User File #639147151797864439

local function ptr_is_invalid(ptr)
    return ptr < 0x02000000 or ptr > 0x0203FFFF
end

local function get_x_pos()
    local base_addr = 0x02006614 -- appears to be a constant in the code

    local ptr = memory.read_u32_le(base_addr, "System Bus")
    if (ptr_is_invalid(ptr)) then
        return 0
    end

    local ptr_ptr = memory.read_u32_le(ptr + 4, "System Bus")
    if (ptr_is_invalid(ptr_ptr)) then
        return 0
    end

    -- seems to be a variable offset added at this point, but usually (always?) 0?
    -- if this breaks, that offset probably needs to be considered

    local ptr_ptr_ptr = memory.read_u32_le(ptr_ptr + 4, "System Bus")
    if (ptr_is_invalid(ptr_ptr_ptr)) then
        return 0
    end

    local ptr_ptr_ptr_ptr = memory.read_u32_le(ptr_ptr_ptr + 4, "System Bus")
    if (ptr_is_invalid(ptr_ptr_ptr_ptr)) then
        return 0
    end

    local ptr_ptr_ptr_ptr_ptr = memory.read_u32_le(ptr_ptr_ptr_ptr + 0, "System Bus")
    if (ptr_is_invalid(ptr_ptr_ptr_ptr_ptr)) then
        return 0
    end

    return memory.read_u32_le(ptr_ptr_ptr_ptr_ptr + 0x17C, "System Bus")
end

local x_pos = get_x_pos()
local last_x_pos = x_pos

while true do
    x_pos = get_x_pos()
    local x_speed = x_pos - last_x_pos
    last_x_pos = x_pos
    gui.text(5, 5, string.format("X Speed: %d", x_speed), nil, "topright")
    
    emu.frameadvance()
end