charmap("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ#@-,'>!♥·")

fn load_bg()
    // Tell the NES which VRAM address we want to upload to:
    ppu_reset_addr($2000)

    // Upload the tile data:
    for UU i = 0; i < 960; i += 1
        {PPUDATA}($2C)

    // Then the attributes:
    for U i = 0; i < 64; i += 1
        {PPUDATA}(%00000000)

fn write_u(U x, AA addr)
    ppu_reset_addr(addr)
    fence
    {PPUDATA}(x >> 4)
    {PPUDATA}(x & %1111)
    fence

fn write_uu(UU x, AA addr)
    ppu_reset_addr(addr)
    fence
    {PPUDATA}(x.b >> 4)
    {PPUDATA}(x.b & %1111)
    {PPUDATA}(x.a >> 4)
    {PPUDATA}(x.a & %1111)
    fence

fn write_uuu(UUU x, AA addr)
    ppu_reset_addr(addr)
    fence
    {PPUDATA}(x.c >> 4)
    {PPUDATA}(x.c & %1111)
    {PPUDATA}(x.b >> 4)
    {PPUDATA}(x.b & %1111)
    {PPUDATA}(x.a >> 4)
    {PPUDATA}(x.a & %1111)
    fence

// Variables:
data /test_data
    [] test_arr
        U(0)
        U(1)
        U(2)

omni data /test_omni
    [] omni_arr
        U(4)
        U(5)
        U(6)

vars /globals
    CCC/test_data test_ptr = @test_arr
    UUU test_ptr_cast = UUU(@test_arr)

    CC/test_omni omni_ptr = @omni_arr
    UU omni_ptr_cast = UU(@omni_arr)

// COMMMENT THIS OUT IN MAIN FOR COMPARISON
fn init_globals()
: employs /globals
    test_ptr = @test_arr
    test_ptr_cast = UUU(@test_arr)
    omni_ptr = @omni_arr
    omni_ptr_cast = UU(@omni_arr)

nmi main_nmi()
    ppu_upload_oam_poll_pads(0)

    // compare normal data ptrs
    write_uuu(UUU(test_ptr), $218E)
    write_uuu(test_ptr_cast, $21CE)

    // compare omni data ptrs
    write_uu(UU(omni_ptr), $2198)
    write_uu(omni_ptr_cast, $21D8)
    ppu_reset_scroll(0, 0)

mode main()
: nmi main_nmi
: employs /test_data/test_omni
    palette = example_palette
    ppu_upload_palette()

    load_bg()
    // COMMENT THIS OUT FOR COMPARISON
    init_globals()

    {PPUCTRL}(PPUCTRL_NMI_ON)
    {PPUMASK}(PPUMASK_ON | PPUMASK_NO_CLIP)
    while true
        nmi

// Define the tileset (commonly called CHR):
chrrom
    file(fmt, "tiles.png")
    file(fmt, "tiles.png")