dos33fsprogs/demosplash/credits.s
2019-11-02 15:47:58 -04:00

403 lines
6.4 KiB
ArmAsm

; Uses the 40x48d page1/page2 every-1-scanline pageflip mode
; self modifying code to get some extra colors (pseudo 40x192 mode)
; by deater (Vince Weaver) <vince@deater.net>
credits:
;===================
; init screen
jsr TEXT
jsr HOME
bit KEYRESET
;===================
; init vars
lda #0
sta DRAW_PAGE
;==================
; setup graphics
jsr create_update_type1
jsr setup_rasterbars
;=============================
; Load graphic page0
lda #<credits_low
sta GBASL
lda #>credits_low
sta GBASH
lda #$c ; load image to $c00
jsr load_rle_gr
lda #4
sta DRAW_PAGE
jsr gr_copy_to_current ; copy to page1
; GR part
bit PAGE1
bit LORES ; 4
bit SET_GR ; 4
bit FULLGR ; 4
; jsr wait_until_keypressed
;=============================
; Load graphic page1
lda #<credits_high
sta GBASL
lda #>credits_high
sta GBASH
lda #$c ; load to $c00
jsr load_rle_gr
lda #0
sta DRAW_PAGE
jsr gr_copy_to_current
; ; GR part
bit PAGE0
; jsr wait_until_keypressed
;==============================
; setup graphics for vapor lock
;==============================
jsr vapor_lock
; vapor lock returns with us at beginning of hsync in line
; 114 (7410 cycles), so with 5070 lines to go
; GR part
bit LORES ; 4
bit SET_GR ; 4
bit FULLGR ; 4
jsr gr_copy_to_current ; 6+ 9292
; 5070 + 4550 = 9620
; 9292
; 12
; 6
; ====
; 310
; - 3 for jmp
; 307
; Try X=9 Y=6 cycles=307
ldy #6 ; 2
tloopA: ldx #9 ; 2
tloopB: dex ; 2
bne tloopB ; 2nt/3
dey ; 2
bne tloopA ; 2nt/3
jmp credits_loop ; 3
.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
; We want to alternate between page1 and page2 every 65 cycles
; vblank = 4550 cycles to do scrolling
credits_loop:
jsr $9000
;======================================================
; We have 4550 cycles in the vblank, use them wisely
;======================================================
; 4550 -- VBLANK
; -582 -- erase 22+4*(8+6+126) = 582
; -696 -- move+draw 4*(16+26+6+126) = 696
; -10 -- keypress
; -12 -- call/return of draw code
;=======
; 3250
pad_time:
; we erase, then draw
; doing a blanket erase of all 128 lines would cost 3459 cycles!
;=========================
; ERASE
;=========================
lda #$00 ; 2
sta smc_raster_color1_1+1 ; 4
sta smc_raster_color1_2+1 ; 4
sta smc_raster_color2_1+1 ; 4
sta smc_raster_color2_2+1 ; 4
sta smc_raster_color3_1+1 ; 4
;=============
; 22
; erase red
lda red_x ; 4
and #$7f ; 2
tax ; 2
jsr draw_rasterbar ; 6+126
; erase yellow
lda yellow_x ; 4
and #$7f ; 2
tax ; 2
jsr draw_rasterbar ; 6+126
; erase green
lda green_x ; 4
and #$7f ; 2
tax ; 2
jsr draw_rasterbar ; 6+126
; erase red
lda blue_x ; 4
and #$7f ; 2
tax ; 2
jsr draw_rasterbar ; 6+126
;=========================
; MOVE and DRAW
;=========================
;============
; move red
ldy red_x ; 4
lda movement_table,Y ; 4
sta red_x ; 4
and #$7f ; 2
tax ; 2
;==========
; 16
; draw red
lda #$33 ; 2
sta smc_raster_color1_1+1 ; 4
sta smc_raster_color1_2+1 ; 4
lda #$bb ; 2
sta smc_raster_color2_1+1 ; 4
sta smc_raster_color2_2+1 ; 4
lda #$ff ; 2
sta smc_raster_color3_1+1 ; 4
;=============
; 26
jsr draw_rasterbar ; 6+126
;============
; move yellow
ldy yellow_x ; 4
lda movement_table,Y ; 4
sta yellow_x ; 4
and #$7f ; 2
tax ; 2
;==========
; 16
; draw yellow
lda #$88 ; 2
sta smc_raster_color1_1+1 ; 4
sta smc_raster_color1_2+1 ; 4
lda #$dd ; 2
sta smc_raster_color2_1+1 ; 4
sta smc_raster_color2_2+1 ; 4
lda #$ff ; 2
sta smc_raster_color3_1+1 ; 4
;=============
; 26
jsr draw_rasterbar ; 6+126
;============
; move green
ldy green_x ; 4
lda movement_table,Y ; 4
sta green_x ; 4
and #$7f ; 2
tax ; 2
;==========
; 16
; draw green
lda #$44 ; 2
sta smc_raster_color1_1+1 ; 4
sta smc_raster_color1_2+1 ; 4
lda #$cc ; 2
sta smc_raster_color2_1+1 ; 4
sta smc_raster_color2_2+1 ; 4
lda #$ff ; 2
sta smc_raster_color3_1+1 ; 4
;=============
; 26
jsr draw_rasterbar ; 6+126
;============
; move blue
ldy blue_x ; 4
lda movement_table,Y ; 4
sta blue_x ; 4
and #$7f ; 2
tax ; 2
;==========
; 16
; draw blue
lda #$22 ; 2
sta smc_raster_color1_1+1 ; 4
sta smc_raster_color1_2+1 ; 4
lda #$66 ; 2
sta smc_raster_color2_1+1 ; 4
sta smc_raster_color2_2+1 ; 4
lda #$ff ; 2
sta smc_raster_color3_1+1 ; 4
;=============
; 26
jsr draw_rasterbar ; 6+126
;============================
; WAIT for VBLANK to finish
;============================
; Try X=71 Y=9 cycles=3250
ldy #9 ; 2
tloop1: ldx #71 ; 2
tloop2: dex ; 2
bne tloop2 ; 2nt/3
dey ; 2
bne tloop1 ; 2nt/3
lda KEYPRESS ; 4
bpl cno_keypress ; 3
jmp credits_loop
cno_keypress:
jmp credits_loop ; 3
;========================
; Draw a rasterbar
; unroll as memory is free! haha
;========================
; X is location
; 2+22+24+24+24+24+6 = 126
draw_rasterbar:
ldy #0 ; 2
;====
lda y_lookup_l,X ; 4
sta OUTL ; 3
lda y_lookup_h,X ; 4
sta OUTH ; 3
smc_raster_color1_1:
lda #$33 ; 2
sta (OUTL),Y ; 6
;============
; 22
inx ; 2
lda y_lookup_l,X ; 4
sta OUTL ; 3
lda y_lookup_h,X ; 4
sta OUTH ; 3
smc_raster_color2_1:
lda #$bb ; 2
sta (OUTL),Y ; 6
inx ; 2
lda y_lookup_l,X ; 4
sta OUTL ; 3
lda y_lookup_h,X ; 4
sta OUTH ; 3
smc_raster_color3_1:
lda #$ff ; 2
sta (OUTL),Y ; 6
inx
lda y_lookup_l,X ; 4
sta OUTL ; 3
lda y_lookup_h,X ; 4
sta OUTH ; 3
smc_raster_color2_2:
lda #$bb ; 2
sta (OUTL),Y ; 6
inx
lda y_lookup_l,X ; 4
sta OUTL ; 3
lda y_lookup_h,X ; 4
sta OUTH ; 3
smc_raster_color1_2:
lda #$33 ; 2
sta (OUTL),Y ; 6
rts ; 6
red_x: .byte $10
yellow_x: .byte $20
green_x: .byte $30
blue_x: .byte $40