static Poly2Tri.Polygon CreatePolygon(FlattenContour cnt)
{
using (Borrow(out List <Poly2Tri.TriangulationPoint> points))
{
//limitation: poly tri not accept duplicated points! ***
double prevX = 0;
double prevY = 0;
int j = cnt.VertexCount;
for (int i = 0; i < j; ++i)
{
cnt.GetPoint(i, out float x, out float y);
if (x == prevX && y == prevY)
{
if (i > 0)
{
//skip duplicated point, not use
continue;
}
}
else
{
//var triPoint = new Poly2Tri.TriangulationPoint(prevX = x, prevY = y) { userData = p };
//points.Add(triPoint);
points.Add(new Poly2Tri.TriangulationPoint(prevX = x, prevY = y));
}
}
return(new Poly2Tri.Polygon(points.ToArray()));
}
}
static void SeparateToFlattenContourList(float[] polygonXYs, int[] contourEndIndices, List <FlattenContour> contours)
{
int contourCount = contourEndIndices.Length;
int index = 0;
for (int c = 0; c < contourCount; ++c)
{
int endAt = contourEndIndices[c] + 1; //glyph convention***
FlattenContour cnt = new FlattenContour(polygonXYs, index, endAt - index);
//--
//temp hack here!
//ensure=> duplicated points,
//most common => first point and last point
cnt.GetPoint(0, out float p0x, out float p0y);
cnt.GetPoint(cnt.VertexCount - 1, out float p_lastX, out float p_lastY);
if (p0x == p_lastX && p0y == p_lastY)
{
cnt._len -= 2;//
}
index = endAt;
contours.Add(cnt);
}
}
public void PreparePolygons(float[] flattenPolygonXYs, int[] contourEndIndices, List <Poly2Tri.Polygon> outputPolygons)
{
_waitingHoles.Clear();
_flattenContours.Clear();
_otherPolygons.Clear();
//
SeparateToFlattenContourList(flattenPolygonXYs, contourEndIndices, _flattenContours);
//--------------------------
//TODO: review here, add hole or not
// more than 1 contours, no hole => eg. i, j, ;, etc
// more than 1 contours, with hole => eg. a,e , etc
//clockwise => not hole
int cntCount = _flattenContours.Count;
Poly2Tri.Polygon mainPolygon = null;
//
//this version if it is a hole=> we add it to main polygon
//TODO: add to more proper polygon ***
//eg i
//--------------------------
for (int n = 0; n < cntCount; ++n)
{
FlattenContour cnt = _flattenContours[n];
bool cntIsMainPolygon = YAxisPointDown ? !cnt.IsClockwise : cnt.IsClockwise;
if (cntIsMainPolygon)
{
//main polygon
//not a hole
if (mainPolygon == null)
{
//if we don't have mainPolygon before
//this is main polygon
mainPolygon = CreatePolygon(cnt);
if (_waitingHoles.Count > 0)
{
//flush all waiting holes to the main polygon
int j = _waitingHoles.Count;
for (int i = 0; i < j; ++i)
{
mainPolygon.AddHole(_waitingHoles[i]);
}
_waitingHoles.Clear();
}
}
else
{
//if we already have a main polygon
//then this is another sub polygon
//IsHole is correct after we Analyze() the glyph contour
_otherPolygons.Add(CreatePolygon(cnt));
}
}
else
{
//this is a hole
Poly2Tri.Polygon subPolygon = CreatePolygon(cnt);
if (mainPolygon == null)
{
//add to waiting polygon
_waitingHoles.Add(subPolygon);
}
else
{
//add to mainPolygon
mainPolygon.AddHole(subPolygon);
}
}
}
if (_waitingHoles.Count > 0)
{
throw new NotSupportedException();
}
outputPolygons.Add(mainPolygon);
if (_otherPolygons.Count > 0)
{
outputPolygons.AddRange(_otherPolygons);
}
_waitingHoles.Clear();
_flattenContours.Clear();
_otherPolygons.Clear();
}