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 ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.com | www.pragma-pod.nl -----------------------------------------------------------------