LDtk example

[SueHeir]

Hello! I am trying to implement a flowfield from data from the LDtk tiled plugin, and I think I'm getting very confused about the origin/grid system.

the size of the map is a square with 512 pixels.

Right now I have GridCoords for each tile that needs its cost value set to 255. But I am getting the following error. Is get_sector_and_field_cell not using world coords for its input?

let mut flow_field = FlowFieldTilesBundle::new(width as u32 * grid_size as u32, height as u32 * grid_size as u32, width as u32 *grid_size as u32, 10.0);


for level_wall in level_walls {

    let x =  (grid_size as f32 * level_wall.x as f32);
    let y =  (grid_size as f32 * level_wall.y as f32);
    
    if let Some((sector_id, field_cell)) = flow_field.map_dimensions.get_sector_and_field_cell_from_xy(Vec2::new(x, y)) {
        flow_field.sector_cost_fields.set_field_cell_value(sector_id, 255, field_cell, &flow_field.map_dimensions);
    }
}

2025-02-11T05:38:52.153072Z ERROR bevy_flowfield_tiles_plugin::flowfields::sectors: Position is out of bounds of MapDimensions, x 464, y 112, cannot calculate SectorID. Is the actor outside of the map or trying to request route outside of it?

[BlondeBurrito]

So I'm not very familiar with LDtk but I'm assuming it's producing a 2d grid of sprites?

If that's the case then you should be able to determine:

• Number of columns
• Number of rows
• Size of each sprite

So then the bundle inputs:

• map_length = number_of_columns * sprite_size
• map_depth = number_of_rows * sprite_size
• sector_resolution decides how granular the Flowfields are and typically you'll want to maintain ratios between sprite size and column/row numbers (I need to tidy docs around this as it does tend to be confusing). Convention: A Sector is a 10x10 grid of FieldCells, example, if you have a 512pixel * 512pixel world and use a resolution of 256 then you'll have a sector representation of 2x2 (512 / 256 = 2). In terms of FieldCell a 2x2 Sectors means 20x20 FieldCells. The 512x512 size doesn't fit very nicely into a 20x20 representation. It's probably best to calculate it from the ground up, e.g, if the sprites have dimensions 32x32, and the world is made of columns-rows 30x30, then map length/depth is 32 * 30 = 960, and resolution is simply the size of a single sector 32 * 10 = 320. Meaning there'll be 3x3 sectors and a FieldCell matches sprite size of 32x32
• Note just in case actor_size must be less than 10 * sprite_size

Hopefully that helps, if it's still misbehaving feel free to share what width, height, grid_size and your sprite size you've tried in your code and I can probably come up with a recommended resolution value/some guidance