/*
 * 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 TriangleMesh : TriangleIndexVertexArray
{
	public TriangleMesh() : this(true, true)
	{
	}

	public TriangleMesh(bool use32bitIndices, bool use4componentVertices)
	{
		m_use32bitIndices = use32bitIndices;
		m_use4componentVertices = use4componentVertices;
		IndexedMesh meshIndex = new IndexedMesh();
		m_indexedMeshes.Add(meshIndex);
		if (m_use32bitIndices)
		{
			m_32bitIndices = new ObjectArray<int>();
			m_indexedMeshes[0].m_numTriangles = m_32bitIndices.Count / 3;
			m_indexedMeshes[0].m_indexType = PHY_ScalarType.PHY_INTEGER;
			m_indexedMeshes[0].m_triangleIndexStride = 3;
		}
		else
		{
			m_16bitIndices = new ObjectArray<short>();
			m_indexedMeshes[0].m_numTriangles = m_16bitIndices.Count / 3;
			m_indexedMeshes[0].m_triangleIndexBase = null;
			m_indexedMeshes[0].m_indexType = PHY_ScalarType.PHY_SHORT;
			m_indexedMeshes[0].m_triangleIndexStride = 3;
		}

		if (m_use4componentVertices)
		{
			m_4componentVertices = new ObjectArray<IndexedVector3>();
			m_indexedMeshes[0].m_numVertices = m_4componentVertices.Count;
			m_indexedMeshes[0].m_vertexStride = 1;
			m_indexedMeshes[0].m_vertexBase = m_4componentVertices;
		}
		else
		{
			m_3componentVertices = new ObjectArray<float>();
			m_indexedMeshes[0].m_numVertices = m_3componentVertices.Count / 3;
			m_indexedMeshes[0].m_vertexStride = 3;
			m_indexedMeshes[0].m_vertexBase = m_3componentVertices;
		}
	}

	public int FindOrAddVertex(ref IndexedVector3 vertex, bool removeDuplicateVertices)
	{
		//return index of new/existing vertex
		if (m_use4componentVertices)
		{
			if (removeDuplicateVertices)
			{
				IndexedVector3[] rawVertices = m_4componentVertices.GetRawArray();
				for (int i = 0; i < m_4componentVertices.Count; i++)
				{
					if ((rawVertices[i] - vertex).LengthSquared() <= m_weldingThreshold)
					{
						return i;
					}
				}
			}

			m_indexedMeshes[0].m_numVertices++;
			m_4componentVertices.Add(vertex);
			(m_indexedMeshes[0].m_vertexBase as ObjectArray<IndexedVector3>).Add(vertex);
			return m_4componentVertices.Count - 1;
		}
		else
		{
			if (removeDuplicateVertices)
			{
				float[] rawVertices = m_3componentVertices.GetRawArray();
				for (int i = 0; i < m_3componentVertices.Count; i += 3)
				{
					IndexedVector3 vtx = new IndexedVector3(rawVertices[i], rawVertices[i + 1], rawVertices[i + 2]);
					if ((vtx - vertex).LengthSquared() <= m_weldingThreshold)
					{
						return i / 3;
					}
				}
			}

			m_3componentVertices.Add(vertex.X);
			m_3componentVertices.Add(vertex.Y);
			m_3componentVertices.Add(vertex.Z);
			m_indexedMeshes[0].m_numVertices++;
			(m_indexedMeshes[0].m_vertexBase as ObjectArray<float>).Add(vertex.X);
			(m_indexedMeshes[0].m_vertexBase as ObjectArray<float>).Add(vertex.Y);
			(m_indexedMeshes[0].m_vertexBase as ObjectArray<float>).Add(vertex.Z);
			return (m_3componentVertices.Count / 3) - 1;
		}
	}

	public void AddIndex(int index)
	{
		if (m_use32bitIndices)
		{
			m_32bitIndices.Add(index);
			m_indexedMeshes[0].m_triangleIndexBase = m_32bitIndices;
		}
		else
		{
			m_16bitIndices.Add((short)index);
			// not really supported yet.
			m_indexedMeshes[0].m_triangleIndexBase = m_16bitIndices;
		}
	}

	public bool GetUse32bitIndices()
	{
		return m_use32bitIndices;
	}

	public bool GetUse4componentVertices()
	{
		return m_use4componentVertices;
	}

	public int GetNumTriangles()
	{
		if (m_use32bitIndices)
		{
			return m_32bitIndices.Count / 3;
		}

		return m_16bitIndices.Count / 3;
	}

	public override void PreallocateVertices(int numverts)
	{
	//(void) numverts;
	}

	public override void PreallocateIndices(int numindices)
	{
	//(void) numindices;
	}

	private ObjectArray<IndexedVector3> m_4componentVertices;
	private ObjectArray<float> m_3componentVertices;
	private ObjectArray<int> m_32bitIndices;
	private ObjectArray<short> m_16bitIndices;
	private bool m_use32bitIndices;
	private bool m_use4componentVertices;
	public float m_weldingThreshold;
}