На элементе холста я буду создавать ориентировочную точку окружности при каждом щелчке и соединять точки при каждом создании новой точки.
var canvas = new fabric.Canvas("canvas");
var waterPipePoints = [];
var waterPipeLines = [];
canvas.on("mouse:down", function(event) {
var pointer = canvas.getPointer(event.e);
var positionX = pointer.x;
var positionY = pointer.y;
// Add small circle as an indicative point
var circlePoint = new fabric.Circle({
radius: 5,
fill: "blue",
left: positionX,
top: positionY,
selectable: false,
originX: "center",
originY: "center",
hoverCursor: "auto"
});
canvas.add(circlePoint);
// Store the points to draw the lines
waterPipePoints.push(circlePoint);
console.log(waterPipePoints);
if (waterPipePoints.length > 1) {
// Just draw a line using the last two points, so we don't need to clear
// and re-render all the lines
var startPoint = waterPipePoints[waterPipePoints.length - 2];
var endPoint = waterPipePoints[waterPipePoints.length - 1];
var waterLine = new fabric.Line(
[
startPoint.get("left"),
startPoint.get("top"),
endPoint.get("left"),
endPoint.get("top")
],
{
stroke: "blue",
strokeWidth: 4,
hasControls: false,
hasBorders: false,
selectable: false,
lockMovementX: true,
lockMovementY: true,
hoverCursor: "default",
originX: "center",
originY: "center"
}
);
waterPipeLines.push(waterLine);
canvas.add(waterLine);
}
});
canvas.renderAll();
Пожалуйста, проверьте этот пример SandBox: https://codesandbox.io/s/stackoverflow-60753858-fabric-js-1720-26twl