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From: Renaud Aubin <aubin@nibua-r.org>
To: Mailing list for ConTeXt users <ntg-context@ntg.nl>
Subject: Color rendering & transparency with metapost
Date: Sat, 01 Nov 2008 01:38:00 +0100	[thread overview]
Message-ID: <490BA4E8.1010208@nibua-r.org> (raw)

Hi,

I have some trouble using a gradient background (solid) with a 
transparent element :

  \startMPinclusions
    def test_shade (expr a, b) =
    pickup pencircle scaled 1mm ;
    color ca ; ca := \MPcolor{a} ;
    color cb ; cb := \MPcolor{b} ;
    color cc ; cc := \MPcolor{c} ;
    sh := define_linear_shade(origin 
shifted(0cm,.5*\overlayheight),origin,ca,cb) ;
    fill fullsquare xscaled \overlaywidth yscaled \overlayheight 
withshade sh;
    draw origin withcolor cc;
    draw origin shifted(0cm,-.25*\overlayheight) withcolor cc;
    enddef ;
  \stopMPinclusions

  \setupcolors[state=start]
  \definecolor[a][r=.57254902,g=.784313725,b=.917647059]
  \definecolor[b][white]
  \definecolor[c][darkred]
  \starttext
 
  \defineoverlay[bgoverlay][\uniqueMPgraphic{bg_top_shade}]
  \setupbackgrounds[page][background=bgoverlay]
  \startuniqueMPgraphic{bg_top_shade}
    test_shade(origin, origin shifted(0cm,1cm));
    draw fullcircle scaled 10cm shifted (0cm,0.25*\overlayheight) 
withcolor transparent(1,0.5,white) withpen pencircle scaled 2cm;

%%%%%%%% If you comment out the previous line the color rendering is 
definitelly different...

  \stopuniqueMPgraphic
 
  \input knuth
 
\stoptext

I have searched the ML without success, any idea ?

Regards,


Renaud
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             reply	other threads:[~2008-11-01  0:38 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-01  0:38 Renaud Aubin [this message]
2008-10-31 23:40 ` luigi scarso
2008-11-01  1:06   ` Renaud Aubin
2008-11-01  0:36     ` luigi scarso
2008-11-01  1:11     ` Renaud Aubin

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