itch.io

Yes, it's the sprite stacking loop that is easily the most intensive thing in the entire game. This is why sprite stacking is not a commonly seen method in games, it's inherently an unoptimized method of drawing things even using a shader, but I am pulling out all the stops that I can to optimize the effect because I want to use it regardless of its inefficiency. building_parent is what every single building object is connected to for the most part, they all execute that code block with the calculations and I refrain from using the two drawing scripts you found because calling scripts is more intensive than doing it in each object manually. The reason your FPS jumps up by 40% is it's simply drawing far fewer sprites when you set the For loop to 4 and thus calls the draw_sprite_ext command less. For some taller buildings which are around 30-50 sprites I plan on cutting them down and increasing their skew angle to save some CPU.

Perspective must be calculated every single frame because the camera is tied to the view, so pre-rendering each building is unfortunately not an option.

P.S. You can keep tinkering but please do not post images of the full code, the source code is not public.