Re: [ft-devel] Generating Windows text metrics

[Huw Davies]

On Tue, Jan 22, 2013 at 04:03:20PM +0000, Tony Smith wrote:
> 
> In the Windows API function ::CreateFont the height can be passed in two ways.
> A negative height gives metrics for fit to character height and a positive
> heights means fit to cell height.
> Here is the MSDN page for some more details.
> http://msdn.microsoft.com/en-gb/library/windows/desktop/
> dd183499%28v=vs.85%29.aspx
>  
> Can Freetype also generate text metrics for both fit to character height and
> fit to cell height?

Have a look at how it's done in Wine (www.winehq.org)

load_VDMX is used if the font has a VDMX table:
http://source.winehq.org/source/dlls/gdi32/freetype.c#L4212

otherwise the fallback calc_ppem_for_height:
http://source.winehq.org/source/dlls/gdi32/freetype.c#L3919

Elsewhere in that file you'll find how the rest of the metrics are
calculated.

Huw.