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BoundingSphere.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.Globalization; using System.ComponentModel; namespace XnaGeometry { public struct BoundingSphere : IEquatable<BoundingSphere> { #region Public Fields public Vector3 Center; public double Radius; #endregion Public Fields #region Constructors public BoundingSphere(Vector3 center, double radius) { this.Center = center; this.Radius = radius; } #endregion Constructors #region Public Methods public BoundingSphere Transform(Matrix matrix) { BoundingSphere sphere = new BoundingSphere(); sphere.Center = Vector3.Transform(this.Center, matrix); sphere.Radius = this.Radius * ((double)Math.Sqrt((double)Math.Max(((matrix.M11 * matrix.M11) + (matrix.M12 * matrix.M12)) + (matrix.M13 * matrix.M13), Math.Max(((matrix.M21 * matrix.M21) + (matrix.M22 * matrix.M22)) + (matrix.M23 * matrix.M23), ((matrix.M31 * matrix.M31) + (matrix.M32 * matrix.M32)) + (matrix.M33 * matrix.M33))))); return sphere; } public void Transform(ref Matrix matrix, out BoundingSphere result) { result.Center = Vector3.Transform(this.Center, matrix); result.Radius = this.Radius * ((double)Math.Sqrt((double)Math.Max(((matrix.M11 * matrix.M11) + (matrix.M12 * matrix.M12)) + (matrix.M13 * matrix.M13), Math.Max(((matrix.M21 * matrix.M21) + (matrix.M22 * matrix.M22)) + (matrix.M23 * matrix.M23), ((matrix.M31 * matrix.M31) + (matrix.M32 * matrix.M32)) + (matrix.M33 * matrix.M33))))); } public ContainmentType Contains(BoundingBox box) { //check if all corner is in sphere bool inside = true; foreach (Vector3 corner in box.GetCorners()) { if (this.Contains(corner) == ContainmentType.Disjoint) { inside = false; break; } } if (inside) return ContainmentType.Contains; //check if the distance from sphere center to cube face < radius double dmin = 0; if (Center.X < box.Min.X) dmin += (Center.X - box.Min.X) * (Center.X - box.Min.X); else if (Center.X > box.Max.X) dmin += (Center.X - box.Max.X) * (Center.X - box.Max.X); if (Center.Y < box.Min.Y) dmin += (Center.Y - box.Min.Y) * (Center.Y - box.Min.Y); else if (Center.Y > box.Max.Y) dmin += (Center.Y - box.Max.Y) * (Center.Y - box.Max.Y); if (Center.Z < box.Min.Z) dmin += (Center.Z - box.Min.Z) * (Center.Z - box.Min.Z); else if (Center.Z > box.Max.Z) dmin += (Center.Z - box.Max.Z) * (Center.Z - box.Max.Z); if (dmin <= Radius * Radius) return ContainmentType.Intersects; //else disjoint return ContainmentType.Disjoint; } public void Contains(ref BoundingBox box, out ContainmentType result) { result = this.Contains(box); } public ContainmentType Contains(BoundingFrustum frustum) { //check if all corner is in sphere bool inside = true; Vector3[] corners = frustum.GetCorners(); foreach (Vector3 corner in corners) { if (this.Contains(corner) == ContainmentType.Disjoint) { inside = false; break; } } if (inside) return ContainmentType.Contains; //check if the distance from sphere center to frustrum face < radius double dmin = 0; //TODO : calcul dmin if (dmin <= Radius * Radius) return ContainmentType.Intersects; //else disjoint return ContainmentType.Disjoint; } public ContainmentType Contains(BoundingSphere sphere) { double val = Vector3.Distance(sphere.Center, Center); if (val > sphere.Radius + Radius) return ContainmentType.Disjoint; else if (val <= Radius - sphere.Radius) return ContainmentType.Contains; else return ContainmentType.Intersects; } public void Contains(ref BoundingSphere sphere, out ContainmentType result) { result = Contains(sphere); } public ContainmentType Contains(Vector3 point) { double distance = Vector3.Distance(point, Center); if (distance > this.Radius) return ContainmentType.Disjoint; else if (distance < this.Radius) return ContainmentType.Contains; return ContainmentType.Intersects; } public void Contains(ref Vector3 point, out ContainmentType result) { result = Contains(point); } public static BoundingSphere CreateFromBoundingBox(BoundingBox box) { // Find the center of the box. Vector3 center = new Vector3((box.Min.X + box.Max.X) / 2.0f, (box.Min.Y + box.Max.Y) / 2.0f, (box.Min.Z + box.Max.Z) / 2.0f); // Find the distance between the center and one of the corners of the box. double radius = Vector3.Distance(center, box.Max); return new BoundingSphere(center, radius); } public static void CreateFromBoundingBox(ref BoundingBox box, out BoundingSphere result) { result = CreateFromBoundingBox(box); } public static BoundingSphere CreateFromFrustum(BoundingFrustum frustum) { return BoundingSphere.CreateFromPoints(frustum.GetCorners()); } public static BoundingSphere CreateFromPoints(IEnumerable<Vector3> points) { if (points == null) throw new ArgumentNullException("points"); double radius = 0; Vector3 center = new Vector3(); // First, we'll find the center of gravity for the point 'cloud'. int num_points = 0; // The number of points (there MUST be a better way to get this instead of counting the number of points one by one?) foreach (Vector3 v in points) { center += v; // If we actually knew the number of points, we'd get better accuracy by adding v / num_points. ++num_points; } center /= (double)num_points; // Calculate the radius of the needed sphere (it equals the distance between the center and the point further away). foreach (Vector3 v in points) { double distance = ((Vector3)(v - center)).Length(); if (distance > radius) radius = distance; } return new BoundingSphere(center, radius); } public static BoundingSphere CreateMerged(BoundingSphere original, BoundingSphere additional) { Vector3 ocenterToaCenter = Vector3.Subtract(additional.Center, original.Center); double distance = ocenterToaCenter.Length(); if (distance <= original.Radius + additional.Radius)//intersect { if (distance <= original.Radius - additional.Radius)//original contain additional return original; if (distance <= additional.Radius - original.Radius)//additional contain original return additional; } //else find center of new sphere and radius double leftRadius = Math.Max(original.Radius - distance, additional.Radius); double Rightradius = Math.Max(original.Radius + distance, additional.Radius); ocenterToaCenter = ocenterToaCenter + (((leftRadius - Rightradius) / (2 * ocenterToaCenter.Length())) * ocenterToaCenter);//oCenterToResultCenter BoundingSphere result = new BoundingSphere(); result.Center = original.Center + ocenterToaCenter; result.Radius = (leftRadius + Rightradius) / 2; return result; } public static void CreateMerged(ref BoundingSphere original, ref BoundingSphere additional, out BoundingSphere result) { result = BoundingSphere.CreateMerged(original, additional); } public bool Equals(BoundingSphere other) { return this.Center == other.Center && this.Radius == other.Radius; } public override bool Equals(object obj) { if (obj is BoundingSphere) return this.Equals((BoundingSphere)obj); return false; } public override int GetHashCode() { return this.Center.GetHashCode() + this.Radius.GetHashCode(); } public bool Intersects(BoundingBox box) { return box.Intersects(this); } public void Intersects(ref BoundingBox box, out bool result) { result = Intersects(box); } public bool Intersects(BoundingFrustum frustum) { if (frustum == null) throw new NullReferenceException(); throw new NotImplementedException(); } public bool Intersects(BoundingSphere sphere) { double val = Vector3.Distance(sphere.Center, Center); if (val > sphere.Radius + Radius) return false; return true; } public void Intersects(ref BoundingSphere sphere, out bool result) { result = Intersects(sphere); } public PlaneIntersectionType Intersects(Plane plane) { double distance = Vector3.Dot(plane.Normal, this.Center) + plane.D; if (distance > this.Radius) return PlaneIntersectionType.Front; if (distance < -this.Radius) return PlaneIntersectionType.Back; //else it intersect return PlaneIntersectionType.Intersecting; } public void Intersects(ref Plane plane, out PlaneIntersectionType result) { result = Intersects(plane); } public Nullable<double> Intersects(Ray ray) { return ray.Intersects(this); } public void Intersects(ref Ray ray, out Nullable<double> result) { result = Intersects(ray); } public static bool operator == (BoundingSphere a, BoundingSphere b) { return a.Equals(b); } public static bool operator != (BoundingSphere a, BoundingSphere b) { return !a.Equals(b); } public override string ToString() { return string.Format(CultureInfo.CurrentCulture, "{{Center:{0} Radius:{1}}}", this.Center.ToString(), this.Radius.ToString()); } #endregion Public Methods } } Home Free Stuff Politics Contact Copyright 2013 TechnologicalUtopia.com |