AmigaExamples/002.sprite_display/sprite.s

147 lines
4.4 KiB
ArmAsm

include ../include/registers.i
include hardware/dmabits.i
include hardware/intbits.i
LVL3_INT_VECTOR equ $6c
entry:
lea level3InterruptHandler(pc),a3
move.l a3,LVL3_INT_VECTOR
;;
;; sprite_display.asm
;;
;; This example displays the spaceship sprite at location V = 65,
;; H = 128. Remember to include the file hw_examples.i.
;;
;; First, we set up a single bitplane.
;;
LEA CUSTOM,a0 ;Point a0 at custom chips
MOVE.W #$1200,BPLCON0(a0) ;1 bitplane color is on
MOVE.W #$0000,BPL1MOD(a0) ;Modulo = 0
MOVE.W #$0000,BPLCON1(a0) ;Horizontal scroll value = 0
MOVE.W #$0024,BPLCON2(a0) ;Sprites have priority over playfields
MOVE.W #$0038,DDFSTRT(a0) ;Set data-fetch start
MOVE.W #$00D0,DDFSTOP(a0) ;Set data-fetch stop
;; Display window definitions.
MOVE.W #$2C81,DIWSTRT(a0) ;Set display window start
;; Vertical start in high byte.
;; Horizontal start * 2 in low byte.
MOVE.W #$F4C1,DIWSTOP(a0) ;Set display window stop
;; Vertical stop in high byte.
;; Horizontal stop * 2 in low byte.
;;
;; Set up color registers.
;;
MOVE.W #$0008,COLOR00(a0) ;Background color = dark blue
MOVE.W #$0000,COLOR01(a0) ;Foreground color = black
MOVE.W #$0FF0,COLOR17(a0) ;Color 17 = yellow
MOVE.W #$00FF,COLOR18(a0) ;Color 18 = cyan
MOVE.W #$0F0F,COLOR19(a0) ;Color 19 = magenta
;;
;; Move Copper list to $20000.
;;
MOVE.L #$20000,a1 ;Point A1 at Copper list destination
LEA COPPERL(pc),a2 ;Point A2 at Copper list source
CLOOP:
MOVE.L (a2),(a1)+ ;Move a long word
CMP.L #$FFFFFFFE,(a2)+ ;Check for end of list
BNE CLOOP ;Loop until entire list is moved
;;
;; Move sprite to $25000.
;;
MOVE.L #$25000,a1 ;Point A1 at sprite destination
LEA SPRITE(pc),a2 ;Point A2 at sprite source
SPRLOOP:
MOVE.L (a2),(a1)+ ;Move a long word
CMP.L #$00000000,(a2)+ ;Check for end of sprite
BNE SPRLOOP ;Loop until entire sprite is moved
;;
;; Now we write a dummy sprite to $30000, since all eight sprites are activated
;; at the same time and we're only going to use one. The remaining sprites
;; will point to this dummy sprite data.
;;
MOVE.L #$00000000,$30000 ;Write it
;;
;; Point Copper at Copper list.
;;
MOVE.L #$20000,COP1LC(a0)
;;
;; Fill bitplane with $FFFFFFFF.
;;
MOVE.L #$21000,a1 ;Point A1 at bitplane
MOVE.W #1999,d0 ;2000-1(for dbf) long words = 8000 bytes
FLOOP
MOVE.L #$FFFFFFFF,(a1)+ ;Move a long word of $FFFFFFFF
DBF d0,FLOOP ;Decrement, repeat until false.
;;
;; Start DMA.
;;
MOVE.W d0,COPJMP1(a0) ;Force load into Copper
;; program counter
MOVE.W #$83A0,DMACON(a0) ;Bitplane, Copper, and sprite DMA
.mainLoop:
bra.s .mainLoop
level3InterruptHandler:
movem.l d0-a6,-(sp)
.checkVerticalBlank:
lea CUSTOM,a5
move.w INTREQR(a5),d0
and.w #INTF_VERTB,d0
beq.s .checkCopper
.verticalBlank:
move.w #INTF_VERTB,INTREQ(a5) ; Clear interrupt bit
.checkCopper:
lea CUSTOM,a5
move.w INTREQR(a5),d0
and.w #INTF_COPER,d0
beq.s .interruptComplete
.copperInterrupt:
move.w #INTF_COPER,INTREQ(a5) ; Clear interrupt bit
.interruptComplete:
movem.l (sp)+,d0-a6
rte
;;
;; This is a Copper list for one bitplane, and 8 sprites.
;; The bitplane lives at $21000.
;; Sprite 0 lives at $25000; all others live at $30000 (the dummy sprite).
;;
COPPERL:
DC.W BPL1PTH,$0002 ;Bitplane 1 pointer = $21000
DC.W BPL1PTL,$1000
DC.W SPR0PTH,$0002 ;Sprite 0 pointer = $25000
DC.W SPR0PTL,$5000
DC.W SPR1PTH,$0003 ;Sprite 1 pointer = $30000
DC.W SPR1PTL,$0000
DC.W SPR2PTH,$0003 ;Sprite 2 pointer = $30000
DC.W SPR2PTL,$0000
DC.W SPR3PTH,$0003 ;Sprite 3 pointer = $30000
DC.W SPR3PTL,$0000
DC.W SPR4PTH,$0003 ;Sprite 4 pointer = $30000
DC.W SPR4PTL,$0000
DC.W SPR5PTH,$0003 ;Sprite 5 pointer = $30000
DC.W SPR5PTL,$0000
DC.W SPR6PTH,$0003 ;Sprite 6 pointer = $30000
DC.W SPR6PTL,$0000
DC.W SPR7PTH,$0003 ;Sprite 7 pointer = $30000
DC.W SPR7PTL,$0000
DC.W $FFFF,$FFFE ;End of Copper list
;;
;; Sprite data for spaceship sprite. It appears on the screen at V=65 and H=128.
;;
SPRITE:
DC.W $6D60,$7200 ;VSTART, HSTART, VSTOP
DC.W $0990,$07E0 ;First pair of descriptor words
DC.W $13C8,$0FF0
DC.W $23C4,$1FF8
DC.W $13C8,$0FF0
DC.W $0990,$07E0
DC.W $0000,$0000 ;End of sprite data