Guide Layer and Guides

Hi, I'm finding that I need to have guides when developing levels. I.e knowing how far a character can jump, the visible region of the screen, range of sight for an enemy. etc.

It would be great if I could create "guide" layers, which let you create guided shapes (lines, rulers, rectangles, circles etc.) and allow you to move them around the map. It's a very time consuming process creating levels and there's a lot of "guess work" involved when you don't know exactly what your game variables look like on the map. Having guides would allow this data to become visible and speed up the level creation process. For example, knowing how far and high a player can jump, I could make sure the level geometry worked and fine tune problem areas.

The issue does not name files, tests, or entry points. Start by locating the map editor's layer and shape-editing code, then determine how guide layers should be created, moved, displayed, and persisted. Done means level authors can place the requested guide shapes and use them to visualize game-specific measurements on a map.

Written by the indexing model from the issue text.