/// <summary>
/// Build a road inside a district cell
/// </summary>
public List <Road> BuildRoad(DistrictCell cell, bool generateInnerRoads, int subdivisions)
{
//Edges are the bounds of the road and will be part of the road as well
var edges = cell.Edges.ToList();
//find the longest line in the cell as a start line
var longest = FindLongestLineInCell(edges);
//a cell edge can be shared so first remove the line from one of the shared cells
//all edges of the cell are part of the road
var roads = new List <Road>();
foreach (var edge in cell.Edges)
{
//add the original side edge
var road = Road.FromLine(edge);
roads.Add(road);
}
var innerRoads = new List <Road>();
if (generateInnerRoads && subdivisions > 0)
{
//Create another subdivision
roads = GenerateRoad(roads, innerRoads, Road.FromLine(longest.Key), Road.FromLine(longest.Value), subdivisions - 1);
}
//set up a reference to the parent cell
foreach (var road in roads)
{
road.ParentCell = cell;
}
return(roads);
}
private void HandlePossibleRoadIntersections(Line line, Road startLine, Road endLine, List <Road> borders, List <Road> innerRoads)
{
bool flipped = false;
//check for possible intersection,
//if an intersection happens the end point becomes the point of intersection
//has to be reverse because otherwise the lines will intersect with the edges
for (var i = 0; i < innerRoads.Count; i++)
{
var l = innerRoads[i];
//if the line intersects
if (!line.IntersectsWith(l))
{
continue;
}
//find the intersection point
bool parallel = false;
var ip = line.FindIntersectionPoint(l, ref parallel);
//parrallel lines don't intersect so ignore
if (parallel)
{
continue;
}
//Create the new line from the intersection
line = CreateIntersectedLine(line, ip, ref flipped);
//Split the line that is intersected with in 2 new lines
if (flipped)
{
startLine = innerRoads[i];
}
else
{
endLine = innerRoads[i];
}
//stop at the first intersection
break;
}
//Because of the new line the start and end line will have to be split in 2 new lines
//the total of new lines will be 3
//Adjust the borders
borders.Remove(startLine);
borders.Remove(endLine);
//create the split lines
borders.Add(new Road(startLine.Start, line.Start));
borders.Add(new Road(line.Start, startLine.End));
borders.Add(new Road(endLine.Start, line.End));
borders.Add(new Road(line.End, endLine.End));
//Add the new road to the inner roads
innerRoads.Add(Road.FromLine(line));
innerRoads.Remove(startLine);
innerRoads.Remove(endLine);
}
