stgsharp/源代码/StgSharp/Math/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 
//     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 StgSharp.Data.Intrinsic;

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 Matrix22 : IMat
    {

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

        [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 )
        {
            mat.colum0 = c0;
            mat.colum1 = c1;
        }

        public Matrix22( 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 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 Matrix22 operator -( Matrix22 left, Matrix22 right )
        {
            return new Matrix22(
                left.mat.colum0 + right.mat.colum0,
                left.mat.colum1 + right.mat.colum1 );
        }

        [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 )
        {
            return new Matrix22(
                left.mat.colum0 + right.mat.colum0,
                left.mat.colum1 + right.mat.colum1 );
        }

    }
}