When platformers first started appearing, on the early game consoles, they took a tile approach to their levels. Levels were split up into cells, and then each cell would be assigned an ID that would correspond to a tile in perhaps a texture atlas—ooh, we know about them! This had the great benefit of reducing the memory footprint, because you could build an entire level from just a handful of tiles, and that is exactly what we are going to do.
When we build our level out of tiles, we are going to need a tool to help us visualize the level as we go ahead. You could go and do it all by hand, drawing it on paper, noting IDs and cells, and then updating a text file somewhere; however, that will be slow and cumbersome—take it from someone who used to do that!
So what can we use? Well, I have always been fond of a free-to-use tool called Tiled (for more information, visit http://www.mapeditor.org/). It has an amazing feature set, multiple...