From fece5c2bde9036204e592924dfd71e52ca85bc12 Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Wed, 1 May 2019 07:30:08 +0800
Subject: [PATCH] in the following order: sx, sy, sz

---
 src/m_shearing.scad | 47 +++++++++++++++++++++++++++++++++++++--------
 1 file changed, 39 insertions(+), 8 deletions(-)

diff --git a/src/m_shearing.scad b/src/m_shearing.scad
index b4c07005..d7074be0 100644
--- a/src/m_shearing.scad
+++ b/src/m_shearing.scad
@@ -1,15 +1,46 @@
-function m_shearing(sx = [0, 0], sy = [0, 0], sz = [0, 0]) = 
+include <__private__/__m_multiply.scad>;
+
+function _m_shearing_sx(sx) =
     let(
         sx_along_y = sx[0],
-        sx_along_z = sx[1],
-        sy_along_x = sy[0],
-        sy_along_z = sy[1],
-        sz_along_x = sz[0],
-        sz_along_y = sz[1]  
-    )
+        sx_along_z = sx[1]
+    ) 
     [
         [1, sx_along_y, sx_along_z, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [0, 0, 0, 1]
+    ];
+
+function _m_shearing_sy(sy) =
+    let(
+        sy_along_x = sy[0],
+        sy_along_z = sy[1]
+    ) 
+    [
+        [1, 0, 0, 0],
         [sy_along_x, 1, sy_along_z, 0],
+        [0, 0, 1, 0],
+        [0, 0, 0, 1]
+    ];
+
+function _m_shearing_sz(sz) =
+    let(
+        sz_along_x = sz[0],
+        sz_along_y = sz[1]  
+    ) 
+    [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
         [sz_along_x, sz_along_y, 1, 0],
         [0, 0, 0, 1]
-    ];
\ No newline at end of file
+    ];
+
+function m_shearing(sx = [0, 0], sy = [0, 0], sz = [0, 0]) = 
+    __m_multiply(
+        _m_shearing_sy(sz),
+        __m_multiply(
+            _m_shearing_sy(sy),
+            _m_shearing_sx(sx)
+        )
+    );
\ No newline at end of file