NES Vice - Project Doom (U) HUD script for FCEUX

Vice-hud.lua

----------------------------------------------------------------------
-- NES Vice - Project Doom (U) HUD script for FCEUX
--
-- displays position, velocity, acceleration, and HPs.
----------------------------------------------------------------------


----------------------------------------------------------------------
-- 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_s_le(buf, size)
    local n = numdec_u_le(buf, size)
    return num_utos(n, size)
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_be(buf, size)
    local n = numdec_u_be(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_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 signmag8(n)
    local val = bit.band(n, 0x7F)
    if bit.band(n, 0x80) ~= 0 then val = -val end
    return val
end

local function get_objs()
    local objs = {}

    for i = 0, 15 do
        local obj = {}

        obj.hp    = mem_read_u8(0x0280+i)
        obj.invin = bit.band(mem_read_u8(0x02B0+i), 0x7F)
        obj.x     = 0x100 * mem_read_u8(0x0200+i) + mem_read_u8(0x01F0+i)
        obj.y     = 0x100 * mem_read_u8(0x0220+i) + mem_read_u8(0x0210+i)
        obj.x_sub = mem_read_u8(0x01E0+i)
        obj.y_sub = mem_read_u8(0x01B0+i)
        obj.vx    = signmag8(mem_read_u8(0x01D0+i))
        obj.vy    = signmag8(mem_read_u8(0x01A0+i))
        obj.ax    = signmag8(mem_read_u8(0x01C0+i))
        obj.ay    = signmag8(mem_read_u8(0x0190+i))

        objs[i+1] = obj
    end

    return objs
end

local function get_info()
    local info = {}

    info.objs = get_objs()

    info.scroll_x = mem_read_u16_le(0x0B)
    info.scroll_y = mem_read_u8(0x0D)

    info.rand_idx = mem_read_u8(0x94)

    return info
end

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

local function draw_hp(objs)
    local strs = {}
    for i = 1, #objs do
        strs[i] = fmt("%d%s",
            objs[i].hp,
            objs[i].invin ~= 0 and fmt("(%d)", objs[i].invin) or ""
        )
    end

    text(56, 224, "H:" .. table.concat(strs, ","))
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, 192, fmt("%4d", seg_frame))
    end
end

local function draw()
    local info = get_info()
    local objs = info.objs
    local hero = objs[1]

    local x = hero.x + hero.x_sub / 16.0
    local y = hero.y + hero.y_sub / 16.0
    text(0, 8, fmt(
        "P:(%.2f,%.2f) V:(%.2f,%.2f) A:(%.2f,%.2f)",
        x, y,
        hero.vx / 16.0, hero.vy / 16.0,
        hero.ax / 16.0, hero.ay / 16.0
    ))

    text(0, 16, fmt(
        "S:(%d,%d)",
        info.scroll_x, info.scroll_y
    ))

    draw_hp(objs)

    text(200, 192, fmt("R:%3d", info.rand_idx))

    draw_seg()
end

local function main()
    gui.opacity(0.7)

    emu.registerafter(draw)
end

main()