​

function setup() {

  createCanvas(700, 400);

  for(let i = 0; i < 3; i++){

    points.push(createVector(random(0,width), random(0,height)));

  } 

  // # GRID SETTINGS

  let maxCellSize = 10;

  let subdivX = ceil(width / maxCellSize) - 1; // number of x subdivisions

  let subdivY = ceil(height / maxCellSize) - 1; // number of y subdivisions

  let sX = subdivX + 1; // number of columns

  let sY = subdivY + 1; // number of rows

  // # CREATE GRID

  let flatgrid = [];

  // # INSERT POINTS IN GRID

  for(let i = 0 ; i < points.length ; i++){

    // check in which x axis

    let x = ceil(map(points[i].x, 0 , width, 0, sX)); 

    // check in which y axis

    let y = ceil(map(points[i].y, 0 , height, 0, sY));

    // calculate cell id

    let id =  ( (y - 1) * sX + x ) - 1;

​

    // insert into flat grid    

    flatgrid.push(id, points[i].x, points[i].y, 0);

  }

  // # DRAW POINTS

  for(let i = 0 ; i < points.length ; i++){

    circle(points[i].x, points[i].y, 10);

  }

  // # define circle

  stroke(0,255,0);

  noFill();

  let cx = width/2 + 30;

  let cy = height/2 + 30;

  let radius = 150;

  circle(cx, cy, radius * 2);

  // # print grid array

  //print(flatgrid);

  // # DRAW GRID

  let RectWidth = width / sX;

  let RectHeight = height / sY;

  let RectXFit = floor( ( radius * 2 ) / RectWidth ) + 2; // cb de rectangle entier, + 2 pour les bords

  let RectYFit = floor( ( radius * 2 ) / RectHeight ) + 2;

  let xRange = ( (RectXFit % 2 == 0) ? RectXFit + 1 : RectXFit); // convert to odd number

  let yRange = ( (RectXFit % 2 == 0) ? RectYFit + 1 : RectYFit); // convert to odd number

  intersection = getRects(cx, cy, sX, sY, xRange, yRange) // get intersecting rects

  console.log(intersection);

  for(let i = 0 ; i < sX * sY ; i++){

    let RectX =  ( i % sX ) * RectWidth;

    let RectY = floor( i / sX ) * RectHeight;

    if(intersection.includes(i)){

      stroke(0,255,0);

    }

    else{

      stroke(0);

    }

    rect(RectX, RectY, RectWidth, RectHeight);

  }

}

​

function getRects(cx, cy, sX, sY, xRange, yRange){

  // calculate the id of the rectangle that contains the circle

  let x = ceil(map(cx, 0 , width, 0, sX)); 

    // check in which y axis

  let y = ceil(map(cy, 0 , height, 0, sY));

    // calculate cell id

  let id =  ( (y - 1) * sX + x ) - 1;

  // calculate all other 

  let results = [];

  //console.log(id);

  //console.log(ceil(- xRange/2));

  //console.log(floor(xRange/2));

  for(let i =  ceil(- xRange / 2) ; i < ceil( xRange / 2 ) ; i++){

    for(let j = ceil(- yRange / 2) ; j < ceil( yRange / 2 ) ; j++){

      let intersection = id + i + j * sX;

      if(intersection > 0 && intersection < sX * sY){

        results.push(intersection);

      }

    }

  }

  console.log(xRange* yRange)

  return results; 

}

​

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​

​