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Showing posts from 2015


Wow, the scene2d framework has come a long way since I first looked at it, in some pre-1.0 version of LibGDX. In the last hour since the kids have been in bed, I've got almost half of my game UI mocked out using it, and switching from the draft/mockup to the "real thing" should be as easy as modifying the skin file, and then slightly nudging/resizing things. I'd show some code here, but it's all so plain simple, I'm not sure what to even say. It's all super simple layout stuff, along the lines of: privateWindowbuildControlWindow(){floatpaddingLeft=120;Windowwindow=newWindow("Signal",getSkin());window.setPosition(0,0);window.setSize(LifeInSpaceGame.WIDTH,LifeInSpaceGame.HEIGHT/3);window.setMovable(false);window.setResizable(false);Labellabel=newLabel("Radio Filters",getSkin());window.add(label).padLeft(paddingLeft).colspan(3).expandX();window.row();Buttonfilter1=newTextButton(" Filter 1 ",getSkin(),"toggle");…

LibGDX Game Jam

So this week I'm tentatively starting a project for the LibGDX game jam, a month-long jam with the theme "Life in Space"

Part of the jam is the requirement to document your progress, which I'm doing on their website. I'll try to cross-post a lot of it here as well, but my jam project log page is at

The idea of the game is a very short story-based game where you are a researcher here on earth searching through the stars looking for radio signals that would show evidence of extraterrestrial life in space.  Because of the non-action, story theme, it's very different than other games I've done. And because the goal is to crank something small out quickly, it's been fun (for the 2 hours I've worked on it so far) not worrying about good extensible/general design, but writing just enough code to get the job done.

I'll leave you with a very minimal draft screenshot. The top starfield is where you se…

Door work and more

Ok, enemy spawning finally works right. There were a couple of minor bugs in my spawning code that I last posted (c'mon, nobody spotted them? I thought with a million eyes, all bugs are shallow? I guess that means I have a few less than a million readers that are also 6502 assembly programmers!) But I got the bugs taken care of.

I decided the next step, to try to get my brain interested in this project again, was to go ahead and start actually making the first dungeon. Awhile ago I posted a survey to see if I should re-implement the maps from the original Anguna, or make a new adventure. Everyone voted for a new adventure. But it sounds really fun to try to reproduce the first dungeon, at least. So that's what I started on.

And immediately realized that although I had worked out proof-of-concepts for my door code, it wasn't finished. Doors on the top worked. I hadn't finished doors on the bottom. Which required going back and modifying my display kernel code, which mea…

Enemy Spawning

Still working on Crop Insurance. The one nice thing about it is that I'm tracking my hours, which lets me see a better estimate of how much time I spend on my side projects. The answer is about 5-6 hours per week.

No wonder it took 3 years to finish Robo-Ninja.

That being said, I'm feeling a bit stuck on Atari Anguna. I haven't been doing much, because when I do, I've been working on my semi-random enemy spawning routines. And I haven't been happy with it.

The issue is that I don't want enemies spawning stuck in walls, which means:

1. I can go completely random on spawns, but then if it's a collision, try again.
1b. To check for a collision, I either have to do the math to figure out if I've collided with a wall (which on the Atari is non-trivial due to the crazy arrangement of the playfield registers) or
1c. Draw the enemy once, check the collision registers, and then move (which means each try eats up a frame, which could be slow and look really tacky…

CivKeyboard to play store

I haven't said much on here recently. Mainly because most of my non-work time has been doing some paid consulting work, (a project involving converting a farm insurance calculator from excel spreadsheets to a web app).

I do have a few things to say, though:

Robo-Ninja is now on the Amazon app store (it's now free to publish there, and they had an offer of $100 in AWS credit if you publish your first app there before Nov 1, so I took advantage of that!)Do you remember that custom keyboard I made for playing Civ in DOSBox? I decided to go ahead and publish it on the play store. Google onrejected it the first time for "spam" in the text (they didn't like the Civ and DOSBox in the title I guess), but I reworded it and got it listed. (It's still in beta test mode, so that link might not work for you yet....)Robo-Ninja finally hit 1000 downloads this week. Not particularly amazing, but at least people are finding and playing it.I'm still slowly advancing on the …

Girly game (more about ramps?)

So I've got yet another detour in my hobby coding.  While my son and I were working on Robo-Ninja, my daughter kept asking if she could help me design a game.  She had drawn some rough pictures and had some ideas about what it could be like, but we hadn't really done anything with it.

She asked again recently, so I thought it was time to humor her. She decided it would be a cute little game where she could walk around a neighborhood (in a 2-d side scroller, despite me trying to convince her that it should be a top-down game) to visit friends, and collect items.  Eventually we settled on the idea that she's trying to make a leaf collection for school, so she has to collect leaves.

Well, being a 2-d side scroller, and wanting to see if I can churn this out pretty quickly, I decided to reuse a bunch of the codebase from Robo-Ninja.

So with a few hours work, I was able to pull in a bunch of the main classes from Robo-Ninja, clean up a good bit of stuff, and have something work…


Well, turns out that was pretty easy. The new build with collectibles is now in the play store. With a new achievement if you collect all 16 of them.

(which means I had to play through the game yet again to test it. I'm getting pretty good at this silly game by now)

Collectibles in Beginner Mode

Well, it's time to open back up the IDE.

My friend Geoff brought something to my attention, which he's completely right about: In beginner mode, there's a bunch of dead-end passageways, with a yellow dot on the map implying there's something there. But there's nothing there.

Beginner mode, being a bit of an afterthought, doesn't have any of the slow-mo or checkpoint items. There's nothing to replace them, they're just gone. Which is weird and confusing.

I decided that an easy answer is to make them into simple collectible items. You find them, it says something like "you found collectible #3 of 16!"  And maybe have an achievement if you collect them all.  This makes the weird passageways make more sense, and adds a simple extra goal for beginner mode.

It should be pretty straightforward to add, we'll see how it goes.


Well, the release of Robo-Ninja went well. People are playing (and hopefully enjoying) it, so I'm happy as a clam!

I'm spending a little time now in my "free time" focusing on some outside consulting work, but hopefully I'll be back in gear to work hard on Anguna Atari soon!

Until then, I was recently thinking about how I ended up handling slopes/ramps in Robo-Ninja, and how my code ended up getting really messy after a few iterations. I decided (now that I'm finished) to do some research about how other people have implemented them, and ended up finding this awesome article that talks about the standard methods for handling the mechanics of platform games.

It's pretty awesome.

Release!!!! (And beginner mode)

And....Robo-Ninja is released!  It's up on the Play Store (although might take a few hours to appear for everyone).   Thanks for your help, everyone who tested, contributed graphics, ideas, etc.

Or, if you want to donate $1.00 and get to play the "harder" mode, use this one:

And for all you of you that found the game too difficult, you can thank my friend Bryan who finally convinced me to add an easier "beginner mode."  If you start in beginner mode, the game is 10% slower, and, more importantly, you have unlimited uses of the slowmo and checkpoint items. Being able to set a checkpoint after each set of obstacles makes the game a lot more playable if you aren't into crazy frustrating challenges.

You still have to pick one mode or the other at the start, and if you pick beginner mode, you don't get any achievements or get to post to the leaderboards (big whoop, eh?).

Good enough? Beta Test time

Ok, I think I found a cheesy solution to the problem (which involves looping the laser sound continuously the entire time you're playing, but mostly at zero volume), although I still see an occasional stutter right as you start a map.

I don't think I'm going to let that hold me up though.

If anyone wants to take a stab at it, I've got a build up on Google's Play's beta test system that I'm thinking of pushing to release, that you can try out:

Just follow that link, and give it a whirl. Feel free to email me any bugs, or leave comments here.

If nothing drastic appears, I'll probably release it in the next couple days!

So close...but so laggy

I'm so almost done. Most of the bugs are gone.

Except there's one thing that I just can't seem to resolve. There's some weird gotcha in libgdx's audio engine (on Android) where there will be a brief pause, or drop in framerate, whenever a sound effect stops playing. During most of the game, there's very few sounds, so it's not a huge issue, but the lasers that the blue guards shoot (and that Robo-Ninja shoots) are causing problems.

I've tried all sorts of things, but I just can't seem to work around it.

I've got a couple more things to try, and if those don't work, then I'm giving up and removing the laser sounds. Ugh.

Testing and Fixing

I remember this point with Anguna. Every couple nights, I'd go to bed and say "I think I'm done," but the next day I'd find 5 more bugs. My wife would laugh at me each time I'd think I was done.

I've been playing a lot of Robo-Ninja, and finding a fair number of little bugs. I spent tonight figuring out what was going on, and fixing a bunch of them, but there's still a small handful left.

Then I get to do this again.

And again.

Someday, I'll play through the game, and won't find a single bug. Today is not that day.

Robo-Ninja first draft finished?

Tonight I finished the last few features of Robo-Ninja (at least for the Android version, I'd still like to make some tweaks for a Chrome version), finished changing things to use Chris's awesome graphics, and fixed the last couple of known bugs.
The first "maybe" build is currently building on my Jenkins server. Tomorrow I get to start intensive testing (otherwise known as "playing through the game over and over until I'm sick of it") to see how many more bugs I can find and squash before releasing it.
It sure feels nice to be almost finished.
For those of you that signed up to be actual testers on the play store, I'll try to get the test build posted tomorrow if there's no glaring immediate issues.  
If anyone wants to test and hasn't done so, let me know. (In the comments below, or you can email me)

Retrospex 32 Review

RetrospexInternational recently sent me a couple units of their new handheld device, the Retrospex 32, a new dedicated GameboyAdvance emulator handheld.  To make the unit playable out of the box, they pre-loaded a handful of homebrew games, including Anguna, which is why they were kind enough to send me 2 of the units to play with.  I was pretty excited to get my hands on the device and try it (I loved my old GBA micro with a good flash cart!), and see Anguna running on it. So here's my thoughts after playing with it.

Their website lists the Retrospex 32 for £59.99, which is around $100 USD. It seems like it's marketed toward people into retro-gaming (which makes sense for a dedicated GBA emulator device). At that price, with that target market, and such a limited set of functionality (why not make it a multi-machine emulator, and emulate all the old consoles?), it would hopefully do a really good job of it.

The short version of my review: it doesn't. It has one job (emula…

New UI, and terrible design

Well, now that the main game of Robo-Ninja is done, other than some testing, it's time to go back and rework some of the UI using the amazing graphics that Chris sent me.

Well, in doing so, I've exposed all the bad design choices I made while doing the original UI. Things that should be pretty easy are harder than they should be, based on original assumptions. For example, in my original UI, the button width in a menu automatically changed based on the text width. In Chris's, it doesn't. But based on my "clever" menu code, changing that required a lot more work than it should have.
It doesn't help that, because I'm ready to be finished with the game, instead of going back and reworking the code with the new stuff, I'm just shoving it all together in the quickest way possible. So I've got a lot of dead code that doesn't do anything, layout functions that don't make sense in the new context, etc. 
Oh well. It's going to look a whole …

"Creative" is an adjective

Something that's bothered me recently is the term "Creative" as a noun, to describe certain types of artistic people.  Often graphic designers or marketing folks. (Wiktionary even has an entry for this usage of the word, specifically referring to marketing).  Our companies hire "creatives" to design our websites, marketing materials, flyers, etc.

Why does this bother me? Because this subtly implies that these types of people have some sort of monopoly or ownership of creativity. While we are becoming more an more of a "consumer culture" (fewer people are willing to sing, make art, or write poetry -- instead we leave these up to the "professionals"), terms like this tell the rest of us that we aren't creative. That creativity only belongs to a certain type of worker.

Instead, why aren't we appreciating the different types of creativity exhibited by all sorts of people, and encouraging everyone to create? (Or did we forget that the fir…

7-year old Anguna Bug

So Eli at Piko Interactive was testing Anguna, and kept running into a problem where the main boss would disappear halfway through the fight. Not that the dragon would really go away, but the sprite would disappear, but the collisions/bullets/etc would still continue.

Try as I would, I just couldn't reproduce it. He said it happened 100% of the time. But I couldn't see it happen. He sent me a save state and said that it should happen just right after loading from the save, but I still couldn't reproduce it. Finally, though, I just entered the cheat code to get tons of health, put the phone (emulator) down, and when I picked it up, he was gone.

So after quite a few more experiments, I somewhat sorted it out: It happened at 3ish minutes into the boss fight, every time, like clockwork. But the way I played, I never lasted 3 minutes in that fight. I always played it more aggressively, and was either dead or victorious in a minute or two. I never saw the bug, because I played t…

Atari Green Toady

So the Green Toady in Anguna is the first somewhat difficult challenge the player faces. Unlike the simple slimes in the first few rooms, the Green Toady not only take a number of a hits to defeat, but also has a more difficult movement pattern:

He first wanders slowly and randomly, but as soon as he is lined up (or more accurately, close-to-lined up) with the player (on either the X or Y axis), he pauses, then charges quickly at the player, until he hits a wall.

Tonight's challenge was to get that working on Atari Anguna. This is the most complicated enemy so far on the Atari, and would require a bit more code than the other enemies. The trickiest part was something that should be simple for anyone with any real 6502 experience, but required some thought for me: figuring out a reasonably efficient way to determine if two numbers are within a certain range of each other. (ie I wanted to see if the enemy X position was within 5 (plus or minus) of the player X position).

What I ende…

DS build (probably?) working again!

So again thanks to Sverx, I think I have the DS build of Anguna working again.

In response to one of my previous posts lamenting that I couldn't find a 2008 release of the devkitPro/libnds tools, he mentioned that he had a copy!  He sent me what he had, which turned out to be the windows version.

Although GBA anguna was developed on windows, I developed the DS version on linux. So everything I had was set up for linux, and I'm currently using (and running my builds on) linux.

My first attempt to get it working was to just use my current version of my gcc arm cross-compiler with the 2008 version of libnds, which as I suspected didn't work.  It compiled, but the linker complained about all sorts of things.

I didn't want to go all the way and set up everything in windows yet, so the next try was stupid: use all the windows toolchain compilers via wine. Has anyone EVER run windows versions of gcc on linux using wine before? A terrible idea.  But it seemed to work when I co…


In my previous post about the volatile keyword, Sverx left an insightful comment, noting that because nothing is changing the SRAM data outside of my code, it shouldn't really need to be marked as volatile.  Which is true -- nothing really changes it at run-time.

So what was the actual problem and why did marking it as volatile correct it?

For one thing, as sverx mentions in the comment, SRAM can only be written 8 bits at a time. Which I'm doing (casting my data into 8-bit chars and looping through writing them one at a time). But now I'm wondering if the newer versions of gcc saw that, decided I was stupid, and optimized it into 16- or 32-bit writes. Which would make sense why adding debugging messages in the inner loop would change it.  Marking as volatile might also have been enough to scare the compiler off from over-optimization, and fixed it as well, although not quite as correctly.

Thanks sverx!


So here's where everything's at right now:

GBA Anguna: new content is finished, the rom is being playtested by folks at Piko Interactive (which they've already found (and I've fixed) one bug), hopefully soon will be sent off for production!

Robo-Ninja: The game is pretty close to finished. This week I've been working on the ending sequences and more google play services integration. I might skip the cloud saved games (it looks like a bit of a pain to convert my save game format to work with it, but we'll see).  The biggest change is that Chris (the guy that did the graphics for Anguna and the new awesome Robo-Ninja character graphic) has some great looking designs for improvements to other graphics in the game, including all the UI bits, so I'm planning to wait to see what he comes up with, and probably do a bit of reworking all the UI to use his designs.  (although there's still a little bit of work to do until then: tweaking some level designs, testing,…

Robo-Ninja Boss Fight

My office-mate Tim has been so kind as to play through Robo-Ninja, giving me great feedback along the way. A week or so ago, he finally got to the end -- at least so far. He got to the room right before the main boss. And has been patiently waiting for me to give him a boss to fight.
Well Tim, we're almost there.  I think the boss is done. Although once you kill him, I don't have any sort of victory sequence or anything. He dies and you're just stuck in his room. But hey, progress.
I ended up NOT giving him multiple forms after all. Partially because I'm ready to finish this thing, and partially because while testing it, he seems hard enough already. 
So now there's just a few things left to do: A few map tweaks based on Tim's feedbackFix a couple of bugs in my game engine (again, based on Tim's feedback) Add graphical icons on the teleporter UI (I've had blank placeholders sitting there for months now)Finish the options and license/credits screen (I'…

No DS re-release for now....

So today I download the source to the Nintendo DS version of the Anguna to see if I could easily get it to build, to push the new level to it as well.

Didn't turn out so well so far.

The development kit for GBA and NDS development (devkitPro) has both the compiler toolchains/build tools/etc for development, as well as some libraries for interacting with the various platforms. The libraries are mostly thin wrappers around the basic functionality (nice names for the various registers, utility functions to deal with them, etc), but there's a few other bigger bits, such as sound libraries, etc.

On the GBA, I didn't use any of the devkitPro libraries directly, and instead just managed my own, using just the simple register definitions.

On the NDS, I ended up using a lot more library calls from devkitPro. Which turned out to be the problem here. The NDS libraries on devkitPro have changes significantly in newer releases. And I'm having trouble coming up with a version of the…


I spent about 2 hours last night pounding my head in a wall trying to figure out the solution to a new bug that I ran into: Anguna's save game function was no longer working.

In the GBA, the most common save method is to just write to a magical area of ram that happens to be battery-backed, so it retains its values. So when I save, I write the game state to that area, including a checksum.  On loading, I read the checksum to see if there's a valid game state in ram (as opposed to un-initialized garbage), and if it's valid, load it.

So last night, I was writing the data, but then when I read it back out, the checksums didn't match!

So I started debugging. I logged the first few bytes writing to save, and logged them again as I read them...everything looked right. So the first few bytes were working. I tried again with the last few bytes -- they matched also. Weird.

So I dumped ALL the data to a log upon saving and loading. And Lo And Behold, they matched, and it worked …

Anguna New Level

Ok, I promised I'd share, so here you go.

For the upcoming cartridge release of Anguna by Piko Interactive, we decided to add an additional dungeon level to Anguna, to sweeten the deal for anyone who might buy one. So the past couple weeks I've working like mad to try to add the new content before production of the physical carts starts.

Today, I finished the first draft of the Ice Dungeon, with slippery ice on the ground, a new Golem boss, and a new inventory item (a ring of teleportation):

For now, this dungeon is going to be exclusive to the physical carts you'll soon be able to purchase from Piko Interactive, to try to help them sell these things.

The process has been interesting -- first I had to just get the silly thing to build properly on a modern development environment, then I had to go through and fix a bunch of bugs that originally existed in the game, but somehow never manifested themselves on the older versions of the compiler/toolchain.  Once that was finis…

Anguna Teaser

I've been quiet recently, but working hard. Working on some stuff related to the original Gameboy Advance version of Anguna.  I'll go into more detail later.

The fun part has been re-installing all the tools needed to build and edit Anguna, and realizing that there were a number of bugs that "worked by coincidence" with the older versions of devkitPro, but don't work anymore.  I spent longer than I anticipated just getting everything working again.  It brings back weird memories, looking at this old code. And geez, I don't know how I ever got this game finished, with how difficult it is to debug code on the GBA.  Fun times.

Ok, enough being mysterious for one night.

Playfield editor and Green Toady

Today was an Atari Anguna day.

First, I was working on some new room layouts, and got a little frustrated with the room editor I had been using (Kirk Israel has an incredible 2600 Sprite Editor on his website but his playfield editor leaves a bit to be desired. (mainly, that I couldn't drag to paint, instead had to click each cell, also that I couldn't paste my code into the tool to modify already-existing rooms).

So I decided to rewrite it. The end result isn't perfect, but seemed worth the time. (about an hour and a half). It fixes those issues and a few other minor niggles from Kirk's editor. It's posted at and the code is fully contained in that one page, (other than pulling in dependencies from google) in case anyone wants to take it and improve upon it.

I also started on the next enemy, the Green Toady (the first difficult enemy from the first dungeon in GBA Anguna). I've got him working, but now realized that I don't …

Boss Fight

I'm starting to make progress on the Boss Fight.

Like many games, this fight moves through a few phases, alternating between times where you just have to survive, and times when you actually try to attack back.

The first phase involves lots of jets of fire filling his room that you have to avoid. From the top, the sides, etc. It's tricky, but not too bad, really. I've just about got this phase finished. Next will be a part where you can fly up and try to get a shot off with your laser before he starts shooting fire at you again.

And 2 MORE bytes ram

And today, while the baby was napping, I managed to remove 2 more variables from ram (associated with enemy missiles, that I realized were no longer needed). That frees up TWO MORE ADDITIONAL BYTES.

I now have 14 unused bytes of ram.  That's awesome. I might even be able to support a 4th enemy per room, at this rate.

This post needs a subject

Been slowly chugging away, but not much to say.  Other than a big THANK YOU to Tim Dudek for doing some serious testing of Robo-Ninja. He's helped me fix a number of bugs, performance issues, and a few map issues.

Mostly, I've been setting up the overall structure of the game so that each build (android/desktop/etc) can specify more of the behavior specific to that build. That let me add the Google Play Games integration into the Android version but still have everything else work correctly. I'm also planning to add some help text to non-touchscreen versions (desktop, web, and my new plan to use Google's Arc Welder to make a Chrome App as well) to make it more obvious how to play with a keyboard.

Then, now that I started that, it made sense to finally break Aaron's mode out into a separate build, to remove it from the "real" build. (if you recall, he started making his own levels (Geesh, that was more than 2 years ago. That's an eternity in a kid'…

Play Services

After a lot of work trying to figure out issues with Google and Android SDK libraries, I've got the Google Play Games API working! (by "a lot of work" I mean maybe 3 or 4 hours....I guess that's not so bad)

Based on the results of the votes, the answer sounds like I should go ahead and use the games services to their full potential. Here's a test run of unlocking the first achievement!

This tutorial was super helpful in figuring out how to get started. Although there were a few hiccups that I'll document here in case the answer is helpful to anyone (or myself next time!)

First, I got all sorts of errors with not being able to find the right libraries. As many forums have mentioned, the dependencies specified in the build.gradle file have to match the SDK version that you download using the Android SDK manager. The working combination that folks are recommending as of today (Apr 2015) is the following in build.gradle: