1 files changed, 145 insertions, 0 deletions
diff --git a/metapost/context/base/mp-grid.mp b/metapost/context/base/mp-grid.mp
new file mode 100644
index 000000000..f6e843489
--- /dev/null
+++ b/metapost/context/base/mp-grid.mp
@@ -0,0 +1,145 @@
+%D \module
+%D   [       file=mp-grid.mp,
+%D        version=2000.07.10,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=grid support,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+%D Under construction.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_grid : endinput         ; fi ;
+
+boolean context_grid ; context_grid := true ;
+
+string  fmt_separator  ; fmt_separator  := "@" ;
+numeric fmt_precision  ; fmt_precision  := 3 ;
+boolean fmt_initialize ; fmt_initialize := false ;
+boolean fmt_zerocheck  ; fmt_zerocheck  := true ;
+
+if unknown fmt_loaded : input mp-form ; fi ;
+
+boolean fmt_pictures ; fmt_pictures := true ;
+
+def  do_format = if fmt_pictures :  format else :  formatstr fi enddef ;
+def do_mformat = if fmt_pictures : Mformat else : Mformatstr fi enddef ;
+
+numeric grid_eps ; grid_eps = eps ;
+
+def hlingrid (expr Min, Max, Step, Length, Width) text t =
+  image ( for i=Min step Step until Max+grid_eps :
+    draw (origin--(Width,0)) shifted (0,i*(Length/Max)) t ;
+  endfor ; ) ;
+enddef ;
+
+def vlingrid (expr Min, Max, Step, Length, Height) text t =
+  image ( for i=Min step Step until Max+grid_eps :
+    draw (origin--(0,Height)) shifted (i*(Length/Max),0) t ;
+  endfor ; ) ;
+enddef ;
+
+def hloggrid (expr Min, Max, Step, Length, Width) text t =
+  image ( for i=max(Min,1) step Step until min(Max,10)+grid_eps :
+    draw (origin--(Width,0)) shifted (0,Length*log(i)) t ;
+  endfor ; ) ;
+enddef ;
+
+def vloggrid (expr Min, Max, Step, Length, Height) text t =
+  image ( for i=max(Min,1) step Step until min(Max,10)+grid_eps :
+    draw (origin--(0,Height)) shifted (Length*log(i),0) t ;
+  endfor ; ) ;
+enddef ;
+
+vardef hlintext@#(expr Min, Max, Step, Length, Format) text t =
+  image ( do_initialize_numbers ;
+  for i=Min step Step until Max+grid_eps :
+    draw textext@#(do_format(Format,i)) shifted (0,i*(Length/Max)) t ;
+  endfor ; )
+enddef ;
+
+vardef vlintext@#(expr Min, Max, Step, Length, Format) text t =
+  image ( do_initialize_numbers ;
+  for i=Min step Step until Max+grid_eps :
+    draw textext@#(do_format(Format,i)) shifted (i*(Length/Max),0) t ;
+  endfor ; )
+enddef ;
+
+vardef hlogtext@#(expr Min, Max, Step, Length, Format) text t =
+  image ( do_initialize_numbers ;
+  for i=max(Min,1) step Step until min(Max,10)+grid_eps :
+    draw textext@#(do_format(Format,i)) shifted (0,Length*log(i)) t ;
+  endfor ; )
+enddef ;
+
+vardef vlogtext@#(expr Min, Max, Step, Length, Format) text t =
+  image ( do_initialize_numbers ;
+  for i=max(Min,1) step Step until min(Max,10)+grid_eps :
+    draw textext@#(do_format(Format,i)) shifted (Length*log(i),0) t ;
+  endfor ; )
+enddef ;
+
+vardef hlinlabel@#(expr Min, Max, Step, Length) text t =
+  image (
+  for i=Min step Step until Max+grid_eps :
+    draw thelabel@#(decimal i,(0,i*(Length/Max))) t ;
+  endfor ; )
+enddef ;
+
+vardef vlinlabel@#(expr Min, Max, Step, Length) text t =
+  image (
+  for i=Min step Step until Max+grid_eps :
+    draw thelabel@#(decimal i,(i*(Length/Max),0)) t ;
+  endfor ; )
+enddef ;
+
+boolean numbers_initialized ; numbers_initialized := false ;
+
+def do_initialize_numbers =
+  if not numbers_initialized :
+    init_numbers ( textext.raw("$-$")          ,
+                   textext.raw("$1$")          ,
+                   textext.raw("${\times}10$") ,
+                   textext.raw("${}^-$")       ,
+                   textext.raw("${}^2$")       ) ;
+    numbers_initialized := true ;
+  fi ;
+enddef ;
+
+def initialize_numbers =
+  numbers_initialized := false ; do_initialize_numbers ;
+enddef ;
+
+vardef linlog(expr xy) = (    xpart xy,  log(ypart xy)) enddef ;
+vardef loglin(expr xy) = (log(xpart xy),     ypart xy)  enddef ;
+vardef loglog(expr xy) = (log(xpart xy), log(ypart xy)) enddef ;
+vardef linlin(expr xy) = (   (xpart xy),    (ypart xy)) enddef ;
+
+vardef loglinpath primary p = processpath (p) (loglin) enddef ;
+vardef linlogpath primary p = processpath (p) (linlog) enddef ;
+vardef loglogpath primary p = processpath (p) (loglog) enddef ;
+vardef linlinpath primary p = processpath (p) (linlin) enddef ;
+
+def processpath (expr p) (text pp) =
+  if path p :
+    for i=0 upto length(p)-1 :
+      (pp(point       i    of p)) .. controls
+      (pp(postcontrol i    of p)) and
+      (pp(precontrol (i+1) of p)) ..
+    endfor
+    if cycle p :
+      cycle
+    else :
+      (pp(point length(p) of p))
+    fi
+  elseif pair p :
+    (pp(p))
+  else :
+    p
+  fi
+enddef ;