System.Drawing.FontFamily->IsStyleAvailable always returns true

Question

Im using a PrivateFontCollection to load a font via the AddMemoryFont. I retrieve the FontFamily, and then I query it using IsStyleAvailable to determine what the font supports as styles. However, with myriad fonts every single call to IsStyleAvailable returns true.

PrivateFontCollection pfc = new PrivateFontCollection();
var fontBuffer = Marshal.AllocCoTaskMem(dta.Length);
Marshal.Copy(dta, 0, fontBuffer, dta.Length);
pfc.AddMemoryFont(fontBuffer, dta.Length);

System.Drawing.FontFamily fam = pfc.Families[0];
if (fam.IsStyleAvailable(d.FontStyle.Bold)) //do something

Does anyone know how to get the actual style information from the FontFamily? If you look at the C:\Windows\Fonts folder you can see the supported styles. For example: Agency FB supports Bold; Regular, but when I query it in this fashion I get styles for Underline, Strikeout, and Italic, as well as Bold and Regular.

Is there a better way to go about this?

Answer 1

The font engine in Windows knows how to synthesize a style from the unstyled base font. It isn't particularly difficult to do on paper, just makes the stems fatter to get bold, tilt them to get italic, draw a line to get underline or strike-out. It isn't exactly as pretty as the dedicated outlines that a good designer will create but it certainly gets the job done. So when you ask "can you do that?" then you'll get a resounding "sure thing!"

Since you explicitly added the TTF files, you already know what styles are directly supported without synthesis and should not need to ask. Finding out anyway is perhaps possible with pinvoke and/or digging through the TTF tables but it is going to be ugly and certainly not directly supported by .NET. There's no winapi function I know of that tells you directly.