So its either using text or using metaobj? Too bad, metaobj is quite fun... I still hope you guys can fix this, but it's not urgent (to me). Just as a wild guess I tested the example below today, trying to make use of the things Aditya said, but to no avail. Anyway, what does the [+] after \startMPinclusions? I did not find documentation for that on the wiki. Best regards, Stefan. \startMPinclusions input metaobj; boolean flag; flag := false; \stopMPinclusions \starttext \startMPpage vardef newSegment@\#= assignObj(@\#,"Segment"); ObjPoint a,b; ObjCode "@\#b-@\#a=(1cm,2cm)"; enddef; def drawSegment(suffix n)= draw n.a--n.b; enddef; newSegment.s; s.a=origin; drawObj(s); if flag: draw btex A etex; fi; flag := true; \stopMPpage \stoptext On 22.01.2011 02:38, Aditya Mahajan wrote:
On Sat, 22 Jan 2011, Hans Hagen wrote:
On 20-1-2011 9:59, Taco Hoekwater wrote:
On 01/18/2011 01:17 PM, Stefan Müller wrote:
Hi list,
I'm having some trouble with MetaPost in general and MetaObj in particular.
The core problem is that context mkiv loads the metapost code twice when you are typesetting labels, and that causes trouble for metaobj which does not expect that. Sorry, I do not know of any solution. Maybe Hans does?
not immediately
A suggestion: Currently, ConTeXt does not clear the state of mplib at the end of each graphic. For example
\starttext \startMPcode path p; p := fullcircle scaled 4cm ; \stopMPcode
\startMPcode draw p ; \stopMPcode \stoptext
draws a circle. I am not convinced that this is useful. Resetting the state of mplib after each graphic might be better. Then, after the first run, you could just set the value of mptopdf.texts[..], reset the state of mplib, and then draw the graphic in the second run.
This approach will have less surprises. For example, in simpleslides module, we provide a mechanism for highlighting a part of a picture using arrows. These arrows are thick (typically 5bp). In order to scale the arrows correctly, we set:
autoarrows := true ;
However, in the current implementation, this effect is global. It took a while to realize that this messed up all the figures with arrows that I was drawing in a presentation (where autoarrows := false) is better.
Not resetting the mplib state also has advantages. For example, it allows an easy way to do something on the second path (trivial example, but there are cases when something like this makes the code much shorter):
\startMPinclusions[+] newboolean flag ; flag := false ; \stopMPinclusions
\starttext \startMPpage if flag : fill boundary withcolor 0.5[blue,white] ; else : path boundary ; fi ;
path A, B;
A := fullsquare scaled 3cm ; B := fullsquare scaled 3cm shifted (5cm,0) ;
fill A withcolor white ; fill B withcolor white ;
draw A ; draw btex A etex ; draw B ; draw btex B etex shifted (5cm,0) ;
boundary := (boundingbox currentpicture) enlarged 3mm ;
flag := true ;
\stopMPpage \stoptext
So, perhaps, we can have a `reset` key to \defineMPinstance, and let the user choose whether to reset after each graphic or not. If `reset=yes` is chosen, then such errors would not occur.
Aditya
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