Re: [cc65] tgi_outtext, no more questions, hopefully :)

From: Oliver Schmidt <>
Date: 2009-11-01 21:38:06
Hi Fatih,

> Well, you're technically right, even though Atari fonts are not typographically
> correct, one can assume that the last row is the descender. Should I change
> it?

While adjusting the Apple2 driver to the specs outlined here I had the
same idea, but now I think we rather need to strictly adhere to Uz'

"Then lets define that pixel fonts have their baseline at the bottom
pixel line of the bitmapped characters. This will be different for
vector fonts, but I see pixel fonts as something that should be simple
by design."

The rationale (beside the simplicity):

The TGI kernel is supposed to take care of clipping.

Let's presume a 320x200 pixel screensize and a 8 pixel font height.
Then for a horizonal text without magnification the TGI kernel will
make sure that the y position will be [7..199]. And for a vertical
text without magnification it will make sure that the x position will
be [7..319].

This means that the TGI kernel clipping presumes that the font extends
only to the top (or left) from the drawing position - and the driver
needs to work according to that presumtion in order to have the
clipping work correctly.

Best, Oliver
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Received on Sun Nov 1 21:38:13 2009

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