using the mouse drag event to move the drawing on the canvas (#38)

this usefull for debuging or if you are trying to find a good starting point

sketch.js

@@ -3,6 +3,10 @@
 
 let editor;
 let turtle;
+let xOffset = 0;
+let yOffset = 0;
+let startX = 100;
+let startY = 100;
 let allCases;
 
 function preload() {
@@ -43,6 +47,8 @@ function execute(commands, repcount) {
 }
 
 function goTurtle() {
+  console.log({startX:startX,startY:startY});
+  turtle = new Turtle(startX, startY, 0);
   background(0);
   push();
   turtle.reset();
@@ -92,3 +98,14 @@ function createTestDataView(cases) {
     goTurtle();
   });
 }
+
+function mousePressed() {
+  xOffset = mouseX-startX; 
+  yOffset = mouseY-startX; 
+}
+
+function mouseDragged() {
+    startX = mouseX-xOffset; 
+    startY = mouseY-yOffset; 
+    goTurtle();
+}