NES Star Soldier (J) hitbox display for FCEUX

StarSoldier-hitbox.lua

----------------------------------------------------------------------
-- NES Star Soldier (J) hitbox display for FCEUX
----------------------------------------------------------------------


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

local function array_append(ary, o)
    ary[#ary+1] = o
end

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


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

local OBJ_N    = 24
local BULLET_N =  8
local SHOT_N   = 15

local HERO_HIT_OBJ    = 14
local HERO_HIT_BULLET = 12
local OBJ_HIT_OBJ     = 14
local OBJ_HIT_SHOT    = 12
local BULLET_HIT      =  6
local SHOT_HIT        =  6

local COLOR_HERO_OBJ    = "#00FFFF"
local COLOR_HERO_BULLET = "#FFFF00"
local COLOR_OBJ_OBJ     = "#00FFFF"
local COLOR_OBJ_SHOT    = "#FFFF00"
local COLOR_BULLET      = "#FFFF00"
local COLOR_SHOT        = "#00FF00"

local function get_info()
    local info = {}

    info.hero_x = mem_read_u8(0x3A)
    info.hero_y = mem_read_u8(0x3B)

    info.objs = {}
    for i = 1, OBJ_N do
        if mem_read_u8(0x0400+i-1) ~= 0 then
            local obj = {}
            obj.x = mem_read_u8(0x0418+i-1)
            obj.y = mem_read_u8(0x0430+i-1)
            array_append(info.objs, obj)
        end
    end

    info.bullets = {}
    for i = 1, BULLET_N do
        if mem_read_u8(0x0648+i-1) ~= 0 then
            local bullet = {}
            bullet.x = mem_read_u8(0x0650+i-1)
            bullet.y = mem_read_u8(0x0658+i-1)
            array_append(info.bullets, bullet)
        end
    end

    info.shots = {}
    for i = 1, SHOT_N do
        if mem_read_u8(0x061B+i-1) ~= 0 then
            local shot = {}
            shot.x = mem_read_u8(0x062A+i-1)
            shot.y = mem_read_u8(0x0639+i-1)
            array_append(info.shots, shot)
        end
    end

    return info
end

local function square(x, y, l, color)
    gui.drawbox(x, y, x+l, y+l, "clear", color)
end

local function draw()
    local info = get_info()

    square(info.hero_x, info.hero_y, HERO_HIT_BULLET, COLOR_HERO_BULLET)
    square(info.hero_x, info.hero_y, HERO_HIT_OBJ, COLOR_HERO_OBJ)

    for _, obj in ipairs(info.objs) do
        square(obj.x, obj.y, OBJ_HIT_SHOT, COLOR_OBJ_SHOT)
        square(obj.x, obj.y, OBJ_HIT_OBJ, COLOR_OBJ_OBJ)
    end

    for _, bullet in ipairs(info.bullets) do
        square(bullet.x, bullet.y, BULLET_HIT, COLOR_BULLET)
    end

    for _, shot in ipairs(info.shots) do
        square(shot.x, shot.y, SHOT_HIT, COLOR_SHOT)
    end
end

local function main()
    emu.registerafter(draw)
end

main()