Sunday, April 21, 2013


Since my last post I got a new awesome job and thus worked less on PewPew and Rollin' Droid. An update for PewPew is in preparation though. It will feature basic maintenance stuff (iphone 5 support, sound improvements, small optimisations, etc...), and more importantly a new game mode:


It is inspired copied from Geometry Wars' Pacifism game mode, and even in its unfinished form it's really a lot of fun. It will be available only in PewPew 2 when you finish the 3rd Campaign (in any difficulty).

Concerning Rollin' Droid, I've expanded my ambitions and need to re-do a part of the engine because I feel that my creativity is limited. I can't simply think of a feature and quickly implement it like I could do in PewPew. The hard part about RD's engine is that I have randomly generated levels that are potentially infinitely wide and height so I can't just alloc enough memory in advance. Also, I absolutely want to maintain 60 fps with no hiccups when loading a new area, so I have to create and stream it chunk by chunk to the GPU. To top it off, I can only use integer to have a deterministic game because I want people to be able to replay each other's games across different CPUs.

Monday, September 3, 2012

Rollin Droid

I have been working on prototypes for games for a while now. I tried doing:
  • a game where you rotate a shape and avoid projectiles
  • a game where you race in between planets
  • an isometric-real-time-chess game on an infinitely large board where you move a knight
but there was always something in the gameplay that didn't feel right.

Luckily, after playing Line Runner I finally did a prototype that deserved to be turned into a complete game. Line Runner is incredibly addictive, but there are several things that I would have done differently:
  • the player isn't allowed to make mistakes: one mistake and it's an immediate Game Over.
  • you play on a horizontal line. It would be better if you could move up or down.
Here's what Rollin Droid (my interpretation of Line Runner) currently looks like:

During the development I realized that I could implement wall jumps which allowed players to climb up tunnels and change direction.
Wall jumping unfortunately creates a big problem: if the player mistakenly wall jumps somewhere he's not supposed to, he ends up going in the wrong way and is very frustrated of not being able to change his direction until he finds a place where he can wall jump again. This problem isn't yet entirely solved, but can be mitigated with smart level design.

The main character is a little bugdroid that skates and collects donuts. In the game, he's a ragdoll animated using box2D, so his body/head/arms/accessories correctly reacts to his movements :-)
I doubt Apple would be very happy if I released the game on the App Store with a bugdroid as the main character, so the game on iOS (and the other non-android OS) will probably feature an other character.

Friday, June 29, 2012

"as seen at the Google IO"

I was watching the live broadcast of the Google IO when I got the pleasant surprise of seeing PewPew 2 as the (currently displayed) recommended app.

Completely unrelated, and much more importantly, Sébastien Huss has ported PewPew 2 to the Pandora consoleI've been meaning to port it to this console for a long time because it has 2 physical joysticks.
I really want to thank him as he did all the work quickly, and without any of my help.

It should be noted that porting PewPew to the Pandora would have been totally impossible had I used any closed component (Unity 3D, UDK, Marmelade, ShiVa3D...) ;-)

Thursday, April 12, 2012

Memcaching the right stuff

I am hosting PewPew's scores on the Google App Engine. I chose the GAE because it was free for small websites that stay under a free quota. Unfortunately for me, they recently lowered the free quota, and I started having to pay the minimum fee of $9/month. It's not much, but I want PewPew to keep on working forever, and $9 per month forever amounts to an infinite amount of money, which I don't plan on having.

There were two areas where I was over the free quota: the database was too large (the free quota is 1GB), and I was using to much CPU for the database requests.

Reducing the database size

The database was taking more than 1GB because I never deleted any of the submitted scores/replay. I wrote an handler that erased the lowest scores. Erasing ~400k scores cost me approximately 4$.
If you have a database with tens of millions of entries, doing operations on them can become expensive!
The handler could only erase 1000 entries at a time before timing out, so I "automatized" its call.
Now, I only have ~100k entries left, taking 792 MB. Out of those, 491 MB are used by the replays, which amounts to 23.5 days of non-stop action.

Reducing the CPU usage

I thought optimizing the CPU usage was just going to be a matter of caching the queries. Turns out, there's a right way and a wrong way to do that.

Initially, the scores for the 8 game modes were generated this way:
    for level in levels:
      query_str = get_query(level)
      scores = db.GqlQuery(query_str)
      for entry in scores:
        #write the score, player_name

And to cache the results, I did this :
    for level in levels:
      query_str = get_query(level)
      scores = memcache.get(query_str)
      if scores is None:
        scores = db.GqlQuery(query_str)
        memcache.set(query_str, scores, 60 * 60 * 24)
      for entry in scores:
        #write the score, player_name

But doing this did not improve my CPU usage, and profiling my app showed that I was still doing a lot of database call, even though none appear in my code. I assume I was not caching the entries, only references to the results. Reading the entries still required doing some database calls:

The correct way to do things is to manually put in the cache the strings and numbers you need to store, not references to the entries in your database.
Once this was done, I got the expected 8 memcache calls and divided the response time by 40:

Now the players can get the scores instantly, and I am back to paying $0/forever.

Wednesday, January 4, 2012


When writing this post I often wrote "iCon" instead of "icon"... Damn you Apple.
Anyway I got a folder full of different icons for PewPew, and I thought it would be cool to look at the evolution.

The first icon shows the classic ship shooting at an enemy, but when resized to 47x47 pixels (the original iPhone's icon size) it looked like crap.

So I simplified it and ended up with this. I like its purified appearance a lot but I decided to make it more eye-catching because I want people to download and play the game!

Up to now I was using Adobe Flash (!) to create the graphics. I decided to learn a bit about Photoshop and was able to add a glowing outline and some gradients.
It's interesting to note that the glowing outline is done the same way in Photoshop and in-game: blur the original image and compose the result with the original using additive blending. 

I later found a Photoshop iOS icon template with which I obtained this icon. However it attracted a lot of (deserved) criticism on the Android market, because the iOS glossy look negatively stood out on Android devices.

So I removed the gloss (but kept the roundness), played with the color balance, and obtained the current PP1 icon.

In parallel I was working on PP2 (and its icon). I considered putting 2 ships on the icon, but it would have suggested multiplayer and I did not want to mislead the customers.

It seems that I attempted to unify the icons of PP1 and PP2, and ended up with this. It was a failure and was never used.

After a while I realized that the PP2's icon actually looked very plain compared to other game's icons and realized the power of adding textures. This is the current (and likely final) PP2 icon.

During my last round of experimentations I tried different color scheme and liked this one very much. I ended up not using it, but it inspired me for the Android Market banner.

Edit (23/01/2012): a reddit post complaining about the lack of coherence with the icons on Android made me discover the Android Guidelines for the application's icons.

These are the two new (and hopefully final) icons.

Tuesday, November 22, 2011

Space War

Today, while doing my daily googling of PewPew-related news, I found a piano version of PewPew's main theme!

I hope an a capella version is coming.

Thursday, October 27, 2011


At one point during the development of PewPew, I wanted the players to be able to enter their name for the online high scores and replays. At first I started to use the native iOS keyboard,  and for a couple of months that's all there was.

But because I always wanted to have as few OS-specific code as possible to make the porting to different OS as simple as possible, I decided to implement my own keyboard.
It was going to be a lot of boring work though, so I kept postponing for later... And then, one day, I got in I saw this:

Extract from Gunnm, a fantastic manga.

I immediately wanted to have this keyboard in PewPew, and two days later it was done. And it looked great:
custom keyboard = seamless integration.

Besides the speed gain when porting to a new platform and the code simplification, there are many other advantages to having a custom keyboard. PewPew's font does not contain all the characters, so I can show only the characters that can be entered. Also, you can have custom colors in your nickname, and by having a custom keyboard I can make it very easy for the users to specify them:

Of course, there are disadvantages to using a custom keyboard: the users aren't used to the layout, they can't copy paste, the native keyboards are likely capable of detecting false key-presses, etc... but when you just want to enter your nickname, those things are not important.

Thursday, October 20, 2011


Quick post to say that I released an update for both PewPew and PewPew 2, that includes a new game mode called Asteroids.
It's of course an homage to the classic 1979 game, albeit PewPew style: lots of shooting, and lots of enemies.

A few notes: To keep the retro mood going on, the ship's color is forced to white. The asteroids' shape is generated at run time: it was faster for me to write code than to draw manually them :-) Added bonus: they have a unique shape every time. Final note: I resisted the urge of making the asteroids rotate, to stay closer to the original. A game developer's life is tough.

Tuesday, August 30, 2011

PewPew in Bangkok

I was until very recently doing an internship in Singapore. I got to visit southeast asia, and while in Bangkok I saw this advertisement in the metro:

It made my day :)

XPeria Play support

While it's true that Android's openness cause fragmentation which increases the work of the developers, it also allows the creation of new markets and opportunities.
The XPeria PLAY by Sony Ericsson is one of those opportunities, and allows mobile game developers frustrated by the touch screen to have fun ;-)

As you can see, it has buttons, but most importantly for me, it has two touch-joysticks (I just invented that term, and now that I think about it, it doesn't mean anything).
I recently released a version of PewPew 2 optimized for the XPeria PLAY, and will be doing the same for PewPew 1 soon.

Sony Ericsson has been really awesome with the whole thing. After exchanging a few emails they rapidly sent an XPeria PLAY simply after I promised I would bring PewPew to their phone. No stupid contracts or anything, they just trusted me. Really cool.

Now the phone itself is fantastic and feels really solid, and the joysticks are surprisingly usable. It is thicker than most phones, but that's to be expected from the slide out gamepad. The GPU is great and in fact it's the Android phone I tested where PewPew runs best.
You can read a more detailed review over at engadget, but overall if you like playing games it's a great phone.