selimanac / defold-tile-raycast

Ray Casting in tiled worlds using DDA algorithm.

Tile Raycast

Ray Casting in tiled worlds using DDA algorithm. It is very effective solution for tile based worlds like platformers or any top-down games.
This implementation based on https://lodev.org/cgtutor/raycasting.html and https://www.youtube.com/watch?v=NbSee-XM7WA

Installation

You can use Tiled Ray Cast in your own project by adding this project as a Defold library dependency. Open your game.project file and in the dependencies field under project add:

https://github.com/selimanac/defold-tile-raycast/archive/refs/heads/master.zip

Example

https://github.com/selimanac/defold-tile-raycast-platformer

API

raycast.init (tile_width, tile_height, tilemap_width, tilemap_height, tiles, target_tiles)

Initial setup for raycast.

PARAMETERS

• tile_width (int) - Single tile width
• tile_height (int) - Single tile height
• tilemap_width (int) - Tilemap width
• tilemap_height (int) - Tilemap height
• tiles (table) - Single dimensional tiles table generated from your tilemap (or from your source).
• target_tiles (table) - Not passible tile IDs from your tilesource (walls, grounds etc...).

EXAMPLE

	
    local tiles = {
		4,2,2,2,0,2,2,2,2,2,
		2,2,2,2,0,2,2,2,2,2,
		2,2,2,2,0,2,2,2,2,2,
		2,2,1,2,2,2,2,2,2,2,
		2,2,2,2,2,2,2,2,2,2,
		1,2,1,2,2,2,1,1,1,1,
		1,1,1,2,2,2,1,1,1,1,
		1,1,1,2,1,2,1,3,1,1,
		1,1,1,1,2,1,1,1,4,1,
		1,1,1,2,2,2,2,1,1,3,
        1,1,1,1,1,1,1,1,1,1  
	}

    local tile_width = 32
    local tile_height = 32
    local target_tiles = {2, 3, 4}
    local tilemap_width = 10
    local tilemap_height = 11

    raycast.init(tile_width, tile_height, tilemap_width, tilemap_height, tiles, target_tiles)

raycast.cast (ray_from, ray_to)

Perform raycast on tilemap. Returns only first successful hit.

PARAMETERS

• ray_from (Vector3) - Start position of ray
• ray_to (Vector3) - End position of ray

RETURN

• hit (boolean) - If hit or not
• tile_x (int) - ile x position
• tile_y (int) - Tile y position
• array_id (int) - ID of the array for Tilemap array
• tile_id (int) - ID of the tile from tilesource for Tilemap
• intersection_x (number) - Ray intersection point x
• intersection_y (number) - Ray intersection point y
• side (int) - Which side hit. 0 for LEFT-RIGHT, 1 for TOP-BOTTOM

EXAMPLE

	
    local ray_from = go.get_position(ray_start_url)
    local ray_to = go.get_position(ray_end_url)

    local hit, tile_x, tile_y, array_id, tile_id, intersection_x, intersection_y, side = raycast.cast(ray_from, ray_to)

     if hit then
        print("tile_x: " .. tile_x)
        print("tile_y: " .. tile_y)
        print("array_id " .. array_id)
        print("tile_id " .. tile_id)
        print("intersection_x " .. intersection_x)
        print("intersection_y " .. intersection_y)
        print("Side " .. side) -- 0 for LEFT-RIGHT, 1 for TOP-BOTTOM
    else
        print("No result found")
    end

raycast.reset ()

Clear all tile and timemap data.