Archive for the ‘Uncategorized’ Category

Spectrograms with Overtone

Posted: December 22, 2013 in Uncategorized

spectrograms are fascinating: the ability to visualise sound in terms of its constituent frequencies. I’ve been playing with Overtone lately, so decided to create a mini-library to produce spectrograms from Overtone buffers.

Here’s a sample output:


This particular image is a visualisation of part of a trumpet fanfare. I like it because you can clearly see the punctuation of the different notes, and the range of strong harmonics above the base note. Read on for some more details on how this works.



This is a visualisation I made for UPSingapore‘s “Data in the City” hackathon.


It shows a dynamic visualisation of 24 hours of mobile call data. The colours change to indicate the volume of mobile calls being made in each location throughout the course of the day.

The visualisation code is here and some details of how it was made follow below.

The animated video is here on youtube.


To help people with their graphical endeavours in Clojure, I created a new library Imagez which provided a set of handy image processing functions.

Inverted Ant


Last week I joined the “7 Day Roguelike Challenge” and wrote the game Alchemy. The goals I set myself were.

  • Complete a playable roguelike game in 7 days
  • Learn more about Clojure!
  • Share some of my experiences

Having successfully completed the first two goals, this is my attempt to deliver on the last point. In this (somewhat extended) post I’m going to describe my experiences using Clojure for the 7DRL challenge – with discussion how to get the most out of Clojure for game development.


Alchemy Day 7: Completion!

Posted: March 18, 2013 in Uncategorized

Final day of coding on Alchemy!

It was a bit of a scramble to bring everything together and tune the gameplay, but it all somehow worked out as a finished game in the end.

2013-03-17 Final 7DRL screenshot

You can download the final .jar file here:

And then run it in the usual way (either double click it, or do “java -jar alchemy.jar”). You need Java 1.6 or higher.


Today I focused on a key gameplay element: the crafting and use of potions

2013-03-16 Alchemy

Potions offer a lot of interesting gameplay:

  • You can drink them for (hopefully!) positive effects
  • You can throw them at monsters
  • You can use an analysis lab (pictures) to identify a potion and determine what ingredients a potion requires. This costs you a potion though…
  • You can create them if you find the right ingredients and know the recipe. But ingredients are scarce! So you need to plan with care….


Today was about getting dungeon generation working:

2013-03-16 Dungeon building

I was going for a fairly traditional Rogue-style effect in my dungeons: Rooms connected by twisty corridors. I’m quite pleased with how it is starting to look.

My algorithm is roughly:

– Recursively sub-divide the dungeon into zones, BSP-style
– At each division, add one or two connection points between the zones. The connection points will be either doors or corridors
– At the lowest level, build either a specific room with the connections turned into doors or a set of twist passages

I’m still working on room decoration: I maintain a list of rooms and after the basic level is laid out I run a “decorate” function that adds items of interest, monsters and other scenery to specific rooms.