dos33fsprogs/games/keen/engine_enemies.s
Vince Weaver a6a9c0ce28 keen: hook up more of level7
don't have quite enough tiles :(
2024-04-22 22:16:01 -04:00

437 lines
6.9 KiB
ArmAsm

;=======================
; move enemies
;=======================
move_enemies:
ldx #0
move_enemies_loop:
cpx NUM_ENEMIES
bne keep_on_moving
jmp done_move_enemies_loop
keep_on_moving:
; only move if out
; only move every 4th frame to slow things down
lda FRAMEL
and #$3
bne move_enemy_frame_skip
lda enemy_data_out,X
bne enemy_is_out
move_enemy_frame_skip:
jmp done_move_enemy
enemy_is_out:
;=======================================
; check if falling
; i.e., if something under feet
;=======================================
clc
lda enemy_data_tiley,X
adc #2 ; point below feet
tay
lda tilemap_lookup_high,Y
; adc #>big_tilemap
sta load_foot1_smc+2
lda tilemap_lookup_low,Y
sta load_foot1_smc+1
ldy enemy_data_tilex,X
load_foot1_smc:
lda small_tilemap,Y
cmp HARDTOP_TILES
bcs no_enemy_fall ; if hardtop tile, don't fall
inc enemy_data_tiley,X ; fall one tiles worth
no_enemy_fall:
;============================
; not falling, so do actions
;============================
; if walking, walk
; if searching, search
dec enemy_data_count,X
bne enemy_action
enemy_new_state:
jsr random16
lda SEEDL
and #$3
sta enemy_data_state,X
jsr random16
lda SEEDL
and #$f
clc
adc #4
sta enemy_data_count,X
enemy_action:
lda enemy_data_state,X
cmp #YORP_STUNNED
beq goto_done_move_enemy
cmp #YORP_SEARCH
beq enemy_search
cmp #YORP_JUMP
beq enemy_jump
bne enemy_walk
goto_done_move_enemy:
jmp done_move_enemy
enemy_search:
lda enemy_data_direction,X
eor #$FF
clc
adc #1
sta enemy_data_direction,X
; TODO: face keen when done
jmp done_move_enemy
enemy_jump:
; make sure we don't jump for too long
; hack
lda enemy_data_count,X
and #$3
sta enemy_data_count,X
; jump a bit
dec enemy_data_tiley,X
; fallthrough
;=======================================
; move sideways
; until you hit something
;=======================================
enemy_walk:
; check if moving right/left
lda enemy_data_direction,X
bmi enemy_facing_left
enemy_facing_right:
;==============================
; check if barrier to the right
clc
lda enemy_data_tiley,X
adc #1 ; point to feet
tay
; adc #>big_tilemap
lda tilemap_lookup_high,Y
sta load_right_foot_smc+2
lda tilemap_lookup_low,Y
sta load_right_foot_smc+1
ldy enemy_data_tilex,X
iny ; to the right
load_right_foot_smc:
lda small_tilemap,Y
cmp ALLHARD_TILES
bcc no_right_barrier ; skip if no right barrier
; hit right barrier
lda enemy_data_direction,X
eor #$ff ; ff->00, 01->fe
clc
adc #1
sta enemy_data_direction,X
jmp done_move_enemy
no_right_barrier:
; move to the right
lda enemy_data_x,X
clc
adc #1
sta enemy_data_x,X
cmp #2
bne move_right_noflo
; moved to next tile
lda #0
sta enemy_data_x,X
lda enemy_data_tilex,X
clc
adc #1
sta enemy_data_tilex,X
move_right_noflo:
jmp done_move_enemy
enemy_facing_left:
;==============================
; check if barrier to the left
clc
lda enemy_data_tiley,X
adc #1 ; point to feet
tay
; adc #>big_tilemap
lda tilemap_lookup_high,Y
sta load_left_foot_smc+2
lda tilemap_lookup_low,Y
sta load_left_foot_smc+1
ldy enemy_data_tilex,X
dey ; look to the left
load_left_foot_smc:
lda small_tilemap,Y
cmp ALLHARD_TILES
bcc no_left_barrier ; skip if no right barrier
; hit left barrier
lda enemy_data_direction,X
eor #$ff ; ff->00, 01->fe
clc
adc #1
sta enemy_data_direction,X
jmp done_move_enemy
no_left_barrier:
; move to the left
sec
lda enemy_data_x,X
sbc #1
sta enemy_data_x,X
bpl move_left_noflo
; adjust tile
lda #1
sta enemy_data_x,X
lda enemy_data_tilex,X
sec
sbc #1
sta enemy_data_tilex,X
move_left_noflo:
done_move_enemy:
inx
; cpx NUM_ENEMIES
; beq totally_done_move_enemies
jmp move_enemies_loop
done_move_enemies_loop:
totally_done_move_enemies:
rts
;=================
; draw enemies
;=================
draw_enemies:
ldy #0
draw_enemies_loop:
cpy NUM_ENEMIES
beq done_draw_enemies
; see if out
lda enemy_data_out,Y
beq done_draw_enemy
; see if exploding
lda enemy_data_exploding,Y
beq draw_proper_enemy
;draw_exploding_enemy:
; asl
; tax
; lda enemy_explosion_sprites,X
; sta INL
; lda enemy_explosion_sprites+1,X
; sta INH
; lda FRAMEL
; and #$3
; bne done_exploding
; move to next frame
; lda enemy_data+ENEMY_DATA_EXPLODING,Y
; clc
; adc #1
; sta enemy_data+ENEMY_DATA_EXPLODING,Y
; cmp #4
; bne done_exploding
; lda #0
; sta enemy_data+ENEMY_DATA_OUT,Y
;done_exploding:
; jmp draw_enemy
; otherwise draw proper sprite
draw_proper_enemy:
; lda enemy_data+ENEMY_DATA_TYPE,Y
; tax
; lda enemy_sprites,X
; sta INL
; lda enemy_sprites+1,X
; sta INH
lda enemy_data_state,Y
cmp #YORP_STUNNED
bne draw_enemy_walk
lda #<yorp_sprite_stunned
sta INL
lda #>yorp_sprite_stunned
jmp draw_enemy_common
draw_enemy_walk:
lda enemy_data_direction,Y
bmi draw_enemy_left
draw_enemy_right:
lda #<yorp_sprite_walking_right
sta INL
lda #>yorp_sprite_walking_right
jmp draw_enemy_common
draw_enemy_left:
lda #<yorp_sprite_walking_left
sta INL
lda #>yorp_sprite_walking_left
draw_enemy_common:
sta INH
;======================
; calculate X and Y
; tiles are 2x4 in size
sec
lda enemy_data_tilex,Y
sbc TILEMAP_X
asl
clc
adc enemy_data_x,Y ; Add in X offset
sta XPOS
sec
lda enemy_data_tiley,Y
sbc TILEMAP_Y
asl
asl
clc
adc enemy_data_y,Y ; Add in Y offset
sta YPOS
draw_enemy:
tya
pha
jsr put_sprite_crop
pla
tay
done_draw_enemy:
iny
; cpy NUM_ENEMIES
; beq exit_draw_enemy
jmp draw_enemies_loop
done_draw_enemies:
exit_draw_enemy:
rts
enemy_explosion_sprites:
.word enemy_explosion_sprite1
.word enemy_explosion_sprite1
.word enemy_explosion_sprite2
.word enemy_explosion_sprite3
enemy_explosion_sprite1:
.byte 2,2
.byte $d9,$d9
.byte $9d,$9d
enemy_explosion_sprite2:
.byte 2,2
.byte $9A,$9A
.byte $A9,$A9
enemy_explosion_sprite3:
.byte 2,2
.byte $7A,$5A
.byte $A5,$A7
;YORP = 0
;YORP_WALK = 0
;YORP_JUMP = 1
;YORP_SEARCH = 2
;YORP_WALK2 = 3
;YORP_STUNNED= 4
;LEFT = $FF
;RIGHT = $1
;enemy_data_out: .byte 1, 0, 0, 0, 0, 0, 0, 0
;enemy_data_exploding: .byte 0, 0, 0, 0, 0, 0, 0, 0
;enemy_data_type: .byte YORP, YORP, YORP, YORP, YORP, YORP,YORP,YORP
;enemy_data_direction: .byte RIGHT, LEFT, LEFT, LEFT, LEFT, RIGHT,RIGHT,LEFT
;enemy_data_tilex: .byte 19, 38, 45, 69, 81, 89, 92, 100
;enemy_data_tiley: .byte 13, 4, 4, 13, 4, 4, 13, 10
;enemy_data_x: .byte 0, 0, 0, 0, 0, 0, 0, 0
;enemy_data_y: .byte 0, 0, 0, 0, 0, 0, 0, 0
;enemy_data_state: .byte 0, 0, 0, 0, 0, 0, 0, 0
;enemy_data_count: .byte 8, 8, 8, 8, 8, 8, 8, 8
; question: when do they activate? When do they move when offscreen?
; enemy behavior
; Yorp:
; two behaviors, walking with random jump
; walking, reverses direction if hits barrier
; stopping, looking left/right few times then walking at Keen