Copying from
http://lists.cairographics.org/archives/cairo/2014-November/025824.html
Something I noticed while debugging
this is hb-view appears to be emitting a lot of empty glyphs. In large
documents this will unnecessarily increase the file size and increase
rendering time.
Adding some debug to cairo_show_text_glyphs and using the sample text:
کے
I get:
cairo_show_text_glyphs num_glyphs: 5
glyph 0: 1005
glyph 1: 1006
glyph 2: 1007
glyph 3: 248
glyph 4: 409
Using ttx I can see that
<mtx name="glyph01005" width="0" lsb="0"/>
<mtx name="glyph01006" width="0" lsb="0"/>
<mtx name="glyph01007" width="0" lsb="0"/>
and
<TTGlyph name="glyph01005" xMin="0" yMin="0" xMax="0" yMax="0">
<contour>
<pt x="0" y="0" on="1"/>
</contour>
<instructions><assembly>
</assembly></instructions>
</TTGlyph>
<TTGlyph name="glyph01006" xMin="0" yMin="0" xMax="0" yMax="0">
<contour>
<pt x="0" y="0" on="1"/>
</contour>
<instructions><assembly>
</assembly></instructions>
</TTGlyph>
<TTGlyph name="glyph01007" xMin="0" yMin="0" xMax="0" yMax="0">
<contour>
<pt x="0" y="0" on="1"/>
</contour>
<instructions><assembly>
</assembly></instructions>
</TTGlyph>
Original issue reported on code.google.com by behdad@google.com on 25 Nov 2014 at 7:04
Original issue reported on code.google.com by
behdad@google.com
on 25 Nov 2014 at 7:04