//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="Matrix32.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 
//     THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//     
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
using StgSharp.Internal.Intrinsic;

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

namespace StgSharp.Mathematics
{
    [StructLayout(
            LayoutKind.Explicit,
            Size = ( 5 * 4 * sizeof( float ) ) + sizeof( bool ),
            Pack = 16 )]
    public struct Matrix32 : IMatrix<Matrix32>
    {

        [FieldOffset( 5 * 4 * sizeof( float ) )] internal bool isTransposed;

        [FieldOffset( 0 )] internal ColumnSet2 mat;
        [FieldOffset( 2 * 4 * sizeof( float ) )] internal ColumnSet3 transpose;

        [FieldOffset( 0 )] internal Vec3 colum0;
        [FieldOffset( 4 * 4 )] internal Vec3 colum1;

        internal Matrix32( Vector4 c0, Vector4 c1 )
        {
            Unsafe.SkipInit( out this );
            isTransposed = false;
            mat.colum0 = c0;
            mat.colum1 = c1;
        }

        public Matrix32()
        {
            Unsafe.SkipInit( out this );
            isTransposed = false;
        }

        public unsafe Matrix32( float a00, float a01, float a10, float a11, float a20, float a21 )
        {
            Unsafe.SkipInit( out this );
            isTransposed = false;
            mat.colum0 = new Vector4( a00, a10, a20, 0 );
            mat.colum1 = new Vector4( a01, a11, a21, 0 );
        }

        public unsafe float this[ int rowNum, int columNum ]
        {
            get
            {
                if( ( rowNum > 2 ) || ( rowNum < 0 ) ) {
                    throw new ArgumentOutOfRangeException( nameof( columNum ) );
                }
                if( ( columNum > 1 ) || ( columNum < 0 ) ) {
                    throw new ArgumentOutOfRangeException( nameof( columNum ) );
                }
                InternalTranspose();
                fixed( float* p = &this.transpose.m00 )
                {
                    ulong pbit = ( ( ulong )p ) + ( ( ( ulong )sizeof( Vector4 ) ) * ( ( ulong )rowNum ) ) + ( ( ( ulong )sizeof( float ) ) * ( ( ulong )columNum ) );
                    return *( float* )pbit;
                }
            }
            set
            {
                if( ( rowNum > 2 ) || ( rowNum < 0 ) ) {
                    throw new ArgumentOutOfRangeException( nameof( columNum ) );
                }
                if( ( columNum > 1 ) || ( columNum < 0 ) ) {
                    throw new ArgumentOutOfRangeException( nameof( columNum ) );
                }
                InternalTranspose();
                fixed( float* p = &this.transpose.m00 )
                {
                    ulong pbit = ( ( ulong )p ) + ( ( ( ulong )sizeof( Vector4 ) ) * ( ( ulong )rowNum ) ) + ( ( ( ulong )sizeof( float ) ) * ( ( ulong )columNum ) );
                    *( float* )pbit = value;
                }
                isTransposed = false;
            }
        }

        public Vec3 VerticalVecMultiply( Vec2 vec )
        {
            return ( colum0 * vec.X ) + ( colum1 * vec.Y );
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        internal unsafe void InternalTranspose()
        {
            if( !isTransposed )
            {
                fixed( ColumnSet2* source = &this.mat )
                {
                    fixed( ColumnSet3* target = &this.transpose ) {
                        InternalIO.Intrinsic.transpose23( source, target );
                    }
                }

                isTransposed = true;
            }
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Matrix32 operator -( Matrix32 left, Matrix32 right )
        {
            return new Matrix32(
                left.mat.colum0 - right.mat.colum0, left.mat.colum1 - right.mat.colum1 );
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Matrix32 operator *( Matrix32 mat, float value )
        {
            return new Matrix32( mat.mat.colum0 * value, mat.mat.colum1 * value );
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Matrix32 operator *( Matrix32 left, Matrix22 right )
        {
            left.InternalTranspose();
            return new Matrix32(
                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 ),

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

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Matrix33 operator *( Matrix32 left, Matrix23 right )
        {
            left.InternalTranspose();
            return new Matrix33(
                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 ),

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

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Matrix34 operator *( Matrix32 left, Matrix24 right )
        {
            left.InternalTranspose();
            return new Matrix34(
                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 ),

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

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Matrix32 operator /( Matrix32 mat, float value )
        {
            return new Matrix32( mat.mat.colum0 / value, mat.mat.colum1 / value );
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static unsafe Matrix32 operator +( Matrix32 left, Matrix32 right )
        {
            Matrix32 ret = new Matrix32();
            InternalIO.Intrinsic.add_mat_2( &left.mat, &right.mat, &ret.mat );
            return ret;
        }

    }
}