WebGL: 3D application development - HTML5 in Action - page 409

Listing 9.17. core.js—Vlad Vukićević utilities
Progress check!
Run index.html now and check your browser's console. You should see the screen shown
in figure 9.7 , possibly without the missing-file error. If you get additional errors or have
trouble with your engine's code as you proceed, you might find it easier and less frustrating
to replace the engine files with chapter 9 ' s source code instead of debugging files. Debug-
ging WebGL is a bit of a nightmare because browsers don't have easily accessible graphic
monitoring tools.