///<summary>Finds the next adjacent edge to [edge], ie the adjacent edge that creates the smallest angle</summary>
private static LinedefSide NextEdge(LinedefSide edge, Dictionary <Linedef, int> visited_lines)
{
// Get relevant vertices
Vertex vertex; // Vertex to be tested
Vertex vertex_prev; // 'Previous' vertex
if (edge.Front)
{
vertex = edge.Line.End;
vertex_prev = edge.Line.Start;
}
else
{
vertex = edge.Line.Start;
vertex_prev = edge.Line.End;
}
// Find next connected line with the lowest angle
float min_angle = Angle2D.PI2;
LinedefSide next = null;
foreach (Linedef line in vertex.Linedefs)
{
// Ignore original line
if (line == edge.Line)
{
continue;
}
// Ignore if zero-length
if (line.Start.Position == line.End.Position)
{
continue;
}
// Get next vertex
Vertex vertex_next;
bool front = true;
if (line.Start == vertex)
{
vertex_next = line.End;
}
else
{
vertex_next = line.Start;
front = false;
}
// Ignore already-traversed lines
int side = (front ? 1 : 2);
if (visited_lines.ContainsKey(line) && (visited_lines[line] & side) == side)
{
continue;
}
// Determine angle between lines
float angle = Angle2D.GetAngle(new Vector2D(vertex_prev.Position.x, vertex_prev.Position.y),
new Vector2D(vertex.Position.x, vertex.Position.y),
new Vector2D(vertex_next.Position.x, vertex_next.Position.y));
// Check if minimum angle
if (angle < min_angle)
{
min_angle = angle;
if (next == null)
{
next = new LinedefSide(line, front);
}
else
{
next.Line = line;
next.Front = front;
}
}
}
// Return the next edge found
if (next == null)
{
return(null);
}
if (!visited_lines.ContainsKey(next.Line))
{
visited_lines.Add(next.Line, 0);
}
visited_lines[next.Line] |= (next.Front ? 1 : 2);
return(next);
}
/// <summary>Find the closest edge within the current outline (that isn't part of the current outline)</summary>
private LinedefSide FindInnerEdge()
{
//DebugConsole.WriteLine("FindInnerEdge: processing " + vertex_valid.Count + " verts");
// Find rightmost non-discarded vertex
vertex_right = null;
foreach (Vertex v in vertex_valid)
{
// Set rightmost if no current rightmost vertex
if (vertex_right == null)
{
vertex_right = v;
continue;
}
// Check if the vertex is rightmost
if (v.Position.x > vertex_right.Position.x)
{
vertex_right = v;
}
}
// If no vertex was found, we're done
if (vertex_right == null)
{
//DebugConsole.WriteLine("FindInnerEdge: no vertex_right");
return(null);
}
// Go through vertex's connected lines, to find
// the line with the smallest angle parallel with
// the right side of the bbox
Linedef eline = null;
float min_angle = float.MaxValue;
foreach (Linedef line in vertex_right.Linedefs)
{
// Ignore if zero-length
if (line.Start == line.End)
{
continue;
}
// Get opposite vertex
Vertex opposite = (line.Start == vertex_right ? line.End : line.Start);
// Determine angle
float angle = Angle2D.GetAngle(new Vector2D(vertex_right.Position.x + 32, vertex_right.Position.y),
new Vector2D(vertex_right.Position.x, vertex_right.Position.y),
new Vector2D(opposite.Position.x, opposite.Position.y));
// Check if minimum
if (angle < min_angle)
{
min_angle = angle;
eline = line;
}
}
// If no line was found, something is wrong (the vertex may have no attached lines)
if (eline == null)
{
// Discard vertex and try again
vertex_valid.Remove(vertex_right);
//DebugConsole.WriteLine("vertex_valid: " + vertex_valid.Count + " verts after Remove (in FindInnerEdge)");
return(FindInnerEdge());
}
// Determine appropriate side
return(new LinedefSide(eline, (vertex_right == eline.Start)));
}
