auto-accept/www/js/svg.js

function getPathShapeBetweenPoints(p1, p2, corners) {
    let d = `M ${p1.x},${p1.y} L `;
    if(corners == 4){
        // draw inbetween p1 & p2.
        d += ` ${p1.x},${p2.y} ${p2.x},${p2.y}  ${p2.x},${p1.y}  ${p1.x},${p1.y} `;
    }
    else{
        // find center of circle that describes the polygon of which p1 and p2 are part
        // it's _not_ the center between the two points, as p1 and p2 are corners on the shape

        // distance between p1 and p2
        const length = Math.sqrt(Math.pow(p1.x-p2.x,2)+ Math.pow(p1.y - p2.y, 2));

        const segmentAngle = Math.PI * 2 / corners;
        // TODO: can we find a way to draw not from the first 3 segments, but have the 
        // cursor span as many segment as possible 
        // const segmentsAngle = Math.floor(180/segmentAngle) * segmentAngle;

        const radius = (length*.5)/Math.sin(segmentAngle);

        const rotation = Math.atan2((p2.y -p1.y),(p2.x - p1.x)) + (Math.PI/2-segmentAngle);

        const dx = Math.cos(rotation) * radius;// * Math.sign(p2.x - p1.x);
        const dy = Math.sin(rotation) * radius;// * Math.sign(p2.y - p1.y);
        // we now have the center:
        const cx = p2.x - dx;
        const cy = p2.y - dy;

        // startpoint in relation to circle
        const sx = cx - p1.x;
        const sy = cy - p1.y;

        let startRot = Math.asin(sx / radius);
        if(sy>0){startRot = -1 * startRot + Math.PI;}
        
        for (let a = 0; a < Math.PI*2; a += segmentAngle) {
            let x = radius * Math.sin(a-startRot) + cx;
            let y = radius * Math.cos(a-startRot) + cy;
            d += ` ${x},${y}`;
        }

    }
    return d + ' Z';
}

export {getPathShapeBetweenPoints};