wizard-wipeout/src-server/Server/Map.hs

module Server.Map where

import qualified Data.Matrix as M
import System.Random

import Library.Types
import Server.Map.Snippets

-- | This function procedurally generates the Arena for the game
generateArena
  :: Int   -- ^ Map's width
  -> Int   -- ^ Map's height
  -> Float -- ^ Probability for a tile to be an item spawner
  -> IO Arena -- ^ resulting Arena
generateArena arenaWidth arenaHeight spawnerChance = do
  undefined

-- | Generate basic Map of Air and Walls
generateMap
  :: Int    -- ^ Map's width
  -> Int    -- ^ Map's height
  -> IO Map -- ^ resulting Map
generateMap mapWidth mapHeight = do
  let initMap = M.matrix mapWidth mapHeight (const Air)
  divide 0 0 mapHeight mapWidth initMap
  where
    divide :: Int -> Int -> Int -> Int -> Map -> IO Map
    divide rowOffset colOffset rowSize colSize tilemap
      | rowSize <= 3 || colSize <= 3 = pure tilemap
      | otherwise                    = do
        -- position wall intersection at random
        crossRow <- randomRIO (2, rowSize - 1)
        crossCol <- randomRIO (2, colSize - 1)

        -- position wall passages at random wall tiles
        rowHole1 <- randomRIO (1, crossRow - 1)
        rowHole2 <- randomRIO (crossRow + 1, rowSize - 1)
        colHole1 <- randomRIO (1, crossCol - 1)
        colHole2 <- randomRIO (crossCol + 1, colSize - 1)

        -- determine all possible passages
        let holes =
              [ (rowHole1, crossCol)
              , (rowHole2, crossCol)
              , (crossRow, colHole1)
              , (crossRow, colHole2)
              ]

        -- drop one of the passages randomly
        -- randomDropIndex <- randomRIO (0, length allHoles - 1)
        let -- randomDrop = allHoles !! randomDropIndex
            -- holes = filter (/= randomDrop) allHoles

            crossedMap = M.mapPos
              (\(r, c) tile ->
                if (r - rowOffset == crossRow || c - colOffset == crossCol) &&
                  (r - rowOffset <= rowSize || c - colOffset <= colSize)
                then if (r - rowOffset, c - colOffset) `elem` holes
                  then Air
                  else Wall
                else tile
                )
              tilemap

        divide rowOffset colOffset (crossRow - 1) (crossCol - 1) =<<
          divide rowOffset (colOffset + crossCol + 1) (crossRow - 1) (colSize - crossCol - 1) =<<
            divide (rowOffset + crossRow + 1) colOffset (rowSize - crossRow - 1) (crossCol - 1) =<<
              divide
                (rowOffset + crossRow + 1)
                (colOffset + crossCol + 1)
                (rowSize - crossRow - 1)
                (colSize - crossCol - 1)
                crossedMap