main.lua

local sti = require("sti")
local gamera = require("gamera")
--love.window.setFullscreen(true)

-- create a new orthogonal map that is 64x64 tiles, each tile is 32x32 pixels
local map = {
  orientation = "orthogonal",
  width = 64,
  height = 64,
  tilewidth = 32,
  tileheight = 32,
  tilesets = {},
  layers = {}
}

-- create a tileset from an image (Liberated Pixel Cup terrain_atlas.png from opengameart.org)
local tileset = {
  name = "terrain_atlas",
  firstgid = 1,
  tilewidth = 32,
  tileheight = 32,
  spacing = 0,
  margin = 0,
  image = "terrain_atlas.png",
  imagewidth = 1024,
  imageheight = 1024,
  tileoffset = {x = 0, y = 0},
  tilecount = 1024,
  tiles = {}
}
table.insert(map.tilesets, tileset)

-- create a layer of the map, with the same height/width as the map
function addLayer(map, name)
  local layer = {
    type = "tilelayer",
    name = name,
    x = 0,
    y = 0,
    width = 64,
    height = 64,
    visible = true,
    opacity = 1,
    offsetx = 0,
    offsety = 0,
    properties = {},
    encoding = "lua",
    data = {}
  }
  table.insert(map.layers, layer)
  return layer
end
local layer = addLayer(map, "grass")

-- populate the layer with a default tile ID
function populateLayer(layer, tile_id)
  for i=1, layer.width * layer.height do
    table.insert(layer.data, tile_id)
  end
end

-- helper function to get the ID of a tile from the tileset using x,y coordinates
function getTileID(tileset, x, y)
  local width = tileset.imagewidth / tileset.tilewidth
  return x + y * width + 1 -- +1 because Tile ID 0 represents an empty tile
end

-- create a grass background layer
local grass_tile_id = getTileID(tileset, 22, 3)
populateLayer(layer, grass_tile_id)

-- helper function to set a tile in the layer based on x,y coordinates
function setTile(layer, x, y, tile_id)
  layer.data[x + y * layer.width + 1] = tile_id -- +1 because Tile ID 0 represents an empty tile
end

-- create a layer for the path
local path_layer = addLayer(map, "path")
populateLayer(path_layer, 0)

for x=0, path_layer.width - 1 do
  setTile(path_layer, x, 5, getTileID(tileset, 19, 2))
  setTile(path_layer, x, 6, getTileID(tileset, 19, 3))
  setTile(path_layer, x, 7, getTileID(tileset, 19, 4))
end

-- create a layer for objects like
local objects_layer = addLayer(map, "objects")
populateLayer(objects_layer, 0)
setTile(objects_layer, 1, 1, getTileID(tileset, 30, 0))
setTile(objects_layer, 2, 1, getTileID(tileset, 31, 0))
setTile(objects_layer, 1, 2, getTileID(tileset, 30, 1))
setTile(objects_layer, 2, 2, getTileID(tileset, 31, 1))
setTile(objects_layer, 1, 3, getTileID(tileset, 30, 2))
setTile(objects_layer, 2, 3, getTileID(tileset, 31, 2))
setTile(objects_layer, 1, 4, getTileID(tileset, 30, 3))
setTile(objects_layer, 2, 4, getTileID(tileset, 31, 3))
setTile(objects_layer, 1, 5, getTileID(tileset, 30, 4))
setTile(objects_layer, 2, 5, getTileID(tileset, 31, 4))

local tileMap = sti(map)
local w, h = tileMap.tilewidth * tileMap.width, tileMap.tileheight * tileMap.height
local camera = gamera.new(0, 0, w, h)

function love.draw()
  local dt = love.timer.getDelta()
  camera:draw(function(l, t, w, h)
    tileMap:update(dt)
    tileMap:setDrawRange(-l, -t, w, h)
    tileMap:draw()
  end)
end