Created attachment 8529923 [details] imagedata-stride-linux.png The demo at http://js1k.com/2014-dragons/demo/1854 displays with with looks like an incorrect stride in Nightly on my linux machine. See the attached screenshot, where voxel edges are sloped and there's a discontinuity along x=y. The demo looks correct in Nightly on my Mac.
I did find I was able to reproduce this in a version 38 build I have lying around, but it doesn't occur anymore in nightly (as of 2015-06-19) for me. Could you verify if this is fixed in recent nightlies for you?
Thanks for checking. I'll check the same machine next time I have a chance. Hopefully monday.
I can no longer reproduce with Nightly 41.0a1 (2015-06-22).