Problems with item "RotationCenter" in item "Extrusion" in the property "CustomShapeGeometry"

[Regina Henschel]

Hi Miklos,

Miklos Vajna schrieb am 25.11.2021 um 09:33:
> Hi Regina,
> 
> On Wed, Nov 24, 2021 at 04:50:38PM +0100, Regina Henschel <rb.henschel at t-online.de> wrote:
>> The situation is different. All specifications and our own description in
>> API use "fraction of shape size", but our internal property "RotationCenter"
>> uses Hmm.
>>
>> I have two ways to fix it:
>> A
>> Change our internal property to use "fraction of shape size".
>> B
>> Keep Hmm for our internal property and change description in API and change
>> all import/export filters.
>>
>> So which way to go, A or B?
> 
> Oh, I see. It's a difficult trade-off. :-) We try hard not to break old
> documents, but there were precedents like your commit
> bc886f523872d4f9845c188c7d525d72a1a60946 where a relatively obscure
> feature was just fixed instead of caring about old documents. Perhaps
> this is a similar category?

I would say yes. There was never an UI for "RotationCenter". So files, 
which use this feature are made by editing file source or using macros. 
User who are able to do that, will be able to change the values in their 
files to use "fraction of shape size".

So I will try to go with A. (But first I need to update my local build, 
which needs some time on Windows.)

> 
> (This would avoid the cost of intruducing a compat flag for this.)
> 
>> In case you wonder about OOXML: OOXML has no corresponding property. But we
>> likely need to use "RotationCenter" when implementing import filter for
>> groups with <scene3d> child element, because our own group has no properties
>> and therefor the <scene3d> properties need to be converted to custom shape
>> extrusion properties on the child elements of the group.
> 
> Sure, that's a different topic. My understanding is that our 3D objects
> don't retain any editable text

Yes, text is converted to curves in "true" 3D objects.

, so if we ever support OOXML's <scene3d>
> properly, then quite possibly we would need to handle that schene on
> normal (we call them 2D) custom shapes.

Custom shapes would need to be extended too, because currently ODF has 
no way to describe "include text into 3D". The text is currently always 
in front of the extruded shape.

> 
> https://wiki.documentfoundation.org/Development/Budget2022#3D_rotation_of_Impress_shapes
> has more details on this.

I have added some comments to that proposal.

Kind regards
Regina