so much work :(

PveTeam.Math/Matrix4x4D.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Numerics;
 
 namespace PveTeam.Mathematics
 {
@@ -9,10 +10,73 @@ namespace PveTeam.Mathematics
             M31, M32, M33, M34,
             M41, M42, M43, M44;
 
+        #region Static fields
+        public static Matrix4x4D Identity => new Matrix4x4D(
+            1, 0, 0, 0,
+            0, 1, 0, 0,
+            0, 0, 1, 0,
+            0, 0, 0, 1);
+        public static Matrix4x4D Zero => new Matrix4x4D(9);
+        #endregion
+
+        #region Constructors
+        public Matrix4x4D(Double value) : this(value, value, value, value, value, value, value, value, value, value, value, value, value, value, value, value) { }
+        public Matrix4x4D(Matrix4x4 value) : this(value.M11, value.M12, value.M13, value.M14, value.M21, value.M22, value.M23, value.M24, value.M31, value.M32, value.M33, value.M34, value.M41, value.M42, value.M43, value.M44) { }
+        public Matrix4x4D(Double m11, Double m12, Double m13, Double m14,
+            Double m21, Double m22, Double m23, Double m24,
+            Double m31, Double m32, Double m33, Double m34,
+            Double m41, Double m42, Double m43, Double m44)
+        {
+            M11 = m11;
+            M12 = m12;
+            M13 = m13;
+            M14 = m14;
+            M21 = m21;
+            M22 = m22;
+            M23 = m23;
+            M24 = m24;
+            M31 = m31;
+            M32 = m32;
+            M33 = m33;
+            M34 = m34;
+            M41 = m41;
+            M42 = m42;
+            M43 = m43;
+            M44 = m44;
+        }
+        #endregion
+
+        #region Instance methods
+        #endregion
+
+        #region Static methods
+        #endregion
+
+        #region Operators
+        #endregion
+
+        #region Operator methods
+        #endregion
+
+        #region Equals
+        public override int GetHashCode()
+            => M11.GetHashCode() + M12.GetHashCode() + M13.GetHashCode() + M14.GetHashCode()
+            + M21.GetHashCode() + M22.GetHashCode() + M23.GetHashCode() + M24.GetHashCode()
+            + M31.GetHashCode() + M32.GetHashCode() + M33.GetHashCode() + M34.GetHashCode()
+            + M41.GetHashCode() + M42.GetHashCode() + M43.GetHashCode() + M44.GetHashCode();
+
+        public override bool Equals(object obj)
+        {
+            if (!(obj is Matrix4x4D))
+                return false;
+            return Equals((Matrix4x4D)obj);
+        }
+
         public bool Equals(Matrix4x4D other)
             => M11 == other.M11 && M12 == other.M12 && M13 == other.M13 && M14 == other.M14
             && M21 == other.M21 && M22 == other.M22 && M23 == other.M23 && M24 == other.M24
             && M31 == other.M31 && M32 == other.M32 && M33 == other.M33 && M34 == other.M34
             && M41 == other.M41 && M42 == other.M42 && M43 == other.M43 && M44 == other.M44;
+        #endregion
     }
 }