use built-in matrix multi

src/__private__/__m_multiply.scad

@@ -1,13 +0,0 @@
-function __m_multiply(ma, mb) = 
-    let(
-        c1 = [mb[0][0], mb[1][0], mb[2][0], mb[3][0]],
-        c2 = [mb[0][1], mb[1][1], mb[2][1], mb[3][1]],
-        c3 = [mb[0][2], mb[1][2], mb[2][2], mb[3][2]],
-        c4 = [mb[0][3], mb[1][3], mb[2][3], mb[3][3]]
-    )
-    [
-        [ma[0] * c1, ma[0] * c2, ma[0] * c3, ma[0] * c4],
-        [ma[1] * c1, ma[1] * c2, ma[1] * c3, ma[1] * c4],
-        [ma[2] * c1, ma[2] * c2, ma[2] * c3, ma[2] * c4],
-        [ma[3] * c1, ma[3] * c2, ma[3] * c3, ma[3] * c4]
-    ];

src/along_with.scad

@@ -7,11 +7,10 @@
 * @see https://openhome.cc/eGossip/OpenSCAD/lib-along_with.html
 *
 **/ 
-
+ 
 include <__private__/__angy_angz.scad>;
 include <__private__/__is_vector.scad>;
 include <__private__/__to3d.scad>;
-include <__private__/__m_multiply.scad>;
 
 // Becuase of improving the performance, this module requires m_rotation.scad which doesn't require in dotSCAD 1.0. 
 // For backward compatibility, I directly include m_rotation here.
@@ -56,7 +55,7 @@ module along_with(points, angles, twist = 0, scale = 1.0) {
         i == leng_rot_matrice - 2 ? 
                [
                    rot_matrice[leng_rot_matrice_minus_one], 
-                   __m_multiply(rot_matrice[leng_rot_matrice_minus_two], rot_matrice[leng_rot_matrice_minus_one])
+                   rot_matrice[leng_rot_matrice_minus_two] * rot_matrice[leng_rot_matrice_minus_one]
                ] 
                : cumulated_rot_matrice_sub(i, rot_matrice);
 
@@ -66,7 +65,7 @@ module along_with(points, angles, twist = 0, scale = 1.0) {
             curr_matrix = rot_matrice[i],
             prev_matrix = matrice[len(matrice) - 1]
         )
-        concat(matrice, [__m_multiply(curr_matrix, prev_matrix)]);
+        concat(matrice, [curr_matrix * prev_matrix]);
 
     // align modules
 

src/m_cumulate.scad

@@ -8,12 +8,10 @@
 *
 **/
 
-include <__private__/__m_multiply.scad>;
-
 function _m_cumulate(matrice, i) = 
     i == len(matrice) - 2 ?
-        __m_multiply(matrice[i], matrice[i + 1]) :
+        matrice[i] * matrice[i + 1] :
-        __m_multiply(matrice[i], _m_cumulate(matrice, i + 1));
+        matrice[i] * _m_cumulate(matrice, i + 1);
 
 function m_cumulate(matrice) = 
     len(matrice) == 1 ? matrice[0] : _m_cumulate(matrice, 0);

src/m_multiply.scad

@@ -1,13 +0,0 @@
-/**
-* m_multiply.scad
-*
-* @copyright Justin Lin, 2019
-* @license https://opensource.org/licenses/lgpl-3.0.html
-*
-* @see https://openhome.cc/eGossip/OpenSCAD/lib-m_multiply.html
-*
-**/
-
-include <__private__/__m_multiply.scad>;
-
-function m_multiply(ma, mb) = __m_multiply(ma, mb);

src/m_rotation.scad

@@ -8,8 +8,6 @@
 *
 **/
 
-include <__private__/__m_multiply.scad>;
-
 function _q_rotation(a, v) = 
     let(
         half_a = a / 2,
@@ -77,11 +75,7 @@ function _to_avect(a) =
 
 function _xyz_rotation(a) =
     let(ang = _to_avect(a))
-    __m_multiply(
+    _m_zRotation(ang[2]) * _m_yRotation(ang[1]) * _m_xRotation(ang[0]);
-        _m_zRotation(ang[2]), __m_multiply(
-            _m_yRotation(ang[1]), _m_xRotation(ang[0])
-        )
-    );
 
 function m_rotation(a, v) = 
     v == undef ? _xyz_rotation(a) : _q_rotation(a, v);

src/m_shearing.scad

@@ -8,7 +8,6 @@
 *
 **/
 
-include <__private__/__m_multiply.scad>;
 include <__private__/__m_shearing.scad>;
 
 function m_shearing(sx = [0, 0], sy = [0, 0], sz = [0, 0]) = __m_shearing(sx, sy, sz);

src/path_extrude.scad

@@ -11,7 +11,6 @@
 include <__private__/__is_vector.scad>;
 include <__private__/__to3d.scad>;
 include <__private__/__angy_angz.scad>;
-include <__private__/__m_multiply.scad>;
 
 // Becuase of improving the performance, this module requires m_rotation.scad which doesn't require in dotSCAD 1.0. 
 // For backward compatibility, I directly include m_rotation here.
@@ -74,7 +73,7 @@ module path_extrude(shape_pts, path_pts, triangles = "SOLID", twist = 0, scale =
         i == leng_rot_matrice - 2 ? 
                [
                    rot_matrice[leng_rot_matrice_minus_one], 
-                   __m_multiply(rot_matrice[leng_rot_matrice_minus_two], rot_matrice[leng_rot_matrice_minus_one])
+                   rot_matrice[leng_rot_matrice_minus_two] * rot_matrice[leng_rot_matrice_minus_one]
                ] 
                : cumulated_rot_matrice_sub(i);
 
@@ -84,7 +83,7 @@ module path_extrude(shape_pts, path_pts, triangles = "SOLID", twist = 0, scale =
             curr_matrix = rot_matrice[i],
             prev_matrix = matrice[len(matrice) - 1]
         )
-        concat(matrice, [__m_multiply(curr_matrix, prev_matrix)]);
+        concat(matrice, [curr_matrix * prev_matrix]);
 
     cumu_rot_matrice = cumulated_rot_matrice(0);
 

src/shear.scad

@@ -8,7 +8,6 @@
 *
 **/
 
-include <__private__/__m_multiply.scad>;
 include <__private__/__m_shearing.scad>;
 
 module shear(sx = [0, 0], sy = [0, 0], sz = [0, 0]) {