31 Jul
2023
31 Jul
'23
8:21 p.m.
Native GDI+ goes to great pains to make it look like fonts can be scaled without any distortion, so what you are seeing may be font metrics scaled from the font's em size to the size of the font you're drawing. I doubt it's based on the font geometry.
We don't do this because it's a lot of work to make the fonts look worse, as native GDI+ has to mess with character spacing a lot to achieve this.
It could be that the "gap" I'm seeing between MeasureString and MeasureCharacterRanges is "wiggle room" added by GDI+ to make it more likely that the text can fit in a scaled rectangle.