Posted by dxli on Oct 26, 2024; 8:53pm
URL: https://forum.librecad.org/Text-missing-or-garbeled-in-DXF-file-tp5725500p5725508.html

Using elliptic arcs could be a hack, but not really compatible with dxf polylines:

https://documentation.help/AutoCAD-DXF/WS1a9193826455f5ff18cb41610ec0a2e719-79f0.htm

I am not clear on whether it's the right way to go. Right now, we use only line segments and arcs in fonts, so anisotropic scaling is not possible. A quick could be replacing all arcs by elliptic, and a separate scaling factor (meaning a x-/y-direction 2d factor) can scale the font entities, even for anisotropic cases. Good thing the change could be limited to the text class.

Another choice could be quadratic splines(lc_splinepoints), as dxf supports polylines with quadratic splines, but the changes would be in both the text level and also at dxf level.

Mtext also has performance and correctness issues. One reason for poor performance could be excess update() calls, due to the tree structures of text. Text alignment needs to based on bounding boxes,

https://github.com/LibreCAD/LibreCAD/issues/1894

After that, we need to fix right-to-left, and top-to-bottom language support.

sand1024 wrote

@dxli - It's funny, yet after this post I'm thinking whether we may add support of elliptic arcs to polyline as segment types (in addition to existing line and arc entities) to handle proper scaling of arcs...
That might be nice feature as is, plus we'll get better scaling and also get rid of fonts with arc related issues..