On 5/19/2016 10:35 PM, Meer, Hans van der wrote:
With \definecolor[colorname][r=,g=,b=] one defines a color of name "colorname"
for use in ConTeXt and in Metapost.
A transparentcolor comes with \definecolor[transparentcolorname][r=,g=,b=,a=,t=]
Problem: how to define a transparent color with
\definetransparentcolor[#1][#2][#3]{...}.
To be called for example as \definetransparentcolor[transparentcolorname][colorname][0.5]
for color "colorname" with transparency 0.5.
I tried to do this by intercepting from \definecolor the vales "r=,g=,b=" in a
macro \colornamergb to be called as \csname..\endcsname for the varying colorname and
feeding that to a definecolor-variant. However, the parsing of r=,g=,b= then goes wrong
(\futurelet balking).
Question: is there a direct way to derive a transparent colorvariant from a
parent one without transparency? The usefulness of this comes from the fact
that for things like \definecolor[lighthoneydew][r=.894117,g=.95,b=.894117] the
numbers need not be feed more than once.
\starttext
\definespotcolor[redA][red][p=1]
\definespotcolor[redB][red][p=.5]
\definespotcolor[redC][redB][t=.5,a=1]
\definespotcolor[redD][redA][t=.25,a=1]
\redA test
\redB test
\redC test
\redD test
\stoptext
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Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | www.pragma-ade.com | www.pragma-pod.nl
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