Files
aqhomecontrol/avr/modules/lcd2/font/font12x20.asm
2025-06-02 21:13:44 +02:00

130 lines
2.9 KiB
NASM

; ***************************************************************************
; copyright : (C) 2025 by Martin Preuss
; email : martin@libchipcard.de
;
; ***************************************************************************
; * This file is part of the project "AqHome". *
; * Please see toplevel file COPYING of that project for license details. *
; ***************************************************************************
; ***************************************************************************
; code
.cseg
; ---------------------------------------------------------------------------
; @routine font12x20MonoHandlerFn
;
; Handler for 12x20 Mono Fonts
;
font12x20MonoHandlerFn:
cpi r23, FONT_FN_RENDER
breq font12x20MonoRenderCharacter
bigjmp FONT_GenericHandler
; @end
; ---------------------------------------------------------------------------
; @routine font12x20RenderCharacter
; @param R16 character to write
; @param R1:R0 background color
; @param R3:R2 foreground color
; @param Z pointer to font
; @param X pointer to RAM to store data to
; @param r18 char width in pixel
; @param r19 char height in pixel
; @clobbers r17, r18, r23, r24, r25, x
font12x20MonoRenderCharacter:
push zl
push zh
rcall font12x20GetCharPosInFont ; (r17, r24, r25, z)
ldi r25, 20 ; 20 bytes height
font12x20MonoRenderCharacter_loop1:
ldi r24, 12 ; 16 bits
ldi r23, 8
lpm r17, Z+
font12x20MonoRenderCharacter_loop2:
dec r23
brne font12x20MonoRenderCharacter_haveByte
lpm r17, Z+
ldi r23, 8
font12x20MonoRenderCharacter_haveByte:
lsr r17
brcs font12x20MonoRenderCharacter_writeForeground
st X+, r0
st X+, r1
rjmp font12x20MonoRenderCharacter_loop2end
font12x20MonoRenderCharacter_writeForeground:
st X+, r2
st X+, r3
font12x20MonoRenderCharacter_loop2end:
dec r24
brne font12x20MonoRenderCharacter_loop2
dec r25
brne font12x20MonoRenderCharacter_loop1
ldi r18, 12
ldi r19, 20
pop zh
pop zl
ret
; @end
; ---------------------------------------------------------------------------
; @routine font12x20GetCharPosInFont
; @param R16 character to write
; @param Z pointer to font
; @return Z pointer to begin of char data
; @clobbers r17, r24, r25, z
font12x20GetCharPosInFont:
mov r24, r16
adiw zh:zl, FONT_OFFS_FIRSTCHAR
lpm r24, Z+ ; first char num
lpm r25, Z+ ; num of chars
sub r16, r24
brcs font12x20GetCharPosInFont_ret
cp r16, r25
brcc font12x20GetCharPosInFont_ret
mov r24, r16
clr r25
lsl r24 ; x2
rol r25
lsl r24 ; x4
rol r25
add r24, r16 ; x5
adc r25, r16
sub r25, r16
lsl r24 ; x10
rol r25
lsl r24 ; x20
rol r25
lsl r24 ; x40
rol r25
add zl, r24
adc zh, r25
font12x20GetCharPosInFont_ret:
ret
; @end