"These seemed like a good idea at the time." But that was in 2013 and
while that might have been acceptable back then, it's not anymore, it's
all just a complex abstraction that prevents any reasonable resource
reuse and forces a dedicated draw call for each use.
Just do this directly from the corresponding Primitives instead.
Deprecating those allows me to eventually deprecate the (also
overengineered) ResourceManager class, at which point Magnum should be
finally free from the worst design decisions from 15 years ago.
Unfortunately several examples still rely on it (while it only makes
them more complex, not better), have to wait until those are cleaned up
first.
These are all just minor off-by-one errors, nothing to worry about.
Except maybe for that one case with MeshTools::compile() but the rest of
the image renders fine, so it's not like I'd have some critical issue
there.
I spent some time trying ForceRenderer3D to produce the same image as
ForceRenderer2D but it *does not want* to show the arrowhead to me, so I
gave up.