Re: resolution and zoom issues

From: Tomas Frydrych (
Date: Tue Apr 30 2002 - 15:44:23 EDT

  • Next message: Leonard Rosenthol: "Re: resolution and zoom issues"

    > The correct behavior when zooming is (IMHO) to simply adjust
    > the scaling factor for all objects - provided that everything is able
    > to be affine transformed. Now that we are (hopefully) moving to a
    > consistant font system (FreeType) which supports affines on the data -
    > text is easily addressed by simply specifying that to FT as part of
    > the glyph extraction process. (NOTE: we may have to modify/patch
    > Pango to support this - I don't know).

    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. 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.

    The other option is to use the transform functions in FT, which
    would allow us to do other transformations than linear zooming
    when we want to; 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.


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