Rotation of picture

[wlzza]

Hi there, I'm trying to make a compass for my game using VX. I need to know what is the command for rotating a picture to a certain angle but on it's centre x y. So far this is what i have figured out...

@pic = Sprite.new

@pic.bitmap = Cache.picture("Compass")

@pic.ox = @pic.bitmap.width / 2

@pic.oy = @pic.bitmap.height / 2

@pic.x = 100

@pic.y = 100

Now how to rotate it to eg. 90degrees?

Thanks in advance.

 

[khmp]

@pic.angle = 90

I believe that's all you need. Moving the draw point to the center you already have. Is there a problem that you have with the above line or didn't you know about it?

Good luck with your compass wlzza! :thumb:

 

[Jason]

@pic.angle = 90

I believe that's all you need. Moving the draw point to the center you already have. Is there a problem that you have with the above line or didn't you know about it?

Good luck with your compass wlzza! :thumb:

Would there be any way to do that on XP ? Would it be the same syntax or something different ?

 

[khmp]

Nope. The syntax is the same. Sprite.angle = angle for VX and XP.

 

[wlzza]

Is it possible to actually see it rotate? For instance, takes about 5 frames to rotate to 90 degrees.

 

[Jason]

Well if you know how to make a wait command in RGSS2, I suppose you could do;

wait 1 frames
rotate 10 degrees
wait 1 frame
rotate 10 degrees

Although I don't know how to do wait commands with scripting, so I can't help. (Besides, there's probably a more logical way of doing it, lol)

 

[khmp]

Some psuedo code for ya. I think the math should work but let me know.

class Wlzza_Compass

 

  Frames_To_Rotate = 5

 

  ... # Other code

 

  def update

 

    if @frames_left > 0

      degrees_to_move = @pic.angle - @destination_angle / Frames_To_Rotate

      @pic.angle += degrees_to_move

      @frames -= 1

    else

      # Just in case the division leaves a remainder

      @pic.angle = @destination_angle if @pic.angle != @destination_angle

    end

 

    ... # Other code

 

  end

 

  ... # Other code

 

  def initialize_rotate( destination_angle )

    @destination_angle = destination_angle

    @frames_left = Frames_To_Rotate

  end

end

 

[wlzza]

Thanks! Hmmmm.. the picture kinda distorts after it finished its rotation. I guess I have to think of a "graphical" way out of this...