Detailed text rendering

[HansOlsson]

In https://github.com/modelica/ModelicaStandardLibrary/pull/3638 it was noted that tools differ in the text-rendering, primarily in icons.

There are two issues: font-size and how the text is centered in the extent:

For the font-size the difference is that Dymola just uses the font-size for the text, whereas SystemModeler renders the font-size in the original coordinate system and then scales it similarly as other primitives, thus: In Dymola a suitable font-size is 10 for an icon in the package-browser. In Wolfram SystemModeler a suitable font-size is 800. I have not investigated other tools.

The extent-difference is more subtle, but visible. It should be investigated further (as I don't fully understand it yet, @DagBruck ?). At least one of these should be clarified to get consistent rendering in this linked PR.

[HansOlsson]

It would be good to have this clarified.

[HansOlsson]

Phone meeting: Possibly that extent is irrelevant, and the difference is due to different fonts.

Specifying the font-size that is used for a diagram should possibly be a different setting; the goal with that setting is to get a consistent size for different texts and without having to ensure that the extent has the same height.

Poll (when actually specifying fontSize):

• Specifying font-size for Icon (will be scaled down, 110): Henrik
• Specifying font-size for Diagram (as default component size, 11): Dag, Ben, Hans,
• Delay decision: (Dag), Elena, Gerd, Markus, (Henrik)
• Abstain: Martin, Stephan, Delay.

[henrikt-ma]

Considering that we should provide migration paths for both tools and libraries adhering to the respective interpretations, the following would seem like a pragmatic solution:

• Deprecate the use of fontSize in Text inside an Icon.
• Introduce fontSizeIcon and fontSizeDiagram that are only allowed for Text inside an Icon, and where fontSizeIcon defines the font size in the Icon's coordinate system, while fontSizeDiagram defines the fontsize when the icon is drawn on a diagram layer (regardless of how the extent of the icon is scaled).

According to this design, tools can go ahead and implement a deprecation warning and support for the new size specifiers. Users upgrading their tool can keep using their libraries as they were developed, albeit with a deprecation warning, and addressing the deprecation warning is a simple matter of replacing fontSize by either fontSizeIcon or fontSizeDiagram depending on preferred interpretation. Of course, a tool can even offer to do this automatically.

Open question regarding fontSizeDiagram:

• Obviously the size seen on the diagram doesn't depend on how the icon is scaled, but what about flipping and rotation?

[henrikt-ma]

Here's an alternative solution coming out of a coffee break discussion at MathCore:

• Introduce a Boolean scale which is mandatory for Text inside an Icon. Also specify that scale either has no meaning or is not allowed for Text in other contexts.
• When scale = true, scale the text with the extent, similar to any other graphic item in the icon.
• When scale = false use fontSize when showing the icon on a diagram layer, regardless of how the extent of the icon is scaled.

In practice, the effect of making scale mandatory corresponds to making fontSize deprecated in the proposal above. One could even make this explicit by saying that not specifying scale is deprecated, and that tool-dependent behavior should be expected in this case.

The questions about flipping and rotation should of course also be answered in case of scale = false.

Would it be safe to say that a Text with scale = false should be excluded when showing an icon in places like a package browser?

[DagBruck]

I'm all in favor of deprecating the fontSize attribute in icons. I don't see the need to add new font size attributes, I think the concept of a zero-width bounding box to specify the height to be much better and already scales to whatever icon size is used by by browsers in the tool.

I can see the argument

But all icons should have the same size of their names texts regardless of how big I have made the icon.

But in that case, wouldn't it make more sense to set that as an attribute of the diagram where the icons are placed? Or maybe as a tool option.