dos33fsprogs/ootw/ootw_cavern.s
2019-01-20 00:52:07 -05:00

255 lines
3.3 KiB
ArmAsm

; Cavern scene (with the slugs)
ootw_cavern:
;===========================
; Enable graphics
bit LORES
bit SET_GR
bit FULLGR
;==================
; setup drawing
lda #0
sta DRAW_PAGE
lda #1
sta DISP_PAGE
;===================
; setup room boundaries
lda #0
sta LEFT_LIMIT
lda #37
sta RIGHT_LIMIT
;=============================
; Load background to $c00
lda #$0c
sta BASH
lda #$00
sta BASL ; load image off-screen $c00
lda #>(cavern_rle)
sta GBASH
lda #<(cavern_rle)
sta GBASL
jsr load_rle_gr
;=============================
; Load quake background to $1000
jsr gr_make_quake
;=================================
; copy to both pages $400/$800
jsr gr_copy_to_current
jsr page_flip
jsr gr_copy_to_current
;=================================
; setup vars
lda #0
sta GAIT
sta GAME_OVER
;============================
; Cavern Loop (not a palindrome)
;============================
cavern_loop:
;==========================
; check for earthquake
earthquake_handler:
lda FRAMEH
and #3
bne earth_mover
lda FRAMEL
cmp #$ff
bne earth_mover
earthquake_init:
lda #200
sta EQUAKE_PROGRESS
lda #0
sta BOULDER_Y
jsr random16
lda SEEDL
and #$1f
clc
adc #4
sta BOULDER_X
earth_mover:
lda EQUAKE_PROGRESS
beq earth_still
and #$8
bne earth_calm
lda #2
bne earth_decrement
earth_calm:
lda #0
earth_decrement:
sta EARTH_OFFSET
dec EQUAKE_PROGRESS
jmp earth_done
earth_still:
lda #0
sta EARTH_OFFSET
earth_done:
;================================
; copy background to current page
lda EARTH_OFFSET
bne shake_shake
no_shake:
jsr gr_copy_to_current
jmp done_shake
shake_shake:
jsr gr_copy_to_current_1000
done_shake:
;===============
; handle slug death
lda SLUGDEATH
beq still_alive
collapsing:
lda SLUGDEATH_PROGRESS
cmp #18
bmi still_collapsing
really_dead:
lda #$ff
sta GAME_OVER
jmp just_slugs
still_collapsing:
tax
lda collapse_progression,X
sta INL
lda collapse_progression+1,X
sta INH
lda PHYSICIST_X
sta XPOS
lda PHYSICIST_Y
sec
sbc EARTH_OFFSET
sta YPOS
jsr put_sprite
lda FRAMEL
and #$1f
bne no_collapse_progress
inc SLUGDEATH_PROGRESS
inc SLUGDEATH_PROGRESS
no_collapse_progress:
jmp just_slugs
still_alive:
;===============
; check keyboard
jsr handle_keypress
;===============
; draw physicist
jsr draw_physicist
just_slugs:
;===============
; draw slugs
jsr draw_slugs
;======================
; draw falling boulders
lda BOULDER_Y
cmp #38
bpl no_boulder
lda #<boulder
sta INL
lda #>boulder
sta INH
lda BOULDER_X
sta XPOS
lda BOULDER_Y
sta YPOS
jsr put_sprite
lda FRAMEL
and #$3
bne no_boulder
inc BOULDER_Y
inc BOULDER_Y
no_boulder:
;=======================
; page flip
jsr page_flip
;========================
; inc frame count
inc FRAMEL
bne frame_no_oflo_c
inc FRAMEH
frame_no_oflo_c:
; pause?
; see if game over
lda GAME_OVER
cmp #$ff
beq done_cavern
; see if left level
cmp #1
bne still_in_cavern
lda #37
sta PHYSICIST_X
jmp ootw_pool
still_in_cavern:
; loop forever
jmp cavern_loop
done_cavern:
rts