[Mono] Basis/Transforms Array operator comments and improvements

The behavior for Basis and Transform2D is unchanged, and Transform gets new behavior. All of the behavior is identical to GDScript's behavior. 

5 files changed, 109 insertions, 74 deletions

diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/Basis.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/Basis.cs
index d38589013e..55408fecb8 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/Basis.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/Basis.cs
@@ -93,11 +93,15 @@ namespace Godot
             }
         }
 
-        public Vector3 this[int columnIndex]
+        /// <summary>
+        /// Access whole columns in the form of Vector3.
+        /// </summary>
+        /// <param name="column">Which column vector.</param>
+        public Vector3 this[int column]
         {
             get
             {
-                switch (columnIndex)
+                switch (column)
                 {
                     case 0:
                         return Column0;
@@ -111,7 +115,7 @@ namespace Godot
             }
             set
             {
-                switch (columnIndex)
+                switch (column)
                 {
                     case 0:
                         Column0 = value;
@@ -128,50 +132,22 @@ namespace Godot
             }
         }
 
-        public real_t this[int columnIndex, int rowIndex]
+        /// <summary>
+        /// Access matrix elements in column-major order.
+        /// </summary>
+        /// <param name="column">Which column, the matrix horizontal position.</param>
+        /// <param name="row">Which row, the matrix vertical position.</param>
+        public real_t this[int column, int row]
         {
             get
             {
-                switch (columnIndex)
-                {
-                    case 0:
-                        return Column0[rowIndex];
-                    case 1:
-                        return Column1[rowIndex];
-                    case 2:
-                        return Column2[rowIndex];
-                    default:
-                        throw new IndexOutOfRangeException();
-                }
+                return this[column][row];
             }
             set
             {
-                switch (columnIndex)
-                {
-                    case 0:
-                    {
-                        var column0 = Column0;
-                        column0[rowIndex] = value;
-                        Column0 = column0;
-                        return;
-                    }
-                    case 1:
-                    {
-                        var column1 = Column1;
-                        column1[rowIndex] = value;
-                        Column1 = column1;
-                        return;
-                    }
-                    case 2:
-                    {
-                        var column2 = Column2;
-                        column2[rowIndex] = value;
-                        Column2 = column2;
-                        return;
-                    }
-                    default:
-                        throw new IndexOutOfRangeException();
-                }
+                Vector3 columnVector = this[column];
+                columnVector[row] = value;
+                this[column] = columnVector;
             }
         }
 
diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/Mathf.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/Mathf.cs
index ddfed180b5..4f7aa99df8 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/Mathf.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/Mathf.cs
@@ -130,7 +130,7 @@ namespace Godot
 
         public static real_t InverseLerp(real_t from, real_t to, real_t weight)
         {
-           return (weight - from) / (to - from);
+            return (weight - from) / (to - from);
         }
 
         public static bool IsEqualApprox(real_t a, real_t b)
@@ -151,12 +151,12 @@ namespace Godot
 
         public static bool IsInf(real_t s)
         {
-           return real_t.IsInfinity(s);
+            return real_t.IsInfinity(s);
         }
 
         public static bool IsNaN(real_t s)
         {
-           return real_t.IsNaN(s);
+            return real_t.IsNaN(s);
         }
 
         public static bool IsZeroApprox(real_t s)
diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/StringExtensions.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/StringExtensions.cs
index e096d37a6f..b85a00d869 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/StringExtensions.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/StringExtensions.cs
@@ -264,7 +264,8 @@ namespace Godot
                     instanceIndex++;
                     toIndex++;
                 }
-            } else
+            }
+            else
             {
                 while (true)
                 {
diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/Transform.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/Transform.cs
index 0b84050f07..aa8815d1aa 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/Transform.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/Transform.cs
@@ -15,6 +15,76 @@ namespace Godot
         public Basis basis;
         public Vector3 origin;
 
+        /// <summary>
+        /// Access whole columns in the form of Vector3. The fourth column is the origin vector.
+        /// </summary>
+        /// <param name="column">Which column vector.</param>
+        public Vector3 this[int column]
+        {
+            get
+            {
+                switch (column)
+                {
+                    case 0:
+                        return basis.Column0;
+                    case 1:
+                        return basis.Column1;
+                    case 2:
+                        return basis.Column2;
+                    case 3:
+                        return origin;
+                    default:
+                        throw new IndexOutOfRangeException();
+                }
+            }
+            set
+            {
+                switch (column)
+                {
+                    case 0:
+                        basis.Column0 = value;
+                        return;
+                    case 1:
+                        basis.Column1 = value;
+                        return;
+                    case 2:
+                        basis.Column2 = value;
+                        return;
+                    case 3:
+                        origin = value;
+                        return;
+                    default:
+                        throw new IndexOutOfRangeException();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Access matrix elements in column-major order. The fourth column is the origin vector.
+        /// </summary>
+        /// <param name="column">Which column, the matrix horizontal position.</param>
+        /// <param name="row">Which row, the matrix vertical position.</param>
+        public real_t this[int column, int row]
+        {
+            get
+            {
+                if (column == 3)
+                {
+                    return origin[row];
+                }
+                return basis[column, row];
+            }
+            set
+            {
+                if (column == 3)
+                {
+                    origin[row] = value;
+                    return;
+                }
+                basis[column, row] = value;
+            }
+        }
+
         public Transform AffineInverse()
         {
             Basis basisInv = basis.Inverse();
diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/Transform2D.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/Transform2D.cs
index 77ea3e5830..e72a44809a 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/Transform2D.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/Transform2D.cs
@@ -54,11 +54,15 @@ namespace Godot
             }
         }
 
-        public Vector2 this[int rowIndex]
+        /// <summary>
+        /// Access whole columns in the form of Vector2. The third column is the origin vector.
+        /// </summary>
+        /// <param name="column">Which column vector.</param>
+        public Vector2 this[int column]
         {
             get
             {
-                switch (rowIndex)
+                switch (column)
                 {
                     case 0:
                         return x;
@@ -72,7 +76,7 @@ namespace Godot
             }
             set
             {
-                switch (rowIndex)
+                switch (column)
                 {
                     case 0:
                         x = value;
@@ -89,38 +93,22 @@ namespace Godot
             }
         }
 
-        public real_t this[int rowIndex, int columnIndex]
+        /// <summary>
+        /// Access matrix elements in column-major order. The third column is the origin vector.
+        /// </summary>
+        /// <param name="column">Which column, the matrix horizontal position.</param>
+        /// <param name="row">Which row, the matrix vertical position.</param>
+        public real_t this[int column, int row]
         {
             get
             {
-                switch (rowIndex)
-                {
-                    case 0:
-                        return x[columnIndex];
-                    case 1:
-                        return y[columnIndex];
-                    case 2:
-                        return origin[columnIndex];
-                    default:
-                        throw new IndexOutOfRangeException();
-                }
+                return this[column][row];
             }
             set
             {
-                switch (rowIndex)
-                {
-                    case 0:
-                        x[columnIndex] = value;
-                        return;
-                    case 1:
-                        y[columnIndex] = value;
-                        return;
-                    case 2:
-                        origin[columnIndex] = value;
-                        return;
-                    default:
-                        throw new IndexOutOfRangeException();
-                }
+                Vector2 columnVector = this[column];
+                columnVector[row] = value;
+                this[column] = columnVector;
             }
         }