Canvas element

The graphical output in the freecode editor uses the html canvas element with WebGL. If you can not see any contents in the canvas make sure that your browser supports WebGL and that it is enabled. In Chrome for Windows it might help to enter chrome://flags/ and enable the "Override software rendering list" setting.

When you are creating your own implementation this document (that is also linked in the creator) can give you an overview of what is possible and how it is done. https://app.futureskill.com/media/freecode_graphics_v3.pdf