Hello

Trying to modify the example script on simple curves in the learning section to take a line from an image on screen and copy it into the form of a full circle with the aim of ultimately making a rectangular image into a circle / disc (sort of a polar coordinates effect).  No problem reiterating through the source image from top left to bottom right however I'm not to sure of the math to calculate the curve (which later will need to increase in radius pixel by pixel).  Seem to remember curves are culated with pi but beyond that I'm not sure where to start and simply keep getting diagonal lines.  Below is where I am (which does not work because vsa is a float) anyone able to help me with this math / whats the ratio to move down and accross by each loop??

a+
gar

PImage v_image;
float vsa;

void setup()
{
 size(700, 800);
 background(0);
 noLoop();
 
 //loadimage
 v_image = loadImage("rock1.jpg");
 image(v_image, 100, 20);
}



void draw()
{
 for(int i = 0; i < v_image.width; i++)
 {
   //vsa = (vsa - 0.5) * 1.8; //scale from -2 to 2
   //vsa = vsa * vsa;
   //if(vsa > 1) { vsa = 1; }

   copy(v_image, i + 1, 1, 1, 1, 100 + i, vsa, 1, 1);
 }
}