src/ol/interaction/Extent.js
function(point) {
      let x_ = null;
      let y_ = null;
      if (point[0] == extent[0]) {
        x_ = extent[2];
      } else if (point[0] == extent[2]) {
        x_ = extent[0];
      }
      if (point[1] == extent[1]) {
        y_ = extent[3];
      } else if (point[1] == extent[3]) {
        y_ = extent[1];
      }
      if (x_ !== null && y_ !== null) {
        return [x_, y_];
      }
      return null;
    }
function(point) {
      let x_ = null;
      let y_ = null;
      if (point[0] == extent[0]) {
        x_ = extent[2];
      } else if (point[0] == extent[2]) {
        x_ = extent[0];
      }
      if (point[1] == extent[1]) {
        y_ = extent[3];
      } else if (point[1] == extent[3]) {
        y_ = extent[1];
      }
      if (x_ !== null && y_ !== null) {
        return [x_, y_];
      }
      return null;
    }
function ( point ) { let x_ = null ; let y_ = null ; if ( point [ 0 ] == extent [ 0 ] ) { x_ = extent [ 2 ] ; } else if ( point [ 0 ] == extent [ 2 ] ) { x_ = extent [ 0 ] ; } if ( point [ 1 ] == extent [ 1 ] ) { y_ = extent [ 3 ] ; } else if ( point [ 1 ] == extent [ 3 ] ) { y_ = extent [ 1 ] ; } if ( x_ !== null && y_ !== null ) { return [ x_ , y_ ] ; } return null ; }
find the extent corner opposite the passed corner
find the extent corner opposite the passed corner