ancilla.lua

local type_to_name = { -- {{{
    -- 0x00
    '..',
    'Somar Blast',
    'Fire Shot',
    'Unused',
    'Beam Hit',
    'Boom',
    'Wall Hit',
    'Bomb',
    'Door Debr',
    'Arrow',
    '*Wall Arrow',
    'Ice Shot',
    'Sword Beam',
    'Sword Spark',
    'Unused',
    'Unused',

    -- 0x10
    'Unused',
    'Ice Spread',
    'Unused',
    '*Ice Sparkle',
    'Unused',
    'Jump Splash',
    'Ham Stars',
    'Shov Dirt',
    'EtherFX',
    'BombosFX',
    'Torch/PowFX',
    'Wall Sparks',
    'QuakeFX',
    'Bonk',
    'BootDust',
    'Hookshot',

    -- 0x20
    'Bed Spread',
    'Zzzzs',
    'Got Item',
    'Bun/Capoof',
    'Grave Moving',
    '???',
    'Sword Spark',
    'Bird',
    'Pond Item',
    'Pend/crystal',
    'Spin Spark',
    'Spin Spark2',
    'Som Block',
    '???',
    '???',
    'Torch flame',

    -- 0x30
    'Pre Byrna',
    'Byrna Spark',
    'Flame Blob',
    'Expl Wall',
    'SW Burn',
    'MS Hurray',
    'Flute Dig',
    'WV Expl',
    'Bird Flute',
    'Som Plat Blast',
    'SBomb Expl',
    'Unused',
    '*Sword Spark',
    'Item Splash',
    '3D Crystal',
    'Bush Poof',

    -- 0x40
    'Dwarf Trans',
    'Water @ Wishing & Swamp',
    'Wishing Rupee',
    'GT Seal Broken',
} -- }}}

local TEXT_TOP = 70

-- UTIL

local function tohex(num)
    return string.format('%X', num)
end

local function call_for_each_bank(address, fn, ...)
    for i = 0x00, 0x1F do
        fn(bit.lshift(i, 16) + address, unpack(arg))
    end
    fn(0x7E0000 + address, unpack(arg))
end


-- ANCILLA

local function get_ancillae()
    local ancillae = {}
    for i=0, 9 do
        local ancilla = {
            index = i,
            type = memory.readbyte(0x7E0C4A + i),
            x = bit.bor(memory.readbyte(0x7E0C04 + i), bit.lshift(memory.readbyte(0x7E0C18 + i), 8)),
            y = bit.bor(memory.readbyte(0x7E0BFA + i), bit.lshift(memory.readbyte(0x7E0C0E + i), 8)),
        }
        ancilla['name'] = type_to_name[ancilla['type'] + 1]
        table.insert(ancillae, ancilla)
    end
    return ancillae
end

local function get_camera()
    return {
        ['x'] = memory.readwordsigned(0xe2),
        ['y'] = memory.readwordsigned(0xe8),
    }
end


-- LOGIC
local function draw_ancilla(ancilla, camera)
    local pos = ancilla['index']
    gui.text(6, TEXT_TOP + 8 + 8 * pos, tohex(ancilla['index']) .. ': '.. ancilla['name'])

    if ancilla['type'] > 0 then
        local x = ancilla['x'] - camera['x']
        local y = ancilla['y'] - camera['y']
        gui.text(x, y, tohex(ancilla['index']), 'red')
    end
end

local function iterate_ancillae()
    local camera = get_camera()

    local ancillae = get_ancillae()
    for i, ancilla in pairs(ancillae) do
        draw_ancilla(ancilla, camera)
    end

    local sidx = memory.readbyteunsigned(0x7E03C4)

    gui.text(6, TEXT_TOP - 8, tohex(memory.readbyte(0x7E0C5E)) .. ' ' ..
                              tohex(memory.readbyte(0x7E0C5F)) .. ' ' ..
                              tohex(memory.readbyte(0x7E0C60)) .. ' ' ..
                              tohex(memory.readbyte(0x7E0C61)))
    gui.text(6, TEXT_TOP, 'I:' .. tohex(sidx) .. ' ' ..
                          'H:' .. tohex(memory.readbyte(0x7E039D)) .. ' ' ..
                          'E:' .. tohex(memory.readbyte(0x7E03A4)) .. ' ' ..
                          'D:' .. tohex(memory.readbyte(0x7E0C72)))

    for i = 0, 5 do
        local addr = 0x7E0C54 + i
        gui.text(6, TEXT_TOP + 8 + 8 * 10 + 8 * i, tohex(memory.readbyte(addr)))
    end
end


-- EVENTS

function on_write(addr, size)
    if addr < 0x200000 then
        addr = bit.band(addr, 0xFFFF)
        addr = 0x7E0000 + addr
    end

    val = size == 1 and memory.readbyte(addr) or memory.readword(addr)
    local line = "[" .. tohex(memory.getregister("pb"), 2) .. ":" .. tohex(memory.getregister("pc"), 4) .. "] "
                    .. tohex(addr, 6) .. "[" .. tostring(size) .. "] = " .. tohex(val, size == 1 and 2 or 4)
                    .. (size == 1 and "   | " or " | ") .. " F=" .. emu.framecount()
    print(line)
end

call_for_each_bank(0x0000, function (bank_only)
    memory.registerwrite(bank_only + 0xEE, 0x1, on_write)
end)


--[[
local function addancilla()
    local y = bit.band(memory.getregister("y"), 0xFF)
    local a = bit.band(memory.getregister("a"), 0xFF)
    print('+ ancilla:', type_to_name[a+1], '(Y=' .. tohex(y) .. ', A=' .. tohex(a) .. ')')
end

memory.registerexecute(0x1cf537, addancilla)
]]


local function write_ancilla(addr, size)
    if addr < 0x200000 then
        addr = bit.band(addr, 0xFFFF)
        addr = 0x7E0000 + addr
    end

    local slot = bit.band(addr, 0xFFFF) - 0x0C4A
    local val = size == 1 and memory.readbyte(addr) or memory.readword(addr)
    if val > 0 then
        print('+ slot[' .. tohex(slot) .. ']: ' .. type_to_name[val + 1] .. ' (' .. tohex(val) .. ')')
    else
        print('- slot[' .. tohex(slot) .. ']')
    end
end

call_for_each_bank(0x0000, function (bank_only)
    memory.registerwrite(bank_only + 0x0C4A, 0xA, write_ancilla)
end)


-- memory.writebyte(0x7E03A4, 0x0)
-- memory.writebyte(0x7E0C4A + 4, 0x03)
-- memory.writebyte(0x7E0C4A + 3, 0x03)
-- memory.writebyte(0x7E0C4A + 2, 0x03)
-- memory.writebyte(0x7E0C4A + 1, 0x03)

while true do
    iterate_ancillae()
    snes9x.frameadvance()
    -- print('-- F: ' .. emu.framecount())
end