Change of plans + the beginnings of a toolset
So, after some thought, the fixed-vantage FPS idea has been ditched. Side scroller it is!
After spending too much time trying to add solid boundaries for the objects in the first room, I built a tool to help. It's a glorified line-drawing program which saves the boundaries to a JSON file, loaded later by the game. It turns this:
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Into this:
{"solids": [[[100.0, 240.0], [160.0, 240.0], [250.0, 330.0], [190.0, 330.0]]......