local camx
local camy
local HPDISPLAY = true

function findbit(p)
    return 2 ^ (p - 1)
end

function hasbit(x, p)
    return x % (p + p) >= p
end

local function hex(val)
    val = string.format("%X",val)
    if string.len(val) == 1 then
        val = "0" .. val
    end
    return val
end

memory.usememorydomain("BUS")

local function camera()
    camx = mainmemory.read_u16_le(0x1E16)
    camy = mainmemory.read_u16_le(0x1E18)
end

local function player()
    local sword = 0x19C0
    local x = mainmemory.read_u16_le(0x19A4 + 2) - camx
    local y = mainmemory.read_u16_le(0x19A4 + 4) - camy
    local xrad = mainmemory.read_u8(0x019BA)
    local yrad = mainmemory.read_u8(0x019BC)
    gui.drawBox(x+xrad,y+yrad,x-xrad,y-yrad,0xFF0000FF,0x300000FF) -- blue

    -- Player sword:
    if mainmemory.read_u8(sword + 0xE) ~= 0 then
        x = mainmemory.read_u16_le(sword + 2) - camx
        y = mainmemory.read_u16_le(sword + 4) - camy
        xrad = mainmemory.read_u8(sword + 0x16)
        yrad = mainmemory.read_u8(sword + 0x18)
        gui.drawBox(x+xrad,y+yrad,x-xrad,y-yrad,0xFFFFFFFF,0x30FFFFFF) -- white
    end
end

local function findhp(base)
    local offset = mainmemory.read_u8(base + 0xC)
    local ptr = memory.read_u16_le(0x838010 + offset)
    local hp = mainmemory.read_u16_le(ptr + 0x22)
    return hp
end

local function objects()
    for i = 2,31,1 do
        local obase = mainmemory.read_u16_le(0x136E + (i * 2))
        local otype = mainmemory.read_u16_le(obase)

        if obase ~= 0 then
            if mainmemory.read_u8(obase + 0x0E) ~= 0 and mainmemory.read_u16_le(obase) ~= 01 and obase ~= 0x19A4 then
                local x = mainmemory.read_u16_le(obase + 2) - camx
                local y = mainmemory.read_u16_le(obase + 4) - camy
                local xrad = mainmemory.read_u8(obase + 0x16)
                local yrad = mainmemory.read_u8(obase + 0x18)
                gui.drawBox(x+xrad,y+yrad,x-xrad,y-yrad,0xFFFF0000,0x30FF0000)
                if HPDISPLAY == true then
                    local hp = findhp(obase)
                    gui.text(x,y,"HP:" .. hp)
                end
            end
        end
    end

    local pjbase
    --projectiles
    for i = 0,31, 1 do
        pjbase = 0x1BD4 + (0x12 * i)
        local pj_type = mainmemory.read_u8(pjbase)
        local pj_xrad = 0
        local pj_yrad = 0
        if pj_type > 0 then
            local pj_x = mainmemory.read_u16_le(pjbase + 2) - camx
            local pj_y = mainmemory.read_u16_le(pjbase + 4) - camy

            if pj_type == 0x81 or pj_type == 1 then
                pj_xrad = 4
                pj_yrad = 4
                gui.drawBox(pj_x+pj_xrad,pj_y+pj_yrad,pj_x-pj_xrad,pj_y-pj_yrad,0xFFFF0000,0x30FF0000) -- red
            else
                pj_xrad = mainmemory.read_u8(pjbase + 0x16)
                pj_yrad = mainmemory.read_u8(pjbase + 0x18)
                gui.drawBox(pj_x+pj_xrad,pj_y+pj_yrad,pj_x-pj_xrad,pj_y-pj_yrad,0xFFFFFFFF,0x30FFFFFF) -- white
            end
        end
    end

end

while true do
    camera()
    player()
    objects()
    emu.frameadvance()
end