mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-24 03:38:05 +11:00
17 lines
809 B
Plaintext
17 lines
809 B
Plaintext
|
# 6/8 bit columns and smaller fonts
|
||
|
|
|
||
|
|
If your glyphs, including padding, are 6 or 8 pixels wide,
|
||
|
|
you're in luck because pushing them to the LCD can be done in a
|
||
|
|
very efficient manner. Unfortunately, this makes the LCD
|
||
|
|
unsuitable for a Collapse OS shell: 6 pixels per glyph gives us
|
||
|
|
only 16 characters per line, which is hardly usable.
|
||
|
|
|
||
|
|
This is why we have this buffering system. How it works is that
|
||
|
|
we're always in 8-bit mode and we hold the whole area (8 pixels
|
||
|
|
wide by FNT_HEIGHT high) in memory. When we want to put a glyph
|
||
|
|
to screen, we first read the contents of that area, then add
|
||
|
|
our new glyph, offsetted and masked, to that buffer, then push
|
||
|
|
the buffer back to the LCD. If the glyph is split, move to the
|
||
|
|
next area and finish the job.
|
||
|
|
(cont.)
|