dos33fsprogs/games/lemm/move_lemming.s
2022-03-13 01:28:37 -05:00

210 lines
2.6 KiB
ArmAsm

;==========================
; move them
;==========================
move_lemmings:
ldy #0
lda lemming_out,Y
bne really_move_lemming
jmp done_checking_lemming
really_move_lemming:
; bump frame
tya
tax
inc lemming_frame,X ; only can inc with X
lda lemming_status,Y
cmp #LEMMING_FALLING
beq do_lemming_falling
cmp #LEMMING_WALKING
beq do_lemming_walking
cmp #LEMMING_DIGGING
beq do_lemming_digging
jmp done_move_lemming
do_lemming_falling:
inc lemming_y
jsr collision_check_ground
jmp done_move_lemming
do_lemming_walking:
; collision detect walls
lda lemming_y
clc
adc #3 ; waist-high?
tay
lda hposn_high,Y
clc
adc #$20
sta GBASH
lda hposn_low,Y
sta GBASL
clc
lda lemming_x
adc lemming_direction
tay
lda (GBASL),Y
and #$7f
beq walking_no_wall
walking_yes_wall:
lda lemming_direction
eor #$ff
clc
adc #1
sta lemming_direction
lda lemming_x
walking_no_wall:
tya
walking_done:
sta lemming_x
jsr collision_check_ground
jmp done_move_lemming
do_lemming_digging:
lda lemming_y
clc
adc #9
tay
lda hposn_high,Y
clc
adc #$20
sta GBASH
lda hposn_low,Y
sta GBASL
ldy lemming_x
lda (GBASL),Y
and #$7f
beq digging_falling
digging_digging:
lda #$0
sta (GBASL),Y
; lda GBASH
; clc
; adc #$20 ; erase bg
; sta GBASH
; lda #$0
; sta (GBASL),Y
inc lemming_y
jmp done_digging
digging_falling:
lda #LEMMING_FALLING
sta lemming_status
done_digging:
done_move_lemming:
; see if beat level
lda lemming_y
cmp #116
bcc not_done_level
cmp #127
bcs not_done_level
lda lemming_x
cmp #31
bcc not_done_level
; done level
jsr remove_lemming
lda #1
sta LEVEL_OVER
not_done_level:
done_checking_lemming:
rts
;==========================
; remove lemming from game
remove_lemming:
lda #0
sta lemming_out
dec LEMMINGS_OUT
jsr update_lemmings_out
rts
lemming_direction:
.byte 1
lemming_x:
.byte 12
lemming_y:
.byte 45
lemming_out:
.byte $0
lemming_frame:
.byte 0
LEMMING_FALLING = 1
LEMMING_WALKING = 2
LEMMING_DIGGING = 3
lemming_status:
.byte LEMMING_FALLING
lemming_job:
.byte $00
;=============================
; collision check ground
;=============================
collision_check_ground:
lda lemming_y
clc
adc #9
tay
lda hposn_high,Y
clc
adc #$20 ; check bg, not fg
sta GBASH
lda hposn_low,Y
sta GBASL
ldy lemming_x
lda (GBASL),Y
and #$7f
beq ground_falling
ground_walking:
lda #LEMMING_WALKING
jmp done_check_ground
ground_falling:
lda #LEMMING_FALLING
done_check_ground:
sta lemming_status
rts