Added NESPainter, which will handle the visible canvas drawing. Incorperated changes into main.js

app/js/NESPainter.js

+
+export class NESPainter { 
+  constructor(canvas){
+    this.__canvas = null;
+    this.__context = null;
+    this.__scale = 1.0;         // This is the scale the painter will display source information.
+    this.__offset = [0.0, 0.0]; // This is the X,Y offset from origin to display source information.
+
+    if (!canvas)
+      throw new Error("Expected a canvas element.");
+    this.__canvas = canvas
+    this.__context = this.__canvas.getContext("2d");
+    if (!this.__context)
+      throw new Error("Failed to obtain canvas context.");
+  }
+
+  get scale(){
+    return this.__scale;
+  }
+
+  set scale(s){
+    if (typeof(s) !== 'number')
+      throw new TypeError("Expected number value.");
+    this.__scale = Math.max(0.1, Math.min(100.0, s));
+  }
+
+  scale_up(amount=1){
+    this.scale = this.scale + (amount*0.1);
+  }
+
+  scale_down(amount=1){
+    this.scale = this.scale - (amount*0.1);
+  }
+}

app/js/main.js

+import {NESPainter} from "/app/js/NESPainter.js";
 import {NESPalette} from "/app/js/NESPalette.js";
 
-
 function initialize(DOC){
-  var canvas = DOC.getElementById("painter");
-  if (!canvas){
-    throw new Error("DOM Missing painter canvas.");
-  }
-  var ctx = canvas.getContext("2d");
-  if (!ctx){
-    throw new Error("Failed to obtain canvas context.");
-  }
+  var nespainter = new NESPainter(DOC.getElementById("painter"));
+  //if (!canvas){
+  //  throw new Error("DOM Missing painter canvas.");
+  //}
+  //var ctx = canvas.getContext("2d");
+  //if (!ctx){
+  //  throw new Error("Failed to obtain canvas context.");
+  //}
+
+  console.log(nespainter.scale);
+  nespainter.scale_up(5);
+  console.log(nespainter.scale);
 
   var nespal = new NESPalette();
   nespal.set_palette([