Colored Lines Based On Attributes

[Carl Magnuson]

I am attempting to color the walls of different systems with different colors using the -attr flag and a user defined wall:

portion of code in scrap:

line u:wall -attr color "(0.1, 0.2, 0.8);"

1392.9359853260457 -71.62435442682576

1395.5759853260456 125.20564557317425

endline

portion of code in layout:

def l_u_wall (expr P)= 

T:=identity;

if known(ATTR__color):

pickup PenA; 

draw P withpen PenA withcolor ATTR__color\n

fi;

enddef;

initsymbol(\"l_u_wall\");

I am not having any success however.  Is it possible to set and read attributes from lines as I am trying to do? Is somebody aware of an alternate way to pass in a color argument to the metapost definition (instead of defining separate walls for each different colored system)?

Thanks,

Carl

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[Carl Magnuson]

I figured it out with the following command:

"scantokens ATTR_color;\n" +

Scantokens evaluates the string it is applied to, so I just had to change ATTR_color to "color col; col:=red" for example.

Carl

On Sep 11, 2009, at 3:35 PM, Carl Magnuson wrote:

I am attempting to color the walls of different systems with different colors using the -attr flag and a user defined wall:

portion of code in scrap:

line u:wall -attr color "(0.1, 0.2, 0.8);"

1392.9359853260457 -71.62435442682576

1395.5759853260456 125.20564557317425

endline

portion of code in layout:

def l_u_wall (expr P)= 

T:=identity;

if known(ATTR__color):

pickup PenA; 

draw P withpen PenA withcolor ATTR__color\n

fi;

enddef;

initsymbol(\"l_u_wall\");

I am not having any success however.  Is it possible to set and read attributes from lines as I am trying to do? Is somebody aware of an alternate way to pass in a color argument to the metapost definition (instead of defining separate walls for each different colored system)?

Thanks,

Carl

_______________________________________________
Therion mailing list
Therion@...
http://mailman.speleo.sk/mailman/listinfo/therion