Load Specific Terrain

local sprite = require "sprite"
local terrain = require("terrain")("field.png", 60, {"grass", "dirt", "rock"})

return function(size, columns, rows)
    local map = display.newGroup()
    map.Tiles = {}
    for row=-1,rows do
        map.Tiles[row] = {}
        for column=-1,columns do
            local tile = sprite.newSprite(terrain)
            tile:setReferencePoint(display.TopLeftReferencePoint)
            map:insert(tile)
            tile.xScale, tile.yScale = size / tile.width, size / tile.height
            tile.x, tile.y = column * size, row * size
            map.Tiles[row][column] = tile
        end
    end
    return map
end