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Even-odd rule in Metafun (view source)
Revision as of 08:05, 17 December 2020
, 08:05, 17 December 2020FInally created the page!
Metapost doesn't support [https://en.wikipedia.org/wiki/Even%E2%80%93odd_rule even-odd rule] filling so it uses a fake unfilling via a background color. This is problematic in cases when one deals with e.g. transparency. To overcome this difficulty, Metafun implements some extensions, such as <code>eofill</code>. To fill a shape using the even-odd rule we need a sequence of <code>nofill</code> ending with a <code>eofill</code> statement, as it can be seen in the following examples.
== Some examples ==
<context source="yes">
%Adapted from Metafun's manual
\startMPpage
nofill fullsquare scaled 2cm ;
nofill fullsquare scaled 2cm shifted (1cm,0) ;
eofill fullsquare scaled 2cm shifted (0,1cm) withcolor darkred;
\stopMPpage
</context>
<context source="yes">
\startMPpage
path A; A := (unitcircle shifted (-center unitcircle)) scaled 4cm;
path B; B := (unitcircle shifted (-center unitcircle)) scaled 1cm;
path C; C := B shifted (left*1.4cm);
nofill A; nofill B; eofill C withcolor darkblue;
\stopMPpage
</context>
[[Category:Graphics]]
[[Category:Metapost]]
== Some examples ==
<context source="yes">
%Adapted from Metafun's manual
\startMPpage
nofill fullsquare scaled 2cm ;
nofill fullsquare scaled 2cm shifted (1cm,0) ;
eofill fullsquare scaled 2cm shifted (0,1cm) withcolor darkred;
\stopMPpage
</context>
<context source="yes">
\startMPpage
path A; A := (unitcircle shifted (-center unitcircle)) scaled 4cm;
path B; B := (unitcircle shifted (-center unitcircle)) scaled 1cm;
path C; C := B shifted (left*1.4cm);
nofill A; nofill B; eofill C withcolor darkblue;
\stopMPpage
</context>
[[Category:Graphics]]
[[Category:Metapost]]
