How to get touch on one side of screen? (SOLVED)

Questions
3

You can do this from both script components and gui script components. First you need to acquire input so that the script gets calls to it’s on_input function:

function init(self)
    msg.pos(".", "acquire_input_focus")
end

Once you have acquired input focus you will start seeing calls to your on_input() function:

function on_input(self, action_id, action)
     print("I was called with action_id", action_id)
     pprint(action)
end

Any action you define in your input bindings will be passed along as the action_id to the input function when it’s triggered. Touch and mouse button one will be sent with action_id “touch”.

function on_input(self, action_id, action)
     if action_id == hash("touch") and action.pressed then
         print("You touched", action.x, action.y)
         -- action.screen_x and action.screen_y are translated screen coordinates
     end
end

You can read the screen dimensions in two ways:

  1. Get the value from game.project using sys.get_config("display.width") and sys.get_config("display.height"). This will not get updated values if the screen was resized.
  2. Use a custom render script and read render.get_window_width() and render.get_window_height()? to the get the current window dimensions. Do a msg.post() of these values or store them in a shared module for easy access from your script files.

So, to wrap this up I think it’s enough to use the first of the two ways to get screen size and compare that value with the x and y coordinate where the user touched/clicked:

function on_input(self, action_id, action)
     if action_id == hash("touch") and action.pressed then
         if action.x > tonumber(sys.get_config("display.width")) / 2 then
             -- right
         else
             -- left
         end
     end
end

Read more about how input is handled in Defold here.

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