Transport Fever 2 circle on a map

file.lua

local halfX = params.mapSizeX / 2
local halfY = params.mapSizeY / 2

result.layers:Constant(result.heightmapLayer, -10)

local pi = 3.1415923

local mapEdge = 10

local p = {}
local radius = math.min(halfX, halfY) - mapEdge
local circleSteps = 50
for a = 0, circleSteps do
  local angle = pi * 2 / circleSteps * a
  p[#p + 1] = {halfX + radius * math.cos(angle), halfY + radius * math.sin(angle)}
end

-- local data =
local blob = {}
for x = 0, params.mapSizeX - 1 do
  for y = 0, params.mapSizeY - 1 do
    if polygonutil.contains(p, {x, y}) then
      blob[#blob + 1] = {x, y}
    end
  end
end

result.layers:Points(result.heightmapLayer, blob, 1)