stgsharp/StgSharp.Common/Mathematics/Linear/Matrix22.cs

//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="Matrix22.cs"
// Project: StgSharp
// AuthorGroup: Nitload Space
// Copyright (c) Nitload Space. All rights reserved.
//     
// Permission is hereby granted, free of charge, to any person 
// obtaining a copy of this software and associated documentation 
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// including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, 
// and to permit persons to whom the Software is furnished to do so, 
// subject to the following conditions:
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// The above copyright notice and 
// this permission notice shall be included in all copies 
// or substantial portions of the Software.
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// WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
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// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
// ARISING FROM, OUT OF OR IN CONNECTION WITH 
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// -----------------------------------------------------------------------
// -----------------------------------------------------------------------
using StgSharp.Internal.Intrinsic;

using System.Numerics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

namespace StgSharp.Mathematics
{
    [StructLayout(LayoutKind.Explicit, Size = (2 * 2 * 4 * sizeof(float)) + sizeof(bool), Pack = 16)]
    public struct Matrix22 : IMatrix<Matrix22>
    {

        [FieldOffset(2 * 2 * 4 * sizeof(float))]
        internal bool isTransposed = false;

        [FieldOffset(0)]
        internal ColumnSet2 _mat;
        [FieldOffset(2 * 4 * sizeof(float))]
        internal ColumnSet2 _transpose;

        internal Matrix22(ColumnSet2 mat)
        {
            this._mat = mat;
        }

        internal Matrix22(Vector4 c0, Vector4 c1)
        {
            Unsafe.SkipInit(out this);
            isTransposed = false;
            _mat.colum0 = c0;
            _mat.colum1 = c1;
        }

        public Matrix22()
        {
            Unsafe.SkipInit(out this);
            isTransposed = false;
        }

        public Matrix22(float a00, float a01, float a10, float a11)
        {
            Unsafe.SkipInit(out this);
            isTransposed = false;
            _mat.colum0 = new Vector4(a00, a10, 0, 0);
            _mat.colum1 = new Vector4(a01, a11, 0, 0);
        }

        public Matrix22 Transpose
        {
            get
            {
                InternalTranspose();
                return new Matrix22(this._transpose);
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public float Det()
        {
            return (_mat.m00 * _mat.m11) - (_mat.m10 * _mat.m01);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        internal void InternalTranspose()
        {
            if (!isTransposed)
            {
                _transpose = _mat;
                float cache = _transpose.m10;
                _transpose.m10 = _transpose.m01;
                _transpose.m01 = cache;
                isTransposed = true;
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe Matrix22 operator -(Matrix22 left, Matrix22 right)
        {
            Matrix22 ret = new Matrix22();
            InternalIO.Intrinsic.sub_mat_2(&left._mat, &right._mat, &ret._mat);
            return ret;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static Matrix22 operator *(Matrix22 mat, float value)
        {
            return new Matrix22(mat._mat.colum0 * value, mat._mat.colum1 * value);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static Matrix22 operator *(Matrix22 left, Matrix22 right)
        {
            left.InternalTranspose();
            return new Matrix22(
                Vector4.Dot(left._transpose.colum0, right._mat.colum0),
                Vector4.Dot(left._transpose.colum0, right._mat.colum1),

                Vector4.Dot(left._transpose.colum1, right._mat.colum0),
                Vector4.Dot(left._transpose.colum1, right._mat.colum1));
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static Matrix23 operator *(Matrix22 left, Matrix23 right)
        {
            left.InternalTranspose();
            return new Matrix23(
                Vector4.Dot(left._transpose.colum0, right._mat.colum0),
                Vector4.Dot(left._transpose.colum0, right._mat.colum1),
                Vector4.Dot(left._transpose.colum0, right._mat.colum2),

                Vector4.Dot(left._transpose.colum1, right._mat.colum0),
                Vector4.Dot(left._transpose.colum1, right._mat.colum1),
                Vector4.Dot(left._transpose.colum1, right._mat.colum2));
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static Matrix24 operator *(Matrix22 left, Matrix24 right)
        {
            left.InternalTranspose();
            return new Matrix24(
                Vector4.Dot(left._transpose.colum0, right.mat.colum0),
                Vector4.Dot(left._transpose.colum0, right.mat.colum1),
                Vector4.Dot(left._transpose.colum0, right.mat.colum2),
                Vector4.Dot(left._transpose.colum0, right.mat.colum3),

                Vector4.Dot(left._transpose.colum1, right.mat.colum0),
                Vector4.Dot(left._transpose.colum1, right.mat.colum1),
                Vector4.Dot(left._transpose.colum1, right.mat.colum2),
                Vector4.Dot(left._transpose.colum1, right.mat.colum3));
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static Matrix22 operator /(Matrix22 mat, float value)
        {
            return new Matrix22(mat._mat.colum0 / value, mat._mat.colum1 / value);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe Matrix22 operator +(Matrix22 left, Matrix22 right)
        {
            Matrix22 ret = new Matrix22();
            InternalIO.Intrinsic.add_mat_2(&left._mat, &right._mat, &ret._mat);
            return ret;
        }

    }
}