dos33fsprogs/interlace_demo/rasterbars.s
2019-06-11 15:26:45 -04:00

355 lines
5.5 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>
; Zero Page
FRAMEBUFFER = $00 ; $00 - $0F
YPOS = $10
YPOS_SIN = $11
CH = $24
CV = $25
GBASL = $26
GBASH = $27
BASL = $28
BASH = $29
FRAME = $60
BLARGH = $69
DRAW_PAGE = $EE
LASTKEY = $F1
PADDLE_STATUS = $F2
TEMP = $FA
WHICH = $FB
OUTL = $FE
OUTH = $FF
; Soft Switches
KEYPRESS= $C000
KEYRESET= $C010
SET_GR = $C050 ; Enable graphics
FULLGR = $C052 ; Full screen, no text
PAGE0 = $C054 ; Page0
PAGE1 = $C055 ; Page1
LORES = $C056 ; Enable LORES graphics
PADDLE_BUTTON0 = $C061
PADDL0 = $C064
PTRIG = $C070
; ROM routines
TEXT = $FB36 ;; Set text mode
HOME = $FC58 ;; Clear the text screen
WAIT = $FCA8 ;; delay 1/2(26+27A+5A^2) us
start_rasterbars:
;===================
; init screen
jsr TEXT
jsr HOME
bit KEYRESET
;===================
; init vars
lda #0
sta DRAW_PAGE
;=============================
; Load graphic page0
; lda #$0c
; sta BASH
; lda #$00
; sta BASL ; load image to $c00
; lda WHICH
; asl
; asl ; which*4
; tay
; lda pictures,Y
; sta GBASL
; lda pictures+1,Y
; sta GBASH
; 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 #$0c
; sta BASH
; lda #$00
; sta BASL ; load image to $c00
; lda WHICH
; asl
; asl ; which*4
; tay
; lda pictures+2,Y
; sta GBASL
; lda pictures+3,Y
; sta GBASH
; 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
loopA: ldx #9 ; 2
loopB: dex ; 2
bne loopB ; 2nt/3
dey ; 2
bne loopA ; 2nt/3
jmp display_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
display_loop:
.include "rasterbars_screen.s"
;======================================================
; We have 4550 cycles in the vblank, use them wisely
;======================================================
; 4550 -- VBLANK
; -148 -- raster 16+6+126 = 148
; -10 -- keypress
;=======
; 4392
pad_time:
; we erase, then draw
; doing a blanket erase of all 128 lines would cost 3459 cycles!
; move red
ldy red_x ; 4
lda movement_table,Y ; 4
sta red_x ; 4
and #$7f ; 2
tax ; 2
jsr draw_rasterbar ; 6+126
; Try X=3 Y=209 cycles=4390 R2
nop
ldy #209 ; 2
loop1: ldx #3 ; 2
loop2: dex ; 2
bne loop2 ; 2nt/3
dey ; 2
bne loop1 ; 2nt/3
lda KEYPRESS ; 4
bpl no_keypress ; 3
jmp display_loop
no_keypress:
jmp display_loop ; 3
;========================
; Draw a rasterbar
; unroll as memory is free! haha
;========================
; X is location
; 2+22+24+24+24+24+6 = 126
draw_rasterbar:
; clear all lines
ldy #0 ; 2
;====
lda y_lookup_l,X ; 4
sta OUTL ; 3
lda y_lookup_h,X ; 4
sta OUTH ; 3
lda #$33 ; 2
sta (OUTL),Y ; 6
;============
; 22
inx ; 2
lda y_lookup_l,X ; 4
sta OUTL ; 3
lda y_lookup_h,X ; 4
sta OUTH ; 3
lda #$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
lda #$ff ; 2
sta (OUTL),Y ; 6
inx
lda y_lookup_l,X ; 4
sta OUTL ; 3
lda y_lookup_h,X ; 4
sta OUTH ; 3
lda #$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
lda #$33 ; 2
sta (OUTL),Y ; 6
rts ; 6
;==================================
; HLINE
;==================================
; Color in A
; Y has which line
hline:
pha ; 3
ldx gr_offsets,y ; 4+
stx hline_loop+1 ; 4
lda gr_offsets+1,y ; 4+
clc ; 2
adc DRAW_PAGE ; 3
sta hline_loop+2 ; 4
pla ; 4
ldx #39 ; 2
hline_loop:
sta $5d0,X ; 38 ; 5
dex ; 2
bpl hline_loop ; 2nt/3
rts ; 6
;==========================
; Clear gr screen
;==========================
; Color in A
clear_gr:
ldy #46
clear_page_loop:
jsr hline
dey
dey
bpl clear_page_loop
rts
gr_offsets:
.word $400,$480,$500,$580,$600,$680,$700,$780
.word $428,$4a8,$528,$5a8,$628,$6a8,$728,$7a8
.word $450,$4d0,$550,$5d0,$650,$6d0,$750,$7d0
.include "../asm_routines/gr_unrle.s"
.include "../asm_routines/keypress.s"
.align $100
.include "rasterbars_table.s"
.include "movement_table.s"
.include "gr_copy.s"
.include "vapor_lock.s"
.include "delay_a.s"
pictures:
.word k_low,k_high
.include "k_40_48d.inc"
krg:
.byte $0
red_x: .byte $10