Documented xor() function.

CHANGELOG.md

@@ -3,6 +3,12 @@
 This changelog is generated by `changelog.py` using manually added semantic version tags to classify commits as breaking changes, additions or fixes.
 
 
+### [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 |
 
@@ -5862,6 +5863,7 @@ 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 +160,5 @@ 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);

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");