stgsharp/StgSharp.Common/Math/Linear/Vec4.cs

//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="Vec4.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.HighPerformance;
using StgSharp.Internal.Intrinsic;
using StgSharp.Math;

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

namespace StgSharp.Math
{
    [StructLayout( LayoutKind.Explicit, Size = 16, Pack = 16 )]
    public struct Vec4 : IEquatable<Vec4>, IVector<Vec4>
    {

        [FieldOffset( 0 )] internal unsafe fixed float num[ 4 ];

        [FieldOffset( 0 )] internal M128 reg;

        [FieldOffset( 0 )] internal Vector4 vec;
        [FieldOffset( 12 )] public float W;

        [FieldOffset( 0 )] public float X;
        [FieldOffset( 4 )] public float Y;
        [FieldOffset( 8 )] public float Z;

        internal Vec4( Vector4 v )
        {
            Unsafe.SkipInit( out X );
            Unsafe.SkipInit( out Y );
            Unsafe.SkipInit( out Z );
            Unsafe.SkipInit( out W );
            Unsafe.SkipInit( out reg );

            vec = v;
        }

        internal Vec4( M128 v )
        {
            Unsafe.SkipInit( out X );
            Unsafe.SkipInit( out Y );
            Unsafe.SkipInit( out Z );
            Unsafe.SkipInit( out W );
            Unsafe.SkipInit( out vec );

            reg = v;
        }

        public Vec4( Vec3 v3, float w )
        {
            Unsafe.SkipInit( out X );
            Unsafe.SkipInit( out Y );
            Unsafe.SkipInit( out Z );
            Unsafe.SkipInit( out W );
            reg = v3.reg;
            W = w;
        }

        public Vec4( float x, float y, float z, float w )
        {
            vec = new Vector4( x, y, z, w );
        }

        public unsafe Vec2 XY
        {
            get => new Vec2( reg );
            set
            {
                X = value.X;
                Y = value.Y;
            }
        }

        public unsafe Vec3 XYZ
        {
            get => new Vec3( reg );
            set
            {
                float w = W;
                reg = value.reg;
                W = w;
            }
        }

        public static Vec4 One
        {
            get => new Vec4( 1, 1, 1, 1 );
        }

        public static Vec4 Zero
        {
            get => new Vec4( 0, 0, 0, 0 );
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Vec4 Add( Vec4 left, Vec4 right )
        {
            return left + right;
        }

        public override bool Equals( object obj )
        {
            return ( obj is Vec4 v ) ? ( v == this ) : false;
        }

        public override int GetHashCode()
        {
            return vec.GetHashCode();
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Vec4 Subtract( Vec4 left, Vec4 right )
        {
            return left - right;
        }

        public override string ToString()
        {
            return vec.ToString();
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Vec4 operator -( Vec4 left, Vec4 right )
        {
            return new Vec4( left.vec - right.vec );
        }

        public static bool operator !=( Vec4 left, Vec4 right )
        {
            return !( left == right );
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Vec4 operator *( Matrix44 mat, Vec4 vec )
        {
            mat.InternalTranspose();
            return new Vec4(
                Vector4.Dot( mat.transpose.colum0, vec.vec ),
                Vector4.Dot( mat.transpose.colum1, vec.vec ),
                Vector4.Dot( mat.transpose.colum2, vec.vec ),
                Vector4.Dot( mat.transpose.colum3, vec.vec ) );
        }

        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public static Vec4 operator +( Vec4 left, Vec4 right )
        {
            return new Vec4( left.vec + right.vec );
        }

        public static bool operator ==( Vec4 left, Vec4 right )
        {
            return left.vec == right.vec;
        }

        bool IEquatable<Vec4>.Equals( Vec4 other )
        {
            return vec == other.vec;
        }

    }
}