snes: Start adding some sprite code

This includes some common sprite clearing code in svmwgraph
This commit is contained in:
Vince Weaver 2013-01-21 11:49:17 -05:00
parent 44d5009a61
commit 50596ea3b4
6 changed files with 419 additions and 22 deletions

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@ -8,7 +8,9 @@ all: checksum.inc
tb1_snes.sfc: tb1_snes.o snes-hirom.cfg
$(LD) -o tb1_snes.sfc --config snes-hirom.cfg --obj tb1_snes.o
tb1_snes.o: tb1_snes.s snes_init.s opening.s title_screen.s \
tb1_snes.o: tb1_snes.s \
snes_init.s opening.s title_screen.s level_1.s \
svmwgraph.s \
tb1_title.tiles tb1_opening.tiles tbfont.inc
$(AS) -t none -o tb1_snes.o -l tb1_snes.lst -c tb1_snes.s

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@ -1,2 +1,2 @@
.word $d3ee ; Complement of checksum
.word $2c11 ; Unsigned 16-bit sum of ROM
.word $6e57 ; Complement of checksum
.word $91a8 ; Unsigned 16-bit sum of ROM

306
tb_snes/level_1.s Normal file
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@ -0,0 +1,306 @@
; Page zero locations
ball_x = $0000
.setcpu "65816"
.segment "STARTUP"
;================================================
; LEVEL 1
;================================================
level_1:
rep #$20 ; mem/A = 16 bit
.a16
;==========================
; Setup VBLANK routine
;==========================
sei ; disable interrupts
lda #level1_vblank
sta vblank_vector
cli ; enable interrupts
sep #$20 ; mem/A = 8 bit
.a8
;==========================
; Setup Background
;==========================
;==========================
; Setup Sprite
;==========================
; Load Palette for our sprite
; Sprite Palettes start at color 128
lda #128
sta $2121 ; Start at START color
lda #^sprite_palette ; Using ^ before the parameter gets its bank.
ldx #sprite_palette ;
ldy #(16 * 2) ; 2 bytes for every color
; In: A:X -- points to the data
; Y -- Size of data
pha
phx
phb
php ; Preserve Registers
sep #$20
stx $4302 ; Store data offset into DMA source offset
sta $4304 ; Store data bank into DMA source bank
sty $4305 ; Store size of data block
stz $4300 ; Set DMA Mode (byte, normal increment)
lda #$22 ; Set destination register ($2122 - CGRAM Write)
sta $4301
lda #$01 ; Initiate DMA transfer
sta $420B
plp ; Restore registers
plb
plx
pla
; Load sprite data to VRAM
lda #$80
sta $2115
ldx #$0000 ; DEST
stx $2116 ; $2116: Word address for accessing VRAM.
lda #^sprite_data ; SRCBANK
ldx #sprite_data ; SRCOFFSET
ldy #$0100 ; SIZE
; In: A:X -- points to the data
; Y -- Number of bytes to copy (0 to 65535) (assumes 16-bit index)
phb
php ; Preserve Registers
sep #$20
stx $4302 ; Store Data offset into DMA source offset
sta $4304 ; Store data Bank into DMA source bank
sty $4305 ; Store size of data block
lda #$01
sta $4300 ; Set DMA mode (word, normal increment)
lda #$18 ; Set the destination register (VRAM write register)
sta $4301
lda #$01 ; Initiate DMA transfer (channel 1)
sta $420B
plp ; restore registers
plb
;
; Init sprites to be offscreen
jsr svmw_move_sprites_offscreen
; Set our sprite active
; assume 544 byte sprite table in $0000
sep #$20 ; mem/A = 8 bit
.a8
lda #($0)
sta $0000
lda #(224/2 - 16)
sta $0001
stz $0002
lda #%01110000
sta $0003
lda #%01010100
sta $0200
jsr svmw_transfer_sprite
SetupVideo:
rep #$10
sep #$20
; stz $2102
; stz $2103
;=============================
;*********transfer sprite data
;=============================
stz $2102 ; set OAM address to 0
stz $2103
ldy #$0400
sty $4300 ; CPU -> PPU, auto increment, write 1 reg, $2104 (OAM Write)
stz $4302
stz $4303 ; source offset
ldy #$0220
sty $4305 ; number of bytes to transfer
lda #$7E
sta $4304 ; bank address = $7E (work RAM)
lda #$01
sta $420B ; start DMA transfer
; Enable sprite
; sssnnbbb
; ss = size (8x8 in our case)
; nn = name
; bb = base selection
lda #%00000000
sta $2101
lda #%00010001 ; Enable BG1 and sprites
sta $212C
stz $212d
lda #$0F
sta $2100 ; Turn on screen, full Brightness
; lda #$81 ; Enable NMI (VBlank Intterupt) and joypads
; sta $4200 ;
main_loop:
; all work done in interrupt handler
bra main_loop
;=============================
; VBLank Routine
; All the action happens here
;=============================
level1_vblank:
php ; save status register
rep #$30 ; Set A/mem=16 bits, X/Y=16 bits (to push all 16 bits)
.a16 ; tell assembler the A is 16-bits
phb ; save b
pha ; save A
phx ; save X
phy ; save Y
phd ; save zero page
sep #$20 ; A/mem=8 bit
.a8
l1_joypad_read:
lda $4212 ; get joypad status
and #%00000001 ; if joy is not ready
bne l1_joypad_read ; wait
lda $4219 ; read joypad (BYSTudlr)
and #%11110000 ; see if a button pressed
bne done_vblank ; if so, skip and don't move ball
done_joypad:
lda #^x_direction ; get bank for x_direction var (probably $7E)
pha ;
plb ; set the data bank to the one containing x_direction
lda ball_x ; get current ball X value
; in the zero page, which is mirrored on SNES
ldx x_direction ; get x_direction 0=right, 1=left
bne ball_left ; if 1 skip ahead to handle going left
ina ; ball_x += 2
ina
cmp #248 ; have we reached right side?
bne done_moving ; if not, keep moving right
ldx #1 ; if so, switch to moving left
bra done_moving
ball_left:
dea ; ball_x -= 2
dea
bne done_moving ; if not at zero, keep moving left
ldx #0 ; hit wall, switchto moving right
done_moving:
sta ball_x ; save ball_x co-ord
stx x_direction ; save x_direction
;=======================================
; Update the sprite info structure (OAM)
;=======================================
.a8
lda #$0 ; set data bank back to 0
pha
plb
; Setup DMA transfer to copy our OAM structure in the zero page
; into the actual OAM
stz $2102 ; set OAM address to 0
stz $2103
ldy #$0400
sty $4300 ; CPU -> PPU, auto increment, write 1 reg, $2104 (OAM Write)
stz $4302
stz $4303 ; source offset
ldy #$0220
sty $4305 ; number of bytes to transfer
lda #$7E
sta $4304 ; bank address = $7E (work RAM)
lda #$01
sta $420B ;start DMA transfer
done_vblank:
lda $4210 ; Clear NMI flag
rep #$30 ; A/Mem=16 bits, X/Y=16 bits
.a16
pld ; restore saved vaules from stack
ply
plx
pla
plb
sep #$20
plp
rti ; return from interrupt
;============================================================================
; Sprite Data
;============================================================================
; sprite data
.include "sphere.sprite"
; tile data
;tile_pal:
;.include "tb1.pal"
.segment "BSS"
x_direction: .word 0

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@ -190,26 +190,10 @@ ClearPaletteLoop:
plx
;=================================
;**** clear Sprite tables ********
; Clear Sprite Table
;=================================
stz $2102 ;sprites initialized to be off the screen, palette 0, character 0
stz $2103
ldx #$0080
lda #$F0
_Loop08:
sta $2104 ;set X = 240
sta $2104 ;set Y = 240
stz $2104 ;set character = $00
stz $2104 ;set priority=0, no flips
dex
bne _Loop08
ldx #$0020
_Loop09:
stz $2104 ;set size bit=0, x MSB = 0
dex
bne _Loop09
jsr svmw_move_sprites_offscreen
;=====================
;**** clear WRAM *****

101
tb_snes/svmwgraph.s Normal file
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@ -0,0 +1,101 @@
; Various Common Routines
; Called the Super-VMW Graphics Library for various sentimental reasons
.segment "STARTUP"
;====================================
; Move Sprites Offscreen
;====================================
svmw_move_sprites_offscreen:
php ; store status on stack
rep #$30 ; 16bit mem/A, 16 bit X/Y
.a16
.i16
ldx #$0000 ; offset
lda #$0001
; OAM format. Low part is:
; Format is xxxxxxx yyyyyyy cccccccc vhoopppN
; Upper part is X/Y packed
; Xxxxxxxxx = X pos
; Yyyyyyyyy = Y pos
; cccccccc = first tile of sprite
; v/h = vert/horiz flip
; oo = sprite priority
; ppp = palette
; s = sprite size
clear_xy:
sta $0000,X ; page 0?
inx
inx
inx
inx ; skip 4 bytes
cpx #$0200 ; are we 512 bytes yet? (bottom part of OAM)
bne clear_xy
ldx #$0000
lda #$5555 ; set high bit of X, effective setting X to 256
set_top:
sta $0200, X ; writing to top of screen
inx ; increment
inx
cpx #$0020 ; put all 32 values
bne set_top
plp
;=====================================
; transfer sprite
; assumes sprite_data starts at $7e:0000
;=====================================
svmw_transfer_sprite:
php ; save status word
rep #$30 ; 16bit mem/A, 16 bit X/Y
.a16
.i16
; p------b p=special object priority
; aaaaaaaa baaaaaaaa = OAM address
stz $2102 ; set OAM address to 0
stz $2103
; setup DMA transfer
; $4300
; da-ifttt d=direction 0 CPU->PPU 1 PPU->CPU
; a = HDMA address mode
; i = DMA address increment 0=+1 1=-1
; f = fixed transfer 1=no inc, 0=increment
; ttt = transfer mode
; $4301
; pppppppp destination register $2100
ldy #$0400
sty $4300 ; CPU -> PPU, auto increment,
; write 1 reg, $2104 (OAM Write)
stz $4302
stz $4303 ; source offset in RAM (low/high)
; $0000
ldy #$0220
sty $4305 ; number of bytes to transfer
lda #$7E
sta $4304 ; bank address = $7E (work RAM)
lda #$01
sta $420B ; start DMA transfer channel 0
plp ; restore status word
rts

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@ -41,11 +41,14 @@ start_program:
jsr display_opening
jsr display_title
; jsr display_title
jsr level_1
.include "title_screen.s"
.include "opening.s"
.include "level_1.s"
.include "svmwgraph.s"
;============================================================================
@ -72,6 +75,7 @@ wram_fill_byte:
.word $0000 ; Native:COP
.word $0000 ; Native:BRK
.word $0000 ; Native:ABORT
vblank_vector:
.word $0000 ; Native:NMI
.word $0000 ;
.word $0000 ; Native:IRQ