UltimateZoneBuilder/Source/Geometry/SidedefAngleSorter.cs

96 lines
2.5 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.Map;
#endregion
namespace CodeImp.DoomBuilder.Geometry
{
public sealed class SidedefAngleSorter : IComparer<Sidedef>
{
// Variables
private Sidedef baseside;
private Vertex basevertex;
// Constructor
public SidedefAngleSorter(Sidedef baseside, Vertex fromvertex)
{
// Initialize
this.baseside = baseside;
this.basevertex = fromvertex;
// We have no destructor
GC.SuppressFinalize(this);
}
// This calculates the relative angle between two sides
private float CalculateRelativeAngle(Sidedef a, Sidedef b)
{
float s, n, ana, anb;
Vector2D va, vb;
bool dir;
// Determine angles
ana = a.Line.Angle; if(a.Line.End == basevertex) ana += Angle2D.PI;
anb = b.Line.Angle; if(b.Line.End == basevertex) anb += Angle2D.PI;
// Take the difference from angles
n = Angle2D.Difference(ana, anb);
// Get line end vertices a and b that are not connected to basevertex
if(a.Line.Start == basevertex) va = a.Line.End.Position; else va = a.Line.Start.Position;
if(b.Line.Start == basevertex) vb = b.Line.End.Position; else vb = b.Line.Start.Position;
// Determine rotation direction
dir = baseside.IsFront;
if(baseside.Line.End == basevertex) dir = !dir;
// Check to which side the angle goes and adjust angle as needed
s = Line2D.GetSideOfLine(va, vb, basevertex.Position);
if((s < 0) && dir) n = Angle2D.PI2 - n;
if((s > 0) && !dir) n = Angle2D.PI2 - n;
// Return result
return n;
}
// Comparer
public int Compare(Sidedef x, Sidedef y)
{
float ax, ay;
// Calculate angles
ax = CalculateRelativeAngle(baseside, x);
ay = CalculateRelativeAngle(baseside, y);
// Compare results
/*
if(ax < ay) return 1;
else if(ax > ay) return -1;
else return 0;
*/
return Math.Sign(ay - ax);
}
}
}