[Solved] Empty space in tile grid?

[Ryne]

Hi, I was wondering if there was a way to have an empty space in a tile grid without using a transparent tile? I would like to have an empty grid, and just place tiles where I would want platforms, since I'm making a platformer.

[kikito]

Sure. It depends a lot on your code, though. Are you using the tile tutorial?

If so, then you must assign one of the 'numbers' of the map to the empty tile. Assuming that you assign them to 0, you can do this:

Code: Select all

function draw_map()
   for y=1, map_display_h do
      for x=1, map_display_w do                                                        
         if map[y+map_y][x+map_x] ~= 0 -- transparent tiles (0) are ignored
           love.graphics.draw(
              tile[map[y+map_y][x+map_x]],
              (x*tile_w)+map_offset_x,
              (y*tile_h)+map_offset_y )
         end
      end
   end
end

[Ryne]

Great!, thanks again . I might as well ask here before posting another thread, but I would like to spawn a player sprite into a grid coordinate. I'm not sure if that is as easy as it sounds. For example. To draw an animated sprite at a screen coordinate I would use this code:

Code: Select all

anim:draw(100,329)

My first instinct was to try and place the unit into the grid using

Code: Select all

anim:draw(map[1], map[3])

or

Code: Select all

anim:draw(#map[1], #map[3])

but apparently neither of these work. I was also thinking of a more complicated way that would involve converting grid coordinates into screen coordinates but I'm unsure of how to go about doing it. Any Ideas?

[zac352]

Great!, thanks again . I might as well ask here before posting another thread, but I would like to spawn a player sprite into a grid coordinate. I'm not sure if that is as easy as it sounds. For example. To draw an animated sprite at a screen coordinate I would use this code:

Code: Select all

anim:draw(100,329)

My first instinct was to try and place the unit into the grid using

Code: Select all

anim:draw(map[1], map[3])

or

Code: Select all

anim:draw(#map[1], #map[3])

but apparently neither of these work. I was also thinking of a more complicated way that would involve converting grid coordinates into screen coordinates but I'm unsure of how to go about doing it. Any Ideas?

Shouldn't you multiply the position by the tilesize, then subtract the camera?

[kikito]

Usually a mapToWorld and a worldToMap function would be quite useful in general. I'm a bit surprised that the tutorial itself doesn't include that.

Coding real quick and without testing anything at all:

Code: Select all

function mapToWorld(x,y)
    return (x*tile_w)+map_offset_x, (y*tile_h)+map_offset_y )
end
function worldToMap(x,y)
    return math.floor((x - map_offset_x) / tile_w), math.floor((y - map_offset_y) / tile_y) 
end

Then you can use them like this:

Code: Select all

-- transform the coordinates of cell 1,4 into world coordinates
local x,y = mapToWorld(1,4)

-- get the indexes of the cell that holds the coordinates x=200, y=300
local cx,cy = worldToMap(200, 300)

You can actually use mapToWorld to simplify the drawing loop:

Code: Select all

function draw_map()
   for y=1, map_display_h do
      for x=1, map_display_w do                                                       
         if map[y+map_y][x+map_x] ~= 0 -- transparent tiles (0) are ignored
           love.graphics.draw( tile[map[y+map_y][x+map_x]], mapToWorld(x,y)) -- calculations are done inside mapToWorld
         end
      end
   end
end

Now, to answer Ryne's question, in order to draw an animation in cell {3,10} he could do:

Code: Select all

anim:draw(mapToWorld(3,10))

Again, I warn you that the code above is completely untested.

PS: "world", not "screen". In the future you might want to add scrolling.

[Ryne]

Usually a mapToWorld and a worldToMap function would be quite useful in general. I'm a bit surprised that the tutorial itself doesn't include that.

Alright, that makes a lot of sense, thanks a lot for the help guys. I'll post my project once I get a little more finished.