/*
 * 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 System.Diagnostics;
using HumanoidRetargeter.Core.Formats.Mmd.Bullet.LinearMath;

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

internal class TriangleShape : PolyhedralConvexShape, IDisposable
{
	public TriangleShape()
	{
		m_shapeType = BroadphaseNativeTypes.TRIANGLE_SHAPE_PROXYTYPE;
	}

	public TriangleShape(IndexedVector3 p0, IndexedVector3 p1, IndexedVector3 p2) : this(ref p0, ref p1, ref p2)
	{
	}

	public TriangleShape(ref IndexedVector3 p0, ref IndexedVector3 p1, ref IndexedVector3 p2) : base()
	{
		m_shapeType = BroadphaseNativeTypes.TRIANGLE_SHAPE_PROXYTYPE;
		m_vertices1[0] = p0;
		m_vertices1[1] = p1;
		m_vertices1[2] = p2;
	}

	public void Initialize(ref IndexedVector3 p0, ref IndexedVector3 p1, ref IndexedVector3 p2)
	{
		m_shapeType = BroadphaseNativeTypes.TRIANGLE_SHAPE_PROXYTYPE;
		m_vertices1[0] = p0;
		m_vertices1[1] = p1;
		m_vertices1[2] = p2;
	}

	public override void GetPlane(out IndexedVector3 planeNormal, out IndexedVector3 planeSupport, int i)
	{
		GetPlaneEquation(i, out planeNormal, out planeSupport);
	}

	public override int GetNumPlanes()
	{
		return 1;
	}

	public void CalcNormal(out IndexedVector3 normal)
	{
		normal = IndexedVector3.Cross(m_vertices1[1] - m_vertices1[0], m_vertices1[2] - m_vertices1[0]);
		normal.Normalize();
	}

	public virtual void GetPlaneEquation(int i, out IndexedVector3 planeNormal, out IndexedVector3 planeSupport)
	{
		CalcNormal(out planeNormal);
		planeSupport = m_vertices1[0];
	}

	public override void CalculateLocalInertia(float mass, out IndexedVector3 inertia)
	{
		{
		}

		inertia = IndexedVector3.Zero;
	}

	public override bool IsInside(ref IndexedVector3 pt, float tolerance)
	{
		IndexedVector3 normal;
		CalcNormal(out normal);
		//distance to plane
		float dist = IndexedVector3.Dot(ref pt, ref normal);
		float planeconst = IndexedVector3.Dot(ref m_vertices1[0], ref normal);
		dist -= planeconst;
		if (dist >= -tolerance && dist <= tolerance)
		{
			//inside check on edge-planes
			int i;
			for (i = 0; i < 3; i++)
			{
				IndexedVector3 pa, pb;
				GetEdge(i, out pa, out pb);
				IndexedVector3 edge = pb - pa;
				IndexedVector3 edgeNormal = edge.Cross(ref normal);
				edgeNormal.Normalize();
				float dist2 = IndexedVector3.Dot(ref pt, ref edgeNormal);
				float edgeConst = IndexedVector3.Dot(ref pa, ref edgeNormal);
				dist2 -= edgeConst;
				if (dist2 < -tolerance)
				{
					return false;
				}
			}

			return true;
		}

		return false;
	}

	public override String GetName()
	{
		return "Triangle";
	}

	public override int GetNumPreferredPenetrationDirections()
	{
		return 2;
	}

	public override void GetPreferredPenetrationDirection(int index, out IndexedVector3 penetrationVector)
	{
		CalcNormal(out penetrationVector);
		if (index > 0)
		{
			penetrationVector *= -1f;
		}
	}

	public override int GetNumVertices()
	{
		return 3;
	}

	public virtual IndexedVector3[] GetVertexPtr(int i)
	{
		return m_vertices1;
	}

	public override void GetVertex(int i, out IndexedVector3 vert)
	{
		vert = m_vertices1[i];
	}

	public override int GetNumEdges()
	{
		return 3;
	}

	public override void GetEdge(int i, out IndexedVector3 pa, out IndexedVector3 pb)
	{
		GetVertex(i, out pa);
		GetVertex((i + 1) % 3, out pb);
	}

	public override void GetAabb(ref IndexedMatrix trans, out IndexedVector3 aabbMin, out IndexedVector3 aabbMax)
	{
		GetAabbSlow(ref trans, out aabbMin, out aabbMax);
	}

	public override IndexedVector3 LocalGetSupportingVertexWithoutMargin(ref IndexedVector3 dir)
	{
		IndexedVector3 dots = new IndexedVector3(dir.Dot(ref m_vertices1[0]), dir.Dot(ref m_vertices1[1]), dir.Dot(ref m_vertices1[2]));
		return m_vertices1[MathUtil.MaxAxis(ref dots)];
	}

	public override void BatchedUnitVectorGetSupportingVertexWithoutMargin(IndexedVector3[] vectors, IndexedVector4[] supportVerticesOut, int numVectors)
	{
		for (int i = 0; i < numVectors; i++)
		{
			IndexedVector3 dir = vectors[i];
			IndexedVector3 dots = new IndexedVector3(dir.Dot(ref m_vertices1[0]), dir.Dot(ref m_vertices1[1]), dir.Dot(ref m_vertices1[2]));
			supportVerticesOut[i] = new IndexedVector4(m_vertices1[MathUtil.MaxAxis(ref dots)], 0);
		}
	}

	public void Dispose()
	{
		BulletGlobals.TriangleShapePool.Free(this);
	}

	public IndexedVector3[] m_vertices1 = new IndexedVector3[3];
}