mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-11-16 23:20:43 +00:00
83 lines
1020 B
ArmAsm
83 lines
1020 B
ArmAsm
;=========================================================
|
|
; gr_make_quake
|
|
;=========================================================
|
|
; Take image in $c00
|
|
; Copy to $BC00
|
|
; Actually copy lines 2..41 to 0..39
|
|
gr_make_quake:
|
|
|
|
ldx #0
|
|
make_quake_loop:
|
|
lda gr_offsets,x
|
|
sta OUTL
|
|
lda gr_offsets+1,x
|
|
clc
|
|
adc #$B8
|
|
sta OUTH
|
|
|
|
inx
|
|
inx
|
|
|
|
lda gr_offsets,x
|
|
sta INL
|
|
lda gr_offsets+1,x
|
|
clc
|
|
adc #$8
|
|
sta INH
|
|
|
|
ldy #39
|
|
quake_inner:
|
|
lda (INL),Y
|
|
sta (OUTL),Y
|
|
|
|
dey
|
|
bpl quake_inner
|
|
|
|
cpx #40
|
|
bne make_quake_loop
|
|
|
|
; write zeros to the rest
|
|
|
|
quake_clear_bottom:
|
|
lda gr_offsets,x
|
|
sta OUTL
|
|
lda gr_offsets+1,x
|
|
clc
|
|
adc #$B8
|
|
sta OUTH
|
|
|
|
inx
|
|
inx
|
|
|
|
ldy #39
|
|
lda #0
|
|
quake_clear_inner:
|
|
sta (OUTL),Y
|
|
dey
|
|
bpl quake_clear_inner
|
|
|
|
cpx #48
|
|
bne quake_clear_bottom
|
|
|
|
; clear the extra two lines from the original
|
|
quake_clear_extra:
|
|
|
|
ldx #40
|
|
lda gr_offsets,x
|
|
sta OUTL
|
|
lda gr_offsets+1,x
|
|
clc
|
|
adc #$8
|
|
sta OUTH
|
|
|
|
ldy #39
|
|
lda #0
|
|
quake_clear_extra_inner:
|
|
sta (OUTL),Y
|
|
dey
|
|
bpl quake_clear_extra_inner
|
|
|
|
rts ; 6
|
|
|
|
|