Design: 04.01.03/P02

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PROGRAM 2: Appearance of text primitives

CHARACTERISTICS: ynny

OPERATOR SCRIPT:

CHARACTER CONTENT: Two alphabetic text primitives are displayed
successively.  The operator must identify the sequence of
characters in each.

DEGENERATE TEXT DIRECTION VECTORS: Several lines of text are
displayed.  All but one should have a normal horizontal
orientation and similar size.  Identify the one line which is
askew.

TEXT DIRECTION VECTORS: Several boxes containing text are
displayed.  All but one should appear as a single text primitive.
Identify the one box containing overlapping primitives.

DESIGN:

default attributes:
font = 1
precision = STROKE
text alignment = CENTRE,HALF

throughout TDV = text direction vectors

*** *** *** ***   character content   *** *** *** ***

TEST: #SR 9
      "A displayed text primitive should contain the specified
       character string."

set character height = 0.05
set text font = 2
chstr = string of 5 randomly chosen upper-case letters

display <text 3> consisting of chstr:
  position = 0.5,0.5,0.5
  TDV = (1,0,0), (0,1,0)

OPQA/CHARACTER CONTENT: Enter the displayed character string.

if (operator response not= chstr) then
   fail
   goto end_char
endif

set text font = 1
chstr = string of 5 randomly chosen lower-case letters

display <text> consisting of chstr:
  position = 0.5,0.5

OPQA/CHARACTER CONTENT: Enter the displayed character string.
pass/fail depending on (operator response = chstr)

end_char:

*** *** *** ***   degenerate vectors   *** *** *** ***

TEST: #SR 9 10 11
      "The values (1,0,0) and (0,1,0) should be used as text
       direction vectors for all 2D text primitives and also when
       the explicit vectors of a 3D text primitive fail to define
       a plane."

In random order, display on 6 lines:

               1st vector   2nd vector
3D text "ABC"  (0,0,0)      (2,3,4)
3D text "ABC"  (0,0,0)      (0,0,0)
3D text "ABC"  (3,4,5)      (0,0,0)
3D text "ABC"  (1,-2,3)     (3,-6,9) (parallel vectors)
3D text "ABC"  (8,1,0)      (-1,8,0) (not horizontal)
2D text "ABC"   n.a.         n.a.

OPQA/DEGENERATE TEXT DIRECTION VECTORS: Which text line is
  different?
pass/fail depending on
  (operator response = line containing non-horizontal text)

*** *** *** ***   effect of text direction vectors   *** *** *** ***

TEST: #SR 9 10
      "A displayed text primitive should be rotated around the
       text position as specified by the first and second text
       direction vectors."

Divide screen up into 6 square labelled areas
ngsq = no-good square containing error = random from 1 to 6
chstr = "ABC"
zmid = 0.5

for ix = 1 to 6
   xmid,ymid = center of box #ix
   pick random rotation:
      rotx = random from -45.0 to 45.0 degrees
      roty = random from -45.0 to 45.0 degrees
      rotz = random from 0 to 360 degrees
   xf = transformation for rotation, centered at 0,0,0
   calculate equivalent TDVs:
   tdv1x,tdv1y,tdv1z = (1,0,0) transformed by xf
   tdv2x,tdv2y,tdv2z = (0,1,0) transformed by xf

   apply identity matrix as modelling transformation
   draw <text 3> chstr
      position: xmid,ymid,zmid
      TDV: tdv1,tdv2

   if (ix = ngsq) rotz = rotz + 5 degrees
   xf = transformation for rotx,roty,rotz,
        centered at xmid,ymid,0
        then shift by 0.5 in z-direction

   apply xf as modelling transformation
   if (ix <= 3) then
      draw <text 3> chstr
         position: xmid,ymid,0
         TDV: (1,0,0) (0,1,0)
   else
      draw <text> chstr
         position: xmid,ymid
   endif
next ix

OPQA/TEXT DIRECTION VECTORS: Which box contains overlapping text?
pass/fail depending on
  (operator response = box #ngsq)

END PROGRAM 2