refactor matrix constants

Pod/Classes/CATransform3D+float3x3.swift

@@ -10,21 +10,21 @@ import QuartzCore
 import simd
 
 extension CATransform3D {
+    static let addColumn : float4x3 =  {
+        var m = float4x3(diagonal:float3(1,1,0))
+        m[3,2] = 1
+        return m
+    }()
+
+    static let addRow : float3x4 =  {
+        var m = float3x4(diagonal:float3(1,1,0))
+        m[2,3] = 1
+        return m
+    }()
+
     init(_ m: float3x3) {
-        var addColumn = float4x3()
-        addColumn[0,0] = 1
-        addColumn[1,1] = 1
-        addColumn[3,2] = 1
-
-        var addRow = float3x4()
-        addRow[0,0] = 1
-        addRow[1,1] = 1
-        addRow[2,3] = 1
-
-        var result = addRow * m * addColumn
-
+        var result = CATransform3D.addRow * m * CATransform3D.addColumn
         result[2,2] = 1
-
         self.init(result)
     }
 }

Pod/add-column.txt

@@ -0,0 +1 @@
+\begin{bmatrix} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 0 & 1 \end{bmatrix}=\begin{bmatrix} 1 \\ 1 \\ 1 \end{bmatrix}\times \begin{bmatrix} 1 & 1 & 0 & 1 \end{bmatrix}