/*
 * 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 CapsuleShape : ConvexInternalShape
{
	protected CapsuleShape()
	{
		m_shapeType = BroadphaseNativeTypes.CAPSULE_SHAPE_PROXYTYPE;
	}

	public CapsuleShape(float radius, float height) : this()
	{
		m_upAxis = 1;
		m_implicitShapeDimensions = new IndexedVector3(radius, 0.5f * height, radius);
	}

	public override void CalculateLocalInertia(float mass, out IndexedVector3 inertia)
	{
		IndexedMatrix ident = IndexedMatrix.Identity;
		float radius = GetRadius();
		IndexedVector3 halfExtents = new IndexedVector3(radius);
		float val = halfExtents[GetUpAxis()];
		halfExtents[GetUpAxis()] = val + GetHalfHeight();
		const float margin = CollisionMargin.CONVEX_DISTANCE_MARGIN;
		float lx = 2f * (halfExtents.X + margin);
		float ly = 2f * (halfExtents.Y + margin);
		float lz = 2f * (halfExtents.Z + margin);
		float x2 = lx * lx;
		float y2 = ly * ly;
		float z2 = lz * lz;
		float scaledmass = mass * 0.08333333f;
		inertia = scaledmass * (new IndexedVector3(y2 + z2, x2 + z2, x2 + y2));
	}

	public override void SetMargin(float collisionMargin)
	{
		//correct the m_implicitShapeDimensions for the margin
		IndexedVector3 oldMargin = new IndexedVector3(GetMargin());
		IndexedVector3 implicitShapeDimensionsWithMargin = m_implicitShapeDimensions + oldMargin;
		base.SetMargin(collisionMargin);
		IndexedVector3 newMargin = new IndexedVector3(GetMargin());
		m_implicitShapeDimensions = implicitShapeDimensionsWithMargin - newMargin;
	}

	public override void SetLocalScaling(ref IndexedVector3 scaling)
	{
		IndexedVector3 oldMargin = new IndexedVector3(GetMargin());
		IndexedVector3 implicitShapeDimensionsWithMargin = m_implicitShapeDimensions + oldMargin;
		IndexedVector3 unScaledImplicitShapeDimensionsWithMargin = implicitShapeDimensionsWithMargin / m_localScaling;
		base.SetLocalScaling(ref scaling);
		m_implicitShapeDimensions = (unScaledImplicitShapeDimensionsWithMargin * m_localScaling) - oldMargin;
	}

	public override IndexedVector3 LocalGetSupportingVertexWithoutMargin(ref IndexedVector3 vec0)
	{
		IndexedVector3 supVec = IndexedVector3.Zero;
		float maxDot = float.MinValue;
		IndexedVector3 vec = vec0;
		float lenSqr = vec.LengthSquared();
		if (lenSqr < 0.0001f)
		{
			vec = new IndexedVector3(1, 0, 0);
		}
		else
		{
			float rlen = (1.0f) / (float)Math.Sqrt(lenSqr);
			vec *= rlen;
		//vec.Normalize();
		}

		IndexedVector3 vtx;
		float newDot;
		float radius = GetRadius();
		{
			IndexedVector3 pos = IndexedVector3.Zero;
			pos[GetUpAxis()] = GetHalfHeight();
			vtx = pos + vec * (radius) - vec * GetMargin();
			newDot = vec.Dot(ref vtx);
			if (newDot > maxDot)
			{
				maxDot = newDot;
				supVec = vtx;
			}
		}

		{
			IndexedVector3 pos = IndexedVector3.Zero;
			pos[GetUpAxis()] = -GetHalfHeight();
			vtx = pos + vec * (radius) - vec * GetMargin();
			newDot = vec.Dot(ref vtx);
			if (newDot > maxDot)
			{
				maxDot = newDot;
				supVec = vtx;
			}
		}

		return supVec;
	}

	public override void BatchedUnitVectorGetSupportingVertexWithoutMargin(IndexedVector3[] vectors, IndexedVector4[] supportVerticesOut, int numVectors)
	{
		float radius = GetRadius();
		for (int j = 0; j < numVectors; j++)
		{
			float maxDot = float.MinValue;
			IndexedVector3 vec = vectors[j];
			IndexedVector3 vtx;
			float newDot = 0f;
			{
				IndexedVector3 pos = IndexedVector3.Zero;
				pos[GetUpAxis()] = GetHalfHeight();
				vtx = pos + vec * (radius) - vec * GetMargin();
				newDot = vec.Dot(ref vtx);
				if (newDot > maxDot)
				{
					maxDot = newDot;
					supportVerticesOut[j] = new IndexedVector4(vtx, 0);
				}
			}

			{
				IndexedVector3 pos = IndexedVector3.Zero;
				pos[GetUpAxis()] = -GetHalfHeight();
				vtx = pos + vec * (radius) - vec * GetMargin();
				newDot = vec.Dot(ref vtx);
				if (newDot > maxDot)
				{
					maxDot = newDot;
					supportVerticesOut[j] = new IndexedVector4(vtx, 0);
				}
			}
		}
	}

	public override void GetAabb(ref IndexedMatrix trans, out IndexedVector3 aabbMin, out IndexedVector3 aabbMax)
	{
		IndexedVector3 halfExtents = new IndexedVector3(GetRadius());
		halfExtents[m_upAxis] = GetRadius() + GetHalfHeight();
		halfExtents += new IndexedVector3(GetMargin());
		IndexedBasisMatrix abs_b = trans._basis.Absolute();
		IndexedVector3 center = trans._origin;
		IndexedVector3 extent = new IndexedVector3(abs_b._el0.Dot(ref halfExtents), abs_b._el1.Dot(ref halfExtents), abs_b._el2.Dot(ref halfExtents));
		aabbMin = center - extent;
		aabbMax = center + extent;
	}

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

	public int GetUpAxis()
	{
		return m_upAxis;
	}

	public float GetRadius()
	{
		int radiusAxis = (m_upAxis + 2) % 3;
		return m_implicitShapeDimensions[radiusAxis];
	}

	public float GetHalfHeight()
	{
		return m_implicitShapeDimensions[m_upAxis];
	}

	protected int m_upAxis;
}