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I recently dived into the SmartArt support of LibreOffice, which is the component responsible for displaying complex diagrams from PPTX. I focused especially on the case when only document model and the layout constraints are given, not a pre-rendered result.

First, thanks to our partner SUSE for working with Collabora to make this possible.

Accent Process

In this post I would like to present the progress regarding the Accent Process preset, available in PowerPoint — which is used in many documents.

This exposed several shortcomings of the current diagram layout we have in LibreOffice:

  • Values are not read from constraints (there was a reason for this, they can be complex, given that depending on the context, the unit is points or millimeters and the unit is always implicit).

  • ZOrder offsets were ignored.

  • Linear algorithm did not take size from constraints when it came to recursing into child algorithms.

  • Data point assumed that all text for it is a single "run" (i.e. either all text is bold or nothing, not half of it).

  • followSib axis was not implemented for forEach, so when you have arrow shapes between objects, we created N arrows, not N - 1 ones.

  • Connectors were created as invisible shapes and had the wrong width/height aspect.

With all these fixed, we reach a much better state for handling accent process.

Results so far

smartart-accent-process.pptx is what I used for testing of this work.

Here is how the baseline, the current and the reference rendering of the test documents look like:

smartart-accent-process.pptx, baseline

smartart-accent-process.pptx, current

smartart-accent-process.pptx, reference

This is not not perfect yet, but it’s clearly a large improvement, all text is now readable from the diagram!

All this is available in master (towards LibreOffice 6.3), so you can grab a daily build and try it out right now. :-)