Matrix3

DomCR · Feb 17, 2025 · fdf684f · fdf684f
1 parent 49464e1
commit fdf684f
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Showing 5 changed files with 103 additions and 2 deletions.
diff --git a/CSMath/CSMath.projitems b/CSMath/CSMath.projitems
@@ -16,6 +16,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Geometry\LineExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)IVector.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Matrix3.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Matrix3.operators.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Matrix4.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Matrix4.Operators.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)MathHelper.cs" />

diff --git a/CSMath/Matrix3.cs b/CSMath/Matrix3.cs
@@ -1,4 +1,8 @@
-namespace CSMath
+using System;
+using System.Text;
+using System.Threading;
+
+namespace CSMath
 {
 	public partial struct Matrix3
 	{
@@ -81,5 +85,75 @@ public Matrix3(
 			this.m21 = m21;
 			this.m22 = m22;
 		}
+
+		public Matrix3(Matrix4 matrix)
+		{
+			this.m00 = matrix.m00;
+			this.m01 = matrix.m01;
+			this.m02 = matrix.m02;
+			this.m10 = matrix.m10;
+			this.m11 = matrix.m11;
+			this.m12 = matrix.m12;
+			this.m20 = matrix.m20;
+			this.m21 = matrix.m21;
+			this.m22 = matrix.m22;
+		}
+
+		/// <summary>
+		/// Obtains the transpose matrix.
+		/// </summary>
+		/// <returns>Transpose matrix.</returns>
+		public Matrix3 Transpose()
+		{
+			return new Matrix3(this.m00, this.m10, this.m20,
+							this.m01, this.m11, this.m21,
+							this.m02, this.m12, this.m22);
+		}
+
+		/// <summary>
+		/// Gets the rotation matrix from the normal vector (extrusion direction) of an entity.
+		/// </summary>
+		/// <param name="zAxis">Normal vector.</param>
+		/// <returns>Rotation matrix.</returns>
+		public static Matrix3 ArbitraryAxis(XYZ zAxis)
+		{
+			zAxis.Normalize();
+
+			if (zAxis.Equals(XYZ.AxisZ))
+			{
+				return Matrix3.Identity;
+			}
+
+			XYZ wY = XYZ.AxisY;
+			XYZ wZ = XYZ.AxisZ;
+			XYZ aX;
+
+			if ((Math.Abs(zAxis.X) < 1 / 64.0) && (Math.Abs(zAxis.Y) < 1 / 64.0))
+			{
+				aX = XYZ.Cross(wY, zAxis);
+			}
+			else
+			{
+				aX = XYZ.Cross(wZ, zAxis);
+			}
+
+			aX.Normalize();
+
+			XYZ aY = XYZ.Cross(zAxis, aX);
+			aY.Normalize();
+
+			return new Matrix3(aX.X, aY.X, zAxis.X, aX.Y, aY.Y, zAxis.Y, aX.Z, aY.Z, zAxis.Z);
+		}
+
+		/// <inheritdoc/>
+		public override string ToString()
+		{
+			string separator = Thread.CurrentThread.CurrentCulture.TextInfo.ListSeparator;
+			StringBuilder s = new StringBuilder();
+			s.Append(string.Format("|{0}{2} {0}{2} {1}|" + Environment.NewLine, this.m00, this.m01, this.m02, separator));
+			s.Append(string.Format("|{0}{2} {0}{2} {1}|" + Environment.NewLine, this.m10, this.m11, this.m12, separator));
+			s.Append(string.Format("|{0}{2} {0}{2} {1}|", this.m20, this.m21, this.m22, separator));
+			return s.ToString();
+		}
 	}
 }
diff --git a/CSMath/Matrix3.operators.cs b/CSMath/Matrix3.operators.cs
@@ -0,0 +1,12 @@
+namespace CSMath
+{
+	public partial struct Matrix3
+	{
+		public static XYZ operator *(Matrix3 matrix, XYZ value)
+		{
+			return new XYZ(matrix.m00 * value.X + matrix.m01 * value.Y + matrix.m02 * value.Z,
+							matrix.m10 * value.X + matrix.m11 * value.Y + matrix.m12 * value.Z,
+							matrix.m20 * value.X + matrix.m21 * value.Y + matrix.m22 * value.Z);
+		}
+	}
+}
diff --git a/CSMath/Matrix4.Operators.cs b/CSMath/Matrix4.Operators.cs
@@ -52,7 +52,7 @@ public static Matrix4 Multiply(Matrix4 a, Matrix4 b)
 		public static XYZ operator *(Matrix4 matrix, XYZ value)
 		{
 			XYZM xyzm = new XYZM(value.X, value.Y, value.Z, 1);
-			var rows = matrix.GetRows();
+			List<XYZM> rows = matrix.GetRows();
 
 			XYZ result = new XYZ
 			{

diff --git a/CSMath/Matrix4.cs b/CSMath/Matrix4.cs
@@ -1,5 +1,7 @@
 using System;
 using System.Collections.Generic;
+using System.Text;
+using System.Threading;
 
 namespace CSMath
 {
@@ -471,6 +473,18 @@ public override bool Equals(object obj)
 				m30 == other.m30 && m31 == other.m31 && m32 == other.m32;
 		}
 
+		/// <inheritdoc/>
+		public override string ToString()
+		{
+			string separator = Thread.CurrentThread.CurrentCulture.TextInfo.ListSeparator;
+			StringBuilder s = new StringBuilder();
+			s.Append(string.Format("|{0}{4} {1}{4} {2}{4} {3}|" + Environment.NewLine, this.m00, this.m01, this.m02, this.m03, separator));
+			s.Append(string.Format("|{0}{4} {1}{4} {2}{4} {3}|" + Environment.NewLine, this.m10, this.m11, this.m12, this.m13, separator));
+			s.Append(string.Format("|{0}{4} {1}{4} {2}{4} {3}|" + Environment.NewLine, this.m20, this.m21, this.m22, this.m23, separator));
+			s.Append(string.Format("|{0}{4} {1}{4} {2}{4} {3}|", this.m30, this.m31, this.m32, this.m33, separator));
+			return s.ToString();
+		}
+
 		/// <summary>
 		/// Creates a translation matrix.
 		/// </summary>