public static void addToQueue(FlatQueue <float> queue, DelaunatorSharp.Delaunator delauny
, DelaunatorSharp.IPoint[] points, Circumcircles circumcircles, bool[] onEdge, bool[] visited, int i)
{
onEdge[i] = true;
visited[delauny.Triangles[i]] = true;
DelaunatorSharp.IPoint p0 = points[delauny.Triangles[i]];
DelaunatorSharp.IPoint p1 = points[delauny.Triangles[i % 3 == 2 ? i - 2 : i + 1]];
float r = circumcircles.r[i];
float x = circumcircles.x[i];
float y = circumcircles.y[i];
float x0 = (float)p0.X;
float y0 = (float)p0.Y;
float x1 = (float)p1.X;
float y1 = (float)p1.Y;
// var [x0, y0] = p0;
// var[x1, y1] = p1;
float area = (y - y0) * (x1 - x) - (x - x0) * (y1 - y);
float cx = (x0 + x1) / 2;
float cy = (y0 + y1) / 2;
float d = (float)System.Math.Sqrt(System.Math.Pow(cx - x, 2) + System.Math.Pow(cy - y, 2));
// if the center of a circumcircle on the edge lies outside the advancing polygon,
// or inside but less than 0.2 circumradiuses away from the edge, queue it for collapsing
if (area >= 0f || d / r < 0.2f)
{
queue.Push(i, -r);
}
}
// https://observablehq.com/@mourner/adaptive-concave-hull
// https://mapbox.github.io/delaunator/
public static void ComputeHull()
{
string jsonFile = System.IO.Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, "..", "..", "..", "DelaunatorPoints.json");
jsonFile = System.IO.Path.GetFullPath(jsonFile);
string json = System.IO.File.ReadAllText(jsonFile, System.Text.Encoding.UTF8);
// DelaunatorSharp.IPoint[] points = Newtonsoft.Json.JsonConvert.DeserializeObject<DelaunatorSharp.IPoint[]>(json);
DelaunatorSharp.IPoint[] points = Newtonsoft.Json.JsonConvert.DeserializeObject <DelaunatorSharp.Point[]>(json).Cast <DelaunatorSharp.IPoint>().ToArray();
points = EnhancePointDensity(points, 10);
// string json = Newtonsoft.Json.JsonConvert.SerializeObject(points);
// System.IO.File.WriteAllText(jsonFile, json,System.Text.Encoding.UTF8);
BoundingBox bbox = GetBbox(points);
// float width = bbox.maxX - bbox.minX;
float width = bbox.maxX * 6;
float padding = (float)System.Math.Round(width * 0.02);
float scale = (width - 2 * padding) / (bbox.maxX - bbox.minX);
float height = (float)System.Math.Ceiling(scale * (bbox.maxY - bbox.minY)) + 2 * padding;
width = width + 2 * padding;
DelaunatorSharp.Delaunator delauny = new DelaunatorSharp.Delaunator(points);
Circumcircles circumcircles = ComputeCircumcircles(points, delauny);
FlatQueue <float> queue = new FlatQueue <float>();
bool[] onEdge = new bool[delauny.Halfedges.Length];
bool[] visited = new bool[points.Length];
for (int i = 0; i < delauny.Halfedges.Length; i++)
{
if (delauny.Halfedges[i] == -1)
{
addToQueue(queue, delauny, points, circumcircles, onEdge, visited, i); // start with convex hull edges
}
}
// var ctx = DOM.context2d(width, height);
int imageCount = 0;
System.Drawing.Bitmap bmp = new System.Drawing.Bitmap((int)width, (int)height);
using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bmp))
{
// Draw(delauny, points, bbox, circumcircles, g, padding, scale, queue, onEdge);
// bmp.Save(@"D:\TestImage" + imageCount + ".png", System.Drawing.Imaging.ImageFormat.Png);
// imageCount++;
while (true)
{
int?i = queue.Pop();
if (i == null)
{
break;
}
int i1 = delauny.Halfedges[i.Value % 3 == 2 ? i.Value - 2 : i.Value + 1];
int i2 = delauny.Halfedges[i.Value % 3 == 0 ? i.Value + 2 : i.Value - 1];
if (i1 != -1 && i2 != -1 && !visited[delauny.Triangles[i1]])
{
addToQueue(queue, delauny, points, circumcircles, onEdge, visited, i1);
addToQueue(queue, delauny, points, circumcircles, onEdge, visited, i2);
onEdge[i.Value] = false;
}
// yield draw(ctx, queue, onEdge);
// Draw(delauny, points, bbox, circumcircles, g, padding, scale, queue, onEdge);
// if(System.Environment.OSVersion.Platform == PlatformID.Unix)
// bmp.Save(@"TestImage" + imageCount + ".png", System.Drawing.Imaging.ImageFormat.Png);
// else
// bmp.Save(@"D:\TestImage" + imageCount + ".png", System.Drawing.Imaging.ImageFormat.Png);
// imageCount++;
} // Whend
Draw(delauny, points, bbox, circumcircles, g, padding, scale, queue, onEdge);
if (System.Environment.OSVersion.Platform == System.PlatformID.Unix)
{
bmp.Save(@"TestImage.png", System.Drawing.Imaging.ImageFormat.Png);
}
else
{
bmp.Save(@"D:\TestImage.png", System.Drawing.Imaging.ImageFormat.Png);
}
} // End Using g
System.Console.Write("finished");
}
public static void Draw(
DelaunatorSharp.Delaunator delaunay
, DelaunatorSharp.IPoint[] points
, BoundingBox bbox
, Circumcircles circumcircles
, System.Drawing.Graphics ctx
, float padding
, float scale
, FlatQueue <float> queue
, bool[] onEdge
)
{
// ctx.clearRect(0, 0, width, height);
ctx.Clear(System.Drawing.Color.White);
System.Drawing.Drawing2D.GraphicsPath path1 = new System.Drawing.Drawing2D.GraphicsPath();
int[] t = delaunay.Triangles;
for (int i = 0; i < t.Length; i += 3)
{
DelaunatorSharp.IPoint pt1 = points[t[i + 0]];
float ax = (float)pt1.X;
float ay = (float)pt1.Y;
DelaunatorSharp.IPoint pt2 = points[t[i + 1]];
float bx = (float)pt2.X;
float by = (float)pt2.Y;
DelaunatorSharp.IPoint pt3 = points[t[i + 2]];
float cx = (float)pt3.X;
float cy = (float)pt3.Y;
path1.StartFigure();
path1.AddLine(projX(ax, padding, scale, bbox), projY(ay, padding, scale, bbox), projX(bx, padding, scale, bbox), projY(by, padding, scale, bbox));
path1.AddLine(projX(bx, padding, scale, bbox), projY(by, padding, scale, bbox), projX(cx, padding, scale, bbox), projY(cy, padding, scale, bbox));
path1.CloseFigure();
}
System.Drawing.Pen trianglePen = new System.Drawing.Pen(System.Drawing.Color.FromArgb((int)(0.4 * 255), 0, 200, 0));
trianglePen.Width = 0.5f;
trianglePen.Alignment = System.Drawing.Drawing2D.PenAlignment.Center;
ctx.DrawPath(trianglePen, path1);
System.Drawing.Drawing2D.GraphicsPath path2 = new System.Drawing.Drawing2D.GraphicsPath();
// for (const [x, y] of points)
foreach (DelaunatorSharp.IPoint thisPoint in points)
{
float sx = projX((float)thisPoint.X, padding, scale, bbox);
float sy = projY((float)thisPoint.Y, padding, scale, bbox);
float r = 1.5f;
r = 5;
path2.StartFigure();
path2.AddArc(sx - r / 2.0f, sy - r / 2.0f, r, r, 0.0f, 360.0f);
path2.CloseFigure();
}
System.Drawing.Brush blackBrush = new System.Drawing.SolidBrush(System.Drawing.Color.Black);
ctx.FillPath(blackBrush, path2);
// ctx.beginPath();
System.Drawing.Drawing2D.GraphicsPath path3 = new System.Drawing.Drawing2D.GraphicsPath();
// path3.StartFigure();
for (int i = 0; i < onEdge.Length; i++)
{
if (!onEdge[i])
{
continue;
}
DelaunatorSharp.IPoint pt1 = points[t[i]];
float ax = (float)pt1.X;
float ay = (float)pt1.Y;
DelaunatorSharp.IPoint pt2 = points[t[i % 3 == 2 ? i - 2 : i + 1]];
float bx = (float)pt2.X;
float by = (float)pt2.Y;
path3.StartFigure();
path3.AddLine(projX(ax, padding, scale, bbox), projY(ay, padding, scale, bbox), projX(bx, padding, scale, bbox), projY(by, padding, scale, bbox));
path3.CloseFigure();
// ctx.moveTo(projX(ax), projY(ay));
// ctx.lineTo(projX(bx), projY(by));
// ctx.closePath();
}
// path3.CloseFigure();
System.Drawing.Pen hullPen = new System.Drawing.Pen(System.Drawing.Color.Blue);
hullPen.Width = 2.0f;
ctx.DrawPath(hullPen, path3);
System.Drawing.Drawing2D.GraphicsPath path4 = new System.Drawing.Drawing2D.GraphicsPath();
foreach (int i in queue.ids)
{
// ctx.beginPath();
path4.StartFigure();
float sr = circumcircles.r[i] * scale;
float sx = projX(circumcircles.x[i], padding, scale, bbox);
float sy = projY(circumcircles.y[i], padding, scale, bbox);
//ctx.moveTo(sx + sr, sy);
//ctx.arc(sx, sy, sr, 0, Math.PI* 2, false);
//ctx.strokeStyle = 'rgba(200,0,0,1)';
//ctx.lineWidth = 1;
//ctx.stroke();
//ctx.fillStyle = 'rgba(255,255,0,0.2)';
//ctx.fill();
path4.AddArc(sx - sr / 2.0f, sy - sr / 2.0f, sr, sr, 0.0f, 360.0f);
path4.CloseFigure();
}
System.Drawing.SolidBrush circleBrush = new System.Drawing.SolidBrush(System.Drawing.Color.FromArgb((int)(0.2 * 255), 255, 255, 0));
System.Drawing.Pen redCircle = new System.Drawing.Pen(System.Drawing.Color.FromArgb(255, 200, 0, 0));
redCircle.Width = 1;
redCircle.Alignment = System.Drawing.Drawing2D.PenAlignment.Center;
ctx.FillPath(circleBrush, path4);
ctx.DrawPath(redCircle, path4);
}
