As I only use one transparency method anyway I could also fix this by passing a
numeric instead of a pair and use the standard withtransparency (I don’t like
overriding a standard MetaFun method, one never knows what might break in
future updates).
vardef Foo( expr w, h, fillColor, fillTransparency) =
show "FOO:", w, h, fillColor, fillTransparency;
save pic; picture pic;
save circ; path circ;
circ := (fullcircle xyscaled (h,h));
pic := image (
fill (circ shifted (w-h/2,-h/2)) withcolor fillColor withtransparency
(1,fillTransparency);
);
pic
enddef;
picture pic;
pic := Foo( 150, 50, (0.686,1.000,1.000), 0.5);
draw pic;
\stopMPpage
\stoptext
> On 9 Apr 2020, at 18:06, Hans Hagen <j.ha...@xs4all.nl> wrote:
>
> On 4/9/2020 4:58 PM, Gerben Wierda wrote:
>> \starttext
>> \startMPpage[instance=doublefun]
>> vardef Foo( expr w, h, fillColor, fillTransparency) =
>> show "FOO:", w, h, fillColor, fillTransparency;
>> save pic; picture pic;
>> save circ; path circ;
>> circ := (fullcircle xyscaled (h,h));
>> pic := image (
>> fill (circ shifted (w-h/2,-h/2)) withcolor fillColor withtransparency
>> fillTransparency;
>> );
>> pic
>> enddef;
>> pic := Foo( 150, 50, (0.686,1.000,1.000), (1,1.000));
>> draw pic;
>> \stopMPpage
>> \stoptext
>
> Maybe this definition is better then but I need to test it more
>
> \starttext
> \startMPpage[instance=doublefun]
>
> def withtransparency expr t =
> if pair t :
> withprescript "tr_alternative=" & decimal
> transparency_alternative_to_number(xpart t)
> withprescript "tr_transparency=" & decimal ypart t
> else :
> mfun_with_transparency (transparency_alternative_to_number(t))
> fi
> enddef ;
>
> def mfun_with_transparency (expr a) expr t =
> withprescript "tr_alternative=" & decimal a
> withprescript "tr_transparency=" & decimal t
> enddef ;
>
> vardef Foo ( expr w, h, fillColor, fillTransparency) =
> image (
> fill fullcircle xyscaled (h,h) shifted (w-h/2,-h/2)
> withcolor fillColor
> withtransparency fillTransparency
> ;
> )
> enddef;
>
> vardef FooX ( expr w, h, fillColor) =
> image (
> fill fullcircle xyscaled (h,h) shifted (w-h/2,-h/2)
> withcolor fillColor
> withtransparency (normaltransparent, .5)
> ;
> )
> enddef;
>
> vardef FooY ( expr w, h, fillColor) =
> image (
> fill fullcircle xyscaled (h,h) shifted (w-h/2,-h/2)
> withcolor fillColor
> withtransparency normaltransparent .5
> ;
> )
> enddef;
>
> draw Foo ( 350, 50, (0.5,1,0), (1,.5));
> draw FooX ( 250, 50, (1,0.5,1));
> draw FooY ( 150, 50, (1,1,0.5));
>
> \stopMPpage
> \stoptext
>
>
> --
>
> -----------------------------------------------------------------
> Hans Hagen | PRAGMA ADE
> Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
> tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
> -----------------------------------------------------------------
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