%% sgbx0014.mp %% Copyright 2006 Tommy Ekola % % This work may be distributed and/or modified under the conditions of % the LaTeX Project Public License, either version 1.3 of this license % or (at your option) any later version. The latest version of this % license is in http://www.latex-project.org/lppl.txt % % This work has the LPPL maintenance status `maintained'. The Current % Maintainer of this work is Tommy Ekola. The Base Interpreter is % MetaPost. vardef setup_doublearrow (expr source_file, cmdname) = scantokens ("input tgbx0000"); scantokens ("input " & source_file); expandafter def scantokens cmdname expr p = scantokens (cmdname & "__sgbxww")(p) enddef; expandafter vardef scantokens (cmdname & "__sgbxww " & "(expr apth) " & "text text_ = " & "save math_spread, x_height, u, rule_thickness, bar, math_axis," & " asc_height, eps, monospace, fudge, crisp, hair;" & "boolean monospace;" & "math_spread :=" & decimal math_spread & ";" & "x_height# :=" & decimal x_height# & ";" & "u# :=" & decimal u# & ";" & "rule_thickness# :=" & decimal rule_thickness# & ";" & "bar# :=" & decimal bar# & ";" & "math_axis# :=" & decimal math_axis# & ";" & "asc_height# :=" & decimal asc_height# & ";" & "eps :=" & decimal eps & ";" & "monospace :=" & if monospace: "true" else: "false" fi & ";" & "fudge :=" & decimal fudge & ";" & "crisp# :=" & decimal crisp# & ";" & "hair# :=" & decimal hair# & ";") save prevpen; prevpen:=savepen; save x,y; numeric x[], x[]', x[]l, x[]'l, x[]r, x[]'r, y[], y[]', y[]l, y[]'l, y[]r, y[]'r; save spread, w; numeric spread, w; if crisp#>fudge*hair#: crisp#:=fudge*hair#; fi pickup if crisp#=0: nullpen else: pencircle scaled crisp# fi; spread = math_spread[.45x_height#,.55x_height#]; w:=18u#; lft x1 = u#-eps; x2=x1; x7=x8=w-x1; y1=y7; y2=y8; y1-y2=spread; .5[y1,y2]=math_axis#; rt x0 = w-u#+eps; y0 = math_axis#; penpos3(rule_thickness#,0); penpos4(rule_thickness#,0); y3-y1 = y2-y4 = .24asc_height#+eps; x3=x4=x0-6u#-eps; penpos5(rule_thickness#, angle(z4-z0)); z5l=z0; penpos6(rule_thickness#, angle(z3-z0)); z6l=z0; z9 = .381966[.5[z3,z4],z0]; save pp; path pp; pp = z4l{z9-z4}..z6r; save t; numeric t; t = xpart(pp intersectiontimes ((0,y0)--(w,y0))); numeric t[]; t1 = xpart(pp intersectiontimes ( (0,y2-rule_thickness#/2) --(w,y2-rule_thickness#/2))); t2 = xpart(pp intersectiontimes ( (0,y2+rule_thickness#/2) --(w,y2+rule_thickness#/2))); save qq; path qq; qq = z3l{z9-z3}..z5r; save parallelline; vardef parallelline expr ppp = save s, stp; numeric s, stp; stp:=(arclength ppp) div 5pt; if stp=0: stp:=1; fi stp:=(arclength ppp)/stp; if stp > 0: draw for s=0 step stp until arclength ppp - stp: point (arctime s of ppp) of ppp + spread/2* (unitvector direction (arctime s of ppp) of ppp rotated 90) {direction (arctime s of ppp) of ppp}.. endfor {direction (length ppp) of ppp} point (length ppp) of ppp + spread/2* (unitvector direction (length ppp) of ppp rotated 90) withpen pencircle scaled rule_thickness# text_; draw for s=0 step stp until arclength ppp - stp: point (arctime s of ppp) of ppp - spread/2* (unitvector direction (arctime s of ppp) of ppp rotated 90) {direction (arctime s of ppp) of ppp}.. endfor {direction (length ppp) of ppp} point (length ppp) of ppp - spread/2* (unitvector direction (length ppp) of ppp rotated 90) withpen pencircle scaled rule_thickness# text_; fi enddef; save mapto, n; vardef mapto(text t) = hide(numeric n; n:=0; numeric x,x_[],y,y_[]; for z=t: z_[incr n]:=z; endfor; transform T; z_2 = z_1 transformed T; z_4 = z_3 transformed T; z_6 = z_5 transformed T;) T enddef; % Draw the arrow head save doublearrowhead; vardef doublearrowhead(expr T, s, ss) = (subpath(0, xpart((z0..{z4-z9}z4r) intersectiontimes (point s of pp -- point s of pp + (2rule_thickness#,0)))) of (z0..{z4-z9}z4r) --subpath(s,t1) of pp --(xpart point t1 of pp, ypart point t2 of pp) --subpath(t2,t) of pp --subpath(t,t2) of qq --(xpart point t1 of qq, ypart point t2 of qq) --subpath(t1,ss) of qq --subpath(xpart ((z3r{z9-z3}..z0) intersectiontimes (point ss of qq -- point ss of qq + (2rule_thickness#,0))),1) of (z3r{z9-z3}..z0) & cycle) transformed T enddef; save T; transform T; save tt; tt = arctime (arclength apth - (x0 - xpart point t1 of pp)) of apth; if arclength apth = 0: T:=identity shifted (point (length apth) of apth - z0); elseif arclength apth < x0-xpart(point t2 of pp): T:=identity rotatedaround(z0,angle (direction (length apth) of apth)) shifted (point (length apth) of apth - z0); else: T := mapto( z0, point (length apth) of apth, point t1 of pp + (0,rule_thickness#/2), point tt of apth + spread/2*(unitvector direction tt of apth rotated 90), point t1 of qq - (0,rule_thickness#/2), point tt of apth - spread/2*(unitvector direction tt of apth rotated 90)); fi save f,s,ss,ttt; ttt = arctime(arclength apth - (x0-x9)) of apth; vardef f(expr s) = length(point s of (pp transformed T) - point ttt of apth) < length(point 0 of pp - z9) enddef; if f(0) or (arclength apth < x0-x3l): s := 0; else: s := solve f(length pp, 0); fi vardef f(expr ss) = length(point ss of (qq transformed T) - point ttt of apth) < length(point 0 of qq - z9) enddef; if f(0) or (arclength apth < x0-x3l): ss := 0; else: ss := solve f(length qq, 0); fi filldraw doublearrowhead(T,s,ss) text_; % Draw the path if arclength apth > (x0-xpart(point t1 of pp)): parallelline (subpath(0,tt) of apth); fi pickup prevpen; enddef; enddef;