Shown to happen with 2-pixel-high rectangles of any width, but
1-pixel-wide rectangles are fine
Experimentation details about problem:
Real(12,5) (empty with inverted edges) have some render
problems when randomly rendered with size (3x3)
Real(12,6) (black rectangles) are uniforming distributed
when randomly rendered with size (3x3)
Real(12,7) (white rectangles) are uniforming distributed
when randomly rendered with size (3x3)
Real(12,8) (inverted rectangles) appear to render only in
certain columns at (3x3), cf. image below. Notice that one
symptom is that at (3x3), the unaffected columns are grouped
in adjacent pairs:
Real(12,8) (inverted rectangles) appear to render only in
certain columns at (4x4), cf. image below. Notice that one
symptom is that at (4x4), the unaffected columns are grouped
in adjacent groups of three:
Finally fixed after over a day of painful debugging. Real
problem was that XLib’s tilemapper Real(2) routine does not
write into the 64th row of the display. The 16x16 and 8x8 tile
mapping routines were modified accordingly, including setting up
buffer-address-based copy height reductions, buffer clearing,
and copy mode-based buffer clearing.
Real(2) problems, as seen with Metroid by CDI
Fix turned out to have a second part, handling Pic'0’ as Pic'10'
instead of Pic8.
Two byte tokens containing $3F as second byte does not properly
parse in any lineread command