How to make rounded-perpendicular lines with react-konva? - konvajs

Question

I need to make rounded-perpendicular lines with react-konva, is it achievable using existing APIs? If yes, how?
I used bezier API for Line class, it works great. Somehow now I need to revamp the bezier curve to be rounded-perpendicular lines.
Sth like this:

Answer 1

There are many ways you can implement it. You can use tension to create curved lines or use lineCap property.
But to have more control it is better to create a custom shape.
const RADIUS = 20;
const Line = ({ points }) => {
return (
<Shape
points={points}
sceneFunc={(context, shape) => {
const width = points[1].x - points[0].x;
const height = points[1].y - points[0].y;
const dir = Math.sign(height);
const radius = Math.min(RADIUS, Math.abs(height / 2), Math.abs(width / 2));
context.beginPath();
context.moveTo(points[0].x, points[0].y);
context.lineTo(points[0].x + width / 2 - RADIUS, points[0].y);
context.quadraticCurveTo(
points[0].x + width / 2,
points[0].y,
points[0].x + width / 2,
points[0].y + dir * radius
);
context.lineTo(points[0].x + width / 2, points[1].y - dir * radius);
context.quadraticCurveTo(
points[0].x + width / 2,
points[1].y,
points[0].x + width / 2 + radius,
points[1].y
);
context.lineTo(points[1].x, points[1].y);
context.fillStrokeShape(shape);
}}
stroke="black"
strokeWidth={2}
/>
);
};
Demo: https://codesandbox.io/s/757nw05p6