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2f1e635b9d
Pushed all words directly interfacing with ports and memory offsets to low level layers. This saves us the need for keeping those variables in runtime memory.
17 lines
803 B
Plaintext
17 lines
803 B
Plaintext
# 6/8 bit columns and smaller fonts
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If your glyphs, including padding, are 6 or 8 pixels wide,
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you're in luck because pushing them to the LCD can be done in a
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very efficient manner. Unfortunately, this makes the LCD
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unsuitable for a Collapse OS shell: 6 pixels per glyph gives us
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only 16 characters per line, which is hardly usable.
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This is why we have this buffering system. How it works is that
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we're always in 8-bit mode and we hold the whole area (8 pixels
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wide by FNTH high) in memory. When we want to put a glyph to
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screen, we first read the contents of that area, then add our
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new glyph, offsetted and masked, to that buffer, then push the
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buffer back to the LCD. If the glyph is split, move to the next
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area and finish the job.
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(cont.)
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