While working on further development of my Helsinki public transport departures heatmap, I quickly noticed that heatmap.js, as good a library as it is, just can’t quite do all the things I needed it to do as fast as I’d like to get them done.
I decided to move some of the functionality on the server side, but didn’t find a PHP library that would allow me to do that, so I decided to write my own.
I initially tried PHP’s Imagick extension, but wasn’t happy with the performance. Doing a few test runs with GD instead looked more promising. After a few of hours of coding, I had a neat little package that would give me all the heatmaps I could ever want. I’ve uploaded the library to Github: https://github.com/xird/gd-heatmap, in case some else might find it useful.
If you have any feedback or feature requests, please leave a comment.