Building a command line tool to design a farm layout in Stardew Valley, Hacker News

By John Lekberg on February , .

This week’s post will cover a command line tool that helps you play the video game

Stardew Valley .

Stardew Valley is a farming game (like Harvest Moon . You can manually water your crops, or you can use sprinklers to automate the process.

I wrote a Python script, sprinkler-layout , that designs a layout of sprinklers for me, for a given number of sprinklers (eg sprinklers). The goals of the layout are:

water as much land as possible. have a reasonably small perimeter.



 sprinkler-layout 

  #! / usr / bin / env python3  import itertools   class Layout:     “A layout of sprinklers on a grid.”      def __init __ (self):         self._sprinklers=set ()         self._watered_squares=set ()      @classmethod     def generate (cls, *, num_sprinklers, coordinates):         Generate a layout, given:          - how many sprinklers to place.         - which positions to attempt to place them at.          “”         layout=cls ()          while layout.count_sprinklers ()  -radius:             yield x, y             y -=1         while x> -radius:             yield x, y             x -=1         while y     $ sprinkler-layout --help      Usage: sprinkler-layout [-h] --sprinklers N  generate a layout of sprinklers for Stardew Valley.  optional arguments:   -h, --help show this help message and exit   --sprinklers N the number of sprinklers to place     I'm starting a new farming season in Stardew Valley and I have  sprinklers available. I use  sprinkler-layout  to design a layout: 

    $ sprinkler-layout --sprinklers 32      sprinklers  watered squares  (x)  squares, including perimeter wall  square perimeter map of sprinklers (3 by 3 blocks)   ... ... ... ... ..  ... ... ... #.  .. # .. # ... ... ..   ... ... #. .. # ..  ... # .. ... # .. ..  #. .. # ... ... ..   ... ... .. # .. # ..  ... # .. # .. ... ..  #. ... ... #. ..   ... .. # .. # ... ..  ... # .. ... ... #.  ... ... # .. # .. ..   .. # ... ... .. # ..  .... #. ...  ... ... ... ... ..    Then: 
   I construct the required materials  squares of walls for the perimeter).  I clear out enough space for the layout (a grid of  by  (squares).  I place sprinklers as shown in the layout ( # ).  I place the walls around the perimeter.  I use a custom class,  Layout , to represent a sprinkler layout.  Layout  manages the internal state of: 
   Where sprinklers have been placed.   Which positions are watered by the placed sprinklers.    Layout  (has a) (class method) ,  generate , that attempts to position sprinklers by choosing from given positions.  generate  uses a  greedy strategy  to place the sprinklers: 
   Loop until I have placed enough sprinklers:   Get the next position to try. 
  If I can place a sprinkler at this position, do it. 
    I check if I can place a sprinkler by using  sets  of coordinates and checking that these sets are  disjoint : 
   the set of the new sprinkler and its watered squares.   the set of already placed sprinklers and their watered squares. 
  I have a generator function,  spiral_coordinates , the generates positions in a spiral that looks like this: (starting from the center) 
  ( ^ ^ ^ v v>>> ^ ^ v>>>>> ^> ...    I use this technique because it designs good enough layouts for me.  spiral_coordinates  is simple to implement and keeps the overall perimeter of the layout small. 
  The report function,  print_report , computes a  bounding box  that encloses: 
  the sprinklers that have been placed.   the squares that are watered by the placed sprinklers.  Then, I take into account a 1 square thick perimeter wall and report: 
   The dimensions of the bounding box.   The perimeter of the bounding box.  The report generates a map of the placed sprinklers and partitions it into chunks: 
 
 ... ...  ... ... ... #.  .. # .. # ... ... ..   ... ... #. .. # ..  ... # .. ... # .. ..  #. .. # ... ... ..   ... ... .. # .. # ..  ... # .. # .. ... ..  #. ... ... #. ..   ... .. # .. # ... ..  ... # .. ... ... #.  ... ... # .. # .. ..   .. # ... ... .. # ..  .... #. ...  ... ... ... ... ..    I find the map harder to read without the partitioning: 
  ...... ............ #. .. # .. # ........ ....... # ... # .. ... # ..... # .... # ... # ........ ........ # .. # .. ... # .. # ....... # ........ # ... ..... # .. # ..... ... # ........ #. ...... # .. # .... .. # ........ # .. .... # .. # ...... ..............     This week's post covered a Python script that assists people playing Stardew Valley by designing a layout of sprinklers. You learned about: 
   Using Python classes to manage internal state.   Using Python   sets  to check if two sets of positions are disjoint.  Using a simple greedy strategy to make decisions (placing the sprinklers).    My challenge to you: 
   Create a different way to generate coordinates than  spiral_coordinates  . 
  For example, here's what a placement of 8 sprinklers looks like with  spiral_coordinates : 
   (Layout.generate)     num_sprinklers=8,     coordinates=spiral_coordinates () ) .print_report ()     8 sprinklers 42 watered squares  (x)  squares, including perimeter wall 62 square perimeter map of sprinklers (3 by 3 blocks)   ...  #. ....  ... # .. ...   ... ... # ..  #. #. ...  ...   ... # .. # ..  ...    And here's a placement of 8 sprinklers that tries positions only in a horizontal line: 
    from itertools import count  Layout.generate (     num_sprinklers=8,     coordinates=((i, 0) for i in count ()) ) .print_report ()     8 sprinklers 42 watered squares 32 x 5 squares, including perimeter wall 66 square perimeter map of sprinklers (3 by 3 blocks)   ... ... ... ... ... ... ...  #. #. #. #. #. #. #. #.  ... ... ... ... ... ... ...     If you enjoyed this week's post, share it with your friends and stay tuned for next week's post. See you then!