From 9f68fb41dc5456eb849718339e02afcc2f60f868 Mon Sep 17 00:00:00 2001
From: Ian Gulliver <flamingcow@gmail.com>
Date: Sun, 25 Dec 2016 12:57:32 -0800
Subject: [PATCH] Initial coords for Cube

---
 fcad/coord.scad |  4 +++-
 fcad/cube.scad  |  4 ++++
 fcad/model.scad | 28 +++++++++++++++++++++++++++-
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/fcad/coord.scad b/fcad/coord.scad
index 86287bf..08ab285 100644
--- a/fcad/coord.scad
+++ b/fcad/coord.scad
@@ -1,7 +1,9 @@
 // Short for "coordinate system", including translation, rotation, and scale
 // coord:
 //   fKeyType "type" fType(): fTypeCoord "coord"
-//   fKeyTranslation "translation" fCoordTranslation():
+//   fKeyTranslation "translation" fCoordTranslation(): [ x, y, z ]
+//   fKeyRotation "rotation" fCoordRotation(): [ x, y, z ]
+//   fKeyScale "scale" fCoordScale(): [ x, y, z ]
 
 fTypeCoord = "coord";
 
diff --git a/fcad/cube.scad b/fcad/cube.scad
index ce843bd..0297ccf 100644
--- a/fcad/cube.scad
+++ b/fcad/cube.scad
@@ -11,6 +11,10 @@ function fCube(dims) = (
       [4, 5, 7, 6], // +x
       [2, 6, 7, 3], // +y
       [1, 3, 7, 5], // +z
+    ],
+    coords=[
+      [ "/x+,/y+,-z+", fCoord(translation=[x / 2, y / 2, 0]) ],
+      [ "/x+,/y+,+z+", fCoord(translation=[x / 2, y / 2, z]) ],
     ]
   )
 );
diff --git a/fcad/model.scad b/fcad/model.scad
index 38ee1ae..c03a527 100644
--- a/fcad/model.scad
+++ b/fcad/model.scad
@@ -2,6 +2,14 @@
 ///   fKeyType "type" fType(): fTypeModel "model"
 ///   fKeyPoints "points" fModelPoints(): [ [x, y, z], ... ]
 ///   fKeyFaces "faces" fModelFaces(): [ [ pointIdx, ... ], ... ]
+///   fKeyCoords "coords" fModelCoords(): [ [ name, coord ], ... ]
+
+/// Standard model coords names:
+///
+///   [-/+] edge ("/" is midpoint)
+///   [xyz] axis
+///   [-+]  direction
+///   [-/+]x[-+],[-/+]y[-+],[-/+]z[-+]
 
 fTypeModel = "model";
 
@@ -11,12 +19,14 @@ function fIsModel(x) = (
 
 fKeyPoints = "points";
 fKeyFaces = "faces";
+fKeyCoords = "coords";
 
-function fModel(points, faces) = (
+function fModel(points, faces, coords=[]) = (
   [
     [fKeyType, fTypeModel],
     [fKeyPoints, points],
     [fKeyFaces, faces],
+    [fKeyCoords, coords],
   ]
 );
 
@@ -27,3 +37,19 @@ function fModelPoints(model) = (
 function fModelFaces(model) = (
   fMapLookup(fKeyFaces, model)
 );
+
+fCoordAliases = [
+  [ "bottom", "/x+,/y+,-z+" ],
+  [ "top",    "/x+,/y+,+z+" ],
+  [ "center", "/x+,/y+,/z+" ],
+];
+
+function fModelCoords(model) = (
+  fMapLookup(fKeyCoords, model)
+);
+
+function fModelCoord(model, name) = (
+  let(alias = fMapLookup(name, fCoordAliases),
+      realName = alias ? alias : name)
+  fMapLookup(realName, fModelCoords(model))
+);