# waffle_udp_2
# written by John Dannenhoffer

# Valid statements in file are:
#    CPOINT                   create a construction point (not in final waffle)
#    CLINE                    create a construction line (not in final waffle)
#    POINT                    create a waffle point
#    LINE                     create one or more waffle segments
#    SET                      sets a local varaible
#    PATBEG/PATBREAK/PATEND   execute a pattern (loop)
#    IFTHEN/ENDIF
#
# Variants of CPOINT and POINT:
#    POINT <pname> AT <xloc> <yloc>
#          creates point at <xloc,yloc>
#    POINT <pname> ON <lname> FRAC <fracDist>
#          creates point on <lname> at given fractional distance
#    POINT <pname> ON <lname> XLOC <x>
#          creates point on <lname> at given <x>
#    POINT <pname> ON <lname> YLOC <y>
#          creates point on <lname> at given <y>
#    POINT <pname> ON <lname> PERP <pname2>
#          creates point on <lname> that is closest to <pname2>
#    POINT <pname> ON <lname> XSECT <lname2>
#          creates point at intersection of <lname> and <lname2>
#    POINT <pname> OFF <lname> <dist> <pname2>
#          creates point <dist> to the left of <lname> at <pname2>
#
# Variants of CLINE and LINE:
#    LINE . <pname1> <pname2> <attrName1=attrValue1>...
#         creates unnamed line between <pname1> and <pname2> with given attribute(s) (if any)
#    LINE <lname> <pname1> <pname2> <attrName1=attrValue1>...
#         creates line named <lname> between <pname1> and <pname2> with given attribute(s) (if any)
#
# Format of SET:
#    SET     varname  expression
#
# Format of PATBEG/PATBREAK/PATEND:
#    PATBEG   varname  ncopy
#    PATBREAK expr1 op expr2
#        where op is LT LE EQ GE GT NE
#    PATEND
#
# Format of IFTHEN/ENDIF:
#    IFTHEN expr1 op expr2
#        where op is LT LE EQ GE GT NE
#    ENDIF
#
# note: keywords can be in lowercase or UPPERCASE
# note coordinates of existing point <pname> are given by x@<pname> and y@<pname>
# note: variables outside the waffle are avalilable

SET      xA      -2.0
SET      yA      -4.0

UDPARG    waffle    depth    2.0
UDPARG    waffle    progress 1          # prints progess in console
UDPARG    waffle    rebuild  0          # forces waffle to be rebuilt
UDPRIM    waffle    filename <<
   POINT  A    AT  xA   yA
   POINT  B    AT  5.0  4.0
   POINT  C    AT  3.0 -1.0
   LINE   AB   A  B          name=lineAB

   POINT  D    ON AB XLOC x@C
   LINE   .    C  D

   POINT  E    ON AB YLOC y@C
   LINE   .    C  E

   POINT  F    ON AB FRAC  0.1
   LINE   CF   C  F

   POINT  G    at  4.0  4.0
   POINT  H    at  7.0  1.0
   CLINE  GH   G  H

   POINT  I    ON AB XSECT GH
   LINE   .    I  C

   POINT  J    ON AB PERP C
   LINE   .    J  G

   POINT  K    ON GH XLOC 6.0
   LINE   KB   K  B

   POINT  L    ON GH YLOC 3.0
   LINE   .    L  B

   POINT  M    AT  0.1 -5.0
   POINT  N    AT  0.1  5.0
   CLINE  MN   M  N

   POINT  O    ON MN XSECT AB
   CPOINT P    ON MN XSECT CF          # does nothing

   PATBEG i    3
      POINT  Q  ON   KB FRAC (i/3)
      POINT  R  AT   x@Q+1  y@Q
      LINE   .  Q  R  name=!$rung_+i
   PATEND
>>

END