/// <summary>
/// Updates the <see cref="SubdivisionFace"/> keys in the specified dictionaries after the
/// specified <see cref="SubdivisionEdge"/> has been split.</summary>
/// <param name="edge">
/// The <see cref="SubdivisionEdge"/> whose splitting resulted in the current <see
/// cref="SplitEdgeResult"/>.</param>
/// <param name="edgeToFace1">
/// An <see cref="Int32Dictionary{T}"/> that maps the keys of any existing half-edges to the
/// keys of the incident bounded <see cref="Subdivision.Faces"/> of the corresponding <see
/// cref="Subdivision.Edges"/> in a first <see cref="Subdivision"/>.</param>
/// <param name="edgeToFace2">
/// An <see cref="Int32Dictionary{T}"/> that maps the keys of any existing half-edges to the
/// keys of the incident bounded <see cref="Subdivision.Faces"/> of the corresponding <see
/// cref="Subdivision.Edges"/> in a second <see cref="Subdivision"/>.</param>
/// <remarks>
/// <b>UpdateFaces</b> ensures that the mapping between original and intersected faces
/// established by the <see cref="Subdivision.Intersection"/> algorithm is kept up-to-date
/// when edge splitting results in a valid <see cref="CreatedEdge"/>.</remarks>
public void UpdateFaces(SubdivisionEdge edge,
Int32Dictionary <Int32> edgeToFace1, Int32Dictionary <Int32> edgeToFace2)
{
if (CreatedEdge == null)
{
return;
}
int face;
if (edgeToFace1.TryGetValue(edge._key, out face))
{
Debug.Assert(face != 0);
edgeToFace1.Add(CreatedEdge._key, face);
}
if (edgeToFace2.TryGetValue(edge._key, out face))
{
Debug.Assert(face != 0);
edgeToFace2.Add(CreatedEdge._key, face);
}
}
/// <summary>
/// 方法：存入int类型的配置信息。
/// </summary>
/// <param name="key">关键字</param>
/// <param name="value">配置信息</param>
public void PutInt32(string key, int value)
{
Int32Dictionary.Add(key, value);
}
/// <summary>
/// Draws the specified <see cref="Subdivision"/> to the specified <see cref="Canvas"/>.
/// </summary>
/// <param name="canvas">
/// The <see cref="Canvas"/> to draw on.</param>
/// <param name="fontSize">
/// The <see cref="Control.FontSize"/> for all text labels.</param>
/// <param name="division">
/// The <see cref="Subdivision"/> to draw on <paramref name="canvas"/>.</param>
/// <returns>
/// An <see cref="Int32Dictionary{T}"/> that maps the keys of all half-edges in <paramref
/// name="division"/> to the corresponding WPF <see cref="Path"/>.</returns>
internal static Int32Dictionary <Path> DrawSubdivision(
Canvas canvas, double fontSize, Subdivision division)
{
canvas.Children.Clear();
var edges = new Int32Dictionary <Path>(division.Edges.Count);
// draw vertices
const double radius = 2.0;
foreach (PointD vertex in division.Vertices.Keys)
{
var circle = new Ellipse()
{
Width = 2 * radius, Height = 2 * radius,
Stroke = Brushes.Black,
Fill = Brushes.Black
};
Canvas.SetLeft(circle, vertex.X - radius);
Canvas.SetTop(circle, vertex.Y - radius);
canvas.Children.Add(circle);
}
// draw half-edges with keys
foreach (var pair in division.Edges)
{
LineD line = pair.Value.ToLine();
double deltaX = line.End.X - line.Start.X;
double deltaY = line.End.Y - line.Start.Y;
double length = Math.Sqrt(deltaX * deltaX + deltaY * deltaY);
// slightly offset half-edge toward incident face
double offsetX = radius * deltaX / length;
double offsetY = radius * deltaY / length;
double x0 = line.Start.X + offsetX - offsetY;
double y0 = line.Start.Y + offsetX + offsetY;
double x1 = line.End.X - offsetX - offsetY;
double y1 = line.End.Y + offsetX - offsetY;
// draw hook in direction of half-edge
double angle = line.Angle + 0.75 * Math.PI;
Point hookStart = new Point(x1 - deltaX / 4, y1 - deltaY / 4);
Point hookEnd = new Point(
hookStart.X + Math.Cos(angle) * 8,
hookStart.Y + Math.Sin(angle) * 8);
PathFigure[] figures = new PathFigure[] {
new PathFigure(new Point(x0, y0), new PathSegment[] {
new LineSegment(new Point(x1, y1), true)
}, false),
new PathFigure(hookStart, new PathSegment[] {
new LineSegment(hookEnd, true)
}, false)
};
PathGeometry geometry = new PathGeometry(figures);
geometry.Freeze();
Path path = new Path()
{
Stroke = Brushes.Red, Data = geometry
};
canvas.Children.Add(path);
edges.Add(pair.Key, path);
// draw key of current half-edge
double centerX = (line.Start.X + line.End.X) / 2;
double fontSizeX = (pair.Key < 10 && deltaY > 0) ? fontSize / 2 : fontSize;
double textX = centerX - fontSizeX * deltaY / length - fontSize / 1.8;
double centerY = (line.Start.Y + line.End.Y) / 2;
double textY = centerY + fontSize * deltaX / length - fontSize / 1.5;
TextBlock text = new TextBlock(new Run(pair.Key.ToString()));
Canvas.SetLeft(text, textX);
Canvas.SetTop(text, textY);
canvas.Children.Add(text);
}
// draw keys of bounded faces
foreach (var pair in division.Faces)
{
if (pair.Key == 0)
{
continue;
}
PointD centroid = pair.Value.OuterEdge.CycleCentroid;
TextBlock text = new TextBlock(new Run(pair.Key.ToString()));
text.FontWeight = FontWeights.Bold;
Canvas.SetLeft(text, centroid.X - fontSize / 2);
Canvas.SetTop(text, centroid.Y - fontSize / 2);
canvas.Children.Add(text);
}
return(edges);
}