uxn/projects/examples/gui.wallpaper.usm

;scroll { x 2 y 2 wait 1 }

( devices )

|0100 ;System { vector 2 pad 6 r 2 g 2 b 2 }
|0110 ;Console { vector 2 pad 6 char 1 byte 1 short 2 string 2 }
|0120 ;Screen { vector 2 width 2 height 2 pad 2 x 2 y 2 addr 2 color 1 }
|0130 ;Audio { wave 2 envelope 2 pad 4 volume 1 pitch 1 play 1 value 2 delay 2 finish 1 }
|0140 ;Controller { vector 2 button 1 key 1 }
|0160 ;Mouse { vector 2 x 2 y 2 state 1 chord 1 }
|0170 ;File { vector 2 result 2 offset 2 pad 2 name 2 length 2 load 2 save 2 }
|01a0 ;DateTime { year 2 month 1 day 1 hour 1 minute 1 second 1 dotw 1 doty 2 isdst 1 refresh 1 }

|0200
    #90ff =System.r #9000 =System.g #900f =System.b
    #08e0 ~Screen.width #0001 SFT2 SUB2 =scroll.x
    #09b0 =scroll.y
    ,frame =Screen.vector
    #30 =scroll.wait
    BRK

@frame ( -> )
    #ffff
    $loop
    DUP2 ^row JSR
    #0001 ADD2
    DUP2 ~Screen.height LTH2 ^$loop JNZ
    POP2
    ~scroll.wait ^$noscroll JNZ
    ~scroll.y #0001 ADD2 =scroll.y
    BRK

    $noscroll
    ~scroll.wait #01 SUB =scroll.wait
    BRK

@row ( y* -- )
    DUP2 =Screen.y
    ~scroll.y ADD2

    ~Screen.width
    $loop
    #0001 SUB2
    OVR2 OVR2 ~scroll.x ADD2 EOR2 DUP2 #0013 DIV2 #0013 MUL2 SUB2
    DUP #00 EQU ^$draw JNZ
    DUP #05 EQU ^$draw JNZ
    POP2
    $rest
    DUP2 ORA ^$loop JNZ
    POP2 POP2
    JMP2r

    #15 =Screen.color
    JMP2r

    $draw
    OVR2 =Screen.x
    #05 ADD =Screen.color
    ~Screen.y
    DUP2 #0001 ADD2 =Screen.y
    #00 =Screen.color
    =Screen.y
    POP
    ^$rest JMP