dcearth/cities.lua

--Load and save the fixed width plaintext data used by DEFCON.
local t = {}
local io = io
local math = math
local table = table
local tonumber = tonumber
local lfs = love.filesystem
local lg = love.graphics
local locationQuery = require 'locationQuery'
local cities
local points = {}
local caps = {}

t.selected = nil
t.selectionLocked = false

function t.lockSelection()
  t.selectionLocked = true
end

function t.unlockSelection()
  t.selectionLocked = false
end

function t.draw()
  return lg.points( points )
end

function t.drawSelected( )
  local c  = t.selected
  if not c then return end
  lg.circle( "line", c.x, c.y, 1.0 )
end

function t.drawCapitals()
  if cities.visible then lg.points( caps ) end
end

function t.selectNearest( cities, x, y )
  return cities:getClosestPoint(x, y)  --defer to locationQuery
end

local city = {}
local citymt = {__index = city}
function city:formatDisplayInfo()
  return (
    [[
  NAME:    %s
  COUNTRY:   %s
  LONGITUDE: %3.2f
  LATITUDE:  %3.2f
  POP:       %d
  CAPITAL:   %s]]):format( self.name, self.country, self.x, self.y, self.pop, tostring(self.capital) )
end

function t.load( filename )
  
  print( "=== LOADING CITIES. ===" )

  cities = { visible = true, active = false, filename = filename }
  local n = 1
  local idxPts = 1
  local idxCaps = 1
  points = {}
  caps = {}

  for line in assert( lfs.lines( filename ), "Error: could not open cities.dat" ) do

    local _, _, x, y, pop, capital = line:sub( 83 ):find( "(%g+)%s+(%g+)%s+(%g+)%s+(%g+)" )
    if capital then --check against empty or malformed line
      x, y, pop, capital = tonumber( x ), tonumber( y ), tonumber( pop ), ( tonumber( capital ) > 0)
      local city = setmetatable({
        name = line:sub( 1, 39 ):gsub("%s+$",""),
        country = line:sub( 42, 82 ):gsub("%s+$",""),
        x = x, y = y, pop = pop, capital = capital
      }, citymt )
      cities[n]  = city
      n = n + 1

      points[idxPts], points[idxPts + 1] = x, y
      idxPts = idxPts + 2

      if capital then
        caps[idxCaps], caps[idxCaps + 1] = x, y
        idxCaps = idxCaps + 2
      end
    else
      print( "CITIES: malformed line:", line )
    end
  end

  --Multiple inheritance.
  cities = locationQuery.New( cities )
  setmetatable( getmetatable( cities ).__index, {__index = t } )

  print( "=== CITIES LOADED:", filename, n, "===" )
  return cities
end

function t.save( cities )
  local str = {}
  for n, city in ipairs( cities ) do
    str[n] = ("%-41s%-41s%-14f%-14f%-19d %d"):format(
      city.name, city.country, city.x, city.y, city.pop, city.capital and 1 or 0 )
  end
  return assert(table.concat( str, "\n" ))
end

return t