UltimateZoneBuilder/Source/Geometry/SectorTools.cs
2008-05-08 12:04:20 +00:00

476 lines
14 KiB
C#

#region ================== Copyright (c) 2007 Pascal vd Heiden
/*
* Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
* This program is released under GNU General Public License
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#endregion
#region ================== Namespaces
using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Text;
using CodeImp.DoomBuilder.Geometry;
using CodeImp.DoomBuilder.Rendering;
using SlimDX.Direct3D;
using System.Drawing;
using CodeImp.DoomBuilder.Map;
#endregion
namespace CodeImp.DoomBuilder.Geometry
{
/// <summary>
/// This makes a sector from all surrounding lines from a given coordinate.
/// Automatically finds the sidedef/sector properties from surrounding sectors/sidedefs.
/// </summary>
public static class SectorTools
{
#region ================== Constants
#endregion
#region ================== Pathfinding
/// <summary>
/// This finds a potential sector at the given coordinates,
/// or returns null when a sector is not possible there.
/// </summary>
public static List<LinedefSide> FindPotentialSectorAt(Vector2D pos)
{
// Find the nearest line and determine side, then use the other method to create the sector
Linedef l = General.Map.Map.NearestLinedef(pos);
return FindPotentialSectorAt(l, (l.SideOfLine(pos) <= 0));
}
/// <summary>
/// This finds a potential sector starting at the given line and side,
/// or returns null when sector is not possible.
/// </summary>
public static List<LinedefSide> FindPotentialSectorAt(Linedef line, bool front)
{
List<LinedefSide> alllines = new List<LinedefSide>();
// Find the outer lines
Polygon p = FindOuterLines(line, front, alllines);
if(p != null)
{
// Find the inner lines
FindInnerLines(p, alllines);
return alllines;
}
else
return null;
}
// This finds the inner lines of the sector and adds them to the sector polygon
private static void FindInnerLines(Polygon p, List<LinedefSide> alllines)
{
Vertex foundv;
bool vvalid, findmore;
Linedef foundline;
float foundangle = 0f;
bool foundlinefront;
do
{
findmore = false;
// Go for all vertices to find the right-most vertex inside the polygon
foundv = null;
foreach(Vertex v in General.Map.Map.Vertices)
{
// More to the right?
if((foundv == null) || (v.Position.x >= foundv.Position.x))
{
// Vertex is inside the polygon?
if(p.Intersect(v.Position))
{
// Vertex has lines attached?
if(v.Linedefs.Count > 0)
{
// Go for all lines to see if the vertex is not of the polygon itsself
vvalid = true;
foreach(LinedefSide ls in alllines)
{
if((ls.Line.Start == v) || (ls.Line.End == v))
{
vvalid = false;
break;
}
}
// Valid vertex?
if(vvalid) foundv = v;
}
}
}
}
// Found a vertex inside the polygon?
if(foundv != null)
{
// Find the attached linedef with the smallest angle to the right
float targetangle = Angle2D.PIHALF;
foundline = null;
foreach(Linedef l in foundv.Linedefs)
{
// We need an angle unrelated to line direction, so correct for that
float lineangle = l.Angle;
if(l.End == foundv) lineangle += Angle2D.PI;
// Better result?
float deltaangle = Angle2D.Difference(targetangle, lineangle);
if((foundline == null) || (deltaangle < foundangle))
{
foundline = l;
foundangle = deltaangle;
}
}
// We already know that each linedef will go from this vertex
// to the left, because this is the right-most vertex in this area.
// If the line would go to the right, that means the other vertex of
// that line must lie outside this area and the mapper made an error.
// Should I check for this error and fail to create a sector in
// that case or ignore it and create a malformed sector (possibly
// breaking another sector also)?
// Find the side at which to start pathfinding
Vector2D testpos = new Vector2D(100.0f, 0.0f);
foundlinefront = (foundline.SideOfLine(foundv.Position + testpos) < 0.0f);
// Find inner path
List<LinedefSide> innerlines = FindClosestPath(foundline, foundlinefront, true);
if(innerlines != null)
{
// Make polygon
LinedefTracePath tracepath = new LinedefTracePath(innerlines);
Polygon innerpoly = tracepath.MakePolygon();
// Check if the front of the line is outside the polygon
if(!innerpoly.Intersect(foundline.GetSidePoint(foundlinefront)))
{
// Valid hole found!
alllines.AddRange(innerlines);
p.InsertChild(innerpoly);
findmore = true;
}
}
}
}
// Continue until no more holes found
while(findmore);
}
// This finds the outer lines of the sector as a polygon
// Returns null when no valid outer polygon can be found
private static Polygon FindOuterLines(Linedef line, bool front, List<LinedefSide> alllines)
{
Linedef scanline = line;
bool scanfront = front;
do
{
// Find closest path
List<LinedefSide> pathlines = FindClosestPath(scanline, scanfront, true);
if(pathlines != null)
{
// Make polygon
LinedefTracePath tracepath = new LinedefTracePath(pathlines);
Polygon poly = tracepath.MakePolygon();
// Check if the front of the line is inside the polygon
if(poly.Intersect(line.GetSidePoint(front)))
{
// Outer lines found!
alllines.AddRange(pathlines);
return poly;
}
else
{
// Inner lines found. This is not what we need, we want the outer lines.
// Find the right-most vertex to start a scan from there towards the outer lines.
Vertex foundv = null;
foreach(LinedefSide ls in pathlines)
{
if((foundv == null) || (ls.Line.Start.Position.x > foundv.Position.x))
foundv = ls.Line.Start;
if((foundv == null) || (ls.Line.End.Position.x > foundv.Position.x))
foundv = ls.Line.End;
}
// If foundv is null then something is horribly wrong with the
// path we received from FindClosestPath!
if(foundv == null) throw new Exception("FAIL!");
// From the right-most vertex trace outward to the right to
// find the next closest linedef, this is based on the idea that
// all sectors are closed.
Vector2D lineoffset = new Vector2D(100.0f, 0.0f);
Line2D testline = new Line2D(foundv.Position, foundv.Position + lineoffset);
scanline = null;
float foundu = float.MaxValue;
foreach(Linedef ld in General.Map.Map.Linedefs)
{
// Line to the right of start point?
if((ld.Start.Position.x > foundv.Position.x) ||
(ld.End.Position.x > foundv.Position.x))
{
// Line intersecting the y axis?
if( !((ld.Start.Position.y > foundv.Position.y) &&
(ld.End.Position.y > foundv.Position.y)) &&
!((ld.Start.Position.y < foundv.Position.y) &&
(ld.End.Position.y < foundv.Position.y)))
{
// Check if this linedef intersects our test line at a closer range
float thisu;
ld.Line.GetIntersection(testline, out thisu);
if((thisu > 0.00001f) && (thisu < foundu) && !float.IsNaN(thisu))
{
scanline = ld;
foundu = thisu;
}
}
}
}
// Did we meet another line?
if(scanline != null)
{
// Determine on which side we should start the next pathfind
scanfront = (scanline.SideOfLine(foundv.Position) < 0.0f);
}
else
{
// Appearently we reached the end of the map, no sector possible here
return null;
}
}
}
else
{
// Can't find a path
return null;
}
}
while(true);
}
/// <summary>
/// This finds the closest path from the beginning of a line to the end of the line.
/// When turnatends is true, the algorithm will continue at the other side of the
/// line when a dead end has been reached. Returns null when no path could be found.
/// </summary>
public static List<LinedefSide> FindClosestPath(Linedef startline, bool startfront, bool turnatends)
{
return FindClosestPath(startline, startfront, startline, startfront, turnatends);
}
/// <summary>
/// This finds the closest path from the beginning of a line to the end of the line.
/// When turnatends is true, the algorithm will continue at the other side of the
/// line when a dead end has been reached. Returns null when no path could be found.
/// </summary>
public static List<LinedefSide> FindClosestPath(Linedef startline, bool startfront, Linedef endline, bool endfront, bool turnatends)
{
List<LinedefSide> path = new List<LinedefSide>();
Dictionary<Linedef, int> tracecount = new Dictionary<Linedef, int>();
Linedef nextline = startline;
bool nextfront = startfront;
do
{
// Add line to path
path.Add(new LinedefSide(nextline, nextfront));
if(!tracecount.ContainsKey(nextline)) tracecount.Add(nextline, 1); else tracecount[nextline]++;
// Determine next vertex to use
Vertex v = nextfront ? nextline.End : nextline.Start;
// Get list of linedefs and sort by angle
List<Linedef> lines = new List<Linedef>(v.Linedefs);
LinedefAngleSorter sorter = new LinedefAngleSorter(nextline, nextfront, v);
lines.Sort(sorter);
// Source line is the only one?
if(lines.Count == 1)
{
// Are we allowed to trace along this line again?
if(turnatends && (!tracecount.ContainsKey(nextline) || (tracecount[nextline] < 3)))
{
// Turn around and go back along the other side of the line
nextfront = !nextfront;
}
else
{
// No more lines, trace ends here
path = null;
}
}
else
{
// Trace along the next line
Linedef prevline = nextline;
if(lines[0] == nextline) nextline = lines[1]; else nextline = lines[0];
// Are we allowed to trace this line again?
if(!tracecount.ContainsKey(nextline) || (tracecount[nextline] < 3))
{
// Check if front side changes
if((prevline.Start == nextline.Start) ||
(prevline.End == nextline.End)) nextfront = !nextfront;
}
else
{
// No more lines, trace ends here
path = null;
}
}
}
// Continue as long as we have not reached the start yet
// or we have no next line to trace
while((path != null) && ((nextline != endline) || (nextfront != endfront)));
// If start and front are not the same, add the end to the list also
if((path != null) && ((startline != endline) || (startfront != endfront)))
path.Add(new LinedefSide(endline, endfront));
// Return path (null when trace failed)
return path;
}
#endregion
#region ================== Sector Making
// This makes the sector from the given lines and sides
public static Sector MakeSector(List<LinedefSide> alllines)
{
Sidedef source = null;
Sector newsector = General.Map.Map.CreateSector();
// Check if any of the sides already has a sidedef
// Then we use information from that sidedef to make the others
foreach(LinedefSide ls in alllines)
{
if(ls.Front)
{
if(ls.Line.Front != null)
{
source = ls.Line.Front;
source.Sector.CopyPropertiesTo(newsector);
break;
}
}
else
{
if(ls.Line.Back != null)
{
source = ls.Line.Back;
source.Sector.CopyPropertiesTo(newsector);
break;
}
}
}
// If we couldn't find anything, try the other sides
if(source == null)
{
foreach(LinedefSide ls in alllines)
{
if(ls.Front)
{
if(ls.Line.Back != null)
{
source = ls.Line.Back;
source.Sector.CopyPropertiesTo(newsector);
break;
}
}
else
{
if(ls.Line.Front != null)
{
source = ls.Line.Front;
source.Sector.CopyPropertiesTo(newsector);
break;
}
}
}
}
// Go for all sides to make sidedefs
foreach(LinedefSide ls in alllines)
{
if(ls.Front)
{
// Create sidedef is needed and ensure it points to the new sector
if(ls.Line.Front == null) General.Map.Map.CreateSidedef(ls.Line, true, newsector);
if(ls.Line.Front.Sector != newsector) ls.Line.Front.ChangeSector(newsector);
if(source != null) source.CopyPropertiesTo(ls.Line.Front); else source = ls.Line.Front;
}
else
{
// Create sidedef is needed and ensure it points to the new sector
if(ls.Line.Back == null) General.Map.Map.CreateSidedef(ls.Line, false, newsector);
if(ls.Line.Back.Sector != newsector) ls.Line.Back.ChangeSector(newsector);
if(source != null) source.CopyPropertiesTo(ls.Line.Back); else source = ls.Line.Back;
}
// Update line
ls.Line.ApplySidedFlags();
}
// Return the new sector
return newsector;
}
// This joins a sector with the given lines and sides
public static Sector JoinSector(List<LinedefSide> alllines, Sidedef original)
{
// Go for all sides to make sidedefs
foreach(LinedefSide ls in alllines)
{
if(ls.Front)
{
// Create sidedef is needed and ensure it points to the new sector
if(ls.Line.Front == null)
{
General.Map.Map.CreateSidedef(ls.Line, true, original.Sector);
ls.Line.ApplySidedFlags();
}
original.CopyPropertiesTo(ls.Line.Front);
}
else
{
// Create sidedef is needed and ensure it points to the new sector
if(ls.Line.Back == null)
{
General.Map.Map.CreateSidedef(ls.Line, false, original.Sector);
ls.Line.ApplySidedFlags();
}
original.CopyPropertiesTo(ls.Line.Back);
}
}
// Return the new sector
return original.Sector;
}
#endregion
}
}