Design: 04.02.03.02/P15

This is an abstract, language-independent design. Grim details may be found in the corresponding source code. You may return to the documentation for the module containing this program design, or to the entire hierarchical table of topics covered by the PVT.


PROGRAM 15: Appearance of character expansion factor and
            character spacing

CHARACTERISTICS: ynny

OPERATOR SCRIPT:

CHARACTER EXPANSION AND SPACING IN HORIZONTAL TEXT: Several
horizontal lines containing a text string are drawn with various
values for the character attributes.  The expected character body
positions are outlined with a dotted line and a dashed baseline
is drawn, usually of different colors than the text itself.
Identify the single line in which the characters either do NOT
fall within the dotted boxes or are NOT aligned on the baseline.
Since the boxes are character bodies, they are bounded by the
topline and bottomline, and thus may be somewhat larger
vertically than the enclosed character.  In the case of
overlapping characters due to negative character spacing,
half-boxes are drawn, so that the boxes themselves don't overlap.

CHARACTER EXPANSION AND SPACING IN VERTICAL TEXT: Same as above,
except that the text choices are vertical columns, not horizontal
lines.  Note that the expected position is aligned on the
vertical centerline (not left- or right-justified); the actual
characters, therefore, must not appear to the left or right of
the expected box.

DESIGN:

set all ASFs to BUNDLED

use <inquire text extent> with
  text font                  = 1
  character height           = 1
  character spacing          = 0
  character expansion factor = 1
  text string                = "WWiig!"
to determine
  ncbht = nominal character body height
  ncbwd = nominal character body width

set text path = RIGHT
numlin = number of lines = 6
ngline = random number from 1 to numlin
for ix = 1 to numlin
   randomly select, to fit on one line
      chht  = character height
      chexp = expansion factor
      chsp  = character spacing

   set character height = chht
   set text index = ix
   set text rep #ix: font,   precision, expansion, spacing, color
                     1,      STROKE,    chexp,     chsp,    1

   calculate expected character boxes
   if (ix = ngline) then
      distort character boxes
   endif
   draw in character boxes, using dotted line style, color #2

   display text "WWiig!" on line ix
next ix

TEST: #SR 3 5 6 45 50 57 58 59 61 62
      "The size and shape of a text string displayed with STROKE
       precision in a monospaced font on a horizontal text path
       should conform exactly to the character height, expansion
       factor, and spacing in effect."

OPQA/CHARACTER EXPANSION AND SPACING IN HORIZONTAL TEXT:
  In which line are the characters of the text string NOT aligned
  within dotted character boxes and on the dashed baseline?
pass/fail depending on (operator picks location ngline)

set text path = DOWN
numcol = number of columns = 6
ngcol  = random number from 1 to numcol
for ix = 1 to numcol
   randomly select, to fit in one column
      chht  = character height
      chexp = expansion factor
      chsp  = character spacing

   set character height = chht
   set text index = ix
   set text rep #ix: font,   precision, expansion, spacing, color
                     1,      STROKE,    chexp,     chsp,    1

   calculate expected character boxes
   if (ix = ngcol) then
      distort character boxes
   endif
   draw in character boxes, using dotted line style, color #2
   display text "WWiig!" in column ix
next ix

TEST: #SR 3 5 6 45 50 57 58 59 61 62
      "The size and shape of a text string displayed with STROKE
       precision in a monospaced font on a vertical text path
       should conform exactly to the character height, expansion
       factor, and spacing in effect."

OPQA/CHARACTER EXPANSION AND SPACING IN VERTICAL TEXT:
  In which column are the characters of the text string NOT
  aligned within dotted character boxes and on the dashed
  centerline?
pass/fail depending on (operator picks location ngcol)

bestfn = a stroke text font other than 1, preferably not #2 and
         not monospaced

bestsc = best score so far for font properties = -1
bestfn = best font so far = -1
for ix = each available non-#1 stroke font
   thisfn = ixth font from <inquire text facilities>
   use <inquire text extent> with
     text font                  = thisfn
     character height           = 1
     character spacing          = 0
     character expansion factor = 1
     text string                = "WWW"
   to determine
     tcbhtw = nominal character body height for W
     tcbwdw = nominal character body width for W

   use <inquire text extent> with
     text font                  = thisfn
     character height           = 1
     character spacing          = 0
     character expansion factor = 1
     text string                = "iii"
   to determine
     tcbhti = nominal character body height for i
     tcbwdi = nominal character body width for i

   if (thisfn = 2) then
      fnscor = score for this font = 0
   else
      fnscor = score for this font = 1
   endif

   if (ncbwdi approx= ncbwdw) then
      do nothing
   else
      add 2 to fnscor
   endif

   if (fnscor > bestsc) then
      best font so far:
      bestsc = fnscor
      bestfn = thisfn
      ncbhtw = tcbhtw
      ncbwdw = tcbwdw
      ncbhti = tcbhti
      ncbwdi = tcbwdi
      if (fnscor .ge. 3) then
         got a non-2, non-monospaced font: goto got_font
      endif
   endif
next stroke font

if (bestsc <= -1) then
   message: skipping tests for proportionately spaced fonts; none
            available.
   goto endit
endif

got_font:

set text path = LEFT
numlin = number of lines = 6
ngline = random number from 1 to numlin
for ix = 1 to numlin
   randomly select, to fit on one line
      chht  = character height
      chexp = expansion factor
      chsp  = character spacing

   set character height = chht
   set text index = ix
   set text rep #ix: font,   precision, expansion, spacing, color
                     bestfn, STROKE,    chexp,     chsp,    1

   calculate expected character boxes
   if (ix = ngline) then
      distort character boxes
   endif
   draw in character boxes, using dotted line style, color #2
   display text "WWiiiW" on line ix
next ix

TEST: #SR 3 5 6 50 57 58 59 61 62
      "The size and shape of a text string displayed with STROKE
       precision in any font on a horizontal text path should
       conform exactly to the character height, expansion factor,
       and spacing in effect."

OPQA/CHARACTER EXPANSION AND SPACING IN HORIZONTAL TEXT:
  In which line are the characters of the text string NOT aligned
  within dotted character boxes and on the dashed baseline?
pass/fail depending on (operator picks location ngline)

set text path = UP
numcol = number of columns = 6
ngcol  = random number from 1 to numcol
for ix = 1 to numcol
   randomly select, to fit in one column
      chht  = character height
      chexp = expansion factor
      chsp  = character spacing

   set character height = chht
   set text index = ix
   set text rep #ix: font,   precision, expansion, spacing, color
                     bestfn, STROKE,    chexp,     chsp,    1

   calculate expected character boxes
   if (ix = ngcol) then
      distort character boxes
   endif
   draw in character boxes, using dotted line style, color #2
   display text "WWiiiW" in column ix
next ix

TEST: #SR 3 5 6 50 57 58 59 61 62
      "The size and shape of a text string displayed with STROKE
       precision in any font on a vertical text path should
       conform exactly to the character height, expansion factor,
       and spacing in effect."

OPQA/CHARACTER EXPANSION AND SPACING IN VERTICAL TEXT:
  In which column are the characters of the text string NOT
  aligned within dotted character boxes and on the dashed
  centerline?
pass/fail depending on (operator picks location ngcol)

endit:

END PROGRAM 15