dos33fsprogs/megademo/waterfall.s

627 lines
11 KiB
ArmAsm

; Lo-res cycle-counting water transparency hack
; by deater (Vince Weaver) <vince@deater.net>
; Zero Page
;FRAMEBUFFER = $00 ; $00 - $0F
;YPOS = $10
YPOS_SIN = $11
BIRD_STATE = $E0
BIRD_DIR = $E1
OLD_XPOS = $F4
; location we don't care about
DUMMY = $300
waterfall:
;===================
; init screen
jsr TEXT
jsr HOME
bit PAGE0
;===================
; init vars
lda #0
sta BIRD_DIR
sta BIRD_STATE
sta FRAME
sta OLD_XPOS
lda #4
sta DRAW_PAGE
sta XPOS
;=============================
; Load foreground to graphic page1 (apple page2)
lda #$0c
sta BASH
lda #$00
sta BASL ; load image to $c00
lda #<waterfall_page1
sta GBASL
lda #>waterfall_page1
sta GBASH
jsr load_rle_gr
jsr gr_copy_to_current ; copy to page1
;=============================
; Load bg to memory
lda #$0c
sta BASH
lda #$00
sta BASL ; load image to $c00
lda #<waterfall_page2
sta GBASL
lda #>waterfall_page2
sta GBASH
jsr load_rle_gr
;==============================
; setup graphics for vapor lock
;==============================
jsr vapor_lock ; 6
; vapor lock returns with us at beginning of hsync in line
; 114 (7410 cycles), so with 5070 lines to go
jsr gr_copy_to_current ; 6+ 9292
; now we have 322 left
; GR part
bit LORES ; 4
bit SET_GR ; 4
bit FULLGR ; 4
; 322 - 12 = 310
; -3 for jmp
; 307
; Try X=9 Y=6 cycles=307
ldy #6 ; 2
wfloopA:ldx #9 ; 2
wfloopB:dex ; 2
bne wfloopB ; 2nt/3
dey ; 2
bne wfloopA ; 2nt/3
jmp wf_display_loop
wf_jump_table:
.word (display_even-1)
.word (display_odd-1)
.word (display_three-1)
.word (display_four-1)
.align $100
;================================================
; Display Loop
;================================================
; each scan line 65 cycles
; 1 cycle each byte (40cycles) + 25 for horizontal
; Total of 12480 cycles to draw screen
; Vertical blank = 4550 cycles (70 scan lines)
; Total of 17030 cycles to get back to where was
; jump_table
; 38 + display_odd
; we have 3 (the jmp back)
; = 3 cycles that need to be eaten by the vblank
wf_display_loop:
inc FRAME ; 5
lda FRAME ; 3
and #$30 ; 2
; 0011 0000, so more or less div by 16, 3.75Hz
lsr ; 2
lsr ; 2
lsr ; 2
tay ; 2 ; 18
lda wf_jump_table+1,y ; 4
pha ; 3
lda wf_jump_table,y ; 4
pha ; 3
rts ; 6 ; 38
wf_display_loop_return:
vblank:
;======================================================
; We have 4550 cycles in the vblank, use them wisely
;======================================================
; do_nothing should be 4550
; -3 letfover from HBLANK code
; ** -9
; -49 check for keypress
; -2252 copy screen
; -2231 draw sprite
; =============
; 15 cycles
; 15 cycles
inc YPOS ; 5
nop ; 2
nop ; 2
lda YPOS ; 3
lda YPOS ; 3
;=========================
; Clear background
;=========================
jsr gr_copy_row22 ; 6+ 2246
;=========
; 2252
;==========================
; draw bird sprite
;==========================
; 8 prefix
; bird_walk_right= 14 + 2175 2206 (need 17)
; bird_stand_right= 13 + 2190 2206 (need 3)
; bird_walk_left= 15 + 2175 2206 (need 16)
; bird_stand_left= 14 + 2190 2206 (need 2)
; call to sprite 17 postfix
;====================================================
; 2231
lda BIRD_STATE ; 3
and #1 ; 2
ldx BIRD_DIR ; 3
bne bird_left
bird_right:
; 2
cmp #1 ; 2
beq bird_walk_right
; 2
bird_stand_right:
ldx #>bird_rider_stand_right ; 2
ldy #<bird_rider_stand_right ; 2
lda YPOS ; nop=3
jmp wf_draw_bird ; 3
bird_walk_right:
; 3
ldx #>bird_rider_walk_right ; 2
ldy #<bird_rider_walk_right ; 2
jmp kill_less_time ; 3
bird_left:
; 3
cmp #1 ; 2
beq bird_walk_left
bird_stand_left:
; 2
ldx #>bird_rider_stand_left ; 2
ldy #<bird_rider_stand_left ; 2
nop ; nop=2
jmp wf_draw_bird ; 3
bird_walk_left:
; 3
ldx #>bird_rider_walk_left ; 2
ldy #<bird_rider_walk_left ; 2
wf_kill_time:
nop ; 2 ; need to kill 16
kill_less_time:
lda YPOS ; nop=3 ; need to kill 14
lda YPOS ; nop=3
lda YPOS ; nop=3
lda YPOS ; nop=3
nop ; 2
jmp wf_draw_bird ; 3
wf_draw_bird:
stx INH ; 3
sty INL ; 3
lda #22 ; 2
sta YPOS ; 3
jsr put_sprite ; 6
;=========
; 17 + 2190
;====================
; Handle keypresses
; if no keypress, 9
; if keypress, 6+43 = 49
lda KEYPRESS ; 4
bmi wf_keypress
; 2
wf_no_keypress:
; kill 40 cycles
ldx #0 ; 2
inc YPOS,X ; 6
inc YPOS,X ; 6
inc YPOS,X ; 6
inc YPOS,X ; 6
inc YPOS,X ; 6
inc YPOS,X ; 6
nop ; 2
jmp wf_display_loop ; 3
;===================================================
; key was pressed handling takes 12 + 20 + 11 = 43
wf_keypress:
; 1
bit KEYRESET ; 4
inc BIRD_STATE ; 5
and #$5f ; mask keypress ; 2
is_it_right:
cmp #$15 ; right arrow ; 2
bne is_it_left
; 2
inc XPOS ; 5
lda #0 ; 2
sta BIRD_DIR ; 3
lda YPOS ; 3-cycle nop ; 3
convoluted:
jmp adjust_xpos ; 3 ; 20 if right
is_it_left:
; 5
cmp #$8 ; left arrow ; 2
beq is_left ; 3
; -1
cmp #0 ; space? ; 2
bne not_space ; 3
rts
; nop ; 2
; lda YPOS ; 3-cycle nop ; 3
not_space:
jmp convoluted ; 3
; ------ 20 if neither
is_left:
dec XPOS ; 5 ; 20 if left
lda #1 ; 2
sta BIRD_DIR ; 3
adjust_xpos:
lda XPOS ; 3
and #$1f ; keep in 0-31 range ; 2
sta XPOS ; 3
jmp wf_display_loop ; 3
.align $100
.include "gr_unrolled_copy.s"
; even odd three four
;twinkle: 1111 1111 0110 1111
;falls: 000 010 010 000
; 000 000 010 010
; 010 000 000 010
; 010 010 000 000
;ground: 0101 1010 1010 0101
; PAGE0=54 PAGE1=55
;=================================
; Display Even
;=================================
display_even:
lda #$55 ; 2
; twinkle 11 falls 0011 ground 0101
sta wf_modify1+1 ; 4
sta wf_modify2+1 ; 4
sta wf_modify5+1 ; 4
sta wf_modify6+1 ; 4
sta wf_modify8+1 ; 4
sta wf_modify10+1 ; 4
lda #$54
; twinkle 11 falls 0011 ground 0101
sta wf_modify3+1 ; 4
sta wf_modify4+1 ; 4
sta wf_modify7+1 ; 4
sta wf_modify9+1 ; 4
jmp first_four_lines ; 3
;============
; 47
;=================================
; Display Odd
;=================================
display_odd:
lda #$55 ; 2
; twinkle 11 falls 1001 ground 1010
sta wf_modify1+1 ; 4
sta wf_modify2+1 ; 4
sta wf_modify3+1 ; 4
sta wf_modify6+1 ; 4
sta wf_modify7+1 ; 4
sta wf_modify9+1 ; 4
lda #$54
; twinkle 11 falls 1001 ground 1010
sta wf_modify4+1 ; 4
sta wf_modify5+1 ; 4
sta wf_modify8+1 ; 4
sta wf_modify10+1 ; 4
jmp first_four_lines ; 3
;============
; 47
;=================================
; Display Three
;=================================
display_three:
lda #$55 ; 2
; twinkle 00 falls 1100 ground 1010
sta wf_modify3+1 ; 4
sta wf_modify4+1 ; 4
sta wf_modify7+1 ; 4
sta wf_modify9+1 ; 4
lda #$54
; twinkle 00 falls 1100 ground 1010
sta wf_modify1+1 ; 4
sta wf_modify2+1 ; 4
sta wf_modify5+1 ; 4
sta wf_modify6+1 ; 4
sta wf_modify8+1 ; 4
sta wf_modify10+1 ; 4
jmp first_four_lines ; 3
;============
; 47
;=================================
; Display Four
;=================================
display_four:
lda #$55 ; 2
; twinkle 11 falls 0110 ground 0101
sta wf_modify1+1 ; 4
sta wf_modify2+1 ; 4
sta wf_modify4+1 ; 4
sta wf_modify5+1 ; 4
sta wf_modify8+1 ; 4
sta wf_modify10+1 ; 4
lda #$54
; twinkle 11 falls 0110 ground 0101
sta wf_modify3+1 ; 4
sta wf_modify6+1 ; 4
sta wf_modify7+1 ; 4
sta wf_modify9+1 ; 4
jmp first_four_lines ; 3
;============
; 47
.align $100
first_four_lines:
; line 0-3 = 65*4 = 260
; -38
; -47
; -2
; -2
; -25
;=========================
; 146
lda #146 ; 2
jsr delay_a ; 25+146
ldy #4 ; 2
twinkle_stars:
twinkle_loop:
; page1 for 4 lines, 65 - 4 = 61 -2 = 59 - 25 = 34
; line 0
wf_modify1:
bit PAGE1 ; 4
lda #34 ; 2
jsr delay_a ; 25+34
; line 1
bit PAGE1 ; 4
lda #34 ; 2
jsr delay_a ; 25+34
; line 2
bit PAGE1 ; 4
lda #34 ; 2
jsr delay_a ; 25+34
; line 3
wf_modify2:
bit PAGE1 ; 4
lda #27 ; 2
jsr delay_a ; 25+27
; below: 7 if not zero
; 7 (including ldy later) if is zero
dey ; 2
beq twinkle_loop_done ; 3
;-1
jmp twinkle_loop ; 3
twinkle_loop_done:
ldy #31 ; 2
falls_loop:
;=== line 0
bit PAGE0 ; 4
; delay 31
lda #4 ; 2
jsr delay_a ; 25+4
; delay 11
wf_modify3:
bit PAGE0 ; 4
lda YPOS ; 3
bit PAGE0 ; 4
; delay 19
nop ; 2
nop ; 2
asl DUMMY ; 6
asl DUMMY ; 6
lda YPOS ; 3
;=== line 1
bit PAGE0 ; 4
; delay 31
lda #4 ; 2
jsr delay_a ; 25+4
; delay 11
wf_modify4:
bit PAGE0 ; 4
lda YPOS ; 3
bit PAGE0 ; 4
; delay 19
nop ; 2
nop ; 2
asl DUMMY ; 6
asl DUMMY ; 6
lda YPOS ; 3
;=== line 2
bit PAGE0 ; 4
; delay 31
lda #4 ; 2
jsr delay_a ; 25+4
; delay 11
wf_modify5:
bit PAGE1 ; 4
lda YPOS ; 3
bit PAGE0 ; 4
; delay 19
nop ; 2
nop ; 2
asl DUMMY ; 6
asl DUMMY ; 6
lda YPOS ; 3
;== line 3
bit PAGE0 ; 4
; delay 31
lda #4 ; 2
jsr delay_a ; 25+4
; delay 11
wf_modify6:
bit PAGE1 ; 4
lda YPOS ; 3
bit PAGE0 ; 4 ; 46
; delay 21 - 7 from loop
nop ; 2
nop ; 2
asl DUMMY ; 6
nop ; 2 ; 58
dey ; 2
beq falls_loop_done ; 3
; -1
jmp falls_loop ; 3
falls_loop_done:
ldy #12 ; 2
ground_loop:
;==== line 0
wf_modify7:
bit PAGE0 ; 4
; delay 61
lda #34 ; 2
jsr delay_a ; 25+34
;==== line 1
wf_modify8:
bit PAGE1 ; 4
; delay 61
lda #34 ; 2
jsr delay_a ; 25+34
;==== line 2
wf_modify9:
bit PAGE0 ; 4
; delay 61
lda #34 ; 2
jsr delay_a ; 25+34
;=== line 3
wf_modify10:
bit PAGE1 ; 4
; delay 54
lda #27 ; 2
jsr delay_a ; 25+27
dey ; 2
beq ground_loop_done ; 3
; -1
jmp ground_loop ; 3
ground_loop_done:
nop ; 2
jmp wf_display_loop_return ; 3
; Moved to megademo.s
;.include "waterfall_page1.inc"
;.include "waterfall_page2.inc"