This function convert a text shape to a set of polygons for the 3D viewer.
Texts shapes are a bit special and can generate a lot of small overlapping polygons.
These polygons are now merged before being added to the list of polygons handled
by the 3D viewer draw functions.
Locally merging polygons is usually not efficient but in this case it can speedup
the 3D viewer (up to 10x).
Mainly noticeable for silkscreen layers when the "copper" thickness is shown
Since EDA_TEXT is a base class, we can just force the child classes to pass the correct iu scaled size
ALLOW_BOLD_THICKNESS removed because it's a pre-custom font holdover
When building the connectivity database, we should not be using the
connectivity to check for shapes.
To make this deterministic, we introduce two flags (ALWAYS_FLASH and
NEVER_FLASH) that are used with connectivity building to determine
whether a pad is flashed for connectivity or not. ZONE <-> PAD/VIA
connectivity will be checked with ALWAYS_FLASHED and all other
connectivity will be checked with NEVER_FLASHED if they are marked for
potential annular ring removal. If they are not marked for removal,
they will be checked ALWAYS_FLASHED.
Fixes https://gitlab.com/kicad/code/kicad/issues/11114
Jeff Young
jean-pierre charras
Mark Roszko
Seth Hillbrand