System.setCpuSpeed(804)

Graphics.init()

-- Patch for latest lpp-3ds commit
System.currentDirectory(string.sub(System.currentDirectory(),1,-2))

local appdir = System.currentDirectory()..'/rsrc'
local scrdir = System.currentDirectory()..'/screenshots'
local lvldir = System.currentDirectory()..'/levels'

local c_white = Color.new(255,255,255)
local c_light = Color.new(178,216,255)

-- Localize all most used functions and variables so they will be accessed faster
local Screen_waitVblankStart = Screen.waitVblankStart
local Graphics_drawImage = Graphics.drawImage
local TOP_SCREEN = TOP_SCREEN
local Screen_flip = Screen.flip
local Graphics_drawPartialImage = Graphics.drawPartialImage
local Graphics_drawLine = Graphics.drawLine
local Graphics_initBlend = Graphics.initBlend
local Graphics_termBlend = Graphics.termBlend
local Controls_read = Controls.read
local Controls_check = Controls.check
local Controls_readTouch = Controls.readTouch
local KEY_A = KEY_A
local KEY_X = KEY_X
local KEY_Y = KEY_Y
local KEY_R = KEY_R
local KEY_START = KEY_START
local KEY_SELECT = KEY_SELECT

Screen_waitVblankStart()
Graphics_initBlend(TOP_SCREEN)
img_bg_load = Graphics.loadImage(appdir..'/bg_load.png')
Graphics_drawImage(0, 0, img_bg_load)
Graphics_termBlend()
Screen_flip()

local i=0
local load_filevariable = {}
local load_filepath = {}

    i=i+1; load_filevariable[i]='img_ship01'; load_filepath[i] = '/ship01.png'
    i=i+1; load_filevariable[i]='img_ship_death'; load_filepath[i] = '/ship_death.png'

    i=i+1; load_filevariable[i]='img_en_death'; load_filepath[i] = '/en_death.png'
    i=i+1; load_filevariable[i]='img_boss_death'; load_filepath[i] = '/boss_death.png'
    i=i+1; load_filevariable[i]='img_en01'; load_filepath[i] = '/en01.png'
    i=i+1; load_filevariable[i]='img_en02'; load_filepath[i] = '/en02.png'
    i=i+1; load_filevariable[i]='img_en03'; load_filepath[i] = '/en03.png'
    i=i+1; load_filevariable[i]='img_en04'; load_filepath[i] = '/en04.png'
    i=i+1; load_filevariable[i]='img_en05'; load_filepath[i] = '/en05.png'
    i=i+1; load_filevariable[i]='img_boss01'; load_filepath[i] = '/boss01.png'
    i=i+1; load_filevariable[i]='img_boss02'; load_filepath[i] = '/boss02.png'


    i=i+1; load_filevariable[i]='img_bullet01'; load_filepath[i] = '/bullet01.png'
    i=i+1; load_filevariable[i]='img_bullet02'; load_filepath[i] = '/bullet02.png'
    i=i+1; load_filevariable[i]='img_bullet03'; load_filepath[i] = '/bullet03.png'
    i=i+1; load_filevariable[i]='img_bullet04'; load_filepath[i] = '/bullet04.png'
    i=i+1; load_filevariable[i]='img_bullet05'; load_filepath[i] = '/bullet05.png'
    i=i+1; load_filevariable[i]='img_shot01'; load_filepath[i] = '/shot01.png'
    i=i+1; load_filevariable[i]='img_shot02'; load_filepath[i] = '/shot02.png'
    i=i+1; load_filevariable[i]='img_shot03'; load_filepath[i] = '/shot03.png'
    i=i+1; load_filevariable[i]='img_shot04'; load_filepath[i] = '/shot04.png'
    i=i+1; load_filevariable[i]='img_shot05'; load_filepath[i] = '/shot05.png'

    i=i+1; load_filevariable[i]='img_bg_menu'; load_filepath[i] = '/bg_menu.png'
    i=i+1; load_filevariable[i]='img_bg_game'; load_filepath[i] = '/bg_game.png'

    i=i+1; load_filevariable[i]='img_menubutton_play'; load_filepath[i] = '/menubutton_play.png'
    i=i+1; load_filevariable[i]='img_menubutton_diff'; load_filepath[i] = '/menubutton_diff.png'
    i=i+1; load_filevariable[i]='img_menubutton_level'; load_filepath[i] = '/menubutton_level.png'
    i=i+1; load_filevariable[i]='img_menubutton_option'; load_filepath[i] = '/menubutton_option.png'
    i=i+1; load_filevariable[i]='img_menubutton_exit'; load_filepath[i] = '/menubutton_exit.png'

    i=i+1; load_filevariable[i]='img_diff_meter'; load_filepath[i] = '/diff_meter.png'
    i=i+1; load_filevariable[i]='img_diff_meter_pip'; load_filepath[i] = '/diff_meter_pip.png'
    i=i+1; load_filevariable[i]='img_menu_invalid'; load_filepath[i] = '/menu_invalid.png'
    i=i+1; load_filevariable[i]='img_warning'; load_filepath[i] = '/warning.png'
    i=i+1; load_filevariable[i]='img_clear'; load_filepath[i] = '/clear.png'

    i=i+1; load_filevariable[i]='img_font_numbers'; load_filepath[i] = '/font_numbers.png'

load_filecount = i+1

local i=0
local c_line = c_light
while i<load_filecount do --load them one by one on each frame of the loading screen
    if load_filevariable[i] ~= nil then
        if System.doesFileExist(appdir..load_filepath[i]) then
            _G[load_filevariable[i]] = Graphics.loadImage(appdir..load_filepath[i])
        else
            c_line = Color.new(255,0,0)
        end
    end
    i=i+1
    Screen_waitVblankStart()
    Graphics_initBlend(TOP_SCREEN)
    Graphics_drawImage(0, 0, img_bg_load)
    Graphics_drawLine(163, 163+math.ceil(i/load_filecount*76), 175, 175, c_line)
    Graphics_termBlend()
    Screen_flip()
end

glyph_l = {}
glyph_r = {}
glyph_w = {}
function g_init(char, l, r)
    glyph_l[char] = l
    glyph_r[char] = r
    glyph_w[char] = r-l+1
end
g_init('0',1,8)
g_init('1',9,16)
g_init('2',17,25)
g_init('3',25,32)
g_init('4',33,40)
g_init('5',41,48)
g_init('6',49,56)
g_init('7',57,64)
g_init('8',65,72)
g_init('9',73,80)

--remember to blend the gpu to what screen you want before calling this function, and termblend afterwards
function gpu_drawtext(x, y, text)
    local text_u = string.upper(text) --my font system is caps-only. This may be slowing down the system though, consider not having this failsafe (instead loading all strings in as uppercase by default)
    local i_str=0 --the current position in the string
    local i_chr='' --the current character in the string
    local str_width = 0 --width in pixels of the string
    local str_length = string.len(text)
    local cw --character width
    while i_str < str_length do
        i_str = i_str + 1
        i_chr = string.sub(text_u, i_str, i_str)
        cw = glyph_w[i_chr]
        if cw ~= nil then --as long as the character exists
            Graphics_drawPartialImage(x+str_width, y, glyph_l[i_chr], 1, cw, 14, img_font_numbers)
            str_width = str_width + cw + 2
        end
    end
end

dofile(appdir..'/ds_list_init.lua')
dofile(appdir..'/ds_queue_init.lua')

dofile(appdir..'/object.lua')

function loadlevel(num)
    local f = io.open(lvldir.."/level"..num..".dat",FREAD)
    local filesize = io.size(f)
    local str = io.read(f,0,filesize)
    io.close(f)

    --"|T-######|enemy|direction|px|"
    local i = 0
    local a = string.find(str, "|T-",1,true) --find the first new line
    local v = string.sub(str, 1, 4) --obtain version
    if v ~= "v001" then
        a=nil
        return true;
    else
        while a~=nil do --as long as there's more newlines
            local t = tonumber(string.sub(str, a+3, a+8)) --the six characters after T- is the time
            local en = string.sub(str, a+10, a+13) --enemy id
            local d = string.sub(str, a+15, a+15) --direction the enemy is coming from (T, L, R)
            local px = tonumber(string.sub(str, a+17, a+19))
            larray.time[i] = t
            larray.enid[i] = en
            larray.dir[i] = d
            larray.pix[i] = px
            i = i+1
            a = string.find(str, "|T-",a+5,true)
        end
    end
end

function onscreen(x,y)
    if x>-5 and x<405 and y>-5 and y<405 then
        return true
    else
        return false
    end
end

larray = {}
larray.time = {}
larray.enid = {}
larray.dir = {}
larray.pix = {}

function menu_init()
    menu = true
    menu_selector = 0
    invalid_level = false
    if game_started == true then
        while bulletlist.size>0 do ds_list_delete(bulletlist,0) end
        while shotlist.size>0 do ds_list_delete(shotlist,0) end
        while enemylist.size>0 do ds_list_delete(enemylist,0) end
    else
        difficulty = 1
        level_select = 1
    end
end

function game_init()
    if loadlevel(level_select) == true then --failed to load level because version mismatch
        menu = true
        invalid_level = true
    else
        difficulty = math.floor(difficulty)
        game_started = true
        beam_id = -1
        weapon = 1
        player_x = 200
        player_y = 200
        player_shot = 0
        player_speed = 1
        player_alive = true
        player_death = 0
        timer = 0
        spawnindex = 0
        warning_flash = 0
        stage_boss = ''
        stage_clear = -1
    end
end

function angle(x1,y1,x2,y2)
    local rise = y2-y1
    local run = x2-x1
    local a = math.atan(run,rise)
    return math.deg(a)%360
end

pad = Controls_read()
oldpad = pad

menu_init()
while true do
    Screen_waitVblankStart()
    pad = Controls_read()
    tx_old,ty_old = tx,ty
    tx,ty = Controls_readTouch()

    if (Controls_check(pad,KEY_SELECT)) and not (Controls_check(oldpad,KEY_SELECT)) then
        local i=0
        while i<50 do
            if System.doesFileExist(scrdir.."/screenshot"..i..".png") then
                i=i+1
            else
                System.takeScreenshot(scrdir.."/screenshot"..i..".png",false)
                break;
            end
        end
    end

    if menu == true then --MENU SCREEN \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

        if (Controls_check(pad,KEY_DUP)) and not (Controls_check(oldpad,KEY_DUP)) then
            menu_selector = math.max(0,menu_selector-1)
        end
        if (Controls_check(pad,KEY_DDOWN)) and not (Controls_check(oldpad,KEY_DDOWN)) then
            menu_selector = math.min(4,menu_selector+1)
        end

        Graphics_initBlend(TOP_SCREEN)

        Graphics_drawImage(0, 0, img_bg_menu) --PLAY BUTTON
        if menu_selector == 0 then
            Graphics_drawPartialImage(50,70, 0,16, 103,16, img_menubutton_play, c_white)
            if (Controls_check(pad,KEY_A)) and not (Controls_check(oldpad,KEY_A)) then
                if System.doesFileExist(lvldir.."/level"..level_select..".dat") then
                    menu = false
                    game_init()
                else
                    invalid_level = true
                end
            end
        else Graphics_drawPartialImage(50,70, 0,0, 103,16, img_menubutton_play, c_white) end

        if menu_selector == 1 then --DIFFICULTY SELECTION
            if (Controls_check(pad,KEY_DLEFT)) then
                difficulty = math.max(1,difficulty-0.125)
            end
            if (Controls_check(pad,KEY_DRIGHT)) then
                difficulty = math.min(16,difficulty+0.125)
            end
            Graphics_drawPartialImage(50,95, 0,16, 103,16, img_menubutton_diff, c_white)
        else Graphics_drawPartialImage(50,95, 0,0, 103,16, img_menubutton_diff, c_white) end
        Graphics_drawImage(180, 95, img_diff_meter)
        Graphics_drawPartialImage(180,95, 0,0, 6+(4*math.floor(difficulty)),16, img_diff_meter_pip)

        if menu_selector == 2 then --LEVEL SELECTION
            if (Controls_check(pad,KEY_DLEFT)) then
                invalid_level = false
                if (Controls_check(pad,KEY_Y)) then
                    level_select = math.max(0,level_select-1)
                elseif not (Controls_check(oldpad,KEY_DLEFT)) then
                    level_select = math.max(0,level_select-1)
                end
            end
            if (Controls_check(pad,KEY_DRIGHT)) then
                invalid_level = false
                if (Controls_check(pad,KEY_Y)) then
                    level_select = level_select + 1
                elseif not (Controls_check(oldpad,KEY_DRIGHT)) then
                    level_select = level_select + 1
                end
            end
            Graphics_drawPartialImage(50,120, 0,16, 103,16, img_menubutton_level, c_white)
        else Graphics_drawPartialImage(50,120, 0,0, 103,16, img_menubutton_level, c_white) end
        gpu_drawtext(180,122, tostring(level_select))
        if invalid_level then
            Graphics_drawImage(180, 140,img_menu_invalid)
        end

        --options
        if menu_selector == 3 then Graphics_drawPartialImage(50,145, 0,16, 103,16, img_menubutton_option, c_white)
        else Graphics_drawPartialImage(50,145, 0,0, 103,16, img_menubutton_option, c_white) end
        --exit
        if menu_selector == 4 then Graphics_drawPartialImage(50,170, 0,16, 103,16, img_menubutton_exit, c_white)
        else Graphics_drawPartialImage(50,170, 0,0, 103,16, img_menubutton_exit, c_white) end

        Graphics_termBlend()

    else --GAMEPLAY \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
        --player controls
        if player_alive==true then
            player_speed = 4
            if beam_id > 0 then player_speed = 2 end
            if (Controls_check(pad,KEY_R)) then
                player_speed = player_speed/2
            end
            if (Controls_check(pad,KEY_DUP)) and player_alive==true then
                player_y = math.max(10,player_y - player_speed)
            end
            if (Controls_check(pad,KEY_DDOWN)) and player_alive==true then
                player_y = math.min(230,player_y + player_speed)
            end
            if (Controls_check(pad,KEY_DLEFT)) and player_alive==true then
                player_x = math.max(10,player_x - player_speed)
            end
            if (Controls_check(pad,KEY_DRIGHT)) and player_alive==true then
                player_x = math.min(390,player_x + player_speed)
            end
            if (Controls_check(pad,KEY_Y)) then --show controls on bottom screen?
                if weapon == 1 then
                    if player_shot > 6 then
                        player_shot = 0
                        object_create(player_x, player_y, 'shot01', img_shot01, shotlist, 180) -- x-3 y-8
                    end
                elseif weapon == 2 then
                    if player_shot > 16 then
                        player_shot = 0
                        object_create(player_x, player_y, 'shot02', img_shot02, shotlist, 180)
                    end
                elseif weapon == 3 then
                    if player_shot > 20 then
                        player_shot = 0
                        object_create(player_x, player_y, 'shot03', img_shot03, shotlist, 180)
                    end
                elseif weapon == 4 then
                    if player_shot > 10 and player_shot < 100000 then
                        player_shot = 100000
                        beam_id = object_create(player_x, player_y, 'shot04', img_shot04, shotlist, 180)
                    end
                elseif weapon == 5 then
                    if player_shot > 18 then
                        player_shot = 0
                        object_create(player_x, player_y, 'shot05', img_shot05, shotlist, 180)
                    end
                end
            elseif Controls_check(oldpad,KEY_Y) then --Y was recently released
                if weapon == 4 and beam_id > -1 then
                    player_shot = 0
                    object_destroy(shotlist, beam_id)
                    beam_id = -1
                end
            end
            if (Controls_check(pad,KEY_X)) and not (Controls_check(oldpad,KEY_X)) and beam_id < 0 then
                weapon = weapon + 1
                if weapon > 5 then weapon = 1 end
            end
        end
        player_shot = player_shot + 1

        Graphics_initBlend(TOP_SCREEN) --\\\\\

        Graphics_drawImage(0, 0, img_bg_game)
        --OBJECT EVENT LIST \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
        --enemy actions
        local i = 0
        while i<enemylist.size do
            local id = ds_list_find_value(enemylist, i)
            local t = obj.type[id]
            local ox = obj.x[id]
            local oy = obj.y[id]

            if t == 'en01' then --enemy ship 1 (targeter)
                if obj.target[id] > 0 then
                    obj.y[id] = oy + (math.cos(math.rad(obj.dir[id]))*2)
                    obj.x[id] = ox + (math.sin(math.rad(obj.dir[id]))*2)
                    obj.target[id] = obj.target[id] - 2
                end
                Graphics_drawImage(obj.x[id]-6, obj.y[id]-6, img_en01)
                obj.clock[id] = obj.clock[id] + 1
                if obj.clock[id] > 100 then
                    obj.clock[id] = 0
                    object_create(ox, oy+4, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y))
                    if difficulty > 5 then
                        object_create(ox, oy+4, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+(30 - difficulty))
                        object_create(ox, oy+4, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-(30 - difficulty))
                    end
                    if difficulty > 10 then
                        object_create(ox, oy+4, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+2*(30 - difficulty))
                        object_create(ox, oy+4, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-2*(30 - difficulty))
                    end
                end
            elseif t == 'en02' then --enemy ship 2 (bomber)
                if obj.target[id] > 0 then
                    obj.y[id] = oy + (math.cos(math.rad(obj.dir[id]))*2)
                    obj.x[id] = ox + (math.sin(math.rad(obj.dir[id]))*2)
                    obj.target[id] = obj.target[id] - 2
                end
                Graphics_drawImage(ox-6, oy-7, img_en02)
                obj.clock[id] = obj.clock[id] + 1
                if obj.clock[id] > 128 then
                    obj.clock[id] = difficulty*5
                    object_create(ox, oy, 'b02', img_bullet02, bulletlist, 180)
                end
            elseif t == 'en03' then --enemy ship 3 (strafer)
                obj.y[id] = oy + (math.cos(math.rad(obj.dir[id]))*0.5)
                obj.x[id] = ox + (math.sin(math.rad(obj.dir[id]))*0.5)
                Graphics_drawImage(ox-10, oy-4, img_en03)
                obj.clock[id] = obj.clock[id] + 1
                if obj.clock[id] > 20 then
                    obj.clock[id] = difficulty/3
                    object_create(ox, oy, 'b03', img_bullet03, bulletlist, 180)
                end
                obj.target[id] = obj.target[id] - 1
                if obj.target[id] < 0 then
                    if not onscreen(ox,oy) then
                        object_destroy(enemylist, id)
                    end
                end
            elseif t == 'bo01' then --boss 01
                local bhp = obj.hp[id]
                if obj.target[id] > 0 then
                    obj.y[id] = oy + 0.25
                    obj.target[id] = obj.target[id] - 0.25
                    if obj.target[id] < 0.25 then
                        obj.hp[id] = stage_boss_hp
                    end
                else
                    obj.clock[id] = obj.clock[id] + 1 --clock doesn't tick if boss isn't onscreen
                end

                Graphics_drawImage(ox-29, oy-16, img_boss01)
                if bhp > 0.66*stage_boss_hp then
                    if obj.clock[id] == 35 then
                        object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y))
                        object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+(25 - difficulty))
                        object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-(25 - difficulty))
                        object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+2*(25 - difficulty))
                        object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-2*(25 - difficulty))
                        if difficulty > 5 then
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+3*(25 - difficulty))
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-3*(25 - difficulty))
                        end
                        if difficulty > 10 then
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+4*(25 - difficulty))
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-4*(25 - difficulty))
                        end
                    elseif obj.clock[id] == 70 then
                        object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+0.5*(25 - difficulty))
                        object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-0.5*(25 - difficulty))
                        object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+1.5*(25 - difficulty))
                        object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-1.5*(25 - difficulty))
                        if difficulty > 5 then
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+2.5*(25 - difficulty))
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-2.5*(25 - difficulty))
                        end
                        if difficulty > 10 then
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+3.5*(25 - difficulty))
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-3.5*(25 - difficulty))
                        end
                    elseif obj.clock[id] > 70 then
                        obj.clock[id] = 1
                    end

                elseif bhp > 0.33*stage_boss_hp then
                    if obj.clock[id] == 50 then
                        local o=0 --please replace the following with a while statement and an incrementally increasing i, for the love of god
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+6*(22 - difficulty)); obj.hp[o]=-0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+4*(22 - difficulty)); obj.hp[o]=-0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+2*(22 - difficulty)); obj.hp[o]=-0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-0*(22 - difficulty)); obj.hp[o]=-0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-2*(22 - difficulty)); obj.hp[o]=-0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-4*(22 - difficulty)); obj.hp[o]=-0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-6*(22 - difficulty)); obj.hp[o]=-0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-8*(22 - difficulty)); obj.hp[o]=-0.5
                        if difficulty > 3 then
                            object_create(ox-18, oy, 'b02', img_bullet02, bulletlist, 0);
                        end
                    elseif obj.clock[id] ==100 then
                        local o=0
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-6*(25 - difficulty)); obj.hp[o]=0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-4*(25 - difficulty)); obj.hp[o]=0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)-2*(25 - difficulty)); obj.hp[o]=0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+0*(25 - difficulty)); obj.hp[o]=0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+2*(25 - difficulty)); obj.hp[o]=0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+4*(25 - difficulty)); obj.hp[o]=0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+6*(25 - difficulty)); obj.hp[o]=0.5
                        o=object_create(ox, oy, 'b01', img_bullet01, bulletlist, angle(ox, oy, player_x, player_y)+8*(25 - difficulty)); obj.hp[o]=0.5
                        if difficulty > 3 then
                            object_create(ox+18, oy, 'b02', img_bullet02, bulletlist, 0);
                        end
                    elseif obj.clock[id] >100 then
                        obj.clock[id] = 1
                    end

                else
                    local cl = obj.clock[id]
                    local sw = 45+difficulty*3 --point at which the rotation direction "switches"
                    local ang = 0.1+(difficulty>>7)
                    if ang*cl < sw then
                        if cl % (15 - math.floor(difficulty/5)) == 0 then
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, ang*cl)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, ang*cl+60)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, ang*cl+120)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, ang*cl+180)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, ang*cl+240)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, ang*cl+300)
                        end
                    else
                        if cl % (15 - math.floor(difficulty/5)) == 0 then
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, 2*sw - ang*cl)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, 2*sw - ang*cl +60)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, 2*sw - ang*cl +120)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, 2*sw - ang*cl +180)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, 2*sw - ang*cl +240)
                            object_create(ox, oy, 'b01', img_bullet01, bulletlist, 2*sw - ang*cl +300)
                        end
                        if ang*cl == 2*sw then
                            obj.clock[id] = 0
                        end
                    end
                end

            end

            i = i+1
        end

        --enemy bullets
        local i = 0
        while i<bulletlist.size do
            local id = ds_list_find_value(bulletlist, i)
            local t = obj.type[id]
            local ox = obj.x[id]
            local oy = obj.y[id]
            if t == 'b01' then
                if not onscreen(ox,oy) then
                    object_destroy(bulletlist, id)
                else
                    obj.y[id] = obj.y[id] + (math.cos(math.rad(obj.dir[id]))*2)
                    obj.x[id] = obj.x[id] + (math.sin(math.rad(obj.dir[id]))*2)
                    Graphics_drawImage(obj.x[id]-1, obj.y[id]-1, img_bullet01)
                    obj.dir[id] = obj.dir[id] + obj.hp[id] --b01 bullets can have a "spin" applied to them
                    --collision check
                    local px = player_x
                    local py = player_y
                    if ox<px+3 and ox>px-3 and oy<py+3 and oy>py-3 then
                        object_destroy(bulletlist, id)
                        player_alive = false
                    end
                end
            elseif t == 'b02' then
                if not onscreen(ox,oy) then
                    object_destroy(bulletlist, id)
                else
                    obj.y[id] = obj.y[id] + 1
                    Graphics_drawImage(obj.x[id]-1, obj.y[id]-5, img_bullet02)
                    --collision check (also, make this bullet explode into more)
                    local px = player_x
                    local py = player_y
                    if ox<px+3 and ox>px-3 and oy<py+6 and oy>py-6 then
                        object_destroy(bulletlist, id)
                        player_alive = false
                    end
                end
            elseif t == 'b03' then
                if not onscreen(ox,oy) then
                    object_destroy(bulletlist, id)
                else
                    obj.y[id] = obj.y[id] +1.5+(difficulty>>3)
                    Graphics_drawImage(obj.x[id]-4, obj.y[id]-3, img_bullet03)
                    --collision check
                    local px = player_x
                    local py = player_y
                    if ox<px+5 and ox>px-5 and oy<py+4 and oy>py-4 then
                        object_destroy(bulletlist, id)
                        player_alive = false
                    end
                end
            elseif t == 'b04' then

            end
            i = i+1
        end

        --friendly bullets
        local i = 0
        while i<shotlist.size do
            local id = ds_list_find_value(shotlist, i)
            local t = obj.type[id]
            local ox = obj.x[id]
            local oy = obj.y[id]
            local shotw = 0
            local shoth = 0
            local speed = 0
            local power = 0
            local graph = img_shot01
            if t=='shot01' then
                shotw = 9; shoth = 3; speed = 8; power = 4; graph = img_shot01
            elseif t=='shot02' then
                shotw = 23; shoth = 6; speed = obj.clock[id]/8; power = 12; graph = img_shot02
                obj.clock[id]=obj.clock[id]+1
            elseif t=='shot03' then
                shotw = 9; shoth = 9; speed = 4; power = 8; graph = img_shot03
            elseif t=='shot04' then
                shotw = 9; shoth = 480; speed = 0; power = 0.3; graph = img_shot04
                ox = player_x
                oy = player_y - 10
            elseif t=='shot05' then
                shotw = 5; shoth = 5; speed = 5; power = 3; graph = img_shot05
            end

            obj.y[id] = oy + (math.cos(math.rad(obj.dir[id]))*speed)
            obj.x[id] = ox + (math.sin(math.rad(obj.dir[id]))*speed)

            if not onscreen(ox,oy) then --once the ship is prevented from leaving bounds, you can remove the latter part of this check
                object_destroy(shotlist, id)
            else
                --collision check
                local j=0
                local range=400; local target=-1; --tracer variables
                while j<enemylist.size do
                    local idc = ds_list_find_value(enemylist, j)
                    local tx=obj.x[idc]
                    local ty=obj.y[idc]
                    if t=='shot05' then --tracer calculations
                        local nr = math.sqrt((tx-ox)^2 + (ty-oy)^2)
                        if range > nr then
                            range = nr
                            target = idc
                        end
                    end
                    if ox<tx+8+(shotw/2) and ox>tx-8-(shotw/2) and oy<ty+8+(shoth/2) and oy>ty-8-(shoth/2) then
                        obj.hp[idc] = obj.hp[idc] - power
                        if obj.hp[idc] < 1 then
                            local dty = obj.type[idc]
                            if dty == 'en01' or dty == 'en02' or dty == 'en03' then
                                object_create(tx, ty, 'end', img_en_death, fxlist)
                            elseif dty == 'bo01' then
                                object_create(tx, ty, 'bod', img_boss_death, fxlist)
                            end
                            object_destroy(enemylist, idc)
                        end
                        if t~='shot04' then --beam continues to hit, so we don't delete it yet unlike other bullets
                            object_destroy(shotlist, id)
                            target = -1
                            j=enemylist.size
                        end
                    end
                    j=j+1
                end
                if target>0 then --turning to face a close target
                    local ang = angle(ox,oy, obj.x[target], obj.y[target])
                    local fac = obj.dir[id]
                    local off = ((ang-fac+180)%360)-180
                    obj.dir[id]=obj.dir[id] + (off / math.abs(off))
                end

                Graphics_drawImage(math.floor(ox-shotw/2), math.floor(oy-shoth/2), graph)
                --end collision check
            end
            i = i+1
        end
        --effects handling
        local i = 0
        while i<fxlist.size do
            local id = ds_list_find_value(fxlist, i)
            local g = obj.graphic[id]
            local t = obj.type[id]
            local ox = obj.x[id]
            local oy = obj.y[id]
            local cl = obj.clock[id]
            local fxw = 0
            local fyh = 0
            if t== 'end' then fxw = 11; fyh = 11;
            elseif t=='bod' then fxw=49; fyh= 19; end

            Graphics_drawPartialImage(math.floor(ox-fxw/2), math.floor(oy-fyh/2), math.floor(cl)*fxw, 0, fxw,fyh, g)
            if cl>6 then
                object_destroy(fxlist, id)
            else
                obj.clock[id] = cl + 0.125
            end
            i=i+1
        end

        --reading data from level array
        local morespawn = true
        while morespawn == true do
            if larray.time[spawnindex] == nil then
                morespawn = false
                stage_clear = 0
            elseif (larray.time[spawnindex] < timer) then
                local ty = larray.enid[spawnindex]
                local D = larray.dir[spawnindex]
                local P = larray.pix[spawnindex]

                local nx =0
                local ny =0
                local dmov=0

                if D == "T" then
                    nx = P
                    ny = -30
                    dmov = 0
                else
                    ny = P
                    if D == "L" then
                        nx = -30
                        dmov = 90
                    else
                        nx = 430
                        dmov = 270
                    end
                end

                local img_ = -1
                local hp_ = -1
                local targ_ = -1
                local spawn_ = -1

                if ty == 'en01' then
                    img_ = img_en01
                    hp_ = 6
                    targ_ = 60
                    spawn_ = 1
                elseif ty == 'en02' then
                    img_ = img_en02
                    hp_ = 14
                    targ_ = 60
                    spawn_ = 1
                elseif ty == 'en03' then
                    img_ = img_en03
                    hp_ = 10
                    targ_ = 60
                    spawn_ = 1
                elseif ty == 'bo01' then
                    stage_boss = ty
                    stage_boss_hp = 300
                    warning_flash = 1
                end

                if spawn_ == 1 then
                    local o = object_create(nx, ny, ty, img_, enemylist, dmov)
                    obj.hp[o] = hp_
                    obj.target[o] = targ_
                end

                spawnindex = spawnindex + 1
            else
                morespawn = false
            end
        end

        --player sprite and death animation
        if player_alive == true then
            Graphics_drawImage(math.floor(player_x-11.5), math.floor(player_y-9), img_ship01)
        elseif player_death < 4 then
            Graphics_drawPartialImage(math.floor(player_x-16.5), math.floor(player_y-16.5), math.floor(player_death)*33, 0, 33,33, img_ship_death)
            player_death = player_death + 0.125
        end

        if warning_flash > 0 then
            warning_flash = warning_flash + 1
            if warning_flash % 30 > 8 then
                Graphics_drawImage(174, 115, img_warning)
            end
            if warning_flash > 120 then
                warning_flash = 0
                local o = object_create(200, -100, 'bo01', img_boss01, enemylist, 0)
                obj.hp[o] = 9999
                obj.target[o] = 150
            end
        end

        if stage_clear == 0 then
            if enemylist.size < 1 then
                stage_clear = 1
            end
        elseif stage_clear == 1 then
            Graphics_drawImage(161, 112, img_clear)
        end

        timer = timer + 1
        Graphics_termBlend()

        if (Controls_check(pad,KEY_START)) and not (Controls_check(oldpad,KEY_START)) then
            menu_init()
        end
    end

    Screen_flip()
    oldpad = pad
end