Stop using as many hacks in sweep_rounded

generic-helpers.scad

@@ -71,28 +71,46 @@ function vector_as_unit(vector) = vector / vector_magnitude(vector);
  */
 function atanv(vector) = atan2(vector.y, vector.x);
 
-/**
- * @brief Affine transformation matrix for 2d rotation on the X,Y plane.
- * @param angle The angle to rotate things by
- * @returns an Affine transformation matrix for use with `multmatrix()`
- */
-function affine_rotation(angle) = [
-    [cos(angle), 0, sin(angle), 0],
+function _affine_rotate_x(angle_x) = [
+    [1,  0, 0, 0],
+    [0, cos(angle_x), -sin(angle_x), 0],
+    [0, sin(angle_x), cos(angle_x), 0],
+    [0, 0, 0, 1]
+];
+
+function _affine_rotate_y(angle_y) = [
+    [cos(angle_y),  0, sin(angle_y), 0],
     [0, 1, 0, 0],
-    [-sin(angle), 0, cos(angle), 0],
+    [-sin(angle_y), 0, cos(angle_y), 0],
+    [0, 0, 0, 1]
+];
+
+function _affine_rotate_z(angle_z) = [
+    [cos(angle_z), -sin(angle_z), 0, 0],
+    [sin(angle_z), cos(angle_z), 0, 0],
+    [0, 0, 1, 0],
     [0, 0, 0, 1]
 ];
 
 
 /**
- * @brief Affine transformation matrix for 2d translation on the X,Y plane.
- * @param vector 2d Vector to translate by.
- * @returns an Affine transformation matrix for use with `multmatrix()`
+ * @brief Affine transformation matrix equivalent of `rotate`
+ * @param angle_vector @see `rotate`
+ * @details Equivalent to `rotate([0, angle, 0])`
+ * @returns An affine transformation matrix for use with `multmatrix()`
  */
-function affine_translation(vector) = [
-    [1, 0, 0, vector.y],
-    [0, 1, 0, 0],
-    [0, 0, 1, vector.x],
+function affine_rotate(angle_vector) =
+    _affine_rotate_z(angle_vector.z) * _affine_rotate_y(angle_vector.y) * _affine_rotate_x(angle_vector.x);
+
+/**
+ * @brief Affine transformation matrix equivalent of `translate`
+ * @param vector @see `translate`
+ * @returns An affine transformation matrix for use with `multmatrix()`
+ */
+function affine_translate(vector) = [
+    [1, 0, 0, vector.x],
+    [0, 1, 0, vector.y],
+    [0, 0, 1, vector.z],
     [0, 0, 0, 1]
 ];
 
@@ -118,39 +136,21 @@ module sweep_rounded(width=10, length=10) {
     ];
     // These contain the translations, but not the rotations
     // OpenSCAD requires this hacky for loop to get accumulate to work!
-    first_translation = affine_translation(path_points[0]);
+    first_translation = affine_translate([path_points[0].y, 0,path_points[0].x]);
     affine_translations = concat([first_translation], [
         for (i = 0, a = first_translation;
             i < len(path_vectors);
-            a=a * affine_translation(path_vectors[i]), i=i+1)
-        a * affine_translation(path_vectors[i])
+            a=a * affine_translate([path_vectors[i].y, 0, path_vectors[i].x]), i=i+1)
+        a * affine_translate([path_vectors[i].y, 0, path_vectors[i].x])
     ]);
 
-    // Affine matrix to rotate around X axis
-    rot_x = 90;
-    x_matrix = [
-        [1, 0, 0, 0],
-        [0, cos(rot_x), -sin(rot_x), 0],
-        [0, sin(rot_x), cos(rot_x), 0],
-        [0, 0, 0, 1]
-    ];
-
-    // Affine matrix to rotate around Z axis
-    z_rot = 90;
-    z_matrix = [
-        [cos(z_rot), -sin(z_rot), 0, 0],
-        [sin(z_rot), cos(z_rot), 0, 0],
-        [0, 0, 1, 0],
-        [0, 0, 0, 1]
-    ];
-
     // Bring extrusion to the xy plane
-    affine_matrix = z_matrix * x_matrix;
+    affine_matrix = affine_rotate([90, 0, 90]);
 
     walls = [
         for (i = [0 : len(path_vectors) - 1])
         affine_matrix * affine_translations[i]
-        * affine_rotation(atanv(path_vectors[i]))
+        * affine_rotate([0, atanv(path_vectors[i]), 0])
     ];
 
     union()
@@ -161,8 +161,7 @@ module sweep_rounded(width=10, length=10) {
             children();
 
             // Rounded Corners
-            multmatrix(walls[i]
-                *x_matrix*x_matrix*x_matrix *z_matrix*z_matrix*z_matrix*z_matrix)
+            multmatrix(walls[i] * affine_rotate([-90, 0, 0]))
             rotate_extrude(angle = 90, convexity = 4)
             children();
         }