reading image in circle area

tady

Hi. i'm finding a way to read image in a circle area. I'm working with pixels from image and using their RGB values to create sound. In this moment i need to find some way how to read only some circle area from that image. I asked uncle Google, but i didn't find anything what worked for me. I found something with a function dist() and mouse position, but i don't know how to use it. Sorry, if my english is bad, i'm learning it.

tady

now i'm using this. i don't know how to set if() for x and y for a circle

  x+=2;
  if (x>500) {
    x=0;
    y+=2;
  }
  if (y>=490) {  //restart
    x=0;
    y=0;
  }

  int loc=x+y*500;
  r=red(img.pixels[loc]);
  g=green(img.pixels[loc]);
  b=blue(img.pixels[loc]);

GoToLoop

https://forum.Processing.org/two/discussion/15921/how-to-enumerate-the-pixels-in-a-region-defined-by-a-particular-ellipse

tady

Thank you!

tady

well, i have this. it's there some way how to move the x and y only in the circle? i didn't find any solution.

int x, y, radius;

void setup() {
  size(400, 400);
  radius=180;
}

void draw() {
  x+=1;
  if (x>width) {
    x=0;
    y+=1;
  }
  if (dist(x, y, width/2, height/2)<radius) {
    stroke(255, 0, 0);
  } else {
    stroke(0, 255, 0);
  }
  point(x, y);
  println(x, y);
  }
}