[gs-bugs] [Bug 698767] - Ghostscript - Poor rendering of Multiple Master fonts

[b***@artifex.com]

http://bugs.ghostscript.com/show_bug.cgi?id=698767

Bug ID: 698767
Summary: Poor rendering of Multiple Master fonts
Product: Ghostscript
Version: master
Hardware: PC
OS: Windows 7
Status: UNCONFIRMED
Severity: normal
Priority: P4
Component: Font API
Assignee: ***@artifex.com
Reporter: ***@artifex.com
QA Contact: gs-***@ghostscript.com
Word Size: ---

Created attachment 14475
--> http://bugs.ghostscript.com/attachment.cgi?id=14475&action=edit
example file

The attached file renders poorly compared to the ancient version 8.71 the
customer is using as a reference.

I *think* the fonts in question are all instances of a Multiple Master font
(Adobe Serif MM) despite the names. I am a little puzzled that we do seem to be
loading one font from disk (NimbusMonoPS-Regular in current code) apparently as
a substitute for Courier which the input file does not use, but is possibly
loaded by the Windows prolog.

Specific problems, when compared to the 8.71 output:

There are dropouts at the tops of curves in the body text, see for example the
h, s, a, p, e in "This chapter applies..."

Inconsistent stem widths, again see the h, p, t and r in the text "This chapter
applies..."

Capital letters are 'squashed' horizontally in some cases. See the D and B in
the bold text "Dialogic Brooktrout" and also the T and F in "TruFax".

Much less noticeable, but... lower case glyphs with a cruve seem to be somewhat
expanded horizontally. See the o in "For detailed hardware..." or all the
characters in 'boards' in the text "Dialogic Brooktrout TruFax boards"

[b***@artifex.com]

http://bugs.ghostscript.com/show_bug.cgi?id=698767

Ken Sharp <***@artifex.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
Customer| |999999
Priority|P4 |P2

[b***@artifex.com]

http://bugs.ghostscript.com/show_bug.cgi?id=698767

Chris Liddell (chrisl) <***@artifex.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Status|UNCONFIRMED |IN_PROGRESS

--- Comment #1 from Chris Liddell (chrisl) <***@artifex.com> ---
The first (and probably biggest) problem is that we ignore almost all the
MultipleMaster entries when serializing the font dictionaries to pass into
Freetype - there's just enough included for Freetype to know it started as an
MM font, but not enough for it to use it as an MM font.

I'll work to resolve that, first, then consider any remaining issues when we
see the results.