snes-asm/legacy/test_gfx/test_gfx.asm
Greg Shuflin 2354e92eaf Move test_gfx rom to subdir
The test_gfx rom is doing some kind of blinking light thing, move it to
a subdir.
2022-01-30 01:26:42 -08:00

208 lines
3.8 KiB
NASM

.include "header.inc"
.include "snes_init.asm"
.include "my_custom.asm"
.EQU PalNum $0000
.EQU VBlankCount $0010
.BANK 0 SLOT 0
.org 0
.section "Vblank"
VBlank:
Set_A_8_XY_16
lda VBlankCount
ina
sta VBlankCount
lda $4210 ; clear NMI flag
rti
.ENDS
.BANK 0 SLOT 0
.ORG 0
.section "Main"
.MACRO Video_Port_Control
;VRAM transfer, word-access, increment by 1
lda #%10000000
sta $2115
.ENDM
;assumes 8-bit a, 16-bit xy
.MACRO Load_Block_to_VRAM ARGS SOURCE DEST SIZE
Video_Port_Control
ldx #DEST
stx $2116 ; $2116/2117 is 2byte address for VRAM upload/download. most significant bit must be 0
lda #:SOURCE ; source bank
ldx #SOURCE ; source offset
ldy #SIZE
stx $4302 ; store data offset into DMA control register
sta $4304 ; store bank into DMA source bank
sty $4305 ; store size of block
lda #$01
sta $4300 ; set DMA mode (word, normal increment)
lda #$18
sta $4301 ; set destination register (VRAM write register) - add value to $2100 to get destination address
; i.e. this is writing to $2118, which when written writes a byte to VRAM
lda #$01
sta $420b ; and start the transfer
.ENDM
Start:
Snes_Init
Set_A_8_XY_16
stz PalNum
Load_Palette_Color $00, $00
Load_Palette_Color $00, $0f
Load_Palette_Color $00, $ff
Load_Palette_Color $ff, $0a
Set_Screen_Brightness %00001111
lda #%00000000 ; 8x8 for all 4 backgrounds, no priority flip, Mode: 4 colors/tile w/ 32 palettes
sta $2105 ; store to screen mode register
; size (last argument) depends on color mode
; location is beginning of VRAM
; put character data at VRAM $0000, tile data at $0400
lda #$04
sta $2107 ; BG1 tile map location (upper 6 bits)
lda #$00
sta $210b ; BG1 character location ($1000 word intervals - can't go over $8000 b/c size of VRAM)
stz $1337
; main screen designation
lda #%00000001
sta $212c ; enable bkg 1,
Load_Block_to_VRAM Tiles, $0000, (8*2*3),
Load_Block_to_VRAM TileMap, $0400, 32
Enable_NMI_And_Joypad
mainloop:
wai
lda VBlankCount
beq SetBack
sbc #$80
beq SetDifferent
jmp mainloop
SetBack:
Reset_Palette_Offset
Load_Palette_Color $00, $00
Load_Palette_Color $00, $0f
Load_Palette_Color $00, $ff
Load_Palette_Color $ff, $0a
jmp mainloop
SetDifferent:
Reset_Palette_Offset
Load_Palette_Color $0f, $f0
Load_Palette_Color $00, $0f
Load_Palette_Color $0a, $00
Load_Palette_Color $00, $00
jmp mainloop
.ENDS
.BANK 1 SLOT 0
.org 0
.section "TileData"
Tiles:
;blank tile
.db $00, $00, $00, $00, $00, $00, $00, $00
.db $00, $00, $00, $00, $00, $00, $00, $00
;face
.db %00000000
.db %00000000
.db %11000011
.db %11000011
.db %11000011
.db %11000011
.db %00111000
.db %00111000
.db %00111000
.db %00111000
.db %10000001
.db %10000001
.db %01000010
.db %01000010
.db %00111100
.db %00111100
; different face
.db %11111111
.db %00000000
.db %11111111
.db %00000000
.db %11000011
.db %00000000
.db %00111000
.db %00111000
.db %00111000
.db %00111000
.db %10000001
.db %10000001
.db %01000010
.db %01000010
.db %00111100
.db %00111100
; each entry in the tile map is two bytes long
; here is the format:
;High Low v: vertical flip h: horizontal flip
;vhopppcc cccccccc o: priority bit p: palette number
; c: Starting character (tile) number
TileMap:
.db $02, $80, $02, $00
.db $02, $80, $02, $00
.db $02, $80, $02, $00
.db $02, $80, $02, $00
.db $02, $80, $02, $00
.db $02, $80, $02, $00
.db $02, $80, $02, $00
.db $02, $80, $02, $00
TileMapEnd:
.ENDS