Re: [cc65] TGI bitmap fnts revisited

From: "Ullrich von Bassewitz"; on Tue, July 12, 2011; at 05:03 PM -0400
>  
> On Tue, Jul 12, 2011 at 11:52:23PM +0300, Karri Kaksonen wrote:
> > I also would like to test that on the Lynx. The Lynx also is capable
> > of scaling bitmap fonts with fractional sizes. Every bitmap can be
> > scaled with a 16-bit integer.
> >  $0100 means 1:1.
> >  $0200 means 2:1
>  
> Is the scale 8.8 fixed-point? If so, that would be quite cool,
> since TGI in the snapshot requires the programmer to specify scaling
> in that format. The TGI kernel uses the fixed-point for the vector
> fonts; and, rounds it to the nearest integer for the bitmap fonts.
> The scaling factors currently look like this:
>  
> ; The following two store an 8.8 fixed point value in the first two bytes,
> ; and a rounded integer value in the third byte. The latter is passed to the
> ; driver to scale the bitmap font. The variables are expected to be in
> ; this order and adjacent.
> _tgi_textscalew:    .res    3           ; Text scale for the width
> _tgi_textscaleh:    .res    3           ; Text scale for the height
>  
> Not sure how to pass this down to the driver in an efficient manner;
> but, if the Lynx really is using 8.8 fixed-point, it would be a pity
> if we wouldn't do that.

I think that a "struct pointer" probably is the only efficient way
to send that info.  Then, the driver would fetch which-ever numbers
it can use.

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