-- test application for table tracker
-- draws a cursor for each device that is placed on the table.
-- see do_timer() for code that parses tracker update messages

new_x, new_y, new_a = 0, 0, 0

myport = 7000

device = {}

function create_scene()
    camera = E.create_camera(E.camera_type_orthogonal)
    pivot  = E.create_pivot()
   
    E.parent_entity(pivot, camera)

    dsp_x0, dsp_y0, dsp_w, dsp_h = E.get_display_union()
    
    E.set_entity_position(pivot, dsp_x0 + dsp_w/2, dsp_y0 + dsp_h/2, 0)

    brush_line = E.create_brush()
    brush_fill = E.create_brush()

    E.set_brush_color(brush_line, 0.2, 0.2, 0.5, 1.0)
    E.set_brush_color(brush_fill, 0.8, 0.8, 0.8, 1.0)
end

function mark_sprite(id)

    local id_string  = E.create_string(string.format("%d", id))
    local pivot      = E.create_pivot ()

    E.set_entity_scale   (id_string, 32, 32, 32)
    E.set_entity_position(id_string, 96, 96, 0 )
    
    E.set_string_line    (id_string, brush_line)
    E.set_string_fill    (id_string, brush_fill)

    E.parent_entity(id_string, pivot)

    return pivot
end

function make_sprite(filename, trans, unlit )
    local image = E.create_image(filename)
    local brush = E.create_brush()

    E.set_brush_flags(brush, E.brush_flag_transparent, trans)
    E.set_brush_flags(brush, E.brush_flag_unlit,       unlit)

    E.set_brush_color(brush, 1.0, 1.0, 1.0, 1.0)
    E.set_brush_image(brush, image)

    local sprite = E.create_sprite(brush)
    E.set_entity_position(sprite, -128, -128, 0)

    return E.create_sprite(brush)
end

function show_device(dev, type)
    for i=1, 3 do
	E.set_entity_flags(dev[i], E.entity_flag_hidden, not (i == type))
    end
end

function do_timer(dt)

    local update = false

    while TT.poll(0) do
        
        local stat, msg_id, msg_xpos, msg_ypos, msg_angle, msg_type = TT.get()

        if stat == TT.OK then
            update = true

            E.print_console("received: " .. msg_id .. 
                            ", " .. msg_xpos ..
                            ", " .. msg_ypos ..
                            ", " .. msg_angle ..
                            ", " .. msg_type .. "\n") 
            
            -- if received a message for a new device, create the device
            
            if not device[msg_id] then
                local id   = msg_id
                device[id] = {}
                
                device[id][1] = make_sprite("data/mark.png",       true, true)
                device[id][2] = make_sprite("data/mark_left.png",  true, true)
                device[id][3] = make_sprite("data/mark_right.png", true, true)
                device[id].id = mark_sprite(id)
                device[id].pv = E.create_pivot()
                    local dgram

                E.parent_entity(device[id][1], device[id].pv)
                E.parent_entity(device[id][2], device[id].pv)
                E.parent_entity(device[id][3], device[id].pv)
                E.parent_entity(device[id].id, device[id].pv)
                
               E.parent_entity(device[id].pv, pivot)
           end
           
           show_device(device[msg_id], msg_type)

           -- update location of device
           
           new_x = msg_xpos * dsp_w + dsp_x0
           new_y = msg_ypos * dsp_h + dsp_y0
           new_a = msg_angle

           local x, y, a = new_x, new_y, new_a

           E.set_entity_rotation(device[msg_id].pv, 0, 0, a)
           E.set_entity_position(device[msg_id].pv, x, y, 0)

       end
   end
   
   return update

end

function do_start()
    create_scene()
    
    E.set_typeface("data/VeraBd.ttf", 0.0001, 0.03125)

    -- Open port to listen for track data

    TT.open(myport)

    E.enable_timer(true)
end

do_start()