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BoundingFrustum.cs in C#
Free, commercially distributable, modifiable, open source code. This class is part of the XnaGeometry library, a 3d library. To download the entire XnaGeometry library, click here. XnaGeometry uses the same function names as XNA so you can use the Microsoft XNA documentation. XnaGeometry will allow you to decouple your calculations from the renderer, and uses doubles for precision. Monogame has rendering support.
#region License /* MIT License Copyright © 2006 The Mono.Xna Team All rights reserved. Authors: Olivier Dufour (Duff) Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #endregion License using System; using System.Collections.Generic; using System.ComponentModel; using System.Runtime.InteropServices; using System.Text; namespace XnaGeometry { public class BoundingFrustum : IEquatable<BoundingFrustum> { #region Private Fields private Matrix matrix; private Plane bottom; private Plane far; private Plane left; private Plane right; private Plane near; private Plane top; private Vector3[] corners; #endregion Private Fields #region Public Fields public const int CornerCount = 8; #endregion #region Public Constructors public BoundingFrustum(Matrix value) { this.matrix = value; CreatePlanes(); CreateCorners(); } #endregion Public Constructors #region Public Properties public Plane Bottom { get { return this.bottom; } } public Plane Far { get { return this.far; } } public Plane Left { get { return this.left; } } public Matrix Matrix { get { return this.matrix; } set { this.matrix = value; this.CreatePlanes(); // FIXME: The odds are the planes will be used a lot more often than the matrix this.CreateCorners(); // is updated, so this should help performance. I hope ;) } } public Plane Near { get { return this.near; } } public Plane Right { get { return this.right; } } public Plane Top { get { return this.top; } } #endregion Public Properties #region Public Methods public static bool operator ==(BoundingFrustum a, BoundingFrustum b) { if (object.Equals(a, null)) return (object.Equals(b, null)); if (object.Equals(b, null)) return (object.Equals(a, null)); return a.matrix == (b.matrix); } public static bool operator !=(BoundingFrustum a, BoundingFrustum b) { return !(a == b); } public ContainmentType Contains(BoundingBox box) { ContainmentType result; this.Contains(ref box, out result); return result; } public void Contains(ref BoundingBox box, out ContainmentType result) { var intersects = false; PlaneIntersectionType type; box.Intersects(ref near, out type); if ( type == PlaneIntersectionType.Front ) { result = ContainmentType.Disjoint; return; } if ( type == PlaneIntersectionType.Intersecting ) intersects = true; box.Intersects(ref left, out type); if ( type == PlaneIntersectionType.Front ) { result = ContainmentType.Disjoint; return; } if ( type == PlaneIntersectionType.Intersecting ) intersects = true; box.Intersects(ref right, out type); if ( type == PlaneIntersectionType.Front ) { result = ContainmentType.Disjoint; return; } if ( type == PlaneIntersectionType.Intersecting ) intersects = true; box.Intersects(ref top, out type); if (type == PlaneIntersectionType.Front) { result = ContainmentType.Disjoint; return; } if (type == PlaneIntersectionType.Intersecting) intersects = true; box.Intersects(ref bottom, out type); if (type == PlaneIntersectionType.Front) { result = ContainmentType.Disjoint; return; } if (type == PlaneIntersectionType.Intersecting) intersects = true; box.Intersects(ref far, out type); if (type == PlaneIntersectionType.Front) { result = ContainmentType.Disjoint; return; } if (type == PlaneIntersectionType.Intersecting) intersects = true; result = intersects ? ContainmentType.Intersects : ContainmentType.Contains; } // TODO: Implement this public ContainmentType Contains(BoundingFrustum frustum) { if (this == frustum) // We check to see if the two frustums are equal return ContainmentType.Contains;// If they are, there's no need to go any further. throw new NotImplementedException(); } public ContainmentType Contains(BoundingSphere sphere) { ContainmentType result; this.Contains(ref sphere, out result); return result; } public void Contains(ref BoundingSphere sphere, out ContainmentType result) { double dist; result = ContainmentType.Contains; Vector3.Dot(ref bottom.Normal, ref sphere.Center, out dist); dist += bottom.D; if (dist > sphere.Radius) { result = ContainmentType.Disjoint; return; } if (Math.Abs(dist) < sphere.Radius) result = ContainmentType.Intersects; Vector3.Dot(ref top.Normal, ref sphere.Center, out dist); dist += top.D; if (dist > sphere.Radius) { result = ContainmentType.Disjoint; return; } if (Math.Abs(dist) < sphere.Radius) result = ContainmentType.Intersects; Vector3.Dot(ref near.Normal, ref sphere.Center, out dist); dist += near.D; if (dist > sphere.Radius) { result = ContainmentType.Disjoint; return; } if (Math.Abs(dist) < sphere.Radius) result = ContainmentType.Intersects; Vector3.Dot(ref far.Normal, ref sphere.Center, out dist); dist += far.D; if (dist > sphere.Radius) { result = ContainmentType.Disjoint; return; } if (Math.Abs(dist) < sphere.Radius) result = ContainmentType.Intersects; Vector3.Dot(ref left.Normal, ref sphere.Center, out dist); dist += left.D; if (dist > sphere.Radius) { result = ContainmentType.Disjoint; return; } if (Math.Abs(dist) < sphere.Radius) result = ContainmentType.Intersects; Vector3.Dot(ref right.Normal, ref sphere.Center, out dist); dist += right.D; if (dist > sphere.Radius) { result = ContainmentType.Disjoint; return; } if (Math.Abs(dist) < sphere.Radius) result = ContainmentType.Intersects; } public ContainmentType Contains(Vector3 point) { ContainmentType result; this.Contains(ref point, out result); return result; } public void Contains(ref Vector3 point, out ContainmentType result) { double val; // If a point is on the POSITIVE side of the plane, then the point is not contained within the frustum // Check the top val = PlaneHelper.ClassifyPoint(ref point, ref this.top); if (val > 0) { result = ContainmentType.Disjoint; return; } // Check the bottom val = PlaneHelper.ClassifyPoint(ref point, ref this.bottom); if (val > 0) { result = ContainmentType.Disjoint; return; } // Check the left val = PlaneHelper.ClassifyPoint(ref point, ref this.left); if (val > 0) { result = ContainmentType.Disjoint; return; } // Check the right val = PlaneHelper.ClassifyPoint(ref point, ref this.right); if (val > 0) { result = ContainmentType.Disjoint; return; } // Check the near val = PlaneHelper.ClassifyPoint(ref point, ref this.near); if (val > 0) { result = ContainmentType.Disjoint; return; } // Check the far val = PlaneHelper.ClassifyPoint(ref point, ref this.far); if (val > 0) { result = ContainmentType.Disjoint; return; } // If we get here, it means that the point was on the correct side of each plane to be // contained. Therefore this point is contained result = ContainmentType.Contains; } public bool Equals(BoundingFrustum other) { return (this == other); } public override bool Equals(object obj) { BoundingFrustum f = obj as BoundingFrustum; return (object.Equals(f, null)) ? false : (this == f); } public Vector3[] GetCorners() { return (Vector3[])this.corners.Clone(); } public void GetCorners(Vector3[] corners) { if (corners == null) throw new ArgumentNullException("corners"); if (corners.Length < 8) throw new ArgumentOutOfRangeException("corners"); this.corners.CopyTo(corners, 0); } public override int GetHashCode() { return this.matrix.GetHashCode(); } public bool Intersects(BoundingBox box) { var result = false; this.Intersects(ref box, out result); return result; } public void Intersects(ref BoundingBox box, out bool result) { var containment = ContainmentType.Disjoint; this.Contains(ref box, out containment); result = containment != ContainmentType.Disjoint; } public bool Intersects(BoundingFrustum frustum) { throw new NotImplementedException(); } public bool Intersects(BoundingSphere sphere) { throw new NotImplementedException(); } public void Intersects(ref BoundingSphere sphere, out bool result) { throw new NotImplementedException(); } public PlaneIntersectionType Intersects(Plane plane) { throw new NotImplementedException(); } public void Intersects(ref Plane plane, out PlaneIntersectionType result) { throw new NotImplementedException(); } public Nullable<double> Intersects(Ray ray) { throw new NotImplementedException(); } public void Intersects(ref Ray ray, out Nullable<double> result) { throw new NotImplementedException(); } public override string ToString() { StringBuilder sb = new StringBuilder(256); sb.Append("{Near:"); sb.Append(this.near.ToString()); sb.Append(" Far:"); sb.Append(this.far.ToString()); sb.Append(" Left:"); sb.Append(this.left.ToString()); sb.Append(" Right:"); sb.Append(this.right.ToString()); sb.Append(" Top:"); sb.Append(this.top.ToString()); sb.Append(" Bottom:"); sb.Append(this.bottom.ToString()); sb.Append("}"); return sb.ToString(); } #endregion Public Methods #region Private Methods private void CreateCorners() { this.corners = new Vector3[8]; this.corners[0] = IntersectionPoint(ref this.near, ref this.left, ref this.top); this.corners[1] = IntersectionPoint(ref this.near, ref this.right, ref this.top); this.corners[2] = IntersectionPoint(ref this.near, ref this.right, ref this.bottom); this.corners[3] = IntersectionPoint(ref this.near, ref this.left, ref this.bottom); this.corners[4] = IntersectionPoint(ref this.far, ref this.left, ref this.top); this.corners[5] = IntersectionPoint(ref this.far, ref this.right, ref this.top); this.corners[6] = IntersectionPoint(ref this.far, ref this.right, ref this.bottom); this.corners[7] = IntersectionPoint(ref this.far, ref this.left, ref this.bottom); } private void CreatePlanes() { // Pre-calculate the different planes needed this.left = new Plane(-this.matrix.M14 - this.matrix.M11, -this.matrix.M24 - this.matrix.M21, -this.matrix.M34 - this.matrix.M31, -this.matrix.M44 - this.matrix.M41); this.right = new Plane(this.matrix.M11 - this.matrix.M14, this.matrix.M21 - this.matrix.M24, this.matrix.M31 - this.matrix.M34, this.matrix.M41 - this.matrix.M44); this.top = new Plane(this.matrix.M12 - this.matrix.M14, this.matrix.M22 - this.matrix.M24, this.matrix.M32 - this.matrix.M34, this.matrix.M42 - this.matrix.M44); this.bottom = new Plane(-this.matrix.M14 - this.matrix.M12, -this.matrix.M24 - this.matrix.M22, -this.matrix.M34 - this.matrix.M32, -this.matrix.M44 - this.matrix.M42); this.near = new Plane(-this.matrix.M13, -this.matrix.M23, -this.matrix.M33, -this.matrix.M43); this.far = new Plane(this.matrix.M13 - this.matrix.M14, this.matrix.M23 - this.matrix.M24, this.matrix.M33 - this.matrix.M34, this.matrix.M43 - this.matrix.M44); this.NormalizePlane(ref this.left); this.NormalizePlane(ref this.right); this.NormalizePlane(ref this.top); this.NormalizePlane(ref this.bottom); this.NormalizePlane(ref this.near); this.NormalizePlane(ref this.far); } private static Vector3 IntersectionPoint(ref Plane a, ref Plane b, ref Plane c) { // Formula used // d1 ( N2 * N3 ) + d2 ( N3 * N1 ) + d3 ( N1 * N2 ) //P = ------------------------------------------------------------------------- // N1 . ( N2 * N3 ) // // Note: N refers to the normal, d refers to the displacement. '.' means dot product. '*' means cross product Vector3 v1, v2, v3; double f = -Vector3.Dot(a.Normal, Vector3.Cross(b.Normal, c.Normal)); v1 = (a.D * (Vector3.Cross(b.Normal, c.Normal))); v2 = (b.D * (Vector3.Cross(c.Normal, a.Normal))); v3 = (c.D * (Vector3.Cross(a.Normal, b.Normal))); Vector3 vec = new Vector3(v1.X + v2.X + v3.X, v1.Y + v2.Y + v3.Y, v1.Z + v2.Z + v3.Z); return vec / f; } private void NormalizePlane(ref Plane p) { double factor = 1f / p.Normal.Length(); p.Normal.X *= factor; p.Normal.Y *= factor; p.Normal.Z *= factor; p.D *= factor; } #endregion } } Home Free Stuff Politics Contact Copyright 2013 TechnologicalUtopia.com |