TODO

Docs

• Rewrite

GUI

• load a "challenge" (starting Grid config + the pieces you can place to solve it)
• wipe board back to challenge
• save new challenges to file
• include the challenges from the official game
• show the laser's path
• improved layoutca
• better way to visualize results other than the message label at bottom left
• show controls (WASD, R, M are used but no visual indicator)
• put the token icon on mouse cursor when dragging it to move it between cells
• swap tokens places if you drag a token onto another cell already holding a token
• cursor changes on hovering tokens
• ctrl z to undo moves
• shortcut keys to move pieces back to bank or "to be added"

Solver backend

• Eliminate panics
• Error enum

How many possible GameBoard configurations are there?

• 12 game pieces; any # from 2-12 pieces may be included; actual # pieces in puzzle = N
• 25 cells, all N pieces must be placed -> 25! / (25 - N)!
• each piece may have 4 rotations, for N pieces, there are 4^N rotation configurations
• so, summation on [2, 12] { 4^N * 25! / (25 - N)! } yields 4.255014734672012e+22

• for choosing rotations of pieces near the edge of the board:
  • gate pieces never point outside of the board
  • check single mirror pieces for if their targets are pointing outside of the board; need at least N targets available pointing into the board
  • laser doesn't point outside of the board
  • laser doesn't point along any row or column which is empty besides the laser
  • if black blocking piece is on the edge, these rules apply to the piece neighboring it 1 row/column inward
• when placing the moveable pieces:

  • pieces never go in their own row and column

    • this will easily narrow down the search space more than any rule
    • if there are L lonely pieces (pieces are on thier own row and column, which are not gate pieces or blocking pieces)) and N pieces left to place:
      • if L = N, the next piece must go on the same row/column as a lonely piece, and the same row/column as another piece (2nd piece not necessarily lonely),
      • placing a piece must decrease the quantity L if L > 0

  • splitting mirror pieces never go on corners

  • gate pieces never go on corners

using parts of the checker for the solver

DFS order:

1. Laser set + rotated
2. All set pieces rotated
3. Set + rotate one token at a time
4. When setting in (3), use the laser path to make assertions: the piece must go in the path of the laser