LangJam GameJam

So I joined the Langjam Gamejam, see here : https://itch.io/jam/langjamgamejam

The idea is to create a programming language, then write a game in that language, then upload it. This sounds fun to me, but I don't have that much time. I have a job and a family and a lot to do because it's coming up on xmas. I doubt I even have 10 hours over the 7 days. Best type quick.

My goal is to get something working. Not run out of time trying to make a clever language or some fancy 3D game. So I missed Sunday already, but I spent a good amount of time thinking about it. I am going to create a lisp-like language and game engine, because that is easy to parse, and I am going to compile that to javascript in an html game I can show on itch.io. I can have most of the game engine libraries written in javascript already and just compile the game language into javascript and stick it into the gaps.

I sketched out a language and wrote a test "game" in it. This should give us a background and two 2d sprites, one of which the player can move left and right. 

(Game
  (Levels 
    (level1
      (background image:"background.png" x:0 y:350)
      (hero image:"GoodGuy.png" x:0 y:0 physics:true
        {
          (tick
          (if (Input Right) (inc x 5))
          (if (Input Left)  (dec x 5)))
        }
      )
      (villain image:"BadGuy.png" physics:true x:100 y:100 
      )
    )
  )
)

The idea is that the language is a tree of game objects that talk to each other. The game engine will do a breadth first walk of the code, drawing anything with an image. Then it will do the same again but call every tick function. Any code in an object will be able to access any other via parent/child reference, so code running in our hero could move the villain via parent/villain/x. I guess that's going to be enough functionality to make a simple game. I spent a few seconds making the 3 png files above and assembled them into what my first test should look like:

Starting now, I will write the compiler in Haskell using megaparsec and the game engine in javascript. If I am successful, I should have a moving version of that picture by tomorrow. Then I can start adding to it and making a game.