Hi Garulfo, Thank you for sharing your nice example: it typesets correctly with mkiv, but it seems to me that with LMTX the text does not appear (at least on my installation of the latest LMTX). Best regards: Otared

On 24 Dec 2020, at 00:14, Garulfo wrote:

Thanks Taco,

I made some progress : https://wiki.contextgarden.net/Talk:Cover_Pages

I now have two additional questions ... ;-)

- How can I deal with "space" characters (because current solution requires to explicitly add the ~ character)

- What would be the work to do in order to make this mechanism directly usable in metapost / metafun, within \startMPpage \stopMPpage, - to avoid switching between \start\stopMPdrawing and TeX - to have something like "draw followtext" in mp-blob.mpiv ?

%------------------------------------------------------------------------------

\setuppapersize [A4]

%------------------------------------------------------------------------------

\def\MyFont{\definedfont[name:% texgyrepagellabold% %exo2black% %agaramondprobold% *default at 55pt]}

%------------------------------------------------------------------------------

\startluacode

function document.outlinepaths(character) local chardata = fonts.hashes.characters[true] -- by unicode local shapedata = fonts.hashes.shapes[true] -- by index local c = chardata[character] if c and c.index and shapedata then local shapeglyphs = shapedata.glyphs or { } local glyph = shapeglyphs[c.index] if glyph and (glyph.segments or glyph.sequence) then local units = shapedata.units or 1000 local factor = 100/units return fonts.metapost.paths(glyph,factor) end end return { } end

function document.defineoutline(char,target) local outlines = document.outlinepaths(char) local nofpaths = #outlines context("\\startMPdrawing") -- ADDED by garulfo context("path %s[] ;",target) context("numeric %sn ; %sn := %s ;",target,target,nofpaths) for i=1,nofpaths do context("%s[%i] := %s ; ",target,i,outlines[i]) end context("\\stopMPdrawing") -- ADDED by garulfo end

\stopluacode

%------------------------------------------------------------------------------

\def\mpdefineoutlines#1#2{\ctxlua{document.defineoutline(\number`#1,"#2")}}

%------------------------------------------------------------------------------

\def\EmptyLetters#1% {% \resetMPdrawing \MPtoks={} % \startMPdrawing picture pic[], pictA ; numeric wid[], len[], pos[], n ; wid[0] := len[0] := pos[0] := n := 0 ; numeric scaling; path pictB , frame ; pair shiftB ; picture monImageA; monImageA := nullpicture; picture monImageB; monImageB := nullpicture; color colorframe; colorframe := 0.6white; % \stopMPdrawing % \MyFont\handletokens#1\with\whatever % \startMPdrawing frame := unitsquare xscaled ( (xpart urcorner monImageB - xpart llcorner monImageB) + 5mm ) yscaled ( (ypart urcorner monImageB - ypart llcorner monImageB) + 5mm ); frame := frame shifted (center monImageB - center frame); addto monImageB contour frame withpostscript "evenodd" withcolor transparent (1,1.,colorframe); draw monImageB ; draw monImageA ; \stopMPdrawing % \MPdrawingdonetrue \getMPdrawing}

%------------------------------------------------------------------------------

\def\whatever#1% {\appendtoks#1\to\MPtoks \setbox\MPbox=\hbox{\MyFont\the\MPtoks}% % \startMPdrawing n := n + 1 ; len[n] := \the\wd\MPbox ; \stopMPdrawing % \mpdefineoutlines{M}{MaLettre} % \startMPdrawing pictA := textext.drt("\MyFont M") ; pictB := MaLettre[1]; scaling := bbheight pictA / bbheight pictB; \stopMPdrawing % \doifinstringelse{~}{#1}{}{% HOW TO PROPERLY COPE WITH SPACES ? \mpdefineoutlines{#1}{MyGlyph} % \startMPdrawing string sb; sb := "i"; pic[n] := textext.drt("\MyFont\setstrut\strut#1") ; % shiftB := - llcorner pic[n]; pic[n] := pic[n] shifted shiftB ; % wid[n] := abs(xpart urcorner pic[n] - xpart llcorner pic[n]) ; pos[n] := len[n]-wid[n] ; % addto monImageB contour ((MyGlyph[1] scaled scaling) shifted ( (pos[n],0) + shiftB)) withpostscript "collect"; % if MyGlyphn > 1 : for ind=2 upto MyGlyphn : if (((xpart llcorner MyGlyph[ind]) > (xpart llcorner MyGlyph[1])) and ((ypart llcorner MyGlyph[ind]) > (ypart llcorner MyGlyph[1])) and ((xpart urcorner MyGlyph[ind]) < (xpart urcorner MyGlyph[1])) and ((ypart urcorner MyGlyph[ind]) < (ypart urcorner MyGlyph[1]))) : % addto monImageA contour (MyGlyph[ind] scaled scaling) shifted ( (pos[n],0) + shiftB) withcolor transparent (1,1.,colorframe); else : addto monImageB contour (MyGlyph[ind] scaled scaling) shifted ( (pos[n],0) + shiftB) withpostscript "collect"; fi; endfor; fi; \stopMPdrawing}}

%============================================================================== %==============================================================================

\starttext

%------------------------------------------------------------------------------

\startuseMPgraphic{MyBackgroundGraphic} path pathbackground ; numeric dimA ; dimA := \the\paperwidth; numeric dimB ; dimB := \the\paperheight; pathbackground := unitsquare xscaled dimA yscaled dimB ; fill pathbackground withshademethod "linear" withshadedirection(0,1) withshadecolors (red,blue); \stopuseMPgraphic

%------------------------------------------------------------------------------

\definelayer[MyBackgroundLayer] \setlayer[MyBackgroundLayer]{\useMPgraphic{MyBackgroundGraphic}} \setupbackgrounds[page][background={MyBackgroundLayer}]

%------------------------------------------------------------------------------

\EmptyLetters{MetaPost~is~fun!} \EmptyLetters{ABCDEFGHIJ} \EmptyLetters{KLMNOPQRST} \EmptyLetters{UVWXYZ!?\&*} \EmptyLetters{abcdefghij} \EmptyLetters{klmnopqrst} \EmptyLetters{uvwxyz<>;:@} \EmptyLetters{0123456789}

%------------------------------------------------------------------------------

\stoptext

Le 21/12/2020 à 16:29, Taco Hoekwater a écrit :

...

...

On 21 Dec 2020, at 16:09, Garulfo wrote:

Hi,

* I try to "remove the paths of text" from a metapost pictures to let the background visible.

* Using https://mailman.ntg.nl/pipermail/ntg-context/2018/thread.html#92725

* I was able to get the following with one glyph (MVE code below)

https://wiki.contextgarden.net/images/d/d2/test_extract_glyphs.pdf

2 questions:

1/ for some fonts (e.g. dejavu vs latin modern) the "encompassing" path of the B glyph can switch from B[1] to B[Bn]. Is there a trick to identify which id match with "the encompassing" path ? What you get is the order of the paths as defined in the font, which is arbitrary, as you discovered. A quick trick (that will not always work, but should work quite well for font variations of alphabetics) is to check the actual arclength of the paths. The longest one will typically be the outer one. But much depends on the font, so a generic solution is likely quite complicated. Consider an outline font’s colon glyph ;)

2/ now, I would like to do the same, but for text... a kind of derivative of "textext" or "outlinetext". Would you please give me some guidelines ? does it already exist ? should I use something like \handletokens, \scantokens ? do you have examples where I can get inspiration ?

Thanks again for your help, Garulfo

%==============================================================================

\starttext

%------------------------------------------------------------------------------

\startluacode

function document.outlinepaths(character) local chardata = fonts.hashes.characters[true] -- by unicode local shapedata = fonts.hashes.shapes[true] -- by index local c = chardata[character] if c and c.index and shapedata then local shapeglyphs = shapedata.glyphs or { } local glyph = shapeglyphs[c.index] if glyph and (glyph.segments or glyph.sequence) then local units = shapedata.units or 1000 local factor = 100/units return fonts.metapost.paths(glyph,factor) end end return { } end

function document.defineoutline(char,target) local outlines = document.outlinepaths(char) local nofpaths = #outlines context("path %s[] ;",target) context("numeric %sn ; %sn := %s ;",target,target,nofpaths) for i=1,nofpaths do context("%s[%i] := %s ; ",target,i,outlines[i]) end end

\stopluacode

%------------------------------------------------------------------------------

\def\mpdefineoutlines#1#2{\ctxlua{document.defineoutline(\number`#1,"#2")}}

%------------------------------------------------------------------------------

\startMPpage

numeric dimA ; dimA := 20cm;

path pathbackground ; pathbackground := unitsquare scaled dimA ; fill pathbackground withshademethod "linear" withshadedirection(0,1) withshadecolors (red,blue);

%--------------------------------------

\mpdefineoutlines{B}{B}

%--------------------------------------

numeric dimB ; dimB := 2cm; numeric vratio ; vratio := 2;

path frame ; frame := unitsquare xscaled (dimA - 2 * dimB) yscaled (dimA / vratio) shifted (dimB , (dimA - (dimA / vratio))/2 );

%--------------------------------------

pair shift ; shift := center frame; numeric scal ; scal := (0.9) * (10cm / (bbheight B[1])) ;

picture monImageB; monImageB := nullpicture; addto monImageB contour (B[1] shifted (- center B[1]) scaled scal) shifted shift withpostscript "collect";

addto monImageB contour frame withpostscript "evenodd";

for i=2 upto Bn : addto monImageB contour (B[i] shifted (- center B[1]) scaled scal) shifted shift; endfor ;

%--------------------------------------

draw monImageB withcolor white;

\stopMPpage

\stoptext ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://context.aanhet.net archive : https://bitbucket.org/phg/context-mirror/commits/ wiki : http://contextgarden.net ___________________________________________________________________________________ Taco Hoekwater Elvenkind BV

---

If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://context.aanhet.net archive : https://bitbucket.org/phg/context-mirror/commits/ wiki : http://contextgarden.net ___________________________________________________________________________________

---

If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://context.aanhet.net archive : https://bitbucket.org/phg/context-mirror/commits/ wiki : http://contextgarden.net ___________________________________________________________________________________

On 12/24/2020 12:14 AM, Garulfo wrote:

Thanks Taco,

I made some progress : https://wiki.contextgarden.net/Talk:Cover_Pages

I now have two additional questions ... ;-)

- How can I deal with "space" characters (because current solution   requires to explicitly add the ~ character)

- What would be the work to do in order to make this mechanism directly   usable in metapost / metafun, within \startMPpage \stopMPpage,   - to avoid switching between \start\stopMPdrawing and TeX   - to have something like "draw followtext" in mp-blob.mpiv ?

Maybe pickup some tricks from this: \starttext \startMPpage StartPage; fill Page withshademethod "linear" withshadedirection(0,1) withshadecolors (red, blue) ; picture p ; p := lmt_outline [ text = "\strut foo f o o", drawcolor = "white", rulethickness = .2 ] ysized 5cm ; draw (p shifted - center p) shifted center Page; StopPage; \stopMPpage \startuseMPgraphic{MyShade} fill OverlayBox withshademethod "linear" withshadedirection(0,1) withshadecolors (red, blue) ; \stopuseMPgraphic \defineoverlay[MyShade][\useMPgraphic{MyShade}] \setupbackgrounds[page][background=MyShade] \startmakeup \definedfont[SerifBold*default @ 50pt] \setupinterlinespace \defineeffect[MyOutline][alternative=outer,rulethickness=1pt] \startcolor[white] \starteffect[MyOutline] \input jojomayer \stopeffect \stopcolor \stopmakeup \stoptext

%------------------------------------------------------------------------------

\setuppapersize  [A4]

%------------------------------------------------------------------------------

\def\MyFont{\definedfont[name:% texgyrepagellabold% %exo2black% %agaramondprobold% *default at 55pt]}

%------------------------------------------------------------------------------

\startluacode

function document.outlinepaths(character)     local chardata  = fonts.hashes.characters[true] -- by unicode     local shapedata = fonts.hashes.shapes[true] -- by index     local c         = chardata[character]     if c and c.index and shapedata then         local shapeglyphs = shapedata.glyphs or { }         local glyph       = shapeglyphs[c.index]         if glyph and (glyph.segments or glyph.sequence) then             local units  = shapedata.units or 1000             local factor = 100/units             return fonts.metapost.paths(glyph,factor)         end     end     return { } end

function document.defineoutline(char,target)     local outlines = document.outlinepaths(char)     local nofpaths = #outlines     context("\\startMPdrawing")                             -- ADDED by garulfo     context("path %s[] ;",target)     context("numeric %sn ; %sn := %s ;",target,target,nofpaths)     for i=1,nofpaths do         context("%s[%i] := %s ; ",target,i,outlines[i])     end     context("\\stopMPdrawing")                              -- ADDED by garulfo end

\stopluacode

%------------------------------------------------------------------------------

\def\mpdefineoutlines#1#2{\ctxlua{document.defineoutline(\number`#1,"#2")}}

%------------------------------------------------------------------------------

\def\EmptyLetters#1% {% \resetMPdrawing \MPtoks={} % \startMPdrawing   picture pic[], pictA ;   numeric wid[], len[], pos[], n ;   wid[0] := len[0] := pos[0] := n := 0 ;   numeric scaling;   path pictB , frame ;   pair shiftB ;   picture monImageA; monImageA := nullpicture;   picture monImageB; monImageB := nullpicture;   color colorframe;  colorframe := 0.6white; % \stopMPdrawing % \MyFont\handletokens#1\with\whatever % \startMPdrawing   frame :=  unitsquare           xscaled ( (xpart urcorner monImageB - xpart llcorner monImageB) + 5mm )           yscaled ( (ypart urcorner monImageB - ypart llcorner monImageB) + 5mm );   frame := frame shifted (center monImageB - center frame);   addto monImageB contour         frame         withpostscript "evenodd"         withcolor transparent (1,1.,colorframe);   draw monImageB ;   draw monImageA ; \stopMPdrawing % \MPdrawingdonetrue \getMPdrawing}

%------------------------------------------------------------------------------

\def\whatever#1%   {\appendtoks#1\to\MPtoks    \setbox\MPbox=\hbox{\MyFont\the\MPtoks}%    %    \startMPdrawing      n := n + 1 ; len[n] := \the\wd\MPbox ;    \stopMPdrawing    %    \mpdefineoutlines{M}{MaLettre}    %    \startMPdrawing    pictA := textext.drt("\MyFont M") ;    pictB := MaLettre[1];    scaling := bbheight pictA / bbheight pictB;    \stopMPdrawing    %    \doifinstringelse{~}{#1}{}{%                HOW TO PROPERLY COPE WITH SPACES ?    \mpdefineoutlines{#1}{MyGlyph}    %    \startMPdrawing      string sb; sb := "i";      pic[n] := textext.drt("\MyFont\setstrut\strut#1") ;      %      shiftB := - llcorner pic[n];      pic[n] := pic[n] shifted shiftB ;      %      wid[n] := abs(xpart urcorner pic[n] - xpart llcorner pic[n]) ;      pos[n] := len[n]-wid[n] ;      %      addto monImageB contour            ((MyGlyph[1] scaled scaling)            shifted ( (pos[n],0) +  shiftB))            withpostscript "collect";      %      if MyGlyphn > 1 :         for ind=2 upto MyGlyphn :             if (((xpart llcorner MyGlyph[ind]) > (xpart llcorner MyGlyph[1])) and                 ((ypart llcorner MyGlyph[ind]) > (ypart llcorner MyGlyph[1])) and                 ((xpart urcorner MyGlyph[ind]) < (xpart urcorner MyGlyph[1])) and                 ((ypart urcorner MyGlyph[ind]) < (ypart urcorner MyGlyph[1]))) :                 %                 addto monImageA contour                       (MyGlyph[ind] scaled scaling)                       shifted ( (pos[n],0) +  shiftB)                       withcolor transparent (1,1.,colorframe);             else :                 addto monImageB contour                       (MyGlyph[ind] scaled scaling)                       shifted ( (pos[n],0) +  shiftB)                       withpostscript "collect";             fi;          endfor;       fi;    \stopMPdrawing}}

%==============================================================================

%==============================================================================

\starttext

%------------------------------------------------------------------------------

\startuseMPgraphic{MyBackgroundGraphic}   path pathbackground ;   numeric dimA ; dimA := \the\paperwidth;   numeric dimB ; dimB := \the\paperheight;   pathbackground :=  unitsquare xscaled dimA yscaled dimB ;   fill pathbackground        withshademethod "linear"        withshadedirection(0,1)        withshadecolors (red,blue); \stopuseMPgraphic

%------------------------------------------------------------------------------

\definelayer[MyBackgroundLayer] \setlayer[MyBackgroundLayer]{\useMPgraphic{MyBackgroundGraphic}} \setupbackgrounds[page][background={MyBackgroundLayer}]

%------------------------------------------------------------------------------

\EmptyLetters{MetaPost~is~fun!} \EmptyLetters{ABCDEFGHIJ} \EmptyLetters{KLMNOPQRST} \EmptyLetters{UVWXYZ!?\&*} \EmptyLetters{abcdefghij} \EmptyLetters{klmnopqrst} \EmptyLetters{uvwxyz<>;:@} \EmptyLetters{0123456789}

%------------------------------------------------------------------------------

\stoptext

Le 21/12/2020 à 16:29, Taco Hoekwater a écrit :

...

...

On 21 Dec 2020, at 16:09, Garulfo wrote:

Hi,

* I try to "remove the paths of text" from a metapost pictures to let   the background visible.

* Using   https://mailman.ntg.nl/pipermail/ntg-context/2018/thread.html#92725

* I was able to get the following with one glyph (MVE code below)

  https://wiki.contextgarden.net/images/d/d2/test_extract_glyphs.pdf

2 questions:

1/ for some fonts (e.g. dejavu vs latin modern) the "encompassing" path    of the B glyph can switch from B[1] to B[Bn]. Is there a trick to    identify which id match with "the encompassing" path ?

What you get is the order of the paths as defined in the font, which is arbitrary, as you discovered.

A quick trick (that will not always work, but should work quite well for font variations of alphabetics) is to check the actual arclength of the paths. The longest one will typically be the outer one.

But much depends on the font, so a generic solution is likely quite complicated. Consider an outline font’s colon glyph ;)

...

2/ now, I would like to do the same, but for text... a kind of    derivative of "textext" or "outlinetext".    Would you please give me some guidelines ?     does it already exist ?     should I use something like \handletokens, \scantokens ?     do you have examples where I can get inspiration ?

Thanks again for your help, Garulfo

%==============================================================================

\starttext

%------------------------------------------------------------------------------

\startluacode

function document.outlinepaths(character)     local chardata  = fonts.hashes.characters[true] -- by unicode     local shapedata = fonts.hashes.shapes[true] -- by index     local c         = chardata[character]     if c and c.index and shapedata then         local shapeglyphs = shapedata.glyphs or { }         local glyph       = shapeglyphs[c.index]         if glyph and (glyph.segments or glyph.sequence) then             local units  = shapedata.units or 1000             local factor = 100/units             return fonts.metapost.paths(glyph,factor)         end     end     return { } end

function document.defineoutline(char,target)     local outlines = document.outlinepaths(char)     local nofpaths = #outlines     context("path %s[] ;",target)     context("numeric %sn ; %sn := %s ;",target,target,nofpaths)     for i=1,nofpaths do         context("%s[%i] := %s ; ",target,i,outlines[i])     end end

\stopluacode

%------------------------------------------------------------------------------

\def\mpdefineoutlines#1#2{\ctxlua{document.defineoutline(\number`#1,"#2")}}

%------------------------------------------------------------------------------

\startMPpage

numeric dimA ; dimA := 20cm;

path pathbackground ; pathbackground :=  unitsquare scaled dimA ; fill pathbackground withshademethod "linear" withshadedirection(0,1) withshadecolors (red,blue);

%--------------------------------------

\mpdefineoutlines{B}{B}

%--------------------------------------

numeric dimB  ; dimB := 2cm; numeric vratio ; vratio := 2;

path frame ; frame :=  unitsquare           xscaled (dimA - 2 * dimB)           yscaled (dimA / vratio)           shifted (dimB , (dimA - (dimA / vratio))/2 );

%--------------------------------------

pair shift ; shift := center frame; numeric scal ; scal := (0.9) * (10cm / (bbheight B[1])) ;

picture monImageB; monImageB := nullpicture; addto monImageB contour       (B[1] shifted (- center B[1]) scaled scal)       shifted shift       withpostscript "collect";

addto monImageB contour       frame       withpostscript "evenodd";

for i=2 upto Bn :   addto monImageB contour         (B[i] shifted (- center B[1]) scaled scal)         shifted shift; endfor ;

%--------------------------------------

draw monImageB withcolor white;

\stopMPpage

\stoptext ___________________________________________________________________________________

If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage  : http://www.pragma-ade.nl / http://context.aanhet.net archive  : https://bitbucket.org/phg/context-mirror/commits/ wiki     : http://contextgarden.net ___________________________________________________________________________________

Taco Hoekwater Elvenkind BV

___________________________________________________________________________________

If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage  : http://www.pragma-ade.nl / http://context.aanhet.net archive  : https://bitbucket.org/phg/context-mirror/commits/ wiki     : http://contextgarden.net ___________________________________________________________________________________

___________________________________________________________________________________

If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage  : http://www.pragma-ade.nl / http://context.aanhet.net archive  : https://bitbucket.org/phg/context-mirror/commits/ wiki     : http://contextgarden.net ___________________________________________________________________________________

-- ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

Much more lean now thanks to your feedbacks. I prefered to "remove the shapes of the letter" rather than doubling the shading. Wikified https://wiki.contextgarden.net/Cover_Pages#.22Empty.22_letters \definecolor [ColorHighA] [h=c4a000] \definecolor [ColorHighB] [h=602217] \definecolor [ColorLow] [0.8(white)] \startMPpage %------------------------------------------------------------------------------ picture tt ; tt := lmt_outline [ kind = "fillup", text = "\definedfont[name:texgyrepagellabold*default]% \framed[frame=off,offset=3mm,align=middle,strut=none] {MetaPost\\is Fun !\\Aujourd'hui\\Today\\*§ 2020 §*}", ] xsized 12cm ; path bb ; bb := boundingbox tt; %------------------------------------------------------------------------------ path pp ; pp := bb enlarged 2cm ; fill pp withshademethod "linear" withshadedirection (2.,0.) withshadecolors (\MPcolor{ColorHighA}, \MPcolor{ColorHighB}); %------------------------------------------------------------------------------ picture Paddmissing; Paddmissing := nullpicture; picture Pwoletters; Pwoletters := nullpicture; numeric testwithin ; %------------------------------------------------------------------------------ for i within tt : if stroked i or filled i : testwithin :=0; for j within tt : if stroked j or filled j: if (((xpart llcorner i) > (xpart llcorner j)) and ((ypart llcorner i) > (ypart llcorner j)) and ((xpart urcorner i) < (xpart urcorner j)) and ((ypart urcorner i) < (ypart urcorner j))) : testwithin :=1; fi; fi; endfor; if testwithin == 1: addto Paddmissing contour (pathpart i) withcolor \MPcolor{ColorLow}; else: addto Pwoletters contour (pathpart i) withpostscript "collect"; fi; fi ; endfor ; %------------------------------------------------------------------------------ addto Pwoletters contour bb withpostscript "evenodd" withcolor \MPcolor{ColorLow}; draw Pwoletters ; draw Paddmissing ; \stopMPpage