tetris.py

Tetris implemented in pygame using bitboards

Why build a game with python and pygame?

I've tried dabbling with both Godot and Unity, but have never progressed very far with either frameworks. When I stumbled upon DaFluffyPotato's channel, I was convinced that doing pygame was definitely a viable option. Given that I work with python during my day job, this was the natural choice to try getting started in game dev again.

Why use bitboards?

I experienced several issues with using collisions to determine if a particular action can be allow; If the current tetrimino is colliding at the bottom, we should lock said tetrimino and generate a new one. What I learnt quickly is that Rects need to be overlapping before it is considered a collision, and my naive solution led to tetriminos getting locked when they are touching at the corners. On hindside, I could have easily adjusted the Rects in the relevant direction when I needed to do collision checks, but my pea brain couldn't figure this out.

Instead, I went back to bitboards, which I've used previously when trying to build a chess game. A bitboard is essentially a binary number where 1's indicate where a particular cell is occupied. A J block can essentially be represented as

001
111

What this allows me to do is I can have a number that represents the state of the board, and shift the active piece around the board to check for collisions. Once all the checks are completed, I can then translate the binary number into a set of coordinates for rendering.

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TODO

Game Logic

• Clearing of lines

  • Identify tiles that should be removed
  • Drop tiles by the number of removed lines
  • Render effect of clearing lines
  • Render effect of dropping tiles
  • BUG: Clearing more than 1 line results in negative shift count bug

• Game UI

  • Center main game in middle of screen
  • Add next piece UI
  • Add stashed piece UI
  • Add score counter
  • Add ghost piece

• Scoring

  • Implement scoring mechanism based on lines cleared
  • Render scores
  • (?) scoreboard

• Piece stash

  • Allow player to stash the existing piece and call the next piece if stash is empty
  • Allow player to swap the current piece with stashed piece

• Scenes

  • Add main menu screen
  • Add pause screen
  • (?) Add high score screen

• Polish

  • Add fancy background with falling tetriminos
  • Having fancy falling tetriminos respond to user input

Credits

• L-Gad Tetriminos Pack