Useful HDMA Codes

These are some HDMA/PPU effects that can be useful to generate unique effects and also be used as a base to generate other combinations. Because it was designed to be used on Super Mario World's RAM mirrors, it may not work on all SNES games without additional code modification.

$0D9B is the $420C mirror.

Inverse Colors

by Ladida

;inverse colors (except status bar)
;messes up sprite priorities D:
;also, dont use message boxes

LDA.b #%10100000	;color subtraction, backdrop color math
STA $40
STA $2131
STZ $2121		;color 00
LDA #$FF		;set
STA $2122		;color
LDA #$7F		;to
STA $2122		;white (7FFF)

REP #$10
LDX #$2C01
STX $4350
LDX.w #MAINSUB
STX $4352
SEP #$10
LDA.b #MAINSUB>>16
STA $4354

LDA #$20
TSB $0D9F
RTS

MAINSUB:
db $25,%00000100,%00011011
db $80,%00000000,%00011111
db $00

Translucent Color Window

by Ladida

;n0ice translucent color window
;wiiqwertyuiop made one but lost the code so i had to make my own code, rrrrr
;some of the code is still his, specifically the hdma
;the window affects everything, including sprites (all palettes) :D
;sprite priorities may be messed up though, lol
;use in levelasm or whatever
;by ladida
;a

STZ $212C		;nothing on main screen
LDA.b #%00011111	;everything on sub screen
STA $212D
LDA.b #%00100000	;backdrop color math enable
STA $40
STA $2131

;LDA.b #%00100000	;enable color window 1
STA $43
STA $2125

STZ $2121
LDA #$BD : STA $2122	;window color low byte (SNES)
LDA #$08 : STA $2122	;window color high byte (SNES)

LDA.b #%01000010	;add in subscreen
STA $44			;also clip to black outside window
STA $2130		;(that just disables the color outside the window)

REP #$10
LDX #$2601		;two regs write once, regs [21]26 and [21]27
STX $4350
LDX.w #.DATA
STX $4352
LDA.b #.DATA>>16
STA $4354
SEP #$10

LDA #$20		;channel 5
TSB $0D9F
RTS

.DATA
db $80 : db $01 : db $00	;scanline : left window : right window
db $50 : db $50 : db $A0	
db $01 : db $01 : db $00	;if left window > right window, terminate window
db $00