NES The Quest of Ki (J) HUD script for FCEUX

QuestOfKi-hud.lua

----------------------------------------------------------------------
-- NES The Quest of Ki (J) HUD script for FCEUX
--
-- displays position and velocity
----------------------------------------------------------------------


----------------------------------------------------------------------
-- util
----------------------------------------------------------------------

local function num_stou(n, size)
    if n < 0 then
        n = n + 2^(8*size)
    end
    return n
end

local function num_utos(n, size)
    if n >= 2^(8*size-1) then
        n = n - 2^(8*size)
    end
    return n
end

local function numdec_u_le(buf, size)
    local n = 0
    for i = 1, size do
        n = n + 2^(8*(i-1)) * buf[i]
    end
    return n
end

local function numdec_s_le(buf, size)
    local n = numdec_u_le(buf, size)
    return num_utos(n, size)
end

local function numdec_u_be(buf, size)
    local n = 0
    for i = 1, size do
        n = n + 2^(8*(size-i)) * buf[i]
    end
    return n
end

local function numdec_s_be(buf, size)
    local n = numdec_u_be(buf, size)
    return num_utos(n, size)
end

local function numdec_s32_le(buf)
    return numdec_s_le(buf, 4)
end

local function numdec_u32_le(buf)
    return numdec_u_le(buf, 4)
end

local function numdec_s24_le(buf)
    return numdec_s_le(buf, 3)
end

local function numdec_u24_le(buf)
    return numdec_u_le(buf, 3)
end

local function numdec_s16_le(buf)
    return numdec_s_le(buf, 2)
end

local function numdec_u16_le(buf)
    return numdec_u_le(buf, 2)
end

local function numdec_s32_be(buf)
    return numdec_s_be(buf, 4)
end

local function numdec_u32_be(buf)
    return numdec_u_be(buf, 4)
end

local function numdec_s24_be(buf)
    return numdec_s_be(buf, 3)
end

local function numdec_u24_be(buf)
    return numdec_u_be(buf, 3)
end

local function numdec_s16_be(buf)
    return numdec_s_be(buf, 2)
end

local function numdec_u16_be(buf)
    return numdec_u_be(buf, 2)
end

local function mem_read_bytes(addr, len)
    local buf = {}
    for i = 1, len do
        buf[i] = memory.readbyte(addr+(i-1))
    end
    return buf
end

local function mem_read_s_le(addr, size)
    local buf = mem_read_bytes(addr, size)
    return numdec_s_le(buf, size)
end

local function mem_read_u_le(addr, size)
    local buf = mem_read_bytes(addr, size)
    return numdec_u_le(buf, size)
end

local function mem_read_s_be(addr, size)
    local buf = mem_read_bytes(addr, size)
    return numdec_s_be(buf, size)
end

local function mem_read_u_be(addr, size)
    local buf = mem_read_bytes(addr, size)
    return numdec_u_be(buf, size)
end

local function mem_read_s32_le(addr)
    return mem_read_s_le(addr, 4)
end

local function mem_read_u32_le(addr)
    return mem_read_u_le(addr, 4)
end

local function mem_read_s24_le(addr)
    return mem_read_s_le(addr, 3)
end

local function mem_read_u24_le(addr)
    return mem_read_u_le(addr, 3)
end

local function mem_read_s16_le(addr)
    return mem_read_s_le(addr, 2)
end

local function mem_read_u16_le(addr)
    return mem_read_u_le(addr, 2)
end

local function mem_read_s32_be(addr)
    return mem_read_s_be(addr, 4)
end

local function mem_read_u32_be(addr)
    return mem_read_u_be(addr, 4)
end

local function mem_read_s24_be(addr)
    return mem_read_s_be(addr, 3)
end

local function mem_read_u24_be(addr)
    return mem_read_u_be(addr, 3)
end

local function mem_read_s16_be(addr)
    return mem_read_s_be(addr, 2)
end

local function mem_read_u16_be(addr)
    return mem_read_u_be(addr, 2)
end

local function mem_read_s8(addr)
    return num_utos(mem_read_u8(addr), 1)
end

local function mem_read_u8(addr)
    return memory.readbyte(addr)
end


----------------------------------------------------------------------
-- main
----------------------------------------------------------------------

local fmt = string.format

local function get_info()
    local info = {}

    info.x  = mem_read_u24_be(0x3A)
    info.y  = mem_read_u24_be(0x3D)
    info.vx = mem_read_s16_be(0x34)
    info.vy = mem_read_s16_be(0x36)

    return info
end

local function text(x, y, str)
    gui.text(x, y, str)
end

local function draw_seg()
    local seg_frame = -1
    if taseditor.engaged() then
        local f_current = emu.framecount()
        for f = f_current, 0, -1 do
            if taseditor.markedframe(f) or f == 0 then
                seg_frame = f_current - f
                break
            end
        end
        text(232, 200, fmt("%4d", seg_frame))
    end
end

local function draw()
    local info = get_info()

    local x  = info.x  / 256.0
    local y  = info.y  / 256.0
    local vx = info.vx / 256.0
    local vy = info.vy / 256.0

    text(0, 8, fmt(
        "P:(%.2f,%.2f) V:(%.2f,%.2f)",
        x, y, vx, vy
    ))

    draw_seg()
end

local function main()
    gui.opacity(0.7)

    emu.registerafter(draw)
end

main()