Omit leading zeros when serializing float Attribute (and other Attributes consisting of floats) into TXML

[Stinkfist0]

Currently f.ex. a default constructed Transform attribute looks like this in TXML:

<attribute value="0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,1.000000,1.000000,1.000000" type="Transform" id="transform" name="Transform"/>

By omitting unnecessary leading zeros in floats we would save a lot of bytes:

<attribute value="0,0,0,0,0,0,1,1,1" type="Transform" id="transform" name="Transform"/>

[jonnenauha]

Yes please :)

[jonnenauha]

Should be fairly trivial too, util func to remove all trailing 0s.

Here https://github.com/realXtend/tundra/blob/tundra2/src/Core/TundraCore/Scene/IAttribute.cpp#L158-163

Then float2/3/4/Quat in the MGL classes https://github.com/realXtend/tundra/blob/tundra2/src/Core/TundraCore/Scene/IAttribute.cpp#L170

[jonnenauha]

Btw is it ok to modify the MGL classes in Tundra? I mean there is some kind of manual merge/diffing step each time we want a new version of MGL in? Are these mods going to make that harder for @cadaver or whoever does that?

[jonnenauha]

Actually maybe its better to just do the to string logic in IAttribute (copying the format from matlib) and do all that stuff via QString::number() etc. So we dont have to touch the math classes.

[Stinkfist0]

Yeah it's probably better to do in IAttribute in order to keep the Tundra-specific mods of MGL at minimum.

[cadaver]

Yes, the more we mod MGL, the more troublesome it is to merge a new version. That is a manual process as Tundra's MGL is just files in the Tundra repo.

Therefore this is indeed preferable to do in eg. IAttribute.

[Stinkfist0]

However, I see no harm in pinging clb regarding this matter; maybe he'd prefer to have this in MGL.

[jonnenauha]

I'm sure the only thing where Jukka uses strings is debug prints if even there, but still reading that stuff is much nicer without extra zeros.

@juj Any input? :)

[juj]

There were functions X::SerializeToString() added to MathGeoLib some time ago, see here juj/MathGeoLib@40d3981

Those functions have the two features:

• X::FromString(obj.SerializeToString()) == obj
• The representation of obj.SerializeToString() should be minimal but readable without extra characters.

Try that form, in particular the %.9g should omit trailing zeros, as opposed to the older %f that was used.

[Stinkfist0]

Ok, nice, I think we can pretty safely modify our MGL copy to use the 'g' modifier.

[jonnenauha]

Sure would be nice to sync whole MGL into Tundra again, seems out last update has been 1 year ago :( SerializeToCodeString also looks it might be useful in Tundra code.

What was the main reason of keeping a copy in Tundra source tree instead of using it as a pre-built dependency?