/*
 * C# / XNA  port of Bullet (c) 2011 Mark Neale <[email protected]>
 *
 * Bullet Continuous Collision Detection and Physics Library
 * Copyright (c) 2003-2008 Erwin Coumans  http://www.bulletphysics.com/
 *
 * This software is provided 'as-is', without any express or implied warranty.
 * In no event will the authors be held liable for any damages arising from
 * the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */
// Adapted from BulletXNA 73b2e1b9: namespace isolation, no XNA rendering, one type per file.
#nullable disable
#pragma warning disable CS1591, CS0168, CS0219, CS0414, CS0660, CS0661, CS0659, CS0693, CS8981, CS0108, CS0114
using System;
using HumanoidRetargeter.Core.Formats.Mmd.Bullet.LinearMath;

namespace HumanoidRetargeter.Core.Formats.Mmd.Bullet.BulletCollision;

internal class SphereBoxCollisionAlgorithm : ActivatingCollisionAlgorithm
{
	public SphereBoxCollisionAlgorithm()
	{
	} // for pool

	public SphereBoxCollisionAlgorithm(PersistentManifold mf, CollisionAlgorithmConstructionInfo ci, CollisionObject col0, CollisionObject col1, bool isSwapped) : base(ci, col0, col1)
	{
		m_isSwapped = isSwapped;
		m_ownManifold = false;
		m_manifoldPtr = mf;
		CollisionObject sphereObj = m_isSwapped ? col1 : col0;
		CollisionObject boxObj = m_isSwapped ? col0 : col1;
		if (m_manifoldPtr == null && m_dispatcher.NeedsCollision(sphereObj, boxObj))
		{
			m_manifoldPtr = m_dispatcher.GetNewManifold(sphereObj, boxObj);
			m_ownManifold = true;
		}
	}

	public void Initialize(PersistentManifold mf, CollisionAlgorithmConstructionInfo ci, CollisionObject col0, CollisionObject col1, bool isSwapped)
	{
		base.Initialize(ci, col0, col1);
		m_isSwapped = isSwapped;
		m_ownManifold = false;
		m_manifoldPtr = mf;
		CollisionObject sphereObj = m_isSwapped ? col1 : col0;
		CollisionObject boxObj = m_isSwapped ? col0 : col1;
		if (m_manifoldPtr == null && m_dispatcher.NeedsCollision(sphereObj, boxObj))
		{
			m_manifoldPtr = m_dispatcher.GetNewManifold(sphereObj, boxObj);
			m_ownManifold = true;
		}
	}

	public override void Cleanup()
	{
		if (m_ownManifold)
		{
			if (m_manifoldPtr != null)
			{
				m_dispatcher.ReleaseManifold(m_manifoldPtr);
				m_manifoldPtr = null;
			}

			m_ownManifold = false;
		}

		m_ownManifold = false;
		BulletGlobals.SphereBoxCollisionAlgorithmPool.Free(this);
	}

	public override void ProcessCollision(CollisionObject body0, CollisionObject body1, DispatcherInfo dispatchInfo, ManifoldResult resultOut)
	{
		//(void)dispatchInfo;
		//(void)resultOut;
		if (m_manifoldPtr == null)
		{
			return;
		}

		CollisionObject sphereObj = m_isSwapped ? body1 : body0;
		CollisionObject boxObj = m_isSwapped ? body0 : body1;
		IndexedVector3 pOnBox = new IndexedVector3();
		;
		IndexedVector3 normalOnSurfaceB = new IndexedVector3();
		float penetrationDepth = 0f;
		IndexedVector3 sphereCenter = sphereObj.GetWorldTransform()._origin;
		SphereShape sphere0 = sphereObj.GetCollisionShape() as SphereShape;
		float radius = sphere0.GetRadius();
		float maxContactDistance = m_manifoldPtr.GetContactBreakingThreshold();
		resultOut.SetPersistentManifold(m_manifoldPtr);
		if (GetSphereDistance(boxObj, ref pOnBox, ref normalOnSurfaceB, ref penetrationDepth, sphereCenter, radius, maxContactDistance))
		{
			resultOut.AddContactPoint(normalOnSurfaceB, pOnBox, penetrationDepth);
		}

		if (m_ownManifold)
		{
			if (m_manifoldPtr.GetNumContacts() > 0)
			{
				resultOut.RefreshContactPoints();
			}
		}
	}

	public override float CalculateTimeOfImpact(CollisionObject body0, CollisionObject body1, DispatcherInfo dispatchInfo, ManifoldResult resultOut)
	{
		return 1f;
	}

	public override void GetAllContactManifolds(PersistentManifoldArray manifoldArray)
	{
		if (m_manifoldPtr != null && m_ownManifold)
		{
			manifoldArray.Add(m_manifoldPtr);
		}
	}

	public bool GetSphereDistance(CollisionObject boxObj, ref IndexedVector3 pointOnBox, ref IndexedVector3 normal, ref float penetrationDepth, IndexedVector3 sphereCenter, float fRadius, float maxContactDistance)
	{
		BoxShape boxShape = boxObj.GetCollisionShape() as BoxShape;
		IndexedVector3 boxHalfExtent = boxShape.GetHalfExtentsWithoutMargin();
		float boxMargin = boxShape.GetMargin();
		penetrationDepth = 1.0f;
		// convert the sphere position to the box's local space
		IndexedMatrix m44T = boxObj.GetWorldTransform();
		IndexedVector3 sphereRelPos = m44T.InvXform(sphereCenter);
		// Determine the closest point to the sphere center in the box
		IndexedVector3 closestPoint = sphereRelPos;
		closestPoint.X = (Math.Min(boxHalfExtent.X, closestPoint.X));
		closestPoint.X = (Math.Max(-boxHalfExtent.X, closestPoint.X));
		closestPoint.Y = (Math.Min(boxHalfExtent.Y, closestPoint.Y));
		closestPoint.Y = (Math.Max(-boxHalfExtent.Y, closestPoint.Y));
		closestPoint.Z = (Math.Min(boxHalfExtent.Z, closestPoint.Z));
		closestPoint.Z = (Math.Max(-boxHalfExtent.Z, closestPoint.Z));
		float intersectionDist = fRadius + boxMargin;
		float contactDist = intersectionDist + maxContactDistance;
		normal = sphereRelPos - closestPoint;
		//if there is no penetration, we are done
		float dist2 = normal.LengthSquared();
		if (dist2 > contactDist * contactDist)
		{
			return false;
		}

		float distance;
		//special case if the sphere center is inside the box
		if (dist2 == 0.0f)
		{
			distance = -GetSpherePenetration(ref boxHalfExtent, ref sphereRelPos, ref closestPoint, ref normal);
		}
		else //compute the penetration details
		{
			distance = normal.Length();
			normal /= distance;
		}

		pointOnBox = closestPoint + normal * boxMargin;
		//	v3PointOnSphere = sphereRelPos - (normal * fRadius);
		penetrationDepth = distance - intersectionDist;
		// transform back in world space
		IndexedVector3 tmp = m44T * pointOnBox;
		pointOnBox = tmp;
		//	tmp = m44T(v3PointOnSphere);
		//	v3PointOnSphere = tmp;
		tmp = m44T._basis * normal;
		normal = tmp;
		return true;
	}

	public float GetSpherePenetration(ref IndexedVector3 boxHalfExtent, ref IndexedVector3 sphereRelPos, ref IndexedVector3 closestPoint, ref IndexedVector3 normal)
	{
		//project the center of the sphere on the closest face of the box
		float faceDist = boxHalfExtent.X - sphereRelPos.X;
		float minDist = faceDist;
		closestPoint.X = (boxHalfExtent.X);
		normal = new IndexedVector3(1.0f, 0.0f, 0.0f);
		faceDist = boxHalfExtent.X + sphereRelPos.X;
		if (faceDist < minDist)
		{
			minDist = faceDist;
			closestPoint = sphereRelPos;
			closestPoint.X = (-boxHalfExtent.X);
			normal = new IndexedVector3(-1.0f, 0.0f, 0.0f);
		}

		faceDist = boxHalfExtent.Y - sphereRelPos.Y;
		if (faceDist < minDist)
		{
			minDist = faceDist;
			closestPoint = sphereRelPos;
			closestPoint.Y = (boxHalfExtent.Y);
			normal = new IndexedVector3(0.0f, 1.0f, 0.0f);
		}

		faceDist = boxHalfExtent.Y + sphereRelPos.Y;
		if (faceDist < minDist)
		{
			minDist = faceDist;
			closestPoint = sphereRelPos;
			closestPoint.Y = (-boxHalfExtent.Y);
			normal = new IndexedVector3(0.0f, -1.0f, 0.0f);
		}

		faceDist = boxHalfExtent.Z - sphereRelPos.Z;
		if (faceDist < minDist)
		{
			minDist = faceDist;
			closestPoint = sphereRelPos;
			closestPoint.Z = (boxHalfExtent.Z);
			normal = new IndexedVector3(0.0f, 0.0f, 1.0f);
		}

		faceDist = boxHalfExtent.Z + sphereRelPos.Z;
		if (faceDist < minDist)
		{
			minDist = faceDist;
			closestPoint = sphereRelPos;
			closestPoint.Z = (-boxHalfExtent.Z);
			normal = new IndexedVector3(0.0f, 0.0f, -1.0f);
		}

		return minDist;
	}

	private bool m_ownManifold;
	private PersistentManifold m_manifoldPtr;
	private bool m_isSwapped;
}