dos33fsprogs/games/peasant/hgr_7x28_sprite.s
Vince Weaver da4412f3f2 peasant: make peasant sprite 7x28 instead of 7x30
not sure why it was 7x30 anyway as we ignored the bottom 2 lines

hopefully makes bg masking easier
2021-08-24 20:58:44 -04:00

136 lines
1.8 KiB
ArmAsm

;===============================================
; hgr 7x28 draw sprite
;===============================================
; SPRITE in INL/INH
; Location at CURSOR_X CURSOR_Y
; left sprite AT INL/INH
; right sprite at INL/INH + 14
; left mask at INL/INH + 28
; right mask at INL/INH + 42
hgr_draw_sprite_7x28:
; set up pointers
lda INL
sta h728_smc1+1
lda INH
sta h728_smc1+2
clc
lda INL
adc #28
sta h728_smc3+1
lda INH
adc #0
sta h728_smc3+2
ldx #0 ; X is row counter
hgr_7x28_sprite_yloop:
txa ; X is current row
clc
adc CURSOR_Y ; add in cursor_y
; calc GBASL/GBASH
tay ; get output ROW into GBASL/H
lda hposn_low,Y
sta GBASL
lda hposn_high,Y
sta GBASH
ldy CURSOR_X
lda (GBASL),Y ; load background
h728_smc3:
and $d000,X ; mask with sprite mask
h728_smc1:
ora $d000,X ; or in sprite
sta (GBASL),Y ; store out
inx
cpx #28
bne hgr_7x28_sprite_yloop
rts
;======================
; save bg 7x28
;======================
save_bg_7x28:
ldx #0
save_yloop:
txa
pha
clc
adc CURSOR_Y
; calc GBASL/GBASH
tax
lda hposn_low,X
sta GBASL
lda hposn_high,X
sta GBASH
pla
tax
ldy CURSOR_X
lda (GBASL),Y
sta save_sprite_7x28,X
inx
cpx #28
bne save_yloop
rts
;======================
; restore bg 7x28
;======================
restore_bg_7x28:
ldx #0
restore_yloop:
txa ; current row
clc
adc CURSOR_Y ; add in y start point
; calc GBASL/GBASH using lookup table
tay
lda hposn_low,Y
sta GBASL
lda hposn_high,Y
sta GBASH
ldy CURSOR_X
lda save_sprite_7x28,X
sta (GBASL),Y
inx
cpx #28
bne restore_yloop
rts
;====================
; save area
;====================
save_sprite_7x28:
.byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
.byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00