actors={
    list={},
    updating=false,

    add=function(actor)
        actor.dx,actor.dy=0,0
        table.insert(actors.list, actor)
    end,

    remove=function(name)
        for i,v in ipairs(actors.list) do
            if v.name and v.name==name then
                table.remove(actors.list,i)
                return
            end
        end
    end,

    search=function(name)
        for i,v in ipairs(actors.list) do
            if v.name and v.name==name then
                return v
            end
        end
    end,

    draw=function()
        for i,v in ipairs(actors.list) do
            local frame=((v.dx+v.dy)%2)*16
            if v.o=='u' then
                sspr(v.gfx.x+frame,v.gfx.y+16,16,16,v.x*8-4+v.dx*2,v.y*8-12+v.dy*2,16,16,v.dy>1)
            elseif v.o=='d' then
                sspr(v.gfx.x+frame,v.gfx.y,16,16,v.x*8-4+v.dx*2,v.y*8-12+v.dy*2,16,16,-v.dy>2)
            elseif v.o=='l' then
                sspr(v.gfx.x+frame,v.gfx.y+32,16,16,v.x*8-4+v.dx*2,v.y*8-12+v.dy*2,16,16)
            elseif v.o=='r' then
                sspr(v.gfx.x+frame,v.gfx.y+32,16,16,v.x*8-4+v.dx*2,v.y*8-12+v.dy*2,16,16,true)
            end
        end
    end,

    update=function()
        if actors.updating then return end
        actors.updating=true

        local needs_sorting=false
        for i,v in ipairs(actors.list) do
            if v.dx==0 and v.dy==0 then
                if v.path then
                    if v.path.pos == #v.path.route then
                        local in_scene = not v.path.keys
                        v.path=nil
                        game.update()
                        if in_scene then scene.cont() end
                        v.keys=nil
                        if v.name == actors.hero then
                            local switch = switches.search(v.x,v.y)
                            if switch then switch.action() end
                        end
                    end
                    if v.path and v.path.pos ~= #v.path.route then
                        v.path.pos=v.path.pos+1
                        local step=string.sub(v.path.route,v.path.pos,v.path.pos)
                        if step=='u' then
                            v.o='u'
                            --check collision!
                            v.y=v.y-1
                            v.dy=4
                            needs_sorting=true
                        elseif step=='d' then
                            v.o='d'
                            --check collision!
                            v.y=v.y+1
                            v.dy=-4
                            needs_sorting=true
                        elseif step=='l' then
                            v.o='l'
                            --check collision!
                            v.x=v.x-1
                            v.dx=4
                        elseif step=='r' then
                            v.o='r'
                            --check collision!
                            v.x=v.x+1
                            v.dx=-4
                        elseif step=='q' then
                            v.o='u'
                        elseif step=='a' then
                            v.o='d'
                        elseif step=='o' then
                            v.o='l'
                        elseif step=='p' then
                            v.o='r'
                        end
                    end
                end
            end
            if v.dx > 0 then
                v.dx=v.dx-1
            elseif v.dx < 0 then
                v.dx=v.dx+1
            elseif v.dy > 0 then
                v.dy=v.dy-1
            elseif v.dy < 0 then
                v.dy=v.dy+1
            end
        end
        if needs_sorting then
            table.sort(actors.list, compare_actors)
        end

        actors.updating=false
    end

}
function compare_actors(a,b)
    return a.y < b.y
end