Player Position Relative to a Specific X and Y

[BlueScope]

Okay, since the title's fucked up again, lemme picture it...

http://img262.imageshack.us/img262/5021/schemern7.jpg[/img]

I try to make the player character look into the direction of a specific object. Picture [1] shows what I have with the code in the following spoiler: The player changes his view according to the position of the respective object, but in a way that'd work for isometric movement; for example, if the object is in the lower-right part of the screen, the player looks down.

Spoiler: turn_towards_object Definition

  def turn_towards_object
    if @object.screen_x >= self.screen_x
      if @object.screen_y >= self.screen_y
        turn_down
      else
        turn_right
      end
    else
      if @object.screen_y >= self.screen_y
        turn_up
      else
        turn_left
      end
    end
  end

Picture [2] shows what I want to get: If the object is 'more in a specific direction than in another' (worst explanation ever, but the picture should do that job), the player should look there.

Thanks in advance.

 

[entrando2]

Change your code for this one:

  def turn_towards_object
    angle = Math.atan2(-(@object.screen_y - self.screen_y),
      @object.screen_x - self.screen_x) * 180 / Math::PI
    if (angle >=-135) && (angle <-45)
      turn_down
    else
      if (angle >=-45) && (angle <45)
        turn_right
      else
        if (angle >=45) && (angle <135)
          turn_up
        else
          if (angle >=135) || (angle < -135)
            turn_left
          end
        end
      end
    end
  end

I don't know how you want to look your PJ if the object it's exactly in a diagonal. To change that, change the >= for > and < for <=.

Final note:
If the PJ looks down when it should look up and viceversa, change the second line to:
angle = Math.atan2((@object.screen_y - self.screen_y),

 

[BlueScope]

The one inbetween your code tags works like a charm, but one last question (I'm not the newest guy to RGSS, but those math stuff is really my weak point):
Can I somehow include an if-statement to only trigger that if the player is about 64px away from @object... just in case you wonder, @object has a pixel-based movement I tried to ebrace the whole code above (without the def-line, of course ) with this conditional:

  def turn_towards_cursor_position
    x_value = (@object.screen_x - self.screen_x).abs
    y_value = (@object.screen_y - self.screen_y).abs
    if x_value > 64 and y_value > 64
      # ...
    end
  end

Didn't work because it scans the whole horizontal and vertical area, and I kinda want only a circle area... well, a rectangular would do the job as well.

Also, thanks up to this point, of course ^^

 

[Zeriab]

Certainly you can.
Just use this, and you don't even have to care about using the absolute values.

if x_value*x_value + y_value*y_value > 64*64
  # ...
end

I have not tested it, but this might do the trick:

  def turn_towards_cursor_position
    x_value = @object.screen_x - self.screen_x
    y_value = @object.screen_y - self.screen_y
    if x_value*x_value + y_value*y_value > 64*64
      if x_value > 0
        if y_value > x_value
          turn_down
        elsif y_value < -x_value
          turn_up
        else
          turn_right
        end
      else
        if y_value > -x_value
          turn_down
        elsif y_value < x_value
          turn_up
        else
          turn_left
        end
      end
    end
  end

The turns may be inverted, though I am sure you know what to do in that case ^_^

 

[BlueScope]

Works perfectly... thanks, dube :p