Merge branch 'martinbudden-pulley_children'

CHANGELOG.md

@@ -3,6 +3,18 @@
 This changelog is generated by `changelog.py` using manually added semantic version tags to classify commits as breaking changes, additions or fixes.
 
 
+### [v15.4.0](https://github.com/nophead/NopSCADlib/releases/tag/v15.4.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v15.3.1...v15.4.0 "diff with v15.3.1")
+*   2021-04-02 [`b2d712b`](https://github.com/nophead/NopSCADlib/commit/b2d712bca94165a338e5f904880d12f9c4c5ecd0 "show commit") [C.P.](# "Chris Palmer") Added `quadratic_real_roots()` and `cubic_real_roots()`.
+
+#### [v15.3.1](https://github.com/nophead/NopSCADlib/releases/tag/v15.3.1 "show release") Fixes [...](https://github.com/nophead/NopSCADlib/compare/v15.3.0...v15.3.1 "diff with v15.3.0")
+*   2021-04-02 [`f3376ed`](https://github.com/nophead/NopSCADlib/commit/f3376edaf186b32f442b94d6d0b42f1ba0c7612c "show commit") [C.P.](# "Chris Palmer") Documented `xor()` function.
+
+### [v15.3.0](https://github.com/nophead/NopSCADlib/releases/tag/v15.3.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v15.2.0...v15.3.0 "diff with v15.2.0")
+*   2021-04-02 [`c073419`](https://github.com/nophead/NopSCADlib/commit/c073419c0b4eddcda4cda5bd0f8d48268b6e58ec "show commit") [C.P.](# "Chris Palmer") Added `opengrab_screw_depth()` function.
+
+### [v15.2.0](https://github.com/nophead/NopSCADlib/releases/tag/v15.2.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v15.1.1...v15.2.0 "diff with v15.1.1")
+*   2021-03-22 [`ca1b34e`](https://github.com/nophead/NopSCADlib/commit/ca1b34e9cad5d82bd878fa4ebf439c0fbdad7f77 "show commit") [C.P.](# "Chris Palmer") Added `sink` parameter to `screw_polysink()` to recess the head.
+
 #### [v15.1.1](https://github.com/nophead/NopSCADlib/releases/tag/v15.1.1 "show release") Fixes [...](https://github.com/nophead/NopSCADlib/compare/v15.1.0...v15.1.1 "diff with v15.1.0")
 *   2021-03-22 [`cbab9ce`](https://github.com/nophead/NopSCADlib/commit/cbab9cea028a204032a91729597572a39ed893a2 "show commit") [C.P.](# "Chris Palmer") Fixed `M6_cs_cap_screw`.
 

readme.md

@@ -2030,6 +2030,7 @@ A permanent magnet that can be magnatized and de-magnatized electronically.
 | `opengrab_depth()` | Module height |
 | `opengrab_pcb()` | The PCB |
 | `opengrab_pcb_z()` | PCB offset from the front |
+| `opengrab_screw_depth()` | Max screw depth in pillars |
 | `opengrab_target_thickness()` | Target sheet thickness |
 | `opengrab_width()` | Module width |
 
@@ -2698,7 +2699,7 @@ Timing belt pulleys, both toothed and plain with internal bearings for idlers.
 ### Modules
 | Module | Description |
 |:--- |:--- |
-| `pulley(type, colour = silver)` | Draw a pulley |
+| `pulley(type, colour = silver)` | Draw a pulley, any children are placed above. |
 | `pulley_assembly(type, colour = silver)` | Draw a pulley with its grub screws in place |
 
 ![pulleys](tests/png/pulleys.png)
@@ -5833,6 +5834,7 @@ Maths utilities for manipulating vectors and matrices.
 | `circle_intersect(c1, r1, c2, r2)` | Calculate one point where two circles in the X-Z plane intersect, clockwise around c1 |
 | `cosh(x)` | hyperbolic cosine |
 | `coth(x)` | hyperbolic cotangent |
+| `cubic_real_roots(a, b, c, d)` | Returns real roots of cubic equation |
 | `degrees(radians)` | Convert degrees to radians |
 | `euler(R)` | Convert a rotation matrix to a Euler rotation vector. |
 | `identity(n, x = 1)` | Construct an arbitrary size identity matrix |
@@ -5840,6 +5842,7 @@ Maths utilities for manipulating vectors and matrices.
 | `map(v, func)` | make a new vector where the func function argument is applied to each element of the vector v |
 | `mapi(v, func)` | make a new vector where the func function argument is applied to each element of the vector v. The func will get the index number as first argument, and the element as second argument. |
 | `nearly_zero(x)` | True if x is close to zero |
+| `quadratic_real_roots(a, b, c)` | Returns real roots of a quadratic equation, biggest first. Returns empty list if no real roots |
 | `radians(degrees)` | Convert radians to degrees |
 | `reduce(v, func, unity)` | reduce a vector v to a single entity by applying the func function recursively to the reduced value so far and the next element, starting with unity as the initial reduced value |
 | `reverse(v)` | Reverse a vector |
@@ -5862,6 +5865,7 @@ Maths utilities for manipulating vectors and matrices.
 | `vec2(v)` | Return a 2 vector with the first two elements of `v` |
 | `vec3(v)` | Return a 3 vector with the first three elements of `v` |
 | `vec4(v)` | Return a 4 vector with the first three elements of `v` |
+| `xor(a,b)` | Logical exclusive OR |
 
 ### Modules
 | Module | Description |

utils/maths.scad

@@ -160,4 +160,30 @@ function mapi(v, func) = [ for (i = [0:len(v)-1]) func(i,v[i]) ]; //! make a new
 function reduce(v, func, unity) = let ( r = function(i,val) i == len(v) ? val : r(i + 1, func(val, v[i])) ) r(0, unity); //! reduce a vector v to a single entity by applying the func function recursively to the reduced value so far and the next element, starting with unity as the initial reduced value
 function sumv(v) = reduce(v, function(a, b) a + b, 0); //! sum a vector of values that can be added with "+"
 
-function xor(a,b) = (a && !b) || (!a && b);
+function xor(a,b) = (a && !b) || (!a && b);     //! Logical exclusive OR
+function cuberoot(x)= sign(x)*abs(x)^(1/3);
+
+function quadratic_real_roots(a, b, c) =        //! Returns real roots of a quadratic equation, biggest first. Returns empty list if no real roots
+    let(2a = 2 * a,
+        2c = 2 * c,
+        det = b^2 - 2a * 2c
+    ) det < 0 ? [] :
+        let(r = sqrt(det),
+            x1 = b < 0 ? 2c / (-b + r) : (-b - r) / 2a,
+            x2 = b < 0 ? (-b + r) / 2a : 2c / (-b - r)
+        ) [x2, x1];
+
+function cubic_real_roots(a, b, c, d) = //! Returns real roots of cubic equation
+    let(b = b / a,
+        c = c / a,
+        d = d / a,
+        inflection = -b / 3,
+        p = c - b^2 / 3,
+        q = 2 * b^3 / 27 - b * c / 3 + d,
+        det = q^2 / 4 + p^3 / 27,
+        roots = !p && !q ? 1 : nearly_zero(det) ? 2 :  det < 0 ? 3 : 1,
+        r = sqrt(det),
+        x = cuberoot(-q / 2 - r) + cuberoot(-q / 2 + r)
+    ) roots == 1 ? [x] :
+      roots == 2 ? [3 * q /p + inflection, -3 * q / p / 2 + inflection] :
+      [for(i = [0 : roots - 1]) 2 * sqrt(-p / 3) * cos(acos(3 * q * sqrt(-3 / p) / p / 2) - i * 120) + inflection];

vitamins/opengrab.scad

@@ -62,6 +62,7 @@ function opengrab_depth() = depth;                               //! Module heig
 function opengrab_target_thickness() = target;                   //! Target sheet thickness
 function opengrab_pcb() = pcb;                                   //! The PCB
 function opengrab_pcb_z() = depth - pillar - pcb_thickness(pcb); //! PCB offset from the front
+function opengrab_screw_depth() = 4;                             //! Max screw depth in pillars
 
 module opengrab() { //! Draw OpenGrab module
     vitamin("opengrab(): OpenGrab V3 electro permanent magnet");

vitamins/pulley.scad

@@ -53,7 +53,7 @@ function pulley_extent(type) = max(pulley_flange_dia(type), pulley_hub_dia(type)
 T_angle = 40;
 GT_r = 0.555;
 
-module pulley(type, colour = silver) { //! Draw a pulley
+module pulley(type, colour = silver) { //! Draw a pulley, any children are placed above.
     teeth = pulley_teeth(type);
     od = pulley_od(type);
 
@@ -138,6 +138,10 @@ module pulley(type, colour = silver) { //! Draw a pulley
         else
             core();
     }
+
+    if($children)
+        translate_z(pulley_height(type))
+            children();
 }
 
 module pulley_assembly(type, colour = silver) { //! Draw a pulley with its grub screws in place