UltimateZoneBuilder/Source/Core/Geometry/Plane.cs
2009-05-21 08:18:34 +00:00

142 lines
3.5 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;
#endregion
namespace CodeImp.DoomBuilder.Geometry
{
public struct Plane
{
#region ================== Constants
#endregion
#region ================== Variables
//
// Plane definition:
// A * x + B * y + C * z + D = 0
//
// A, B, C is the normal
// D is the offset along the normal (negative)
//
private Vector3D normal;
private float offset;
#endregion
#region ================== Properties
public Vector3D Normal { get { return normal; } }
public float Offset { get { return offset; } set { offset = value; } }
public float a { get { return normal.x; } }
public float b { get { return normal.y; } }
public float c { get { return normal.z; } }
public float d { get { return offset; } set { offset = value; } }
#endregion
#region ================== Constructors
/// <summary></summary>
public Plane(Vector3D normal, float offset)
{
#if DEBUG
if(!normal.IsNormalized())
General.Fail("Attempt to create a plane with a vector that is not normalized!");
#endif
this.normal = normal;
this.offset = offset;
}
/// <summary></summary>
public Plane(Vector3D normal, Vector3D position)
{
#if DEBUG
if(!normal.IsNormalized())
General.Fail("Attempt to create a plane with a vector that is not normalized!");
#endif
this.normal = normal;
this.offset = -Vector3D.DotProduct(normal, position);
}
/// <summary></summary>
public Plane(Vector3D p1, Vector3D p2, Vector3D p3)
{
this.normal = Vector3D.CrossProduct(p1 - p2, p3 - p2).GetNormal();
this.offset = -Vector3D.DotProduct(normal, p2);
}
#endregion
#region ================== Methods
/// <summary>
/// This tests for intersection using a position and direction
/// </summary>
public bool GetIntersection(Vector3D position, Vector3D direction, ref float u_ray)
{
float a = Vector3D.DotProduct(normal, direction);
if(a != 0.0f)
{
float b = Vector3D.DotProduct(normal, position);
u_ray = (offset - b) / a;
return true;
}
else
{
return false;
}
}
/// <summary>
/// This returns the smallest distance to the plane and the side on which the point lies.
/// > 0 means the point lies on the front of the plane
/// < 0 means the point lies behind the plane
/// </summary>
public float Distance(Vector3D p)
{
return Vector3D.DotProduct(p, normal) + offset;
}
/// <summary>
/// This returns a point on the plane closest to the given point
/// </summary>
public Vector3D ClosestOnPlane(Vector3D p)
{
float d = Vector3D.DotProduct(p, normal) + offset;
return p - normal * d;
}
/// <summary>
/// This inverts the plane
/// </summary>
public Plane GetInverted()
{
return new Plane(-normal, -offset);
}
#endregion
}
}