First pass at coordinate axes

Makefile

@@ -40,6 +40,7 @@ site/node_modules: node_modules package.json package-lock.json
 	cp package.json package-lock.json tmpproj
 	cd tmpproj && npm install --production
 	cp -r tmpproj/node_modules site
+	touch site/node_modules
 
 dyna3.zip: $(BLDTARGS)
 	zip -r $@ site

src/dyna3.litcoffee

@@ -5,11 +5,37 @@ When you load dyna3, you should initially see a three-dimensional coordinate sys
 
     import {threeLoaded, three as J3} from './externals.js'
 
+    LTx = { dashed: true, plain: false }
+
+    buildAxis = (to, color, tx) ->
+        geom = new J3.Geometry()
+        if tx then mat = new J3.LineDashedMaterial(
+                            {linewidth: 3, color, dashSize: 0.5, gapSize: 0.5})
+        else mat = new J3.LineBasicMaterial {linewidth:3, color}
+        geom.vertices.push(new J3.Vector3(0,0,0))
+        geom.vertices.push to.clone()
+        axis = new J3.Line geom, mat, J3.LineSegments
+        axis.computeLineDistances()
+        axis
+
+    axes = (length) ->
+        ax = new J3.Object3D()
+        dirs = [ new J3.Vector3(length, 0, 0),
+                 new J3.Vector3(0, length, 0),
+                 new J3.Vector3(0, 0, length) ]
+        cols = [ 0xFF0000, 0x00FF00, 0x0000FF ]
+        for i in [0, 1, 2]
+            ax.add buildAxis dirs[i], cols[i], LTx.plain
+            dirs[i].multiplyScalar(-1)
+            ax.add buildAxis dirs[i], cols[i], LTx.dashed
+        ax
+
     main = ->
         renderer = new J3.WebGLRenderer()
         rwd = window.innerWidth
         rht = window.innerHeight
         renderer.setSize rwd, rht
+        renderer.setClearColor 0xeeeeee, 1.0
         document.body.appendChild renderer.domElement
 
         scene = new J3.Scene()
@@ -17,6 +43,7 @@ When you load dyna3, you should initially see a three-dimensional coordinate sys
         material = new J3.MeshBasicMaterial {color: 0xff00ff}
         ball = new J3.Mesh geometry, material
         scene.add ball
+        scene.add axes 10
 
         camera = new J3.PerspectiveCamera 75, rwd/rht, 0.1, 1000
         camera.position.z = 5