Published by Shane O'Sullivan
I am a software engineer and manager from Ireland. I spent 7 years working in Ireland from 2003 – 2010, then ten years in Silicon Valley from 2010 to 2020.
In California I spent about 6.5 years at Facebook Engineering, the last three of which I was an engineering manager in the Ads organisation focusing on customer facing products for creating and managing ads.
At Stripe I built the Developer Productivity organisation, with teams that were responsible for the use of the Ruby language, testing infrastructure, documentation, developer tooling (e.g. IDE integrations) and more.
At Promise, I was Head of Engineering from 2018 – 2020, responsible for building the first few iterations of our products, hiring for all product roles, meeting with clients and investors, and anything else needed to get a tiny startup bootstrapped and successful.
Now I’m back in Ireland, working on my next company. Coming soon (as of early 2023!).
This blog contains my various musings on all things technical/interesting on the interweb and beyond.
View all posts by Shane O'Sullivan
SOS 
Hi, I am recruiting for a Senior DOJO Developer for a daily rate contract in Belfast, can you recommend anyone that might be interested in this?
sbell@morganmckinley.ie
Sorry no, the only Dojo developers I know in Ireland are fully employed
Hello Shane,
I have been trying to use your code for generating a Voronoi Diagram the past couple days. I got it working without much issue but I do have a strange issue that I can’t figure out. I have some screenshots below if you wouldn’t mind taking a look. The first uses 10000 points, the second is 5000 and the first is using 1000 points. It seems the more points I have the more stray lines I get. These lines seem to stretch across the entire diagram and are not pretty, At first I thought it was my line drawing lib but it turns out it isn’t. I tried using this in a windows forms app and in a xna app and both draw exactly the same lines.
Do you have any ideas what would cause this? I am literally just iterating through the edges your code creates and drawing the lines.
http://imgur.com/a/rWhOH
Thank you.
Hi Joey,
I think this can happen if you have two identical points. You should try filtering them out before passing them to the Voronoi algorithm
Shane
Ahh perfect. Thank you. For some reason I just assumed that it wouldn’t very very likely to have 2 points. Well my mistake. Thank you very much.
I have one more question. This one may sound odd.
Lets say I want to generate a very large diagram. Lets say 10,000,000 points. Now I don’t need the entire thing in memory but I could save it to disk. As a test I ran this on your code and it actually crashes from running out or memory (gets to like 2gb and blows up). Now does this sound like that should be a problem? If so what would be the best way to generate a huge “map” or voronoi diagram. I am going to use this in a game in lieu of a tile based system.
Given that the sweep line algorithm uses quite a bit of memory, you’d have to reduce the dimensionality of the problem, perhaps by grouping a number of nearby points together. Alternatively you could divide the map into segments and somehow join them together later, though this could be tricky.
I was thinking about the join thing. Should it work fine if I were to know the out points then make sure those are part of the following generation? The results should tile correctly right?
Hi there! I just wanted to ask if you ever have any problems with hackers?
My last blog (wordpress) was hacked and I ended up losing
several weeks of hard work due to no backup. Do
you have any methods to prevent hackers?