[Therion] metapost symbols

[Stefan Oswald]

Hello, 

here are the results of our Therion meeting yesterday; 
An idea would be to add the factor for density/size of symbols in the source code and adjust these variables in the map editor by a -density {} command in the mapeditor\area\options. Also a -diameter {} command for block points would allow to change block size of each point individually.  


#POINT BLOCK +size adjust (symbolsize)
  
code metapost
     
   def p_blocks_UIS (expr pos,theta,sc,al)=
    symbolsize:=1.0u; %Factor*u; Factor=size of the blocks
    U:=(.5u,.5u);
    T:=identity aligned al rotated theta scaled sc shifted pos;
    pickup PenC;
    thdraw (.0symbolsize,.0symbolsize)--(1.0symbolsize,-.5symbolsize)--(0.0symbolsize,-1.5symbolsize)--(-1.0symbolsize,-1.0symbolsize)--cycle;
    thdraw (.5symbolsize,-.25symbolsize)--(1.0symbolsize,.5symbolsize)--(0.0symbolsize,1.5symbolsize)--(-0.5symbolsize,.5symbolsize);
    thdraw (.0symbolsize,.0symbolsize)--(.0symbolsize,.5symbolsize)--(-1.5symbolsize,.5symbolsize)--(-1.5symbolsize,-0.5symbolsize)--(-0.5symbolsize,-0.5symbolsize);
   enddef;
endcode

#AREA BLOCK +density adjust (distance)

code metapost
      def a_blocks (expr p) =
        distance:=1;
        T:=identity;
        pickup PenC;
        path q, qq; q = bbox p;
        picture tmp_pic; 
        uu := max(u, (xpart urcorner q - xpart llcorner q)/100, (ypart urcorner q - ypart     llcorner q)/100);
        tmp_pic := image(
          for i = xpart llcorner q step distance*uu until xpart urcorner q:
            for j = ypart llcorner q step distance*uu until ypart urcorner q:
              qq := punked (((-.5uu,-.5uu)--(.5uu,-.5uu)--(.5uu,.5uu)--(-.5uu,.5uu)--cycle) 
            randomized (uu/2))
                   rotated uniformdeviate(360) 
                   shifted ((i,j) randomized 1.0uu);
        if xpart (p intersectiontimes qq) < 0:
          thclean qq;
          thdraw qq;
        fi;
            endfor;  
          endfor;
        );
        clip tmp_pic to p;
        draw tmp_pic;
      enddef;  
endcode


greetings, 

Stefan