dos33fsprogs/xmas_2018/wreath.s
Vince Weaver c7707f8b1f xmas2018: play proper music
what a hassle
2018-12-14 01:14:07 -05:00

171 lines
2.9 KiB
ArmAsm

;=====================================
; XMAS2018 -- Wreath Part
;=====================================
wreath:
;===================
; init screen
;===================
; init vars
lda #15
sta XPOS
lda #38
sta YPOS
lda #0
sta FRAME
sta FRAMEH
;=============================
; Load graphic hgr
; lda #<wreath_hgr
; sta LZ4_SRC
; lda #>wreath_hgr
; sta LZ4_SRC+1
; lda #<(wreath_hgr_end-8) ; skip checksum at end
; sta LZ4_END
; lda #>(wreath_hgr_end-8) ; skip checksum at end
; sta LZ4_END+1
; lda #<$2000
; sta LZ4_DST
; lda #>$2000
; sta LZ4_DST+1
; jsr lz4_decode
;==============================
; 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
; so we have 5070 + 4550 = 9620 to kill
; FIXME: clear page0/page1 screens
; jsr gr_copy_to_current ; 6+ 9292
; now we have 322 left
; GR part
; bit HIRES ; 4
bit SET_GR ; 4
bit FULLGR ; 4
; 9620
; -8 mode set
; - 3 for jmp
;=======
; 9609
; Try X=239 Y=8 cycles=9609
ldy #8 ; 2
wrloopA:ldx #239 ; 2
wrloopB:dex ; 2
bne wrloopB ; 2nt/3
dey ; 2
bne wrloopA ; 2nt/3
jmp wreath_begin_loop
.align $100
;================================================
; Wreath 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
wreath_begin_loop:
wreath_display_loop:
; (40*65)-4 = 2596
; 40 lines of LORES
bit LORES ; 4
; Try X=42 Y=12 cycles=2593 R3
lda $0 ; nop ; 3
ldy #12 ; 2
wrloopC:ldx #42 ; 2
wrloopD:dex ; 2
bne wrloopD ; 2nt/3
dey ; 2
bne wrloopC ; 2nt/3
; rest of screen is hires page0
; (152*65)-4 = 9876
bit HIRES ; 4
; Try X=13 Y=139 cycles=9870 R6
nop
nop
nop
ldy #139 ; 2
wrloopE:ldx #13 ; 2
wrloopF:dex ; 2
bne wrloopF ; 2nt/3
dey ; 2
bne wrloopE ; 2nt/3
;======================================================
; We have 4550 cycles in the vblank, use them wisely
;======================================================
; do_nothing should be 4550
; play music 1023
; -10 keypress
; ===========
; 3517
jsr play_music ; 6+1017
; Try X=116 Y=6 cycles=3517
ldy #6 ; 2
wrloop1:ldx #116 ; 2
wrloop2:dex ; 2
bne wrloop2 ; 2nt/3
dey ; 2
bne wrloop1 ; 2nt/3
; no keypress = 10+(24) = 34
lda KEYPRESS ; 4
bpl wr_no_keypress ; 3
; -1
jmp wr_handle_keypress ; 3
wr_no_keypress:
jmp wreath_display_loop ; 3
wr_handle_keypress:
bit KEYRESET ; clear keypress ; 4
rts ; 6