sustainablelab / vector_racing

Graph paper vector racing game

About

Vector racing game: pygame version of the old graph paper and colored pencil game.

Run

$ python ./game.py

Or, simply:

$ ./game.py

Vim shortcut: ;<Space>

Develop

$ make tags

Vim shortcut: ;tg<Space>

Pygame Tips

• To render without alpha transparency, just draw everything (pygame.draw.line(), pygame.draw.circle(), etc.) on one big surface and only blit that surface once per game loop.
• To render with alpha transparency, artwork has to be blitted for the alpha channel to layer its semi-transparent artwork on top of previously blitted artwork.
• Blitting large surfaces is slow.
  • You can blit lots of small areas or you can blit a few large areas. Do not blit lots of large areas. Use FPS to gauge when blitting is impacting performance.
• Creating large surfaces is slow.
• To render fast with alpha transparency:
  • make a temporary drawing surface that is the same size as the final game art surface
  • draw to that temporary surface (pygame.draw.line(), pygame.draw.circle(), etc)
  • every pygame.draw call returns a pygame.Rect that is the smallest rect that encompasses the artwork -- blit only that rect to the final game art surface -- see render_rect_area() in game.py for an example
  • finally, clean up the temporary drawing surface (otherwise bits of old art will get re-blitted)
    • erase the old art by filling the temporary drawing surface with Color(0,0,0)
    • but do not erase the entire temporary drawing surface -- that is slow
    • again, use that rect returned by the draw call to erase the minimum necessary part of the temporary drawing surface