About DrPetter


Ludum Dare 35
Ludum Dare 22
Ludum Dare 21
Ludum Dare 20
Ludum Dare 18
Ludum Dare 16
Ludum Dare 15

DrPetter's Trophies

Seriously... EVERYONE uses SFXR
Awarded by PoV
on December 15, 2010
Master of Distraction
Awarded by LunarCrisis
on April 21, 2008
The "I'd rather do it in C" Prize
Awarded by philhassey
on March 3, 2008
Glorious Particles Award
Awarded by Cthulhu32
on February 25, 2008
RSS Triumph
Awarded by philhassey
on February 4, 2008
The Über Awesome Sound Tool Award
Awarded by Endurion
on December 19, 2007

DrPetter's Archive

Looks familiar?

Posted by
Sunday, December 16th, 2007 11:58 am

It’s Q*bert!

…not really though, but you can sort of modify the landscape by raising or lowering tiles, and the rest adapts to remove any greater-than-two differences between neighbors (basically a hack to avoid situations my draw sort can’t handle :P)

I’m trying really hard to think of a way to use this for gameplay, but it looks like I might be drawing a blank. There’s another mechanic in there as well though, the chain reaction one, but it’s sort of shaky too.  It would be nice if I could at least come up with some pathetic game-ish behavior for all of it before I start digging my nose into gfx and music… but maybe it is not to be. I should probably start tinkering with gfx for now and see if something comes to mind.


Yuck, I need to speed this up.

Posted by
Sunday, December 16th, 2007 4:42 am

I’m still spending most of my time hawking the IRC and tinkering with my playlist… I’ve managed to write a little todo list of the most important things remaining, but so far only one (out of 8 or so) has been ticked off. No signs of actual gameplay or chain reactions yet, but they’re next on the list. All gfx are still placeholder and will hopefully be entirely replaced by the end of it. If I spend more than another 4-5 hours without having the gameplay “pretty much done” then I’ll be in serious trouble. I need at least 5 hours for content creation and then a healthy bunch for final tweaking as well. Tick tock.


Day 1 – it’s over!

Posted by
Saturday, December 15th, 2007 5:19 pm

Yeps. Will try to get a bit of sleep now (a little bit, not too much!), before going at it again tomorrow. I’ve managed to put in a number of things for one day and I guess I should be pleased. Haven’t spent my time very efficiently but I never do. Done maybe 6 hours of work in total so far.

So what I have to work with for tomorrow is this little placeholder guy able to walk 8-directionally and jump/fall on an isometric map. All that’s left of the groundwork is to size the level up, make it scroll and put in some animation code. Then we proceed to game stuff and graphics/audio.

Preparing for the compo I intended to focus primarily on the gameplay and objectives this time around, before doing anything too technical or diving into graphics. So far… no. Will have to keep reminding myself tomorrow that priority #1 is to get it playable and fun if possible. But then again… if it’s still crap when I only have 5-6 hours left I’ll probably leave it like that and make some snazzy gfx anyway, ’cause pretty crap beats crappy crap!


Slow going

Posted by
Saturday, December 15th, 2007 1:58 pm

It’s been another 4 hours almost, and not much has happened as it seems. I’ve wrestled a bit with drawing order for mobile objects in the isometric world, and I think I’ve got something usable now. It’s not as good as I’d like it, but good enough to move on. I might get back to it later. The main problem is probably that I handle map tiles and sprites similarly, despite map tiles having a clear 3D shape that allows more accurate Z ordering. Maybe I’m just stuck in a stupid line of thought here. My approach is to treat objects as billboards and apply a shaky offset thing to make moving objects from poking through the floor, but maybe I could do it in more of a cube/square fashion, using the isometric coordinate system instead of screen coords… I’ll give that some thought tonight, for now things at least look ok in most occurring cases.

Time to eat some and start putting in a bit of gameplay code. Ideal scenario would be to have the majority of code done tonight so I can focus on media and polish tomorrow (oh, and studying for my exam… but that’s a bonus for if I get some extra time left over ;))


There be more organized map elements and a placeholder player sprite with shadow. Topmost blue tile is broken, need to figure out why…. oh right, just struck me – I iterate from 1 and up in the drawing loop instead of starting at zero 😛

First signs of life

Posted by
Saturday, December 15th, 2007 9:37 am

Ok, thought of proto-idea last night. Got a lot of sleep. Refined idea this morning in bed and in shower. Started work on framework code etc (kind of happy with it). Finished that after some 2 hours. Put in a few placeholder sprites and coded simple map drawing.

Prediction: Come voting I’ll get flak for blocky graphics and questionable theme adherence. Just the way I like it. At least this time it won’t be a sidescroller.

More info to come as I implement stuff.


The helm

Posted by
Friday, December 14th, 2007 3:24 pm

Nice and spartan…

Motivational ornaments…

Midnight dinner & X-Files, prep prep prep!

sfxr – sound effects for all!

Posted by
Thursday, December 13th, 2007 6:13 pm

Been tinkering with this over the last couple of days.

EDIT: Official sfxr homepage – http://www.drpetter.se/project_sfxr.html

As the audio geek I am, I find it a bit unfortunate that most LD48 entries are usually silent. I figure it’s probably due to the authors not having a quick ‘n’ easy application at hand for making sound effects and therefore neglecting that aspect of the game in favor of code and, usually, graphics. Even simple sound effects can add a huge amount of immersion and fun to a game, though.

What I present here is, if you will, an MS Paint for sound effects… or something along those lines. It’s meant to make it dead easy for anyone to whip up a few simple sound effects and save them as .WAV files for playback using most game/media libraries like SDL or pygame.

Basic usage involves clicking the left-most buttons to automatically generate random sounds loosely targeted at certain categories. For more advanced users it’s possible to spend some additional time to manually create fairly varied and interesting sound effects.

The interface is based entirely around sliders for controlling sound parameters, along with a few buttons. Even if you don’t want to spend time learning about all the sliders you can still have some fun just hammering away at them and listening to the various sounds that come out.

Hopefully this will mean that there’s no longer any valid excuse for anyone to get N/A in sound!

Download: sfxr.zip (win32, 48 kB) – Latest update: 2007-12-15 (see screenshot)

EDIT: Apparently it sort of works in wine 0.9.50, though with some stability issues. Fortunately though, the good Gerry JJ/mjau managed to port it properly. Here’s a copy of his post:

I ported DrPetter’s excellent sfxr (info) to SDL, so it can now be compiled and run natively in Linux!

Download: sfxr-sdl.tar.gz

Just type ‘make’ to compile. You need SDL and GTK 2.

Source code is obviously included in the portable archive, and anyone is free to use or modify it for anything they please. There’s no need to credit me, although it would be nice if you did. I would also appreciate a little email note if you do create something cool based on my code.

If I get around to making a little update I’ll include source code in the win32 archive as well.


My nameless LD24h8.5 entry

Posted by
Monday, December 3rd, 2007 8:13 am

It’s got MOON, it’s got NO TEXT, and it’s got blocky pixels, chirpy audio and all the other essentials!

This was a strange “compo”, but several interesting games came out of it and I had a good time working on mine. The 24-hour time limit was rather severly busted, but that’s fine I suppose. DQ means surprisingly little around here, especially since this compo had no voting.

As usual for me, the main idea was a technical one and involved using a sphere-mapped rectangular playing area. As one theme was “moon”, this seemed easy enough to work in. The actual game concept was undetermined until rather late in the process. At first I was thinking that maybe you’d drive across the moon in some vehicle, collecting things… but that didn’t happen, so I changed it. The final game is pretty cool imho, where you drop/stack colored chips onto the moon to make them disappear.

This all sounds very lame and boringly puzzly in theory, but the main challenge is the hideous control scheme. You don’t control your position directly, or even your speed, OR the acceleration – but the next-higher derivative! Tap right and you’ll see very little happen at first, but after a few seconds the moon starts slowly rotating in the chosen direction, and then it goes faster and faster unless you compensate in the other direction. It’s very easy to overcompensate and end up in an oscillating back-and-forth motion where you have no real grasp of what the hell you’re doing, but play the game enough and you can enter into a sort of zen state where you can “feel it” and get along pretty well. This is really essential, since you need to position yourself very accurately over the chips to avoid missing (and thereby creating a new stack which needs to be completed and removed).

Unsurprisingly, most people that tried the game hated it. Once I realized where it was going I pretty much tried to make it as evil as possible, much like a lot of old C64 games which you find in some old dusty drawer without a manual and have no idea whatsoever what to do with. You’d start a game and almost instantly die, and the controls weren’t obvious at all or severely broken. Ah, the heritage.

I’m really happy with the music though, sets the mood nicely. Imho the game is worth playing a few minutes for that aspect alone if you’re a retro geek.

Scroll down to the bottom of this post to read some instructions (that you shouldn’t really get if you want the full frustrating experience).

Download: Windows version (575 kB)

Quick instructions: Arrow keys to move/rotate, Z to drop chips. Do not drop like-colored chips on top of each other.
There’s a small cheat which might make the controls a tad easier to grasp – type “showyou” at any point to bring up an acceleration graph in the top-right corner.

7th Swarming of the Machines

Posted by
Monday, December 3rd, 2007 8:12 am

Ah, great compo this was. Tons of sweet games. Unfortunately that also meant fierce competition, and I only managed to snag a best position of 3rd in Fun (which is unusual for me, as I normally do better in the technical categories).

Base idea for the game was to have the level be “swarming”, for an unexpected approach. I figured there could be loose platforms drifting around in space and you’d try to jump around between them, doing… stuff. The gameplay part of it was sketchy at best.

I suppose the better part of the first day was spent getting the platform movement and interaction working, and then I think much of the second day I just sat and tweaked it, fixing bugs. The gameplay elements and final graphics/audio were added in the last two or three hours.

Windows download: 128 kB zip (exe, data, source)

Linux port: 16 kB tar/gz (needs above file for data)

Arcade build a’la Lerc.

Jackie and the BS

Posted by
Tuesday, November 27th, 2007 6:22 am

My first LD entry, for the #7 compo in December 2005.

Story, according to readme.txt:

You’re kidding right? Uhm… Control
Jackie as she tries to escape from her
sugar-induced nightmare by climbing an
ever-growing flower. Flying pigs are
attacking and she needs to feed them
candy until they burst.

Collect delicious pig eggs for score,
and keep a look-out for hearts to boost
your health should you need it.

What more is there to say? You jump around, throw candy, collect eggs and try not to fall into the water as platforms appear and disappear from the randomly growing flower. The flower itself was the most advanced piece of code in this one, and the first thing I started working on. Generally I seem to go about LD compos that way – think of some cool technical concept, then implement it and try to turn it into a retro platformer somehow…

Download, WIN32 binary+src: jackiebs.zip (1.24 MB)

Just starting out, no platforms have grown out yet.

Flower has grown a fair bit and there are tons of platforms.


White pig has eaten too much candy, burst is imminent.

Yet another one of them header images

Posted by
Monday, November 19th, 2007 3:52 pm


Oh my… tricksy post editor this, images in the text box even.

DrPetter’s Dream Land

Posted by
Monday, November 19th, 2007 2:03 pm

Full of red balloons…

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