1 files changed, 61 insertions, 0 deletions
diff --git a/tex/context/base/meta-ini.mkiv b/tex/context/base/meta-ini.mkiv
index 78d17b95d..32f72cfe6 100644
--- a/tex/context/base/meta-ini.mkiv
+++ b/tex/context/base/meta-ini.mkiv
@@ -1364,6 +1364,67 @@
     defaultcolormodel := \ifcase\MPcolormethod1\or1\or3\else3\fi;
 \stopMPinitializations
 
+%D macros
+%D  {mprunvar,mpruntab,mprunset}
+%D
+%D \starttyping
+%D \startMPcode
+%D     passvariable("version","1.0") ;
+%D     passvariable("number",123) ;
+%D     passvariable("string","whatever") ;
+%D     passvariable("point",(1.5,2.8)) ;
+%D     passvariable("triplet",(1/1,1/2,1/3)) ;
+%D     passvariable("quad",(1.1,2.2,3.3,4.4)) ;
+%D     passvariable("boolean",false) ;
+%D     passvariable("path",fullcircle scaled 1cm) ;
+%D     draw fullcircle scaled 20pt ;
+%D \stopMPcode
+%D
+%D \ctxlua{inspect(metapost.variables)}
+%D
+%D \MPrunvar{version} \MPruntab{quad}{3} (\MPrunset{triplet}{,})
+%D
+%D $(x,y) = (\MPruntab{point}{1},\MPruntab{point}{2})$
+%D $(x,y) = (\MPrunset{point}{,})$
+%D \stoptyping
+
+\def\MPrunvar  #1{\ctxcommand{mprunvar("#1")}}           \let\mprunvar\MPrunvar
+\def\MPruntab#1#2{\ctxcommand{mprunvar("#1",\number#2)}} \let\mpruntab\MPruntab
+\def\MPrunset#1#2{\ctxcommand{mprunvar("#1","#2")}}      \let\mprunset\MPrunset
+
+%D We also provide an outputless run:
+
+\unexpanded\def\startMPcalculation
+  {\begingroup
+   \setbox\nextbox\hbox\bgroup
+   \dosinglegroupempty\meta_start_calculation}
+
+\def\meta_start_calculation
+  {\iffirstargument
+     \expandafter\meta_start_calculation_instance
+   \else
+     \expandafter\meta_start_calculation_standard
+   \fi}
+
+\def\meta_start_calculation_instance#1#2\stopMPcalculation
+  {\edef\currentMPinstance{#1}%
+   \let\currentMPgraphicname\empty
+   \edef\currentMPformat{\MPinstanceparameter\s!format}%
+   \meta_enable_include
+   \meta_process_graphic{#2;draw origin}%
+   \egroup
+   \endgroup}
+
+\def\meta_start_calculation_standard#1#2\stopMPcalculation
+  {\let\currentMPinstance\defaultMPinstance
+   \let\currentMPgraphicname\empty
+   \edef\currentMPformat{\MPinstanceparameter\s!format}%
+   \meta_process_graphic{#2;draw origin}%
+   \egroup
+   \endgroup}
+
+\let\stopMPcalculation\relax
+
 %D \macros
 %D   {setupMPgraphics}
 %D