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Reduced problem on char draw

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Daniele Verducci su MatissePenguin
2021-02-28 19:47:08 +01:00
parent 1d4c4f8d3f
commit ddb7c58640
2 changed files with 46 additions and 8 deletions
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11
pat80-io-devices/composite-pal-adapter/software/avr-assembly/character_generator.asm
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@@ -37,17 +37,18 @@ draw_char:
call update_mem_pointer
; The drawing consist of FONT_HEIGHT cycles. Every glyph byte is placed on its own line
; on screen. To do this, we place it LINE_COLUMNS bytes after the previous one.
ldi HIGH_ACCUM, FONT_HEIGHT
clr HIGH_ACCUM
draw_char_loop:
; Load glyph line byte from program memory (and point to the next)
lpm r1, Z+
lpm A, Z+
; Write glyph line to framebuffer at chunk cursor position (Y)
st Y, r1
st Y, A
; Increment chunk cursor position (Y) to next line of the same char column
adiw YH:YL,LINE_COLUMNS
; Decrement loop counter and exit if reached 0
dec HIGH_ACCUM
brne draw_char_loop
inc HIGH_ACCUM
cpi HIGH_ACCUM, FONT_HEIGHT
brlo draw_char_loop
; Char drawing is complete. Increment cursor position
inc POS_COLUMN