stgsharp/StgSharp.Mathematics/Numeric/Graphics/Vec2.cs

//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="Vec2"
// 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.Mathematics;
using StgSharp.Mathematics.Numeric;
using System.Net.Http.Headers;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

namespace StgSharp.Mathematics.Graphics
{
    /// <summary>
    ///   A two dimension vector defined by two elements. Vec2 in World are default used as colum
    ///   vector.
    /// </summary>
    [StructLayout(LayoutKind.Explicit, Size = 16, Pack = 16)]
    public struct Vec2 : IUnmanagedVector<Vec2>
    {

        [FieldOffset(0)] internal unsafe fixed float num[2];

        [FieldOffset(0)]
        internal M128 reg;

        [FieldOffset(0)]
        internal Vector2 v;

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

        internal Vec2(Vector2 vec)
        {
            Unsafe.SkipInit(out reg);
            Unsafe.SkipInit(out X);
            Unsafe.SkipInit(out Y);
            v = vec;
        }

        internal Vec2(M128 vec)
        {
            Unsafe.SkipInit(out reg);
            Unsafe.SkipInit(out X);
            Unsafe.SkipInit(out Y);
            reg = vec;
            reg.Member<ulong>(1) = 0;
        }

        public Vec2(float x, float y)
        {
            v = new Vector2(x, y);
        }

        public static Vec2 Unit => new Vec2(1, 1);

        public static Vec2 Zero => new Vec2(0, 0);

        public static Vec2 One
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get => new Vec2(1, 1);
        }

        public Vec2 XY
        {
            readonly get => this;
            set => this = value;
        }

        public Vec3 XYZ
        {
            readonly get => new(reg);
            set
            {
                reg = value.reg;
                reg.Member<ulong>(1) = 0;
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public float Cross(Vec2 right)
        {
            return X * right.Y - Y * right.X;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public float Dot(Vec2 vec)
        {
            return Vector2.Dot(v, vec.v);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static Vec2 operator -(Vec2 left, Vec2 right)
        {
            return new Vec2(left.v - right.v);
        }

        public static bool operator !=(Vec2 left, Vec2 right)
        {
            return !(left == right);
        }

        public static Vec2 operator *(Vec2 vec, float value)
        {
            return new Vec2(vec.v * value);
        }
        public static Vec2 operator *(float value, Vec2 vec)
        {
            return new Vec2(vec.v * value);
        }

        public static Vec2 operator /(Vec2 vec, float value)
        {
            return new Vec2(vec.v / value);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static Vec2 operator +(Vec2 left, Vec2 right)
        {
            return new Vec2(left.v + right.v);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static bool operator ==(Vec2 left, Vec2 right)
        {
            return left.v == right.v;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static implicit operator Vec2((float, float) tuple)
        {
            return new Vec2(tuple.Item1, tuple.Item2);
        }

    }
}