private void ExtractPath(Shape shape, int from, int to)
{
double factor = 2000.0;
var winding = 0.0;
int length = to - from;
Point pa, pb;
int a, b;
var path = new Path();
int i = 0;
while (i <= length)
{
a = i;
int j = i + 1;
while (j <= length && (Flags[from + j] & GlyphFlag.OnCurve) != GlyphFlag.OnCurve)
j++;
b = (j) % (length + 1);
int padding = j - i;
pa = new Point(Points[from + a].X / factor, Points[from + a].Y / factor);
pb = new Point(Points[from + b].X / factor, Points[from + b].Y / factor);
if(padding > 3)
{
//TODO
var pc = new Point(Points[from + a + 1].X / factor, Points[from + a + 1].Y / factor);
path.AddPathSegment(new QuadraticCurveSegment(pa, pc, pb) { Convex = true });
}
else if(padding == 3)
{
//TODO
var pc = new Point(Points[from + a + 1].X / factor, Points[from + a + 1].Y / factor);
path.AddPathSegment(new QuadraticCurveSegment(pa, pc, pb) { Convex = true });
}
else if(padding == 2)
{
var pc = new Point(Points[from + a + 1].X / factor, Points[from + a + 1].Y / factor);
path.AddPathSegment(new QuadraticCurveSegment(pa, pc, pb) { Convex = true });
}
else
{
path.AddPathSegment(new LineSegment(pa, pb));
}
winding += (pb.X - pa.X) * (pb.Y + pa.Y);
i = j;
}
if (winding >= 0.0)
path.CompositMode = CompositMode.Add;
else
path.CompositMode = CompositMode.Subtract;
foreach(var segment in path.Segments)
{
if(segment is QuadraticCurveSegment)
{
var qcs = segment as QuadraticCurveSegment;
var sign = Math.Sign(((qcs.End.X - qcs.Start.X) * (qcs.ControlPoint.Y - qcs.Start.Y)) - ((qcs.End.Y - qcs.Start.Y) * (qcs.ControlPoint.X - qcs.Start.X)));
if(path.CompositMode == CompositMode.Subtract)
qcs.Convex = sign >= 0.0 ? false : true;
else
qcs.Convex = sign >= 0.0 ? true : false;
}
}
shape.AddPath(path);
}
