Re: [NTG-context] highlighting chars on a path

2009-10-19 Thread luigi scarso
On Sun, Oct 18, 2009 at 9:11 PM, Aurelien Giraud 
aureliengir...@googlemail.com wrote:

 Hello,

 I am new to ConTeXt and I have looked on the internet for a way to do
 something special. Unfortunately I have not found any solution.

 I hope this is the right place for such a question. I apologise otherwise.

 I would like to highlight (e.g. put in bold, or change the color...) any
 character on a page which sits on a chosen path. I would like to be able to
 position for instance an invisible circle on a page and have all the
 characters in contact with this circle change color so that the circle
 become visible via these characters. Is it something I could do with
 ConTeXt?

 Thanks in advance.

 I think yes,but now  I have not time to try.
Something with metapost, maybe.
-- 
luigi
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Re: [NTG-context] highlighting chars on a path

2009-10-19 Thread Mojca Miklavec
On Sun, Oct 18, 2009 at 21:11, Aurelien Giraud wrote:
 Hello,

 I am new to ConTeXt and I have looked on the internet for a way to do
 something special. Unfortunately I have not found any solution.

 I hope this is the right place for such a question. I apologise otherwise.

 I would like to highlight (e.g. put in bold, or change the color...) any
 character on a page which sits on a chosen path. I would like to be able to
 position for instance an invisible circle on a page and have all the
 characters in contact with this circle change color so that the circle
 become visible via these characters. Is it something I could do with
 ConTeXt?

This won't be of any help to you ...
... but I remember seeing one of early luatex showcases with
characters colored in the shape of circular wave (smoothly varying
color - really impressive), but I have no idea if that has ever been
published anywhere. (I'm writing this because I'm also interested to
see that masterpiece again.)

Mojca


I don't know how to do it, but I would bet that it is possible to
misuse luatex for it (before printing out a character you check its
position on page, do some basic math and output the desired color).
It's usually done by overwriting some lua function. Just a tiny
warning if you do get a solution from someone: LuaTeX might not be
absolutely stable in this respect yet, so you need to take in account
some slight possibility that the low level interface undergoes some
changes in future. In that case you might need to adapt your code
after a while. You should not worry about it now, it's just good to
keep it in mind.
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Re: [NTG-context] highlighting chars on a path

2009-10-19 Thread Willi Egger

Hi,

a possible approach could be positional graphisc please refer to  
the METAFUN manual p 139...


Willi
On Oct 19, 2009, at 10:33 AM, luigi scarso wrote:




On Sun, Oct 18, 2009 at 9:11 PM, Aurelien Giraud  
aureliengir...@googlemail.com wrote:

Hello,

I am new to ConTeXt and I have looked on the internet for a way to  
do something special. Unfortunately I have not found any solution.


I hope this is the right place for such a question. I apologise  
otherwise.


I would like to highlight (e.g. put in bold, or change the  
color...) any character on a page which sits on a chosen path. I  
would like to be able to position for instance an invisible circle  
on a page and have all the characters in contact with this circle  
change color so that the circle become visible via these  
characters. Is it something I could do with ConTeXt?


Thanks in advance.

I think yes,but now  I have not time to try.
Something with metapost, maybe.
--
luigi

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ntg-context

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archive  : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
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_


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