stgsharp/源代码/StgSharp/Math/Linear/matrix2x2.cs

//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="matrix2x2.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 
//     files (the “Software”), to deal in the Software without restriction, 
//     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:
//     
//     The above copyright notice and 
//     this permission notice shall be included in all copies 
//     or substantial portions of the Software.
//     
//     THE SOFTWARE IS PROVIDED “AS IS”, 
//     WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
//     INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
//     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
//     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
//     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 System.Numerics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

namespace StgSharp.Math
{
    [StructLayout(LayoutKind.Explicit, Size = (2 * 2 * 4 * sizeof(float)) + sizeof(bool), Pack = 16)]
    public struct Matrix2x2 : IMat
    {

        [FieldOffset(0)]
        internal Mat2 mat;
        [FieldOffset(2 * 4 * sizeof(float))]
        internal Mat2 transpose;
        [FieldOffset(2 * 2 * 4 * sizeof(float))]
        internal bool isTransposed;

        internal Matrix2x2(
            Mat2 mat
            )
        {
            this.mat = mat;
        }

        internal Matrix2x2(
            Vector4 c0,
            Vector4 c1
            )
        {
            mat.colum0 = c0;
            mat.colum1 = c1;
        }

        public Matrix2x2(
            float a00, float a01,
            float a10, float a11
            )
        {
            mat.colum0 = new Vector4(a00, a10, 0, 0);
            mat.colum1 = new Vector4(a01, a11, 0, 0);
        }

        public Matrix2x2 Transpose
        {
            get
            {
                InternalTranspose();
                return new Matrix2x2(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 Matrix2x2 operator -(Matrix2x2 left, Matrix2x2 right)
        {
            return new Matrix2x2(
                left.mat.colum0 + right.mat.colum0,
                left.mat.colum1 + right.mat.colum1
                );
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static Matrix2x2 operator *(Matrix2x2 mat, float value)
        {
            return new Matrix2x2(
                mat.mat.colum0 * value,
                mat.mat.colum1 * value
                );
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static Matrix2x2 operator *(Matrix2x2 left, Matrix2x2 right)
        {
            left.InternalTranspose();
            return new Matrix2x2(
                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 Matrix2x3 operator *(Matrix2x2 left, Matrix2x3 right)
        {
            left.InternalTranspose();
            return new Matrix2x3(
                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 Matrix2x4 operator *(Matrix2x2 left, Matrix2x4 right)
        {
            left.InternalTranspose();
            return new Matrix2x4(
                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 Matrix2x2 operator /(Matrix2x2 mat, float value)
        {
            return new Matrix2x2(
                mat.mat.colum0 / value,
                mat.mat.colum1 / value
                );
        }


        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe Matrix2x2 operator +(Matrix2x2 left, Matrix2x2 right)
        {
            Mat2* refmat = InternalIO.add_mat2(&left.mat, &right.mat);
            Matrix2x2 ret = new Matrix2x2(*refmat);
            InternalIO.deinit_mat2(refmat);
            return ret;
        }



    }
}