[Gzz] PEG vobcoorder_fontscale

[Tuomas Lukka]

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PEG vobcoorder_fontscale--tjl: 
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:Author:   Tuomas Lukka
:Date:     $Date: 2002/11/06 12:28:49 $
:Revision: $Revision: 1.3 $
:Status:   Current

We need to improve the scale mechanism for fonts.

Issues
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- How should getFontScale be used with TextStyle and TextVob?

    RESOLVED: In a bit awkward way, but workable::

        scale = coords.getFontScale(cs)
        height = textStyle.getHeight(scale) / scale
        textcs = coords.ortho(cs, 0, 0, height, height)
        vs.put(textvob, textcs)

    This example puts text that is in the natural height of its textStyle inside
    the coordinate system.

Changes
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Into VobCoorder, add::

    /** Get the scale that vobs put into this coordsys have,
     * for use with AWT font metrics.
     * The semantics depends on the current windowing system:
     * <ul>
     * <li> If fonts in the current system scale in any desirable way,
     *      this method will always return 1.
     * <li> If fonts in the current system change their metrics as a result
     *      of scaling (e.g. AWT), this method returns the ratio between 
     *      the change of coordinates inside the coordinate system and the
     *      change of coordinates in the window coordinates, i.e. the 
magnification
     *      ratio.
     *          If the coordinate system is an anisotropic scaling, the results
     *          are undefined (but should be reasonable, somewhere between the 
two
     *          scales).
     * </ul>
     */
    float getFontScale(int cs);