Font: Invalid Characters

[Bumbala]

Hi experts,

As everybody knows escape characters from 0x00 to 0x20 are reserved by
system. I enumerate characters from 0x21 to 0xFF and display them in
my UI. However, for some fonts, some characters are displayed as
rectangles (or such) which I assume that they are invalid. Is there
any way to detect these invalid characters, so that I don't display
them in my UI.

Thank you.

[Bumbala]

Post by Bumbala
Hi experts,
As everybody knows escape characters from 0x00 to 0x20 are reserved by
system. I enumerate characters from 0x21 to 0xFF and display them in
my UI. However, for some fonts, some characters are displayed as
rectangles (or such) which I assume that they are invalid. Is there
any way to detect these invalid characters, so that I don't display
them in my UI.
Thank you.

Looks like some interop with GetGlyphIndices did the trick.