Re: commit: Layout horizontally with screen units.

From: Martin Sevior (msevior@physics.unimelb.edu.au)
Date: Fri Jan 24 2003 - 21:07:17 EST

  • Next message: Andrew Dunbar: "Re: commit: Layout horizontally with screen units."

    On Sat, 25 Jan 2003, Andrew Dunbar wrote:

    > --- Martin Sevior <msevior@physics.unimelb.edu.au>
    > wrote: > On Fri, 24 Jan 2003, Patrick Lam wrote:
    > >
    > > > On Sat, Jan 25, 2003 at 06:28:22AM +1100, Martin
    > > Sevior wrote:
    > > >
    > > > > I left that in in case we needed to revert.
    > > >
    > > > I think that bonsai/cvs are better at capturing
    > > this sort of information
    > > > than leaving the code looking silly; ifdefs make
    > > the code harder to
    > > > maintain, and it's not like anyone's going to go
    > > and fix up all the evil
    > > > hacks left behind 6 months ago; these things just
    > > accumulate until no
    > > > one remembers why they're there anymore.
    > > >
    > > > > In any case I think abiword in this mode is much
    > > more user-friendly
    > > > > than when using layoutunits. Text does not
    > > extend past the left margin
    > > > > and there are no more disappearing runs in full
    > > justification.
    > > >
    > > > There's something I don't understand about font
    > > handling and layout units.
    > > > I'm going to look into it this weekend and see if
    > > I can understand it
    > > > more. Clearly text should not extend into the
    > > margins, but neither should
    > > > it wrap differently when printing.
    > > >
    > >
    > > We're up against accmulated rounding errors in
    > >
    > > 1. Choosing fonts sizes at low resolution.
    > > 2. Actual font widths on screen can be as small as 4
    > > pixels wide when the
    > > properlay scaled (from a high resolution device)
    > > would be say, 4.3 pixels
    > > 3. Low resolution hinting which shifts scaled fonts
    > > in a undefined manner.
    >
    > Surely then the only ways to guarantee that screen
    > text matches printed text is to scale screen fonts
    > using subpixels but with hinting turned off so that
    > character widths don't vary at small sizes.
    > But then we lose the nice look of small size fonts -
    > I'd only be willing to do this in Print Preview mode.

    In the end we have to place glyphs in the screen at integral values. The
    only way to get close on screen to what will be printed is the adjust EACH
    glyph to be within 0.5 pixels of where it would be on a high resolution
    device. This is what Joaquin is arguing for and what I agree with.

    Cheers

    Martin

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