Found a bug in #zoomasm's 360 projection (the distance estimate scaling was wrong).

Trying to do the maths by hand is too hard, so I copied my #GLSL #DualNumber implementation (for #AutomaticDifferentiation) from my fragm-examples repository, minus the #CPreProcessor macro hell, plus some quaternion-to-rotation-matrix code ported from Python that I found online.

Now it looks okish in the #equirectangular view, need to render some tests at various orientations and inject spatial metadata for viewing in VLC to be more sure I got it right...