Shape on path - Aftereffects Expression

shapeonpath.js

dist = effect("Offset")("Slider"); // Position on path.
w = effect("Width")("Slider"); // Normal direction width.

restpath = thisProperty;
targetpath = thisComp.layer("Path").content("Shape 1").content("Path 1").path; // Target Path

refpt = restpath.points();
refintan = restpath.inTangents();
refouttan = restpath.outTangents();

points =[];
intangents = [];
outtangents = [];
for(i=0; i<refpt.length; i++){
	rest = refpt[i];
	f = dist + rest[0] / thisComp.width;
	
	pathpoint = targetpath.pointOnPath(f);
	pathnormal = targetpath.normalOnPath(f);

	angle = Math.atan2(-pathnormal[0], pathnormal[1]);

	intanx = refintan[i][0] * Math.cos(angle) - refintan[i][1] * Math.sin(angle);
	intany = refintan[i][0] * Math.sin(angle) + refintan[i][1] * Math.cos(angle);

	outtanx = refouttan[i][0] * Math.cos(angle) - refouttan[i][1] * Math.sin(angle);
	outtany = refouttan[i][0] * Math.sin(angle) + refouttan[i][1] * Math.cos(angle);
	
	points.push( pathpoint + pathnormal * rest[1] *w);	
	intangents.push( [intanx, intany * w] );
	outtangents.push( [ outtanx, outtany * w] );
}

createPath(points, intangents, outtangents);