i m creating a virtual wind vane on processing using a potentiometer .Using an Arduino for the same .

So the data to the processing program would be a number between 0 and 360 ( 0 corresponds to north exact ).

Say 0 is North exactly ,so a line starting from origin will point to 0 on a background picture of a degree wheel Im using .

I want the line to rotate by an angle according to the incoming data .

One way of doing this is to  find the co-ordinates where i want the line to end on the picture and use switch() .But this makes the program too long .....imagine 360 cases .

Please tell me if u have an alternate idea to implement this .I hav included a sample code using switch() that I tried out and also the picture.
Thanks!!!

1. int i=0;
   PImage img;
    
   void setup()
   {
     size(500,500);
     img = loadImage("degree-wheel.png");
   }
   
   void draw()
   {
     println(mouseX);
     println(mouseY);
      image(img, 0, 0);
      i++;
      drawNow();
      delay(1000);
   }
   
      void drawNow()
     {
       if(i>4)
       {
        i=0;
       }
       switch(i)
     {
     case 1:
       line(250, 250, 249, 5);
        break;
     case 2:
       line(250, 250, 292, 9);
        break;
       case 3:
       line(250, 250, 372, 38);
        break;
       case 4:
       line(250, 250, 407, 62);
        break;
   }
    }