Chao Memory solver v2 (mGBA script)

main.lua

if cbid then
    return
end
buffer = console:createBuffer("Test buffer")

function indexof(t, v)
    for key, value in pairs(t) do
        if value == v then
            return key
        end
    end
end

function processFrameCore()
    local cardState = emu:read8(0x030019DC) -- 0..1: number of visible cards, else: waiting
    if cardState > 1 then return end

    local cursorX = emu:read8(0x030019AE) -- 0..5
    local cursorY = emu:read8(0x030019AF) -- 0..4

    local revealedCardX = emu:read8(0x030019EA) -- 0..5
    local revealedCardY = emu:read8(0x030019EB) -- 0..4

    local cardDataRaw = emu:readRange(0x03001990, 30) -- flattened 6x5 map (00..0D, FF)
    local cardData = {}
    for i = 0, 29 do
        cardData[i] = string.byte(cardDataRaw, i + 1)
    end

    -- find next target
    local targetPosition
    if cardState == 1 then
        -- find the matching card
        local revealedCardId = cardData[revealedCardY * 6 + revealedCardX]
        local targetId
        if revealedCardId % 2 == 0 then
            targetId = revealedCardId + 1
        else
            targetId = revealedCardId - 1
        end
        targetPosition = indexof(cardData, targetId)
        console:log("Revealed card: "..tostring(revealedCardId))
        console:log("Matching card: "..tostring(targetId).." at "..tostring(targetPosition))
    else
        -- find the closest remaining card
        local targetDistance = 10
        for position, id in pairs(cardData) do
            local x = position % 6
            local y = position // 6
            local distance = math.abs(x - cursorX) + math.abs(y - cursorY)
            if id ~= 255 and distance < targetDistance then
                targetPosition = position
                targetDistance = distance
            end
        end
        console:log("Closest card at: "..tostring(targetPosition))
    end

    for position, id in pairs(cardData) do
        buffer:moveCursor((position % 6) * 3, position // 6)
        if(id ~= 255) then
            buffer:print(tostring(id))
        else
            buffer:print("--")
        end
        buffer:moveCursor(0, 5)
        buffer:print("Going to " .. tostring(targetPosition % 6) .. "," .. tostring(targetPosition // 6))
    end

    local deltaX = (targetPosition % 6) - cursorX
    local deltaY = (targetPosition // 6) - cursorY
    if deltaX < 0 then
        emu:addKey(C.GBA_KEY.LEFT)
    elseif deltaX > 0 then
        emu:addKey(C.GBA_KEY.RIGHT)
    elseif deltaY < 0 then
        emu:addKey(C.GBA_KEY.UP)
    elseif deltaY > 0 then
        emu:addKey(C.GBA_KEY.DOWN)
    else
        emu:addKey(C.GBA_KEY.A)
    end
end


function processFrame()
    buffer:clear()
    if(emu:getKey(C.GBA_KEY.B) ~= 0) then
        buffer:setName("Discarded buffer")
        callbacks:remove(cbid)
        emu:setKeys(0)
        cbid = nil
        return
    end

    -- if we just pressed something, release and skip frame - effectively turboing the key
    if(emu:getKeys() ~= 0) then
        emu:setKeys(0)
        return
    end

    gameState = emu:read8(0x030019D8)
    if gameState == 00 then -- Not in memory game
        buffer:print("Not in Chao Memory")
        emu:addKey(C.GBA_KEY.A)
    elseif gameState == 06 then
        processFrameCore()
    else
        buffer:print("Waiting in Chao Memory")
    end
    
end
cbid = callbacks:add("frame", processFrame)