I've answered my own question. It was a lot easier than I expected! code metapost def a_u_pebbles (expr p) = T:=identity; pickup PenC; path q, qq; q = bbox p; picture tmp_pic; tmp_pic := image( for i = xpart llcorner q step 1.5u until xpart urcorner q: for j = ypart llcorner q step 1.5u until ypart urcorner q: qq := (superellipse((.2u,0),(0,.1u),(-.2u,0),(0,.-.1u),.75)) % randomized (u/25) rotated uniformdeviate(360) shifted ((i,j) randomized 0.8u); if xpart (p intersectiontimes qq) < 0: thdraw qq; thfill qq withcolor(1, 0.85, 0.83); fi; endfor; endfor; ); clip tmp_pic to p; draw tmp_pic; enddef;
def p_u_pebbles (expr pos,theta,sc,al)= U:=(.45u,.35u); T:=identity aligned al rotated theta scaled sc shifted pos; pickup PenC; p:=superellipse((.2u,0),(0,.1u),(-.2u,0),(0,.-.1u),.75); thdraw p rotated 20 shifted (0,.25u); thfill p rotated 20 shifted (0,.25u) withcolor(1, 0.85, 0.83); thdraw p rotated -37 shifted (.25u,-.25u); thfill p rotated -37 shifted (.25u,-.25u) withcolor(1, 0.85, 0.83); thdraw p rotated -62 shifted (-.25u,-.25u); thfill p rotated -62 shifted (-.25u,-.25u) withcolor(1, 0.85, 0.83); enddef; endcode On 16 Nov 2012, at 09:28, Dave Clucas wrote: > In Mulu many of the passages are part filled with sandstone pebbles. > I'd like to create a user area and a user symbol based on pebbles > where the ellipses are filled with a colour (light brown). Can > anybody tell me how to modify the standard definition? > > Dave Clucas > dave at daveclucas.com > http://daveclucas.com > http://mycaves.org > > > Dave Clucas dave at daveclucas.com http://daveclucas.com http://mycaves.org