Re: [NTG-context] question for metapost experts

[Schmitz Thomas A.]

> On 10. Aug 2017, at 14:18, Hans Hagen  wrote:
> 
> p intersection_point q
> 
> (also sets intersection_found)

Boy, impressive and wonderful, thanks a lot!!! It also made me see why I the 
error stopped the compilation: I had a naming conflict between the slide 
background and one of included metapost graphics, so now I can correct this!

All best

Thomas
___
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
___

Re: [NTG-context] question for metapost experts

[Hans Hagen]

On 8/10/2017 2:07 PM, Schmitz Thomas A. wrote:

Hi all,

this one is for all the metapos/metafun experts out there (Alan, are you 
there?). For a counter in one of my slide backgrounds, I have to calculate an 
intersectionpoint, given in percentage of the difference between current page 
and last page. I have always had some difficulties on the first run, when the 
value of the last page isn’t known yet and hence not written to the tuc file, 
but the error


! The paths don't intersect.




used to disappear in subsequent runs. Now, ConTeXt doesn’t compile the file at 
all and stops on this error. There is an error message I haven’t seen before:


intersectionpoint->...The paths don't intersect");
origin.else:0.5[point.x_.o...

;
<*> ... ;z13 = (z11 -- z12) intersectionpoint qw ;
draw z13 withcolor (0.1,0
This error message was generated by an `errmessage'
command, so I can't give any explicit help.
Pretend that you're Miss Marple: Examine all clues,
and deduce the truth by inspired guesses.


Is there a way to make this conditional, such as (pseudocode)


p intersection_point q

(also sets intersection_found)


if q intersects p:
  z = q intersectionpoint p ;
else:
  z = (0,0) ;
fi ;

I hope that this would allow ConTeXt to proceed and calculate the point 
correctly on the second run.

Thanks, and all best

Thomas
___
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
-
___
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
___

[NTG-context] question for metapost experts

[Schmitz Thomas A.]

Hi all,

this one is for all the metapos/metafun experts out there (Alan, are you 
there?). For a counter in one of my slide backgrounds, I have to calculate an 
intersectionpoint, given in percentage of the difference between current page 
and last page. I have always had some difficulties on the first run, when the 
value of the last page isn’t known yet and hence not written to the tuc file, 
but the error 

> ! The paths don't intersect.
> 


used to disappear in subsequent runs. Now, ConTeXt doesn’t compile the file at 
all and stops on this error. There is an error message I haven’t seen before:

> intersectionpoint->...The paths don't intersect");
> origin.else:0.5[point.x_.o...
> 
> ;
> <*> ... ;z13 = (z11 -- z12) intersectionpoint qw ;
> draw z13 withcolor (0.1,0
> This error message was generated by an `errmessage'
> command, so I can't give any explicit help.
> Pretend that you're Miss Marple: Examine all clues,
> and deduce the truth by inspired guesses.

Is there a way to make this conditional, such as (pseudocode)

if q intersects p:
 z = q intersectionpoint p ;
else:
 z = (0,0) ;
fi ; 

I hope that this would allow ConTeXt to proceed and calculate the point 
correctly on the second run.

Thanks, and all best

Thomas
___
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
___