// Define the id of your board in BOARDID
const board = JXG.JSXGraph.initBoard(BOARDID, {boundingbox:[-4,4,4,-4], keepaspectratio:true, axis:true});
var A = board.create('point', [-3,3]);
var B = board.create('point', [3,-2]);
var line = board.create('segment', [A,B]);
var height = 0.5; // height of the curly bracket
// Build the curly bracket
var crl = board.create('curve', [[0],[0]], {strokeWidth:1, strokeColor:'black'});
crl.bezierDegree = 3;
crl.updateDataArray = function() {
var d = [B.X() - A.X(), B.Y() - A.Y()],
dl = Math.sqrt(d[0] * d[0] + d[1] * d[1]),
mid = [(A.X() + B.X()) * 0.5, (A.Y() + B.Y()) * 0.5];
d[0] *= height / dl;
d[1] *= height / dl;
this.dataX = [ A.X(), A.X() - d[1], mid[0], mid[0] - d[1], mid[0], B.X() - d[1], B.X() ];
this.dataY = [ A.Y(), A.Y() + d[0], mid[1], mid[1] + d[0], mid[1], B.Y() + d[0], B.Y() ];
};
// Text
var txt = board.create('text', [
function() {
var d = [B.X() - A.X(), B.Y() - A.Y()],
dl = Math.sqrt(d[0] * d[0] + d[1] * d[1]),
mid = (A.X() + B.X()) * 0.5;
d[1] *= height / dl;
return mid - d[1] + 0.1;
},
function() {
var d = [B.X() - A.X(), B.Y() - A.Y()],
dl = Math.sqrt(d[0] * d[0] + d[1] * d[1]),
mid = (A.Y() + B.Y()) * 0.5;
d[0] *= height / dl;
return mid + d[0] + 0.1;
},
() => 'length=' + B.Dist(A).toFixed(2)
]);
board.update(); // This update is necessary to call updateDataArray the first time.