text does not scale

[byorgey]

f = text "F" <> square 1 # lw none

main = defaultMain (f ||| f # scale 2)

produces

However, since font size is measured in Local units by default, I would expect the F on the right to be twice as big.

[jeffreyrosenbluth]

hmm, The default does not seem to be setting properly.
When I change to

f = text "F" # fontSizeL 1 <> square 1

it renders correctly

[byorgey]

Curiouser and curiouser.

[byorgey]

Oh, I know why. It's because we tried to handle this by making font size a transformable attribute. So when you do text "F" # fontSizeL 1 # scale 2, the transformation has an effect on the font size attribute. However, in the default case, a font size attribute gets added to the diagram at the very end, where it is definitely not affected by any transformations.

[byorgey]

I think having font size be transformable is the wrong way to do this. A potential solution is to (1) make font size not transformable again; (2) add a Double field to Text, storing the average scale applied to it; (3) use that field when rendering to apply some extra scaling, IF the current font size attribute in effect is Local... Note, however, that everything will have been converted to Output by then, so we would have to store an extra Bool in every FontSize attribute, saying whether it began its life as Local.

Actually, this requires a bit more careful thought... we had to be clever about doing the anti-scaling in the right way. Maybe instead of storing the anti-scaled T2 plus a Double for the average scaling, we should just store two T2 values: one intact, and one anti-scaled as now. Then rendering can just pick which one to use based on whether the font size is Local.

[byorgey]

I think I can easily fix this; however, I will also try to write up a summary of the issues of semantics on the wiki, as IRC discussion has shown this is far from settled.

[jeffreyrosenbluth]

There also seems to be a separate (could be related) problem, the SVG backend does not seem to render text with Local fontsize at all.

[byorgey]

Interesting. I'll take a look at that too.