fix(center): Correcting center() functionality (#97)

* Corrected center() and updated tests suites
* Removed centering mutators (UG)
* Added center() proper, which was added by mutators previously
* Cleaned up, and added options.center to center upon a given point
* Updated to determine arrays using Array.isArray()
* Corrected argument passing to centerV2()
* JSDOC changes

Author: z3dev

csg.js

@@ -192,9 +192,6 @@ addTransformationMethodsToPrototype(CAG.prototype)
 addTransformationMethodsToPrototype(CAG.Side.prototype)
 addTransformationMethodsToPrototype(CAG.Vertex.prototype)
 
-addCenteringToPrototype(CSG.prototype, ['x', 'y', 'z'])
-addCenteringToPrototype(CAG.prototype, ['x', 'y'])
-
 CSG.parseOptionAs2DVector = optionsParsers.parseOptionAs3DVector
 CSG.parseOptionAs3DVector = optionsParsers.parseOptionAs3DVector
 CSG.parseOptionAs3DVectorList = optionsParsers.parseOptionAs3DVectorList

src/api/center.js

@@ -1,23 +1,33 @@
 const toArray = require('../core/utils/toArray')
 
-/** NOTE: this is not functional YET !!
- * centers the given object(s) on the given axis
- * @param {Object|Array} object(s) the shapes to center
- * @param {Object} options
+/**
+ * Centers the given object(s) using the given options (if any)
+ * @param {Object} [options] - options for centering
+ * @param {Array} [options.axes=[true,true,true]] - axis of which to center, true or false
+ * @param {Array} [options.center=[0,0,0]] - point of which to center the object upon
+ * @param {Object|Array} objects - the shape(s) to center
+ * @return {Object|Array} objects
+ *
+ * @example
+ * let csg = center({axes: [true,false,false]}, sphere()) // center about the X axis
  */
-const center = (objects, options) => {
+const center = function (options, objects) {
   const defaults = {
-    axes: [1, 1, 1]
+    axes: [true, true, true],
+    center: [0, 0, 0]
+  // TODO : Add addition 'methods' of centering; midpoint, centeriod
   }
   options = Object.assign({}, defaults, options)
-  const {axes} = options
+  const {axes,center} = options
   objects = toArray(objects)
 
   const results = objects.map(function (object) {
-    let b = object.getBounds()
-    return object.translate(axes.map(function (a) {
-      return cAxes.indexOf(a) > -1 ? -(b[0][a] + b[1][a]) / 2 : 0
-    }))
+    let bounds = object.getBounds()
+    let offset = [0,0,0]
+    if (axes[0]) offset[0] = center[0] - (bounds[0].x + ((bounds[1].x - bounds[0].x) / 2))
+    if (axes[1]) offset[1] = center[1] - (bounds[0].y + ((bounds[1].y - bounds[0].y) / 2))
+    if (axes[2]) offset[2] = center[2] - (bounds[0].z + ((bounds[1].y - bounds[0].y) / 2))
+    return object.translate(offset)
   })
   // if there is more than one result, return them all , otherwise a single one
   return results.length === 1 ? results[0] : results

src/api/ops-transformations.js

@@ -118,15 +118,17 @@ function transform (matrix, ...objects) { // v, obj or array
   return object.transform(transformationMatrix)
 }
 
-/** center an object in 2D/3D space
- * @param {Boolean|Array} axis - either an array or single boolean to indicate which axis you want to center on
- * @param {Object(s)|Array} objects either a single or multiple CSG/CAG objects to translate
+
+/**
+ * Center the given object(s) about the given axes
+ * @param {Array|Boolean} axes=[true,true,true]|true  - an array of boolean values that indicate the axes (X,Y,Z) to center upon. A single boolean is also allowed.
+ * @param {...Object} object one or more objects to center, i.e. objects are CSG or CAG
  * @returns {CSG} new CSG object , translated by the given amount
  *
  * @example
- * let movedSphere = center(false, sphere())
+ * let csg = center([true,false,false], sphere()) // center about the X axis
  */
-function center (axis, ...objects) { // v, obj or array
+function center (axes, ...objects) {
   const _objects = (objects.length >= 1 && objects[0].length) ? objects[0] : objects
   let object = _objects[0]
 
@@ -135,7 +137,10 @@ function center (axis, ...objects) { // v, obj or array
       object = object.union(_objects[i])
     }
   }
-  return object.center(axis)
+  if (! Array.isArray(axes)) {
+    axes = [axes,axes,axes]
+  }
+  return object.center(axes)
 }
 
 /** mirror an object in 2D/3D space

src/api/ops-transformations.test.js

@@ -185,7 +185,7 @@ test('transform (multiple items, 2d , translation)', t => {
 test('center (single item)', t => {
   const op1 = cube()
   const obs = center(true, op1)
-  t.deepEqual(obs.properties.cube.center, {_x: 0.5, _y: 0.5, _z: 0.5})
+  t.deepEqual(obs.properties.cube.center, {_x: 0, _y: 0, _z: 0})
 })
 
 test('center (multiple item)', t => {
@@ -201,8 +201,8 @@ test('center (multiple items, 2d)', t => {
   const op2 = circle()
   const obs = center(true, op1, op2)
 
-  sideEquals(t, obs.sides[0], [[1.9807852804032304, 0.8049096779838713], [2, 1]])
-  sideEquals(t, obs.sides[obs.sides.length - 1], [[0, 0], [0.9999999999999998, 0]])
+  sideEquals(t, obs.sides[0], [[0.9807852804032304, -0.19509032201612875], [1, 0]])
+  sideEquals(t, obs.sides[obs.sides.length - 1], [[-1, -1], [-2.220446049250313e-16, -1]])
 })
 
 test('mirror (single item)', t => {

src/core/CAG.js

@@ -16,6 +16,7 @@ const {area, getBounds} = require('./utils/cagMeasurements')
 const {overCutInsideCorners} = require('../api/ops-cnc')
 const {extrudeInOrthonormalBasis, extrudeInPlane, extrude, rotateExtrude} = require('../api/ops-extrusions')
 const cagoutlinePaths = require('../api/cagOutlinePaths')
+const center = require('../api/center')
 const {expand, contract, expandedShellOfCAG} = require('../api/ops-expandContract')
 /**
  * Class CAG
@@ -101,6 +102,11 @@ CAG.prototype = {
     return fromSides(newsides)
   },
 
+  // ALIAS !
+  center: function (axes) {
+    return center({axes: axes}, [this])
+  },
+
   // ALIAS !
   expandedShell: function (radius, resolution) {
     return expandedShellOfCAG(this, radius, resolution)

src/core/CSG.js

@@ -16,6 +16,7 @@ const {projectToOrthoNormalBasis} = require('./utils/csgProjections')
 
 const {lieFlat, getTransformationToFlatLying, getTransformationAndInverseTransformationToFlatLying} = require('../api/ops-cnc')
 const {sectionCut, cutByPlane} = require('../api/ops-cuts')
+const center = require('../api/center')
 const {expand, contract, expandedShellOfCCSG} = require('../api/ops-expandContract')
 
 /** Class CSG
@@ -267,6 +268,11 @@ CSG.prototype = {
     return result
   },
 
+  // ALIAS !
+  center: function (axes) {
+    return center({axes: axes},[this])
+  },
+
   // ALIAS !
   expand: function (radius, resolution) {
     return expand(this, radius, resolution)