Love2D and 'Tiled' - Detect if player is over certain tile/Collision

I created a 50x50 tile map with 32x32 tiles in Tiled and exported it as a Lua file so I can use it in Love2D. I have a player you can move around the world but I'm attempting to convert the player's x and y to where it is corresponding to the tile map and check if that position contains a wall. Tiled's exported map stores the map data in a 1 dimensional array like so...

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}


This makes it where I can't reference the data like data[playerX][playerY] So I just multiplied the values data[playerX*playerY] This is basically what I implemented (mapX and mapY are the player's x and y corresponding to the map)

mapX = math.floor(player.x / 32)
mapY = math.floor(player.y / 32)


and then before I get player input I check if the player's location in regards to the map contains '2' because that resembles a wall in the map data

if map.layers[3].data[mapX*mapY] ~= 2 then
...check input


The player's mapX and mapY do not seem to be correct because it's values never seem to be actually corresponding accurately with the map. Any ideas on doing this a different way or fixing this? If you need more detailed code, please ask.

1 Answer

Indexing a 2D array represented as a 1D array is done like this:

index = x + y * width


Where width is sometimes known as stride.

For more information see https://opengamingalliance.org/wiki_2/index.php/Indexing_into_2D_arrays

• It should be noted though, that since Lua arrays are 1-based instead of 0-based, the expression becomes index = x + y * width + 1. – Thorbjørn Lindeijer Feb 8 '17 at 7:24