Parse

File Parse center.js

Source

            /*
files:
    # compass.js
*/

let centerOfMass = {
    simple(points, origin) {
        /* Synonymous to:

            let totalX = 0;
            let totalY = 0;
            let numPoints = points.length;

            for (let i = 0; i < numPoints; i++) {
                totalX += points[i].x;
                totalY += points[i].y;
            }

            let centerX = totalX / numPoints;
            let centerY = totalY / numPoints;

            return point(centerX, centerY);
         */
        let total = point(0,0)
        if(origin) total.add(origin);

        points.forEach((p) => {
            total = total.add(p)
        })

        return total.divide(points.length);
    }
    , deep(points, origin)  {
        let totalMass = 0;
        let weightedSum = point(0, 0);
        if(origin) weightedSum.add(origin);

        let sinSum = 0;
        let cosSum = 0;

        points.forEach((p) => {
            let mass = p.radius;
            totalMass += mass;
            weightedSum = weightedSum.add(p.multiply(mass));
            // Convert angle to radians for Math.sin/cos
            let theta = p.radians// * Math.PI / 180;
            sinSum += Math.sin(theta) * mass;
            cosSum += Math.cos(theta) * mass;
        });

        let center = weightedSum.divide(totalMass);

        // Weighted average rotation
        let avgTheta = Math.atan2(sinSum / totalMass, cosSum / totalMass);
        center.rotation = avgTheta * 180 / Math.PI;
        center.radius = center.mass = totalMass;
        return center
    }

    , deepRotationAddition(points, origin) {
        /* Synonymous to:

            let totalMass = 0;
            let weightedSumX = 0;
            let weightedSumY = 0;
            let weightedSumRotation = 0;

            for (let i = 0; i < points.length; i++) {
                let mass = points[i].mass;
                // let z = points[i].z
                totalMass += mass;
                weightedSumX += points[i].x * points[i].mass;
                weightedSumY += points[i].y * points[i].mass;
                // weightedSumZ += z * points[i].mass;
                const rotation = points[i].rotation
                weightedSumRotation += rotation * mass
            }


            let centerX = weightedSumX / totalMass;
            let centerY = weightedSumY / totalMass;
            let centerRotation = weightedSumRotation / totalMass;

            let _point = point(centerX, centerY);
            _point.mass = totalMass
            _point.radius = totalMass
            _point.rotation = centerRotation
            return _point

        */
        let totalMass = 0;
        let weightedSum = point(0,0)
        if(origin) weightedSum.add(origin);

        let weightedSumRotation = 0;

        points.forEach((p)=>{
            let mass = p.radius;
            totalMass += mass;
            weightedSum = weightedSum.add(p.multiply(mass))
            weightedSumRotation += p.rotation * mass
        })

        let center = weightedSum.divide(totalMass)

        center.rotation = weightedSumRotation / totalMass;
        center.radius = center.mass = totalMass

        return center
    }
}


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