Re: Pango, Cairo, Scale, and Ink Rectangles

[Behdad Esfahbod <behdad behdad org>]

On 14-11-24 07:13 PM, Yclept Nemo wrote:
> On Mon, Nov 24, 2014 at 5:12 PM, Behdad Esfahbod <behdad behdad org
> <mailto:behdad behdad org>> wrote:
>
>     On 14-11-23 11:15 AM, Yclept Nemo wrote:
>     > This seems impossible if the glyph width/height ratios vary with scale/dpi.
>
>     Turn hinting off.  Like this:
>
>       https://git.gnome.org/browse/pango/tree/examples/cairotwisted.c#n477
>
>
> Thanks,
>
> It is a necessary suggestion, but unfortunately the glyph width/height ratios
> continue to vary.

Continue to vary in the exact same way?  Or varies, but much much closer to
eachother? Please attach full C test code as well as a pointer to the font,
with actual and expected output.


> I'm pretty sure I've followed the example correctly:
>
> Using Pango resolution:
>     cairo_fontoptions = cairo.FontOptions()
>     cairo_fontoptions.set_hint_metrics(cairo.HINT_METRICS_OFF)
>     cairo_fontoptions.set_hint_style(cairo.HINT_STYLE_NONE)
>     ctx.set_font_options(cairo_fontoptions)
>     ctx.identity_matrix()
>     pango_context = PangoCairo.create_context(ctx)
>     PangoCairo.context_set_resolution(pango_context, dpi)
>     l1 = Pango.Layout(pango_context)
>     l1.set_font_description(font_description)
>     l1.set_text("8",1)
>     e1 = l1.get_extents()[0]
>     print(e1.x / Pango.SCALE, ...)
>
> Using Cairo transformations:
>     cairo_fontoptions = cairo.FontOptions()
>     cairo_fontoptions.set_hint_metrics(cairo.HINT_METRICS_OFF)
>     cairo_fontoptions.set_hint_style(cairo.HINT_STYLE_NONE)
>     ctx.set_font_options(cairo_fontoptions)
>     ctx.identity_matrix()
>     ctx.scale(*(scale,)*2)
>     layout = PangoCairo.create_layout(ctx)
>     layout.set_font_description(font_description)
>     layout.set_text("8",1)
>     e1 = layout.get_extents()[0]
>     print(e1.x / Pango.SCALE, ...)
>
> Sincerely,

-- 
behdad
http://behdad.org/