local camx
local camy

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

local function camera()
    camx = memory.readword(0x1E16)
    camy = memory.readword(0x1E18)
end

local function player()
    local sword = 0x19C0
    local x = memory.readword(0x19A4 + 2) - camx
    local y = memory.readword(0x19A4 + 4) - camy
    local xrad = memory.readbyte(0x019BA)
    local yrad = memory.readbyte(0x019BC)
    gui.box(x+xrad,y+yrad,x-xrad,y-yrad,"#0000FF30","#0000FFFF")

    -- Player sword:
    if memory.readbyte(sword + 0xE) ~= 0 then
        x = memory.readword(sword + 2) - camx
        y = memory.readword(sword + 4) - camy
        xrad = memory.readbyte(sword + 0x16)
        yrad = memory.readbyte(sword + 0x18)
        gui.box(x+xrad,y+yrad,x-xrad,y-yrad)
    end

    gui.text(x,y,"P")
end

local function objects()
    for i = 2,31,1 do
        local obase = memory.readword(0x83136E + (i * 2))
        local otype = memory.readword(obase)
        if obase ~= 0 then
            if memory.readbyte(obase + 0x0E) and memory.readword(obase) ~= 01 then
                local x = memory.readword(obase + 2) - camx
                local y = memory.readword(obase + 4) - camy
                local xrad = memory.readbyte(obase + 0x16)
                local yrad = memory.readbyte(obase + 0x18)

                gui.box(x+xrad,y+yrad,x-xrad,y-yrad,"#FF000030","#FF0000FF")
                --gui.text(x,y,"E" .. i .. "/" .. hex(obase) .. "/" .. hex(memory.readword(obase)))

            end
        end
    end

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

            if pj_type == 0x81 then
                pj_xrad = 4
                pj_yrad = 4
                gui.box(pj_x+pj_xrad,pj_y+pj_yrad,pj_x-pj_xrad,pj_y-pj_yrad,"#FF000030","#FF0000FF")
            elseif pj_type == 1 then -- Player's bullets
                pj_xrad = 4
                pj_yrad = 4
                gui.box(pj_x+pj_xrad,pj_y+pj_yrad,pj_x-pj_xrad,pj_y-pj_yrad)
            end
        end
    end

end

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