Re: Tracking in MKII and MKIV

[Hans Hagen <pragma@wxs.nl>]

On 16-8-2011 2:22, Raymond LeClair wrote:

> The graphic designer tells me it is very common to specify the interletter spacing, or tracking, and in fact, he considers this capability to be essential.

intercharacter spacing is ok for titling but for running text ... maybe 
common but not that good (after all it spoils the font design)

> I understand that these, so called, microtypography capabilities are present in pdfTeX fully, but only partially present in LuaTeX (protrusion and expansion), although tracking can be set in a way using \kerncharacters[0.5] in LuaTeX.

pdftex has some inter character kerning features but they are considered 
to be experimental and in context they are supported (see hand-ini.mkii) 
but I must admit that I never used it and have forgotten how to enable it

> However, the quality of the typesetting produced by LuaTeX is completely inadequate, while the quality of the typesetting produced by pdfTeX is very good.

nu clue (yet) but i might as well remove the old mechanism from mkiv as 
we have better ways

> Am I miss-understanding the differences in capability between pdfTeX and LuaTeX in this regard?

yes, see example below (somewhat changed so you might want to wikify it 
as example (it will confuse mojca's number of hits filters as 'twitter' 
and 'ladygaga' might lead to false google lookups).

\definepapersize[LG1][width=9.24in,height=6.87in]
\definepapersize[LP1][width=9.49in,height=7.12in]

\setuppapersize[LG1][LP1]

\setuplayout[location=middle,marking=off]

\definefont[LabelFont][Serif sa 0.583]

\definecharacterkerning [mykerning] [factor=.5]

\startbuffer
     THIS BOOK CONTAINS 988 TWEETS POSTED TO
     TWITTER BY LADYGAGA FROM MARCH 27, 2008
     TO AUGUST 5, 2011. IT WAS PUBLISHED ON
     DEMAND ON AUGUST 14, 2011
\stopbuffer

\startsetups covertext
     \framed
         [
             width=2.38888888889in,
             align=normal,
             frame=off,
             offset=0pt,
             foregroundstyle=\LabelFont
         ]
         {
             \baselineskip10.5pt
             \setcharacterkerning[mykerning]
             \getbuffer
             \par
         }
\stopsetups

\startuniqueMPgraphic{cover}
     StartPage ;
         left_margin := 0.347222222222in ;
         top_margin  := 0.347222222222in ;

     draw
         textext.lrt("\setups[covertext]")
         shifted ulcorner Page
         shifted (left_margin,-top_margin) ;

     StopPage ;
\stopuniqueMPgraphic

\defineoverlay[cover][\uniqueMPgraphic{cover}]

\definelayer
   [page]
   [width=\paperwidth,
    height=\paperheight]

\showframe

\starttext

     % variant one:

     \setupbackgrounds
       [paper]
       [background={cover}]

     \startstandardmakeup\stopstandardmakeup \page

     \setupbackgrounds
       [paper]
       [background=]

     % variant two:

     \setlayer
       [page]
       [preset=lefttop,
        offset=0.347222222222in]
       {\setups[covertext]}

     \setuplayout
       [page]

     \tightlayer[page] \page

     \setuplayout

\stoptext

Hans


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                                           Hans Hagen | PRAGMA ADE
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