/*
 * 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 HumanoidRetargeter.Core.Formats.Mmd.Bullet.LinearMath;

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

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

	public SphereSphereCollisionAlgorithm(PersistentManifold mf, CollisionAlgorithmConstructionInfo ci, CollisionObject body0, CollisionObject body1) : base(ci, body0, body1)
	{
		m_ownManifold = false;
		m_manifoldPtr = mf;
		// for some reason theres no check in 2.76 or 2.78 for a needs collision, just a check on pointer being null.
		if (m_manifoldPtr == null)
		{
			m_manifoldPtr = m_dispatcher.GetNewManifold(body0, body1);
			m_ownManifold = true;
		}
	}

	public virtual void Initialize(PersistentManifold mf, CollisionAlgorithmConstructionInfo ci, CollisionObject colObj0, CollisionObject colObj1)
	{
		base.Initialize(ci, colObj0, colObj1);
		m_ownManifold = false;
		m_manifoldPtr = mf;
		if (m_manifoldPtr == null)
		{
			m_manifoldPtr = m_dispatcher.GetNewManifold(colObj0, colObj1);
			m_ownManifold = true;
		}
	}

	public SphereSphereCollisionAlgorithm(CollisionAlgorithmConstructionInfo ci) : base(ci)
	{
	}

	public override void Initialize(CollisionAlgorithmConstructionInfo ci)
	{
		base.Initialize(ci);
	}

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

		resultOut.SetPersistentManifold(m_manifoldPtr);
		SphereShape sphere0 = body0.GetCollisionShape() as SphereShape;
		SphereShape sphere1 = body1.GetCollisionShape() as SphereShape;
		IndexedVector3 diff = body0.GetWorldTransform()._origin - body1.GetWorldTransform()._origin;
		float len = diff.Length();
		float radius0 = sphere0.GetRadius();
		float radius1 = sphere1.GetRadius();
		if (len > (radius0 + radius1))
		{
			resultOut.RefreshContactPoints();
			return;
		}

		float dist = len - (radius0 + radius1);
		IndexedVector3 normalOnSurfaceB = new IndexedVector3(1, 0, 0);
		if (len > MathUtil.SIMD_EPSILON)
		{
			normalOnSurfaceB = diff / len;
		}

		IndexedVector3 pos1 = body1.GetWorldTransform()._origin + radius1 * normalOnSurfaceB;
		resultOut.AddContactPoint(ref normalOnSurfaceB, ref pos1, dist);
		resultOut.RefreshContactPoints();
	}

	public override float CalculateTimeOfImpact(CollisionObject body0, CollisionObject body1, DispatcherInfo dispatchInfo, ManifoldResult resultOut)
	{
		//not yet
		return 1f;
	}

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

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

		BulletGlobals.SphereSphereCollisionAlgorithmPool.Free(this);
	}

	public bool m_ownManifold;
	public PersistentManifold m_manifoldPtr;
}