This adds a new configuration "font-synthetic-style" to enable or
disable synthetic styles. This is different from "font-style-*" which
specifies a named style or disables a style completely.
Instead, "font-synthetic-style" will disable only the creation of
synthetic styles in the case a font does not support a given style.
This is useful for users who want to obviously know when a font doesn't
support a given style or a user who wants to explicitly only use the
styles that were designed by the font designer.
The default value is to enable all synthetic styles.
Allows for high dpi displays to get odd numbered pixel sizes, for
example, 13.5pt @ 2px/pt for 27px font. This implementation performs
all the sizing calculations with f32, rounding to the nearest pixel
size when it comes to rendering. In the future this can be enhanced
by adding fractional scaling to support fractional pixel sizes.
Key contains pointers into DerivedConfig. Each surface has its own
DerivedConfig. This would cause memory corruption if the surface that
opened the initial font grid deallocates. Instead, let's make sure Key
owns its own DerivedConfig.
Fixes#1670
This fixes two issues:
- If no font families are set, font points would not change the hash.
- DPI changes would not change the hash.
When the hash doesn't change when it should, we reuse a font stack due
to changes in #1662. This would cause some font issues. :)
