Re: trying Chickadee

[Thompson, David]

Hello Zelphir,

First, thanks for trying Chickadee!

On Tue, Sep 4, 2018 at 2:34 PM, Zelphir Kaltstahl
<address@hidden> wrote:
> On my system Chickadee seems to build fine with the usual configure,
> make, make install. However I want to mention something, which might
> indicate a problem.
>
> When I run the example code:
>
> ~~~~~
> (use-modules (chickadee)
>              (chickadee math vector)
>              (chickadee render sprite)
>              (chickadee render texture))
>
> (define sprite #f)
>
> (define (load)
>   (set! sprite (load-image "logo.png")))
>
> (define (draw alpha)
>   (draw-sprite sprite (vec2 256.0 176.0)))
>
> (add-hook! load-hook load)
> (add-hook! draw-hook draw)
>
> (run-game)
> ~~~~~

(Just a heads up: Chickadee 0.3.0 will be released soon and it will
remove the add-hook! stuff. It's an easy change, but be sure to refer
to the updated example code when 0.3.0 is released!)

> It works and the sprite is rendered, however, one core is used to 100%.
> I guess the game loop is rendering the sprite over and over again in a
> non-updated position.

Correct, the game loop doesn't stop because you're not moving
anything. Chickadee's game loop renders frames as often as possible.
If 100% of one CPU core is being used, the likely culprit is that
Chickadee was unable to sync it's drawing with the monitor's refresh
rate, which could cause it to pause a bit after rendering each frame.
Perhaps I could automatically factor in a small usleep call when vsync
is unavailable in order to avoid this situation.

> Another thing is, that I cannot click the close button of the window
> that renders the sprite. I guess because I do not handle the closing
> event in this example code. I need to close it by C-c C-c in my Eshell.

Yes, that's exactly why.  The quit hook is run when the close button
is pressed, but you haven't added anything to handle that hook.  If
you eval (add-hook! quit-hook abort-game) then the game will close
when you click the window's close button.

> Aside from that it seems to work fine. I would like to see development
> in 2D game engines for Guile. I imagine minimalistic libraries / game
> engines and Guile to be a powerful combination! I always wanted to make
> a game (like probably most people in CS :D). Maybe with Guile and
> Chickadee or similar I can grab some new motivation. So far I have not
> tried to build anything complex with Chickadee, but maybe it is already
> possible. I think it would be cool to have a page listing projects using
> Chickadee, even if those projects are not done or only proofs of concepts.

I don't know of anyone that has built anything particularly complex
with Chickadee, but if anyone has that is reading this please let me
know!

I call Chickadee a "game toolkit" rather than an "engine" because it's
simply a collection of handy building blocks that you need to piece
together on your own, whereas an engine has already made major
architecture decisions for you. It's more like building your own
furniture than assembling something from IKEA.  It's a lot easier to
make a collection of essential game utilities that almost every game
developer needs than it is to design an entire engine, so that's why
Chickadee is what it is.  I mentioned elsewhere in this thread that
I'm working on a somewhat minimal game engine built on top of
Chickadee called Starling (sticking with the bird theme) that I think
will help people go from nothing to playable game in much less time.
However, you may not like the abstractions I chose for Starling, but
Chickadee's building blocks will always be there to assemble however
you wish.

- Dave