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Use proper sprites.

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This commit is contained in:
Colin McMillen 2015-05-24 10:43:25 -04:00
parent 77ee989fb0
commit dceedf64ba
5 changed files with 155 additions and 44 deletions
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1
build.bat
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@ -1,4 +1,5 @@
@echo off
pcx2snes sprites.pcx -osprites.asm -b4 -nSprite -d
pcx2snes tiles.pcx -otiles.asm -b2 -nTile -d
wla-65816 -o pewpew.asm pewpew.o
wlalink -vr wlalink.cfg pewpew.smc

147
pewpew.asm
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@ -36,18 +36,31 @@ sep #%00100000 ; 8-bit A
; Memory layout:
; 00-0F: scratch space for functions.
; 10-11: controller state of joypad #1.
; 12-13: controller state of joypad #2.
; 14-17: 32-bit counter of vblanks.
; 20-21: (x, y) coordinates of player.
; 22-24: RGB color values to use for background color, from [0-31].
; 0000-000F: scratch space for functions.
; 0010-0011: controller state of joypad #1.
; 0012-0013: controller state of joypad #2.
; 0014-0017: 32-bit counter of vblanks.
; 0020-0021: (x, y) coordinates of player.
; 0022-0024: RGB color values to use for background color, from [0-31].
;
; Sprite table buffers -- copied each frame to OAM during VBlank, using DMA.
; 0100-02FF: table 1 (4 bytes each: x/y coord, tile #, flip/priority/palette)
; 0300-031F: table 2 (2 bits each: high x-coord bit, size)
Start:
InitializeSNES
jsr LoadPaletteAndTileData
jsr InitializeSpriteTables
; Set sprite size to 16x16 (small) and 32x32 (large).
lda #%01100000
sta OAMSIZE
; Main screen: enable sprites.
lda #%00010000
sta MSENABLE
; Turn on the screen.
; Format: x000bbbb
@ -113,24 +126,24 @@ LoadPaletteAndTileData:
; We could also do this with a DMA transfer (like we do with the tile data
; below), but it seems overkill for just a few bytes. :)
ldx #0
lda #32 ; Palette entries for BG2 start at 32.
lda #128 ; Palette entries for sprites start at 128.
sta CGADDR
-
lda.l TilePalette, x
lda.l SpritePalette, X
sta CGDATA
inx
cpx #8 ; 8 bytes of palette data.
cpx #32 ; 32 bytes of palette data.
bne -
; DMA 0 source address & bank.
ldx #TileData
ldx #SpriteData
stx DMA0SRC
lda #:TileData
lda #:SpriteData
sta DMA0SRCBANK
; DMA 0 transfer size.
; See the helpful comment in tiles.asm to find the size of the tile data.
ldy #384
sty DMA0SIZE
; See the helpful comment in sprites.asm to find the size of the tile data.
ldx #576
stx DMA0SIZE
; DMA 0 control register.
; Transfer type 001 = 2 addresses, LH.
lda #%00000001
@ -139,8 +152,8 @@ LoadPaletteAndTileData:
lda #$18 ; Upper-byte is assumed to be $21, so this is $2118 & $2119.
sta DMA0DST
; $2116 sets the word address for accessing VRAM.
ldy #$0000
sty VMADDR
ldx #$0000
stx VMADDR
; Enable DMA channel 0.
lda #%00000001
sta DMAENABLE
@ -163,10 +176,47 @@ LoadPaletteAndTileData:
sta BG2SC
stz BG12NBA
; Main screen: enable BG2.
lda #%00000010
sta MSENABLE
rts
InitializeSpriteTables:
; This page is a good reference on SNES sprite formats:
; http://wiki.superfamicom.org/snes/show/SNES+Sprites
; It uses the same approach we're using, in which we keep a buffer of the
; sprite tables in RAM, and DMA the sprite tables to the system's OAM
; during VBlank.
rep #%00110000 ; 16-bit A/X/Y.
ldx #$0000
; Fill sprite table 1. 4 bytes per sprite, laid out as follows:
; Byte 1: xxxxxxxx x: X coordinate
; Byte 2: yyyyyyyy y: Y coordinate
; Byte 3: cccccccc c: Starting tile #
; Byte 4: vhoopppc v: vertical flip h: horizontal flip o: priority bits
; p: palette #
lda #$01
-
sta $0100, X ; We keep our sprite table at $0100 and DMA it to OAM later.
inx
inx
inx
inx
cpx #$0200
bne -
; Fill sprite table 2. 2 bits per sprite, like so:
; bits 0,2,4,6 - Enable or disable the X coordinate's 9th bit.
; bits 1,3,5,7 - Toggle Sprite size: 0 - small size 1 - large size
lda #%0101010101010101
-
sta $0100, X
inx
inx
cpx #$0220
bne -
sep #%00100000 ; 8-bit A.
rts
@ -176,6 +226,7 @@ VBlankHandler:
jsr JoypadHandler
jsr SetBackgroundColor
jsr SetPlayerPosition
jsr DMASpriteTables
rti
@ -361,45 +412,59 @@ SetBackgroundColor:
SetPlayerPosition:
; Make sure the high byte of A is zeroed out.
lda #$00
xba
; Get player x and convert it to a scroll offset.
; Copy player coords into sprite table.
lda $0020
ConvertXCoordinate
sta BG2HOFS
xba
sta BG2HOFS
; Make sure the high byte of A is zeroed out.
lda #$00
xba
; Get player y and convert it to a scroll offset.
sta $0100
lda $0021
ConvertYCoordinate
sta BG2VOFS
xba
sta BG2VOFS
sta $0101
; Clear x-MSB so that the sprite is displayed.
lda $0300
and #%11111110
sta $0300
rts
DMASpriteTables:
rep #%00010000 ; 16-bit X/Y.
sep #%00100000 ; 8-bit A.
; Store at the base OAM address.
ldx #$0000
stx OAMADDR
; Default DMA control; destination $2104 (OAM data register).
stz DMA0CTRL
lda #$04
sta DMA0DST
; Our sprites start at $0100 in bank 0 and are #$220 bytes long.
ldx #$0100
stx DMA0SRC
stz DMA0SRCBANK
ldx #$0220
stx DMA0SIZE
; Kick off the DMA transfer.
lda #%00000001
sta DMAENABLE
rts
FillScratch:
lda #$42 ; B
lda #$42 ; ASCII "B"
ldx #0
FillScratchLoop:
-
sta $00, X
inx
cpx #$10
bne FillScratchLoop
bne -
rts
.ENDS
.BANK 1 SLOT 0
.ORG 0
.SECTION "TileData"
.INCLUDE "tiles.asm"
.SECTION "SpriteData"
.INCLUDE "sprites.asm"
.ENDS

17
registers.asm
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@ -24,6 +24,23 @@
; x: 0 = screen on, 1 = screen off, bbbb: Brightness ($0-$F)
.define INIDISP $2100
; $2101: OAM size [OBSEL]
; sssnnbbb s: 000 = 8x8 or 16x16.
; 001 = 8x8 or 32x32.
; 010 = 8x8 or 64x64.
; 011 = 16x16 or 32x32.
; 100 = 16x16 or 64x64.
; 101 = 32x32 or 64x64.
; n: Name selection (upper 4k word addr).
; b: Base selection (8k word seg. addr).
.define OAMSIZE $2101
; $2102-$2103: OAM address register [OAMADDL/OAMADDH]
; aaaaaaaa r000000m a: OAM address.
; r: OAM priority rotation.
; m: OAM address MSB.
.define OAMADDR $2102
; $2105: Screen mode register [BGMODE]
; abcdefff a: BG4 tile size (0=8x8, 1=16x16).
; b: BG3 tile size (0=8x8, 1=16x16).

28
sprites.asm Normal file
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@ -0,0 +1,28 @@
; Created with eKid's pcx2snes converter ;
SpriteData:
.db $10, $00, $28, $10, $A8, $90, $64, $58, $E3, $DC, $30, $0F, $AC, $93, $60, $5F$00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $F8, $00, $80, $00, $70, $80, $0E, $F0, $01, $FE$00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $60, $5F, $AC, $93, $30, $0F, $E3, $DC, $64, $58, $A8, $90, $28, $10, $10, $00$00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
.db $01, $FE, $0E, $F0, $70, $80, $80, $00, $F8, $00, $00, $00, $00, $00, $00, $00$00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
SpritePalette:
.db $1F, $7C, $00, $00, $FF, $7F, $1F, $02, $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00, $00
; 18 tiles (14 spaces)
; 576 bytes

BIN
sprites.pcx Normal file
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