/// <summary>
/// The HLines from this edge, with the HLines at the beginning and end of the newLine split into two.
/// The dictionary's key is the left edge of each HLine.
/// </summary>
private Dictionary <double, HLine> SplitEdge(HLine newLine, double leftY, double rightY)
{
M.Assert(Lines.Count > 0);
Dictionary <double, HLine> splitEdge = new Dictionary <double, HLine>();
foreach (HLine hline in Lines)
{
if (hline.Left < newLine.Left && hline.Right > newLine.Left && leftY > newLine.Y)
{
Dictionary <double, HLine> splitLines1 = hline.Split(newLine.Left);
Dictionary <double, HLine> splitLines2 = new Dictionary <double, HLine>();
foreach (double x in splitLines1.Keys)
{
HLine line = splitLines1[x];
if (line.Left < newLine.Right && line.Right > newLine.Right && line.Y > newLine.Y)
{
splitLines2 = line.Split(newLine.Right);
}
}
foreach (double x in splitLines1.Keys)
{
if (!splitLines2.ContainsKey(x))
{
splitEdge.Add(splitLines1[x].Left, splitLines1[x]);
}
}
foreach (double x in splitLines2.Keys)
{
splitEdge.Add(splitLines2[x].Left, splitLines2[x]);
}
}
else if (hline.Left < newLine.Right && hline.Right > newLine.Right && rightY > newLine.Y)
{
Dictionary <double, HLine> splitLines = hline.Split(newLine.Right);
foreach (double x in splitLines.Keys)
{
splitEdge.Add(splitLines[x].Left, splitLines[x]);
}
}
else
{
splitEdge.Add(hline.Left, hline);
}
}
return(splitEdge);
}
public void AddLineToUpperEdge(HLine newLine)
{
M.Assert(newLine.Y != double.MaxValue);
if (Lines.Count == 0)
{
Lines.Add(newLine);
}
else
{
double leftY = this.YatX(newLine.Left);
double rightY = this.YatX(newLine.Right);
Dictionary <double, HLine> splitEdge = SplitEdge(newLine, leftY, rightY);
List <double> splitXsOnNewLine = SplitXsOnNewLine(newLine);
Dictionary <double, HLine> splitNewLine = newLine.Split(splitXsOnNewLine); // if
List <HLine> newLines = new List <HLine>();
double currentX = splitEdge[0].Left;
foreach (double x in splitEdge.Keys)
{
if (splitNewLine.ContainsKey(x))
{
if (newLine.Y < splitEdge[x].Y)
{
newLines.Add(splitNewLine[x]);
currentX = splitNewLine[x].Right;
}
else
{
newLines.Add(splitEdge[x]);
currentX = splitEdge[x].Right;
}
}
else if (splitEdge[x].Left == currentX)
{
newLines.Add(splitEdge[x]);
currentX = splitEdge[x].Right;
}
}
for (int i = 1; i < newLines.Count; ++i)
{
M.Assert(newLines[i - 1].Right == newLines[i].Left);
}
Lines = null;
Lines = newLines;
}
}
public void AddLineToUpperEdge(HLine newLine)
{
Debug.Assert(newLine.Y != float.MaxValue);
if(Lines.Count == 0)
{
Lines.Add(newLine);
}
else
{
float leftY = this.YatX(newLine.Left);
float rightY = this.YatX(newLine.Right);
Dictionary<float, HLine> splitEdge = SplitEdge(newLine, leftY, rightY);
List<float> splitXsOnNewLine = SplitXsOnNewLine(newLine);
Dictionary<float, HLine> splitNewLine = newLine.Split(splitXsOnNewLine); // if
List<HLine> newLines = new List<HLine>();
float currentX = splitEdge[0].Left;
foreach(float x in splitEdge.Keys)
{
if(splitNewLine.ContainsKey(x))
{
if(newLine.Y < splitEdge[x].Y)
{
newLines.Add(splitNewLine[x]);
currentX = splitNewLine[x].Right;
}
else
{
newLines.Add(splitEdge[x]);
currentX = splitEdge[x].Right;
}
}
else if(splitEdge[x].Left == currentX)
{
newLines.Add(splitEdge[x]);
currentX = splitEdge[x].Right;
}
}
for(int i = 1; i < newLines.Count; ++i)
{
Debug.Assert(newLines[i - 1].Right == newLines[i].Left);
}
Lines = null;
Lines = newLines;
}
}