void DrawOutput()
{
if (_g == null)
{
return;
}
//-----------
//for GDI+ only
bool flipYAxis = chkFlipY.Checked;
int viewHeight = this.panel1.Height;
//-----------
//show tess
_g.Clear(Color.White);
int[] contourEndIndices;
float[] polygon1 = GetPolygonData(out contourEndIndices);
if (polygon1 == null)
{
return;
}
//
if (flipYAxis)
{
var transformMat = new System.Drawing.Drawing2D.Matrix();
transformMat.Scale(1, -1);
transformMat.Translate(0, -viewHeight);
polygon1 = TransformPoints(polygon1, transformMat);
//when we flipY, meaning of clockwise-counter clockwise is changed.
//
//see https://stackoverflow.com/questions/1165647/how-to-determine-if-a-list-of-polygon-points-are-in-clockwise-order
//...(comment)
//...A minor caveat: this answer assumes a normal Cartesian coordinate system.
//The reason that's worth mentioning is that some common contexts, like HTML5 canvas, use an inverted Y-axis.
//Then the rule has to be flipped: if the area is negative, the curve is clockwise. – LarsH Oct 11 '13 at 20:49
}
using (Pen pen1 = new Pen(Color.LightGray, 6))
{
int nn = polygon1.Length;
int a = 0;
PointF p0;
PointF p1;
int contourCount = contourEndIndices.Length;
int startAt = 3;
for (int cnt_index = 0; cnt_index < contourCount; ++cnt_index)
{
int endAt = contourEndIndices[cnt_index];
for (int m = startAt; m <= endAt;)
{
p0 = new PointF(polygon1[m - 3], polygon1[m - 2]);
p1 = new PointF(polygon1[m - 1], polygon1[m]);
_g.DrawLine(pen1, p0, p1);
_g.DrawString(a.ToString(), this.Font, Brushes.Black, p0);
m += 2;
a++;
}
//close contour
p0 = new PointF(polygon1[endAt - 1], polygon1[endAt]);
p1 = new PointF(polygon1[startAt - 3], polygon1[startAt - 2]);
_g.DrawLine(pen1, p0, p1);
_g.DrawString(a.ToString(), this.Font, Brushes.Black, p0);
//
startAt = (endAt + 1) + 3;
}
}
//----------------------------------------------------------------------------
//tess
if (rdoTessSGI.Checked)
{
//SGI Tess Lib
if (!_tessTool.TessPolygon(polygon1, _contourEnds))
{
return;
}
//1.
List <ushort> indexList = _tessTool.TessIndexList;
//2.
List <TessVertex2d> tempVertexList = _tessTool.TempVertexList;
//3.
int vertexCount = indexList.Count;
//-----------------------------
int orgVertexCount = polygon1.Length / 2;
float[] vtx = new float[vertexCount * 2];//***
int n = 0;
for (int p = 0; p < vertexCount; ++p)
{
ushort index = indexList[p];
if (index >= orgVertexCount)
{
//extra coord (newly created)
TessVertex2d extraVertex = tempVertexList[index - orgVertexCount];
vtx[n] = (float)extraVertex.x;
vtx[n + 1] = (float)extraVertex.y;
}
else
{
//original corrd
vtx[n] = (float)polygon1[index * 2];
vtx[n + 1] = (float)polygon1[(index * 2) + 1];
}
n += 2;
}
//-----------------------------
//draw tess result
int j = vtx.Length;
for (int i = 0; i < j;)
{
var p0 = new PointF(vtx[i], vtx[i + 1]);
var p1 = new PointF(vtx[i + 2], vtx[i + 3]);
var p2 = new PointF(vtx[i + 4], vtx[i + 5]);
_g.DrawLine(Pens.Red, p0, p1);
_g.DrawLine(Pens.Red, p1, p2);
_g.DrawLine(Pens.Red, p2, p0);
i += 6;
}
}
else
{
List <Poly2Tri.Polygon> outputPolygons = new List <Poly2Tri.Polygon>();
Poly2TriExampleHelper.Triangulate(polygon1, contourEndIndices, flipYAxis, outputPolygons);
foreach (Poly2Tri.Polygon polygon in outputPolygons)
{
foreach (Poly2Tri.DelaunayTriangle tri in polygon.Triangles)
{
Poly2Tri.TriangulationPoint p0 = tri.P0;
Poly2Tri.TriangulationPoint p1 = tri.P1;
Poly2Tri.TriangulationPoint p2 = tri.P2;
_g.DrawLine(Pens.Red, (float)p0.X, (float)p0.Y, (float)p1.X, (float)p1.Y);
_g.DrawLine(Pens.Red, (float)p1.X, (float)p1.Y, (float)p2.X, (float)p2.Y);
_g.DrawLine(Pens.Red, (float)p2.X, (float)p2.Y, (float)p0.X, (float)p0.Y);
}
}
}
}
void DrawOutput()
{
if (_g == null)
{
return;
}
//-----------
//for GDI+ only
bool drawInvert = chkInvert.Checked;
int viewHeight = this.panel1.Height;
//-----------
//show tess
_g.Clear(Color.White);
int[] contourEndIndices;
float[] polygon1 = GetPolygonData(out contourEndIndices);
if (polygon1 == null)
{
return;
}
//
if (drawInvert)
{
var transformMat = new System.Drawing.Drawing2D.Matrix();
transformMat.Scale(1, -1);
transformMat.Translate(0, -viewHeight);
//
polygon1 = TransformPoints(polygon1, transformMat);
}
using (Pen pen1 = new Pen(Color.LightGray, 6))
{
int nn = polygon1.Length;
int a = 0;
PointF p0;
PointF p1;
int contourCount = contourEndIndices.Length;
int startAt = 3;
for (int cnt_index = 0; cnt_index < contourCount; ++cnt_index)
{
int endAt = contourEndIndices[cnt_index];
for (int m = startAt; m <= endAt;)
{
p0 = new PointF(polygon1[m - 3], polygon1[m - 2]);
p1 = new PointF(polygon1[m - 1], polygon1[m]);
_g.DrawLine(pen1, p0, p1);
_g.DrawString(a.ToString(), this.Font, Brushes.Black, p0);
m += 2;
a++;
}
//close contour
p0 = new PointF(polygon1[endAt - 1], polygon1[endAt]);
p1 = new PointF(polygon1[startAt - 3], polygon1[startAt - 2]);
_g.DrawLine(pen1, p0, p1);
_g.DrawString(a.ToString(), this.Font, Brushes.Black, p0);
//
startAt = (endAt + 1) + 3;
}
}
//----------------------------------------------------------------------------
//tess
if (rdoTessSGI.Checked)
{
//SGI Tess Lib
if (!_tessTool.TessPolygon(polygon1, _contourEnds))
{
return;
}
//1.
List <ushort> indexList = _tessTool.TessIndexList;
//2.
List <TessVertex2d> tempVertexList = _tessTool.TempVertexList;
//3.
int vertexCount = indexList.Count;
//-----------------------------
int orgVertexCount = polygon1.Length / 2;
float[] vtx = new float[vertexCount * 2];//***
int n = 0;
for (int p = 0; p < vertexCount; ++p)
{
ushort index = indexList[p];
if (index >= orgVertexCount)
{
//extra coord (newly created)
TessVertex2d extraVertex = tempVertexList[index - orgVertexCount];
vtx[n] = (float)extraVertex.x;
vtx[n + 1] = (float)extraVertex.y;
}
else
{
//original corrd
vtx[n] = (float)polygon1[index * 2];
vtx[n + 1] = (float)polygon1[(index * 2) + 1];
}
n += 2;
}
//-----------------------------
//draw tess result
int j = vtx.Length;
for (int i = 0; i < j;)
{
var p0 = new PointF(vtx[i], vtx[i + 1]);
var p1 = new PointF(vtx[i + 2], vtx[i + 3]);
var p2 = new PointF(vtx[i + 4], vtx[i + 5]);
_g.DrawLine(Pens.Red, p0, p1);
_g.DrawLine(Pens.Red, p1, p2);
_g.DrawLine(Pens.Red, p2, p0);
i += 6;
}
}
else
{
Poly2Tri.Polygon mainPolygon = Poly2TriExampleHelper.Triangulate(polygon1, contourEndIndices);
foreach (Poly2Tri.DelaunayTriangle tri in mainPolygon.Triangles)
{
Poly2Tri.TriangulationPoint p0 = tri.P0;
Poly2Tri.TriangulationPoint p1 = tri.P1;
Poly2Tri.TriangulationPoint p2 = tri.P2;
_g.DrawLine(Pens.Red, (float)p0.X, (float)p0.Y, (float)p1.X, (float)p1.Y);
_g.DrawLine(Pens.Red, (float)p1.X, (float)p1.Y, (float)p2.X, (float)p2.Y);
_g.DrawLine(Pens.Red, (float)p2.X, (float)p2.Y, (float)p0.X, (float)p0.Y);
}
}
}
