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I'm new to PICO-8, and am trying to get a basic top-down movement system. So far I have this:

 ```left = btn(⬅️) right = btn(➡️) up = btn(⬆️) down = btn(⬇️) xspd = (num(right) - num(left)) * player.speed yspd = (num(down) - num(up)) * player.speed if fget(player.x + xspd, player.y) == 0 then xspd = 0 end if fget(player.x, player.y + yspd) == 0 then yspd = 0 end player.x = player.x + xspd player.y = player.y + yspd```

`num()` takes in a boolean, and outputs a number (true being 1, false being 0)
The problem I have, is that I'm trying to stop the player if they hit a wall (The wall's sprite having flag 0), and I'm not sure what to do. Does anyone know what's going on?

P#116747 2022-09-01 19:13

You are almost there. Read up on how fget works: https://pico-8.fandom.com/wiki/Fget

In short, you have to pass it a tile from the map. To do so, you can get the tile with mget: https://pico-8.fandom.com/wiki/Mget

The thing is, mget works in map cell coordinates, not on screen x and y coordinates, so you have to account for that.

Map collision is relatively simple when you are doing a point collision. If you are having a hard time grasping how to do this, I recommend you check this tutorial series: https://www.lexaloffle.com/bbs/?tid=35135 it's short and straight to the point and it explains a lot of the basics on pico-8.

Where things get a bit more complicated is when you are trying to achieve free movement, because then you can't just rely on a 1 point collision checking system. I wrote a couple of examples for this in the past, you might find them helpful:
https://www.lexaloffle.com/bbs/?pid=112642#p
https://www.lexaloffle.com/bbs/?pid=115726#p

P#116748 2022-09-01 19:25