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%D \module
%D [ file=mp-blob.mpiv,
%D version=2018.04.08,
%D title=\CONTEXT\ \METAPOST\ graphics,
%D subtitle=Blobs,
%D author=Hans Hagen,
%D date=\currentdate,
%D copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.
%D This is a follow up on good old \type {meta-imp-txt}.
if known context_blob : endinput ; fi ;
boolean context_blob ; context_blob := true ;
numeric mfun_blob_n ; mfun_blob_n := 0 ;
picture mfun_blob_c ;
color mfun_blob_b ;
def mfun_reset_tex_blobs =
mfun_blob_n := 0 ;
mfun_blob_c := nullpicture ;
enddef ;
extra_endfig := extra_endfig & "mfun_reset_tex_blobs ; " ;
vardef mfun_inject_blob(expr n) =
mfun_blob_c := nullpicture ;
mfun_blob_b := lua.mp.blob_dimensions(mfun_blob_n,n) ;
addto mfun_blob_c doublepath unitsquare
xscaled redpart mfun_blob_b
yscaled (greenpart mfun_blob_b + bluepart mfun_blob_b)
shifted (0,- bluepart mfun_blob_b)
withprescript "tb_stage=inject"
withprescript "tb_blob=" & decimal lua.mp.blob_index(mfun_blob_n,n) ;
mfun_blob_c
enddef ;
% An example of usage:
newinternal followtextalternative ; followtextalternative := 1 ;
newinternal tracingfollowtext ; tracingfollowtext := 0 ;
newinternal autoscaleupfollowtext ; autoscaleupfollowtext := 2 ;
newinternal autoscaledownfollowtext ; autoscaledownfollowtext := 0 ;
vardef followtext(expr pth, txt) =
image (
mfun_blob_n := mfun_blob_n + 1 ;
if mfun_trial_run :
draw fullcircle scaled 100bp
withprescript "ft_stage=trial"
withprescript "ft_category=" & decimal mfun_blob_n
withpostscript txt ;
else :
save pat, al, at, pl, pc, wid, pos, ap, ad, pic, len, n, sc ;
path pat ; pat := pth ;
numeric al, at, pl, pc, wid, pos, len[], n, sc ;
pair ap, ad ;
picture pic[] ;
len[0] := 0 ;
n := lua.mp.blob_size(mfun_blob_n) ;
sc := 0 ;
for i=1 upto n :
pic[i] := mfun_inject_blob(i) ;
pic[i] := pic[i] shifted - llcorner pic[i] ;
len[i] := len[i-1] + lua.mp.blob_width(mfun_blob_n,i) ;
endfor ;
al := arclength pth ;
if al = 0 :
al := len[n] ;
pat := origin -- (al,0) ;
fi ;
if ((al < len[n]) and (autoscaleupfollowtext > 0)) or
((al > len[n]) and (autoscaledownfollowtext > 0)) :
sc := len[n] /al ;
pat := pat scaled sc ;
al := arclength pat ;
fi ;
if followtextalternative = 1 :
pl := (al-len[n])/(if n>1 : (n-1) else : 1 fi) ;
pc := 0 ;
else : % centered / MP
pl := 0 ;
pc := arclength pat/2 - len[n]/2 ;
fi ;
if tracingfollowtext = 1 :
draw pat withpen pencircle scaled 1pt withcolor blue ;
fi ;
for i=1 upto n :
wid := lua.mp.blob_width(mfun_blob_n,i) ;
pos := len[i]-wid/2 + (i-1)*pl + pc ;
at := arctime pos of pat ;
ap := point at of pat ;
ad := direction at of pat ;
pic[i] := pic[i] shifted (-wid/2,0) rotated(angle(ad)) shifted ap ;
draw pic[i] ;
if tracingfollowtext = 1 :
draw boundingbox pic[i] withpen pencircle scaled .25pt withcolor red ;
draw ap withpen pencircle scaled .50pt withcolor green ;
fi ;
endfor ;
if ((autoscaleupfollowtext = 2) or (autoscaledownfollowtext = 2)) and
(sc <> 0) and (sc <> 1):
currentpicture := currentpicture scaled (1/sc) ;
fi ;
if tracingfollowtext = 1 :
draw boundingbox currentpicture withpen pencircle scaled .25pt withcolor blue ;
fi ;
draw fullcircle scaled 100bp
withprescript "ft_stage=final"
withprescript "ft_category=" & decimal mfun_blob_n ;
fi ;
)
enddef ;
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