Points[i]);
result.AppendTime(s2.TimeStamp[i]);
}
return result;
}
public static SketchStroke ConcatenateStrokes(List<SketchStroke> strokes)
{
SketchStroke result = new SketchStroke();
foreach (SketchStroke stroke in strokes)
{
for (int i = 0; i < stroke.PointsCount; i++)
{
result.AppendPoint(stroke.Points[i]);
result.AppendTime(stroke.TimeStamp[i]);
}
}
return result;
}
public static async Task <Sketch> XMLToSketch(StorageFile file)
{
string text = await FileIO.ReadTextAsync(file);
XDocument document = XDocument.Parse(text);
int minX = Int32.Parse(document.Root.Attribute("frameMinX").Value);
int maxX = Int32.Parse(document.Root.Attribute("frameMaxX").Value);
int minY = Int32.Parse(document.Root.Attribute("frameMinY").Value);
int maxY = Int32.Parse(document.Root.Attribute("frameMaxY").Value);
string label = document.Root.Attribute("label").Value;
List <SketchStroke> strokes = new List <SketchStroke>();
// Itereates through each stroke element
foreach (XElement element in document.Root.Elements())
{
// Initializes the stroke
SketchStroke stroke = new SketchStroke();
// Iterates through each point element
double x, y;
long t;
foreach (XElement pointElement in element.Elements())
{
x = Double.Parse(pointElement.Attribute("x").Value);
y = Double.Parse(pointElement.Attribute("y").Value);
t = Int64.Parse(pointElement.Attribute("time").Value);
SketchPoint point = new SketchPoint(x, y);
stroke.AppendPoint(point);
stroke.AppendTime(t);
}
strokes.Add(stroke);
}
return(new Sketch(minX, maxX, minY, maxY, label, strokes));
}
