sharplib/math/BoundingSphere.cs
2019-06-26 00:03:48 -07:00

540 lines
23 KiB
C#

// Copyright (c) Xenko contributors (https://xenko.com) and Silicon Studio Corp. (https://www.siliconstudio.co.jp)
// Distributed under the MIT license. See the LICENSE.md file in the project root for more information.
//
// -----------------------------------------------------------------------------
// Original code from SlimMath project. http://code.google.com/p/slimmath/
// Greetings to SlimDX Group. Original code published with the following license:
// -----------------------------------------------------------------------------
/*
* Copyright (c) 2007-2011 SlimDX Group
*
* 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.
*/
using System;
using System.Globalization;
using System.Runtime.InteropServices;
using System.Runtime.Serialization;
namespace math
{
/// <summary>
/// Represents a bounding sphere in three dimensional space.
/// </summary>
[DataContract]
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct BoundingSphere : IEquatable<BoundingSphere>, IFormattable
{
/// <summary>
/// An empty bounding sphere (Center = 0 and Radius = 0).
/// </summary>
public static readonly BoundingSphere Empty = new BoundingSphere();
/// <summary>
/// The center of the sphere in three dimensional space.
/// </summary>
public Vector3 Center;
/// <summary>
/// The radious of the sphere.
/// </summary>
public float Radius;
/// <summary>
/// Initializes a new instance of the <see cref="BoundingSphere"/> struct.
/// </summary>
/// <param name="center">The center of the sphere in three dimensional space.</param>
/// <param name="radius">The radius of the sphere.</param>
public BoundingSphere(Vector3 center, float radius)
{
this.Center = center;
this.Radius = radius;
}
/// <summary>
/// Determines if there is an intersection between the current object and a <see cref="math.Ray"/>.
/// </summary>
/// <param name="ray">The ray to test.</param>
/// <returns>Whether the two objects intersected.</returns>
public bool Intersects(ref Ray ray)
{
float distance;
return CollisionHelper.RayIntersectsSphere(ref ray, ref this, out distance);
}
/// <summary>
/// Determines if there is an intersection between the current object and a <see cref="math.Ray"/>.
/// </summary>
/// <param name="ray">The ray to test.</param>
/// <param name="distance">When the method completes, contains the distance of the intersection,
/// or 0 if there was no intersection.</param>
/// <returns>Whether the two objects intersected.</returns>
public bool Intersects(ref Ray ray, out float distance)
{
return CollisionHelper.RayIntersectsSphere(ref ray, ref this, out distance);
}
/// <summary>
/// Determines if there is an intersection between the current object and a <see cref="math.Ray"/>.
/// </summary>
/// <param name="ray">The ray to test.</param>
/// <param name="point">When the method completes, contains the point of intersection,
/// or <see cref="math.Vector3.Zero"/> if there was no intersection.</param>
/// <returns>Whether the two objects intersected.</returns>
public bool Intersects(ref Ray ray, out Vector3 point)
{
return CollisionHelper.RayIntersectsSphere(ref ray, ref this, out point);
}
/// <summary>
/// Determines if there is an intersection between the current object and a <see cref="math.Plane"/>.
/// </summary>
/// <param name="plane">The plane to test.</param>
/// <returns>Whether the two objects intersected.</returns>
public PlaneIntersectionType Intersects(ref Plane plane)
{
return CollisionHelper.PlaneIntersectsSphere(ref plane, ref this);
}
/// <summary>
/// Determines if there is an intersection between the current object and a triangle.
/// </summary>
/// <param name="vertex1">The first vertex of the triangle to test.</param>
/// <param name="vertex2">The second vertex of the triagnle to test.</param>
/// <param name="vertex3">The third vertex of the triangle to test.</param>
/// <returns>Whether the two objects intersected.</returns>
public bool Intersects(ref Vector3 vertex1, ref Vector3 vertex2, ref Vector3 vertex3)
{
return CollisionHelper.SphereIntersectsTriangle(ref this, ref vertex1, ref vertex2, ref vertex3);
}
/// <summary>
/// Determines if there is an intersection between the current object and a <see cref="math.BoundingBox"/>.
/// </summary>
/// <param name="box">The box to test.</param>
/// <returns>Whether the two objects intersected.</returns>
public bool Intersects(ref BoundingBox box)
{
return CollisionHelper.BoxIntersectsSphere(ref box, ref this);
}
/// <summary>
/// Determines if there is an intersection between the current object and a <see cref="math.BoundingSphere"/>.
/// </summary>
/// <param name="sphere">The sphere to test.</param>
/// <returns>Whether the two objects intersected.</returns>
public bool Intersects(ref BoundingSphere sphere)
{
return CollisionHelper.SphereIntersectsSphere(ref this, ref sphere);
}
/// <summary>
/// Determines whether the current objects contains a point.
/// </summary>
/// <param name="point">The point to test.</param>
/// <returns>The type of containment the two objects have.</returns>
public ContainmentType Contains(ref Vector3 point)
{
return CollisionHelper.SphereContainsPoint(ref this, ref point);
}
/// <summary>
/// Determines whether the current objects contains a triangle.
/// </summary>
/// <param name="vertex1">The first vertex of the triangle to test.</param>
/// <param name="vertex2">The second vertex of the triagnle to test.</param>
/// <param name="vertex3">The third vertex of the triangle to test.</param>
/// <returns>The type of containment the two objects have.</returns>
public ContainmentType Contains(ref Vector3 vertex1, ref Vector3 vertex2, ref Vector3 vertex3)
{
return CollisionHelper.SphereContainsTriangle(ref this, ref vertex1, ref vertex2, ref vertex3);
}
/// <summary>
/// Determines whether the current objects contains a <see cref="math.BoundingBox"/>.
/// </summary>
/// <param name="box">The box to test.</param>
/// <returns>The type of containment the two objects have.</returns>
public ContainmentType Contains(ref BoundingBox box)
{
return CollisionHelper.SphereContainsBox(ref this, ref box);
}
/// <summary>
/// Determines whether the current objects contains a <see cref="math.BoundingSphere"/>.
/// </summary>
/// <param name="sphere">The sphere to test.</param>
/// <returns>The type of containment the two objects have.</returns>
public ContainmentType Contains(ref BoundingSphere sphere)
{
return CollisionHelper.SphereContainsSphere(ref this, ref sphere);
}
/// <summary>
/// Constructs a <see cref="math.BoundingSphere"/> that fully contains the given points.
/// </summary>
/// <param name="points">The points that will be contained by the sphere.</param>
/// <param name="result">When the method completes, contains the newly constructed bounding sphere.</param>
public static unsafe void FromPoints(Vector3[] points, out BoundingSphere result)
{
if (points == null) throw new ArgumentNullException("points");
fixed (void* pointsPtr = points)
{
FromPoints((IntPtr)pointsPtr, 0, points.Length, Utilities.SizeOf<Vector3>(), out result);
}
}
/// <summary>
/// Constructs a <see cref="math.BoundingSphere" /> that fully contains the given unmanaged points.
/// </summary>
/// <param name="vertexBufferPtr">A pointer to of vertices containing points.</param>
/// <param name="vertexPositionOffsetInBytes">The point offset in bytes starting from the vertex structure.</param>
/// <param name="vertexCount">The verterx vertexCount.</param>
/// <param name="vertexStride">The vertex stride (size of vertex).</param>
/// <param name="result">When the method completes, contains the newly constructed bounding sphere.</param>
public static unsafe void FromPoints(IntPtr vertexBufferPtr, int vertexPositionOffsetInBytes, int vertexCount, int vertexStride, out BoundingSphere result)
{
if (vertexBufferPtr == IntPtr.Zero)
{
throw new ArgumentNullException("vertexBufferPtr");
}
var startPoint = (byte*)vertexBufferPtr + vertexPositionOffsetInBytes;
//Find the center of all points.
Vector3 center = Vector3.Zero;
var nextPoint = startPoint;
for (int i = 0; i < vertexCount; ++i)
{
Vector3.Add(ref *(Vector3*)nextPoint, ref center, out center);
nextPoint += vertexStride;
}
//This is the center of our sphere.
center /= (float)vertexCount;
//Find the radius of the sphere
float radius = 0f;
nextPoint = startPoint;
for (int i = 0; i < vertexCount; ++i)
{
//We are doing a relative distance comparasin to find the maximum distance
//from the center of our sphere.
float distance;
Vector3.DistanceSquared(ref center, ref *(Vector3*)nextPoint, out distance);
if (distance > radius)
radius = distance;
nextPoint += vertexStride;
}
//Find the real distance from the DistanceSquared.
radius = (float)Math.Sqrt(radius);
//Construct the sphere.
result.Center = center;
result.Radius = radius;
}
/// <summary>
/// Constructs a <see cref="math.BoundingSphere"/> that fully contains the given points.
/// </summary>
/// <param name="points">The points that will be contained by the sphere.</param>
/// <returns>The newly constructed bounding sphere.</returns>
public static BoundingSphere FromPoints(Vector3[] points)
{
BoundingSphere result;
FromPoints(points, out result);
return result;
}
/// <summary>
/// Constructs a <see cref="math.BoundingSphere"/> from a given box.
/// </summary>
/// <param name="box">The box that will designate the extents of the sphere.</param>
/// <param name="result">When the method completes, the newly constructed bounding sphere.</param>
public static void FromBox(ref BoundingBox box, out BoundingSphere result)
{
Vector3.Lerp(ref box.Minimum, ref box.Maximum, 0.5f, out result.Center);
float x = box.Minimum.X - box.Maximum.X;
float y = box.Minimum.Y - box.Maximum.Y;
float z = box.Minimum.Z - box.Maximum.Z;
float distance = (float)(Math.Sqrt((x * x) + (y * y) + (z * z)));
result.Radius = distance * 0.5f;
}
/// <summary>
/// Constructs a <see cref="math.BoundingSphere"/> from a given box.
/// </summary>
/// <param name="box">The box that will designate the extents of the sphere.</param>
/// <returns>The newly constructed bounding sphere.</returns>
public static BoundingSphere FromBox(BoundingBox box)
{
BoundingSphere result;
FromBox(ref box, out result);
return result;
}
/// <summary>
/// Transforms a bounding bounding sphere, yielding the bounding sphere of all points contained by the original one, transformed by the specified transform.
/// </summary>
/// <param name="value">The original bounding sphere.</param>
/// <param name="transform">The transform to apply to the bounding sphere.</param>
/// <param name="result">The transformed bounding sphere.</param>
public static void Transform(ref BoundingSphere value, ref Matrix transform, out BoundingSphere result)
{
Vector3.TransformCoordinate(ref value.Center, ref transform, out result.Center);
var majorAxisLengthSquared = Math.Max(
(transform.M11 * transform.M11) + (transform.M12 * transform.M12) + (transform.M13 * transform.M13), Math.Max(
(transform.M21 * transform.M21) + (transform.M22 * transform.M22) + (transform.M23 * transform.M23),
(transform.M31 * transform.M31) + (transform.M32 * transform.M32) + (transform.M33 * transform.M33)));
result.Radius = value.Radius * (float)Math.Sqrt(majorAxisLengthSquared);
}
/// <summary>
/// Constructs a <see cref="math.BoundingSphere"/> that is the as large as the total combined area of the two specified spheres.
/// </summary>
/// <param name="value1">The first sphere to merge.</param>
/// <param name="value2">The second sphere to merge.</param>
/// <param name="result">When the method completes, contains the newly constructed bounding sphere.</param>
public static void Merge(ref BoundingSphere value1, ref BoundingSphere value2, out BoundingSphere result)
{
// Pre-exit if one of the bounding sphere by assuming that a merge with an empty sphere is equivalent at taking the non-empty sphere
if (value1 == Empty)
{
result = value2;
return;
}
if (value2 == Empty)
{
result = value1;
return;
}
Vector3 difference = value2.Center - value1.Center;
float length = difference.Length();
float radius = value1.Radius;
float radius2 = value2.Radius;
if (radius + radius2 >= length)
{
if (radius - radius2 >= length)
{
result = value1;
return;
}
if (radius2 - radius >= length)
{
result = value2;
return;
}
}
Vector3 vector = difference * (1.0f / length);
float min = Math.Min(-radius, length - radius2);
float max = (Math.Max(radius, length + radius2) - min) * 0.5f;
result.Center = value1.Center + vector * (max + min);
result.Radius = max;
}
/// <summary>
/// Constructs a <see cref="math.BoundingSphere"/> that is the as large as the total combined area of the two specified spheres.
/// </summary>
/// <param name="value1">The first sphere to merge.</param>
/// <param name="value2">The second sphere to merge.</param>
/// <returns>The newly constructed bounding sphere.</returns>
public static BoundingSphere Merge(BoundingSphere value1, BoundingSphere value2)
{
BoundingSphere result;
Merge(ref value1, ref value2, out result);
return result;
}
/// <summary>
/// Tests for equality between two objects.
/// </summary>
/// <param name="left">The first value to compare.</param>
/// <param name="right">The second value to compare.</param>
/// <returns><c>true</c> if <paramref name="left"/> has the same value as <paramref name="right"/>; otherwise, <c>false</c>.</returns>
public static bool operator ==(BoundingSphere left, BoundingSphere right)
{
return left.Equals(right);
}
/// <summary>
/// Tests for inequality between two objects.
/// </summary>
/// <param name="left">The first value to compare.</param>
/// <param name="right">The second value to compare.</param>
/// <returns><c>true</c> if <paramref name="left"/> has a different value than <paramref name="right"/>; otherwise, <c>false</c>.</returns>
public static bool operator !=(BoundingSphere left, BoundingSphere right)
{
return !left.Equals(right);
}
/// <summary>
/// Returns a <see cref="string"/> that represents this instance.
/// </summary>
/// <returns>
/// A <see cref="string"/> that represents this instance.
/// </returns>
public override string ToString()
{
return string.Format(CultureInfo.CurrentCulture, "Center:{0} Radius:{1}", Center.ToString(), Radius.ToString());
}
/// <summary>
/// Returns a <see cref="string"/> that represents this instance.
/// </summary>
/// <param name="format">The format.</param>
/// <returns>
/// A <see cref="string"/> that represents this instance.
/// </returns>
public string ToString(string format)
{
if (format == null)
return ToString();
return string.Format(CultureInfo.CurrentCulture, "Center:{0} Radius:{1}", Center.ToString(format, CultureInfo.CurrentCulture),
Radius.ToString(format, CultureInfo.CurrentCulture));
}
/// <summary>
/// Returns a <see cref="string"/> that represents this instance.
/// </summary>
/// <param name="formatProvider">The format provider.</param>
/// <returns>
/// A <see cref="string"/> that represents this instance.
/// </returns>
public string ToString(IFormatProvider formatProvider)
{
return string.Format(formatProvider, "Center:{0} Radius:{1}", Center.ToString(), Radius.ToString());
}
/// <summary>
/// Returns a <see cref="string"/> that represents this instance.
/// </summary>
/// <param name="format">The format.</param>
/// <param name="formatProvider">The format provider.</param>
/// <returns>
/// A <see cref="string"/> that represents this instance.
/// </returns>
public string ToString(string format, IFormatProvider formatProvider)
{
if (format == null)
return ToString(formatProvider);
return string.Format(formatProvider, "Center:{0} Radius:{1}", Center.ToString(format, formatProvider),
Radius.ToString(format, formatProvider));
}
/// <summary>
/// Returns a hash code for this instance.
/// </summary>
/// <returns>
/// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table.
/// </returns>
public override int GetHashCode()
{
return Center.GetHashCode() + Radius.GetHashCode();
}
/// <summary>
/// Determines whether the specified <see cref="math.Vector4"/> is equal to this instance.
/// </summary>
/// <param name="value">The <see cref="math.Vector4"/> to compare with this instance.</param>
/// <returns>
/// <c>true</c> if the specified <see cref="math.Vector4"/> is equal to this instance; otherwise, <c>false</c>.
/// </returns>
public bool Equals(BoundingSphere value)
{
return Center == value.Center && Radius == value.Radius;
}
/// <summary>
/// Determines whether the specified <see cref="object"/> is equal to this instance.
/// </summary>
/// <param name="value">The <see cref="object"/> to compare with this instance.</param>
/// <returns>
/// <c>true</c> if the specified <see cref="object"/> is equal to this instance; otherwise, <c>false</c>.
/// </returns>
public override bool Equals(object value)
{
if (value == null)
return false;
if (value.GetType() != GetType())
return false;
return Equals((BoundingSphere)value);
}
#if SlimDX1xInterop
/// <summary>
/// Performs an implicit conversion from <see cref="math.BoundingSphere"/> to <see cref="SlimDX.BoundingSphere"/>.
/// </summary>
/// <param name="value">The value.</param>
/// <returns>The result of the conversion.</returns>
public static implicit operator SlimDX.BoundingSphere(BoundingSphere value)
{
return new SlimDX.BoundingSphere(value.Center, value.Radius);
}
/// <summary>
/// Performs an implicit conversion from <see cref="SlimDX.BoundingSphere"/> to <see cref="math.BoundingSphere"/>.
/// </summary>
/// <param name="value">The value.</param>
/// <returns>The result of the conversion.</returns>
public static implicit operator BoundingSphere(SlimDX.BoundingSphere value)
{
return new BoundingSphere(value.Center, value.Radius);
}
#endif
#if SlimDX1xInterop
/// <summary>
/// Performs an implicit conversion from <see cref="math.BoundingSphere"/> to <see cref="Microsoft.Xna.Framework.BoundingSphere"/>.
/// </summary>
/// <param name="value">The value.</param>
/// <returns>The result of the conversion.</returns>
public static implicit operator Microsoft.Xna.Framework.BoundingSphere(BoundingSphere value)
{
return new Microsoft.Xna.Framework.BoundingSphere(value.Center, value.Radius);
}
/// <summary>
/// Performs an implicit conversion from <see cref="Microsoft.Xna.Framework.BoundingSphere"/> to <see cref="math.BoundingSphere"/>.
/// </summary>
/// <param name="value">The value.</param>
/// <returns>The result of the conversion.</returns>
public static implicit operator BoundingSphere(Microsoft.Xna.Framework.BoundingSphere value)
{
return new BoundingSphere(value.Center, value.Radius);
}
#endif
}
}