Flashcard Clash Development Update 4
Adam C. Clifton
3 Mar 2017

Here's what we got done this week on Flashcard Clash, a game that combines RPG battles with Japanese flashcards.

I've continued working on the data editing tools I've talked about in previous updates. It's finally coming together and I've been able to start editing cards with it. There's still a bit more to go, particularly in game, with supporting the extra data I've added to vocabulary and cards.

Kristy's art updates are a lot more interesting:

This week I continued developing the Flashcard Clash app icon.

App Icon – Logo Badge

First I started exploring how to present the Numbat Logic logo on the Flashcard Clash app icon. We'd established that the logo badge would appear on the bottom right corner of the app icon (this position best suited the icon designs) so now it was a matter of creating the badge shape.

To simplify the design and avoid legibility issues at smaller app icon sizes, I opted for using the logo alone, without the “Numbat Logic” logotype. From there I started building shapes that would house the logo while not fighting for attention with the app icon design.

Since the bottom right corner of the app icon is automatically rounded to approx 180 radius when posted on the Apple iTunes store, it really came down to how the top left of the logo badge would interact with the remaining app icon area.

I looked at various curves from full circles, to squares with rounded edges. How the logo stamp flowed back into the app icon edge was also considered, using perpendicular lines or rounded, concave curves.

The various design options can be viewed in the image below. They're presented in both white on orange and orange on white – the Numbat Logic colour palette.

At the end of this design pass, I selected the soft sloping badge shape with the slight concave curve (3rd column, bottom) to use in the app icon design process. Overall, this shape felt harmonious with the app icon, whereas the sharp edged shapes felt obtrusive and dominant.

App Icon – Sketches, Rough Colours & Size Testing

Continuing from last week, the rough paper and pencil sketches were transferred to the computer where they were redrawn and refined in Photoshop.

Here are the four cleaned up sketches.

After reviewing the designs with Adam, we decided to proceed with design #2 and #4 (top right and bottom right). The next step was to explore these two design in colour.

Since we're keeping in style with the in-game graphics, the colours of the Adventurer were already established. For the background I wanted to find colours that contrasted with the Adventurer (and flash cards) and evoked a sense of excitement and the RPG world.

In both designs, blue and purple stood out the most. The blue being reminiscent of the sky and journeying through RPG worlds. Purple relating to magical elements and a colour that frequently appears in game.

The next step was to test our favourite colour schemes to see how they would appear at various icon sizes (48px, 72px, 96px, 144px, *192px, *1024px).

*192px & 1024px are not pictured below.

We couldn't pick a clear winner, so I'll be proceeding with the vector stage and see if one stands out then.

Characters – Setting Up the Pyromancer

An extra side project for the week was helping set up the Pyromancer character for animation and creating a couple of additional assets.

When creating the vector assets of a character, it can be difficult at times to tell how well the parts will convert into animation. This requires some trial and error, and collaboration between artist and animator.

In this instance, the Pyromancer's fireball attack didn't quite translate well, leading to a broken model in the second key pose. Thanks to our animator, Ariane, for supplying screenshots of the Pyromancer setup in Spine, I was able to provide draw-overs to adjust and (hopefully) fix the broken pose.

The draw-over helped me to discover the need for an additional hand to indicate 'letting go' of the fireball in the throwing pose. So I quickly vectored that up for Ariane to use.

Here's how the new hand will look in action, following on from the original hand that 'holds' the fireball.

And that's all for this week!

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Flashcard Clash Development Update 3
Adam C. Clifton
24 Feb 2017

Here's the next development update for Flashcard Clash, a fun game to help study Japanese. This week I’ve been super busy with other stuff, but luckily Kristy and Arianne have been working away.

Editor Updates

Currently the editor, which you can see in last week’s post, as a simple side menu and a main editor that lets you edit one thing at a time. This works well enough, but there’s a bit of jumping around when creating new things.

For example, to create a new monster, you need to first head to the skills section to create their skills, and then go to the monster editor to assign those to the monster. This was going to get even more complex with vocabulary cards, as we’d need to create the vocabulary, attach it to a card and then attach that card to a deck.

My solution to this is to change the editor into a ‘stack’ of windows, so that instead of having to travel to different sections of the editor to create different things, we can just push the window for doing that onto the top of the stack. And when you are finished, pop that window off and go back to what you were doing.

So for example with creating a new monster, instead of having to pre create the skill in a separate section, we can just push the window for that on top of the monster editor, then when we are done, just close that window and go straight back to editing the monster.

It's still a work in progress but hopefully I can finish that all up next week and ship out some new decks.

Art Updates

Today we'll also be introducing the art segment to our weekly Flashcard Clash Development Updates. The art segment will take a look into what we've achieved over the past week in the visual development and production of Flashcard Clash.

Kristy Kate, lead artist and art director of Flashcard Clash will take the reins from here:

Hi there! This past week (or two) have been focused on preparing the app icon for Flashcard Clash and assisting our animator Ariane wrap up the final animation for our first hero character, the Adventurer.

App Icon

The Flashcard Clash app icon is the first artwork visitors will see when browsing for apps on the Apple iTunes and Google Play stores.

It's important for app icons to be clear and easy to identify, so when approaching this design, I knew there would be 3 points to convey:

  • Flashcard Clash is an app utilising flash cards
  • to learn Japanese
  • set in RPG style battles

Clearly, flash cards, Japan and the excitement of RPG battles had to take precedence when choosing what elements to portray in the app icon.

It was also decided that it'd be worth including a stamp of Numbat Logic's logo in the bottom right corner to establish consistency between future apps.

So, I set off brainstorming and sketching ideas for the app icon. As seen in the images below, I went for quite a direct visual approach, incorporating flash cards, a sword (RPG element) and the Japanese flag into the design concepts.

Some of these would be quite clear in establishing that Flashcard Clash is about learning Japanese with flash cards, however the feeling of excitement and adventure from RPG battles wasn't as strong as we would have liked.

The turning point came when I decided to explore the interaction between the sword and flash cards, changing the flash card to the Hiragana character あ (transliteration 'a'). Eventually this lead to pulling the main hero character, the Adventurer, into the mix. This gave the app icon a greater feeling of action and excitement and sent a clearer message of the connection between Japanese flash cards and RPG battle.


From here we marked out our favourites (indicated with blue dots) and I have now transferred the sketches to the computer to start the process of refining and clarifying the designs.

To be continued!

Adventurer Spirit FX

My other task for the week involved finalising a segment of fx animation to play alongside the “Defeat” animation when a character (in this case, the Adventurer) is knocked out.

This proved to be a great lesson in improving my art direction skills as I had an image in my mind of what would happen, but didn't quite explain it to Ariane, our animator, in the best manner.

When the character was knocked out, I thought it would be fun to use a popular visual trope found in anime and manga, where the spirit (or soul) of the character leaves their body and lingers around. TV Tropes calls this “Giving Up The Ghost” if you'd like to know more.

With that in mind, this is the art direction I provided:

And the description: Little spirit “smoke” effect rises up from head.

Not the clearest of descriptions (sorry Ariane!). Ariane got to work and sent me this nifty little rough animation of the spirit rising from the knocked out Adventurer.

Despite the awesome work, unfortunately it wasn't what I was looking for, which is where I learned that I had to get specific when I had a very specific image in mind (it's not like we're mind readers!)

So I created these sketches and sent them back along with a much clearer description and a few animated gifs from anime I found online.

I received the revised rough animation from Ariane and voila, perfect! The frames have now been vectored and they'll soon be compiled into the final animation.

That's it! That's what happened this week!

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Flashcard Clash Development Update 2
Adam C. Clifton
17 Feb 2017

Here's the next development update for Flashcard Clash, a fun game to help study Japanese. Not a lot to publicly show this week, as there's been a bit of backend database tinkering, but i'll get ot that in a bit.

Review Counts

The big change this week was actually pretty simple, changing the 'reviews remaining' counter to show the actual number of answers the player needs to give before they are done.

Some backstory is needed for this. Cards in Flashcard Clash can have multiple 'sides' or questions to them, for example a vocabulary card could have 4:

  • VOCABULARY MEANING -> 猫 -> cat
  • VOCABULARY MEANING -> ねこ -> cat
  • VOCABULARY READING -> cat -> ねこ

I think this gives a deeper understanding as it requires the player to pull out the knowledge in different ways,

  • What is the meaning of this vocabulary?
  • What is the reading of this vocabulary?
  • If you heard this vocabulary, would you know the meaning?
  • Could you produce this vocabulary in a conversation?

So the player will need to answer those four sides correctly before that card is considered completed. Now coming back to the reviews remaining counter, since it was based off cards remaining, it would only tick down sporadically, about once every four questions.

This leads to a bit of ambiguity in how much work actually remains for the day, which can be slightly disheartening. Now that the counter has been changed to show the number of individual answers remaining, it ticks down with each answer, giving in indication of progress every time, which feels better.

Vocabulary Cards

Following up on the new way I’m storing and handling vocab cards from last week, I do not like how the final result is in game.

Currently a vocabulary card in a deck will accept any possible answer, eg: the game might accept お父さん or とーちゃん or ちち for the word "father". Which is all well and good in that you won't get a card wrong if you gave the wrong word that meant the same thing. The bad part is that it was intended for you to learn a specific word, for example in Yotsubato learning とーちゃん for father, and you can skip around that giving a different answer. Which means you'll pass the card and think you've learnt it, but then not be able to read it in the manga since you studied the wrong answer.

I think the correct way to go from here is have a card only cover a specific reading and meaning of a vocabulary. And if you answer with a different reading or meaning, the game can say "that's not the answer we're looking for" and let you correct it and carry on.

But before I do that, I need to update the editor so I can more easily create vocabulary and eventually be able to select what meanings/readings I want for a card.

That's it! That's what happened this week!

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Flashcard Clash Weekly Update #1
Adam C. Clifton
9 Feb 2017

So I'm going to attempt to try and to weekly updates on the status of Flashcard Clash. Even tho I figure most of the changes are all backend technical things that usually don't have any pretty pictures to go along with them. I hope you like words!


I've added prestiging to the game, basicly once you've battled through enough dungeons and it's too hard to contine, you can reset all your characters and the dungeons back to level 1. In doing so, you get rewards for how far you progressed and these rewards make it easier to go deeper the next time round.

Currently the rewards are pretty slim, just a useless gem, and there's not even any fanfare animations or sparkles. But I wanted to add it in anyway as my own personal account was running into a dead end and I needed to reset my progress :P.


We've been working hard behind the scenes with Ariane for a little while now to get our main characters animated before we can start showing them off publicly. One of these characters, the Adventurer, has a scarf that turned out to be a bit of a challenge to animate. A scarf animation is pretty simple technically, the first bone swings backwards and forwards about 15 degrees in a smooth motion, and each child bone swings the same way, but is slightly delayed. Hopefully you can make that out in the animation below:

It's pretty simple to animate the first bone, you just set key frames for the left and right positions and Spine will animate through them in a smooth motion. Which you can see as the red checks in this very exelent diagram I have created.

The trouble comes when animating the second (green) bone, beacuse it's delayed, you can see that it does not have a check on the orange line, which is where the animation starts. Te way Spine works, is all bones will be in their default position at the start of an animation, and the first time they are keyframed, they will jump to the correct position, so you need a keyframe on the orange line.

We could add a new keyframe at the start of the animation, but we'd have to manually work out the start position and somehow adjust the interpolation so it matched the existing stuff. Which all seemed like a bit of a pain.

Note the keyframe on the far left, before the animation starts. Being able to set a keyframe there would be my dream solution to this problem, but alas Spine does not support that.

My solution as a programmer was to overengineer things, and precompute a sin wave and use that to set the angles for the animation. For this I used the most powerful program in the world, Excel.

In the far right columns you can see what angle the bone needs to be at what frame, which was easy enough to setup, but a lot more effort than just having left and right keyframes with smoorth interpolation. The bonus was that for the child bones, we could just copy and paste these keyframes and delay them easily.

Another option mentioned on the Spine forums was to force the animation to loop between a set of frames, ie: use frames 50 to 150 instead of 0 to 100. This would have worked as well but it kind of breaks everything else that expects animations to start at frame 0 and end at the last keyframe, like exporting gifs. The game code would also have to be updated to support this.

Vocabulary Cards

Previously all cards in Flashcard Clash are free standing, with a bit of text for the question and answer. It's a little bit more complex than that, with things like dynamic cards, but it's still all based on a fixed set of text on the cards.

Currently reusing cards between decks is possible, but error prone. So adding a new type of card which is slimplified toto "this card uses this vocabulary" will make it easier to stop cards being accidentally duplicated. Which also means that if you learned a word in one deck, you can skip it in any other deck since the game will know that you already have it.

Longer term i'm looking to have things like automagic substitution for nouns, eg: currently I have a card that switches between "there is a cat" and "there is a dog", but those permutations are fixed. What I'd like to have one day is that if you learn "fish" then that card will dynamicly pull that in and become "there is a fish". That's a long way off, but the first step is building a solid vocabulary in the database to be able to reference.

Currently the only Vocabulary cards are the new ones I'm adding to the Yotsuba decks. I'll need to go back and convert previous cards, and cleanup a lot of those old decks in general, but I'm just focusing on the things I am studying at the moment :P.

That's it! That's what happened this week!

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Audio In Flashcard Clash
Adam C. Clifton
1 Jan 2017

Since Flashcard Clash can be run in the browser, I've tried to keep it as tiny as possible so it can be downloaded quickly. Also keeping the size down allows me to bundle all the assets in with the game on mobile platforms like Android, so there's no ridiculous second download process once launching the game. Specifically with audio assets, there's two parts, music and sound effects.

The music is created by Juhani Junkala in a 'tracked' music format from the 90s called Extended Module or XM. Tracked music allows you to create instruments as sound samples (eg: a single drum hit) then reuse them throughout the song, as opposed to more regular music formats that just stores the final sound data directly (eg: multiple drum beats with a voice singing over it). This means that tracked music can be smaller than the regular formats, which is great for us.

Originally I was using libxm to playback the music, it was easy to add to the game and use, but it sounded too different from the output of MilkyTracker, the tool Juhani was using to create the music. This brings me to what seems to be a common issue with XM music, every piece of software I’ve tried seems to play it differently. I think this is due to there not really being a definitive description of the format since it is based off what people have inferred from digging through the output of FastTracker2, the original tool to create them.

Luckily for me, Miky Tracker is not closed source, and the licensing for their playback library is permissive enough to use in my game. So by using that, I can ensure that the songs will sound exactly as the musician intended. There was just a day of hacking on the library to rip out all the things I didn't need, create a simpler interface for the game to use, and to create a wrapper for the code as it is written in C++ and the game is written in C.

On the sound effects front, instead of using a normal format that stores sound waves like a WAV file, I've forced Juhani to use BFXR instead. BFXR lets you create parameters for sounds, so that they can be generated later by the game. Since we are only storing the parameters and not the actual sound, the asset size is much smaller (currently 28kb vs 2.5mb). While these sounds can be a bit simple, BFXR also allows us to layer them together which improves them somewhat, and since the game is going for an old school JRPG kind of feel that does not hurt either.

BFXR hasn't always been awesome tho, we've had a lot of trouble with it breaking files, and also being very specific about what it can load. I didn't even know that SVN changed the line endings of text files until BFXR files stopped loading after I committed them.

BFXR is also open source, but it was written in AS3, which is a different language from the game. It wook a while to copy the code to C and get it running, but hopefully that’s sorted now and I don't need to spend any more late nights trying to work out why a sound is borked.

We were originally generating the sound effects in real time as the game ran, but it turns out that was VERY slow, especially on the web version. I have since switched to generating the sounds when the game starts up and storing them for play back as needed. This works ok with 30 sounds, but in the future I’ll need to do something smarter to generate sounds as needed (eg: only generate sounds for a monster when you are loading into a battle with that monster).

Once all that's done we have simple waveform data we can pass off to whatever platform we are running on to play the sounds. Currently we are defaulting to 16bit signed ints, but I think I might try to change to float as that's the native format for web browsers and that will mean less data conversion so it will run faster.

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Dev Update 2016-11-07
Adam C. Clifton
7 Nov 2016

Over the last few days i've been working on a little tool to be able to edit battle formations.

A lot of data for the game, like monster stats and battle formations are stored in the database. Obviously it's not wise to directly update these things in the live database, so I need to be able to set it up in such a way that I can make the changes locally and be able to repeat the changes later on the live server.

I do have an existing setup that does something like this, using numbered SQL files. The server keeps track of the last sql file it ran, and will not run it again. So since the server last ran the number 10 file, i can put all my changes into file 11 and test them locally. Once I push it live, i can run a script that will then process file 11 and those changes will go live.

This works pretty well with low level changes, like adding or changing tables, or other simple things. But adding a battle can be a bit painful, as it involves having to add multiple rows and looking up the monster ids. So I created a tool to edit the battles that you can see below.

It's ugly but it works!

It would be too much work to have the tool creating sql files for every change, so I make it just output a simple save file. This save file is loaded by the update script and it makes the changes to the database to match the save. That way I can edit the file as much as I want, test it locally then update on the live server.

It's a little bit simple right now, but in future i'll move more of the static data into this file, like monster stats, stage backgrounds and music. So it's one stop shopping for anybody on the team to be able to make changes to the game.

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Dev Update 2016-09-09
Adam C. Clifton
9 Sep 2016

The art for the endless mode I mentioned in the previous blog post has come in, and you can see it in the image below:

I've been having some issues with the UI systems in Flashcard Clash, and I was expecting to go in and fix them after the alpha release, but supporting different screen sizes has brought this all to a head. The main issue is that a snapping the ui to pixels will make animations less fluid, so things like windows sliding in and out not look as nice.

My plan with supporting different screen sizes is to make a virtual screen of about 640x480 pixels and approximate the actual screen to it. This should make UIs a bit easier to universally layout rather than having to work with the native pixels that could be anyhting between 640 to 4000.

After spending a day or so converting to floating point for the UI, and another day or so trying to make it not look too blurry when compared to pixel perfect coordinates, I started on supporting resoultion changes whilst the game is still running. The UI system was quite easy to update, I just trigger another reflow and the elements correct themselves, but I also had to rerender the SVGs so they are the correct scale for the new screen size. I still need more work to have the Spine model support changing the underlying texture, but that is in third party code that I don't want to deal with so ill postpone that as long as possible.

I don't think there's anything left in the game to do before the first public alpha test, just cleaning up the site and making sure things make sense for new users.

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Dev Update 2016-07-21
Adam C. Clifton
21 Jul 2016

Recently I was lucky enough to have some people try out Flashcard Clash at the Melbourne IGDA meetup. From that I saw two main gameplay issues that I've been working on.

Firstly when entering battle, the game recieves 10 cards from the server and they are all you get for the battle. The problem with this is that when you are getting brand new cards, you should have to answer them a few times in short succession to help drill it in, and the logic to do this is on the server. But with the existing system, you'd have to finish the battle to send your result to the server snd have the card ready for review. So you'd just work through each card in order, taking on new cards even if you should be reviewing older cards first.

I've updated the game to now download one card from the server at a time, so you can answer a card during battle, and then have it come back for review in the same battle. The trade off is that the game now makes a server connection every time you attack, as opposed to once at the start and end of battle. Since I'm the only one playing right now that's not a big issue, but we'll see how that goes once we get some active players. This also updates the counters at the top of the screen in real time which is neat too.

The second change i've made is to the Endless mode. It was all a bit confusing and allowed the player to jump straight to the boss before they were ready. I've changed it now that the player has to proceed through several substages before the boss unlocks. Previously the player was also able to go back to previous dungeons, but later in the game, this leads to a giant menu of every dungeon the player has visited. Now once the player defeats the boss, they move to the next area and are not able to return.

Here's a rough version of the new Endless menu. Kristy will do the art soon!

I've also updated the svg rendering to crop backgrounds to what is actually visible on screen. This is a good speed boost on iPhone where almost half of the background is not visible.

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Dev Update 2016-06-30
Adam C. Clifton
30 Jun 2016

This week has been a lot of playtesting, or should I say actually studying with the game. I've been playing through the Tae Kim decks created by Megumi and fixing any bugs that have popped up.

I had the first actual crash bug in a while related to a badly formatted card causing an infinite loop. Interestingly on Windows, it would plod along forever creating and releasing memory without increasing the total used. Meanwhile on iOS, this same loop will actually run out of memory and crash. I assume the system only fully releases memory once you return control to it.

A second bug had to do with my hiragana to kanji code that I always knew was there. The way the code works is it will auto convert the text the player is entering into hiragana then into kanji if it is part of the answer. Eg: wa-ta-shi-ta-chi becomes わたしたち which is then converted into 私達 as you type. The problem then is when you have another shorter kanji replacement, such as し -> 死 then it triggers first and messes up your string. Eg: わたしたち becomes わた死たち which is not what we want. The current fix is to store the location in the string where the replacement should be happening, so we know 私達 is at the start of a string and 死 is towards the end. It feels a little hacky, but it seems to work nicely for now.

Before and after fixing the bug.

Otherwise there were a lot of little grammar changes to the english answers just to make the game less strict on what it will accept as the correct answer.

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Screenshot Saturday 2016-02-06
Adam C. Clifton
4 Feb 2016

Here's a Final Fantasy 7-like battle transition I've been working on for Flashcard Fight.

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