From: Leonard Rosenthol (leonardr@lazerware.com)
Date: Tue Apr 30 2002 - 16:02:13 EDT
At 8:44 PM +0100 4/30/02, Tomas Frydrych wrote:
>Yes, we will need to patch Pango. There are two ways we can
>approach zooming. If we tell FT to produce the glyphs at the same
>point size but at twice the resolution than the screen has, we will
>get a bitmap that corresponds to 200% zoom.
Yes, but you will get metrics that aren't necessary scaled
appropriately - and you'll continue to get the same problems that you
are experiencing today.
> Patching Pango to
>allow us to change the resolution is very simple and we will have to
>do it anyway to be able to generate PostScript.
Shouldn't have anything to do with PS...
>The other option is to use the transform functions in FT,
And this is what we should be doing...
> which
>would allow us to do other transformations than linear zooming
>when we want to;
Yes, though not necessarily important today (though maybe in
the future for things like rotated text cells, etc.)
>again, adding the api to Pangoft2 for this would
>be straight forward, but I have to confess I havn't got a clue how to
>use the transform matrix and vector.
>
Scaling is easy. A 2x3 affine matrix (which is what
Postscript, PDF, SVG, FreeType, etc. all use) is setup with the base
matrix as [ 1 0 0 1 0 0 ], where the 1's represent the scaling
factor. So to zoom, you just change that to [ scaleX 0 0 scaleY 0 0
] and away you go.
LDR
-- --------------------------------------------------------------------------- Leonard Rosenthol <mailto:leonardr@lazerware.com> <http://www.lazerware.com>
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