Version 2 of the above code, some changes include the ability to reverse paths if this results in a reduced distance for the cutting head to move between paths, and added comments to make the code easier to read.
// Create a new empty layer in position 1 in the layer heirarchy.
// Run the script, all paths will move from their current layer to layer 1 in an optimized order.
// Further optimisation possible with 'Annealing', but this will be a good first run optimization.
// Load into Visual Studio Code, follow steps on this website
// https://medium.com/@jtnimoy/illustrator-scripting-in-visual-studio-code-cdcf4b97365d
// to get setup, then run code when linked to Illustrator.aa
function main() {
if (!app.documents.length) {
alert("You must have a document open.");
return;
}
var docRef = app.activeDocument;
// The below function gets the distance between the end of the endPath vector object
// and the start of the startPath vector object.
function endToStartDistance(endPath, startPath) {
var endPoint = endPath.pathPoints[endPath.pathPoints.length - 1].anchor;
var startPoint = startPath.pathPoints[0].anchor;
var dx = (endPoint[0] - startPoint[0]);
var dy = (endPoint[1] - startPoint[1]);
var dist = Math.pow((Math.pow(dx, 2) + Math.pow(dy, 2)), 0.5);
return dist;
}
// The below function gets the distance between the end of the endPath vector object
// and the end of the startPath vector object.
function endToEndDistance(endPath, startPath) {
var endPoint = endPath.pathPoints[endPath.pathPoints.length - 1].anchor;
var startPoint = startPath.pathPoints[startPath.pathPoints.length - 1].anchor;
var dx = (endPoint[0] - startPoint[0]);
var dy = (endPoint[1] - startPoint[1]);
var dist = Math.pow((Math.pow(dx, 2) + Math.pow(dy, 2)), 0.5);
return dist;
}
// The below function iterates over the supplied list of tempItems (path objects) and checks the distance between
// the end of path objects and the start/end of all other path objects, ordering the objects in the layer heirarchy
// so that there is the shortest distance between the end of one path and the start of the next.
// The function can reverse the direciton of a path if this results in a smaller distance to the next object.
function Optimize(tempItems) {
var lastPath, closest, minDist, delIndex, curItem;
var newLayer = app.activeDocument.layers[1]; // There needs to be an empty layer in position 2 in the layer heirarchy
// This is where the path objects are moved as they are sorted.
lastPath = tempItems[0]; // Arbitrarily take the first item in the list of supplied items
tempItems.splice(0, 1); // Remove the first item from the list of items to be iterated over
lastPath.move(newLayer, ElementPlacement.PLACEATBEGINNING); // Move the first item to the first position in the new layer
while (tempItems.length) { // Loop over all supplied items while the length of this array is not 0.
// Items are removed from the list once sorted.
closest = tempItems[0]; // Start by checking the distance to the first item in the list
minDist = Math.min(endToStartDistance(lastPath, closest), endToEndDistance(lastPath, closest));
// Find the smallest of the distances between the end of the previous path item
// and the start / end of this next item.
delIndex = 0; // The delIndex is the index to be removed from the tempItems list after iterating through
// the entire list.
for (var y = 1, len = tempItems.length; y < len; y++) {
// Iterate over all items in the list, starting at item 1 (item 0 already being used above)
curItem = tempItems[y];
if (endToStartDistance(lastPath, curItem) < minDist || endToEndDistance(lastPath, curItem) < minDist) {
// If either the end / start distance to the current item is smaller than the previously
// measured minDistance, then the current path item becomes the new smallest entry
closest = curItem;
minDist = Math.min(endToStartDistance(lastPath, closest), endToEndDistance(lastPath, closest));
// The new minDistace is set
delIndex = y; // And the item is marked for removal from the list at the end of the loop.
}
}
if (endToEndDistance(lastPath, closest) < endToStartDistance(lastPath, closest)) {
reversePaths(closest); // If the smallest distance is yielded from the end of the previous path
// To the end of the next path, reverse the next path so that the
// end-to-start distance between paths is minimised.
}
closest.move(newLayer, ElementPlacement.PLACEATBEGINNING); // Move the closest path item to the beginning of the new layer
lastPath = closest; // The moved path item becomes the next item in the chain, and is stored as the previous item
// (lastPath) for when the loop iterates again.
tempItems.splice(delIndex, 1); // Remove the item identified as closest in the previous loop from the list of
// items to iterate over. When there are no items left in the list
// The loop ends.
}
}
function reversePaths(theItems) { // This code taken / adapted from https://gist.github.com/Grsmto/bfe1541957a0bb17972d
if (theItems.typename == "PathItem" && !theItems.locked && !theItems.parent.locked && !theItems.layer.locked) {
pathLen = theItems.pathPoints.length;
for (k = 0; k < pathLen / 2; k++) {
h = pathLen - k - 1;
HintenAnchor = theItems.pathPoints[h].anchor;
HintenLeft = theItems.pathPoints[h].leftDirection;
HintenType = theItems.pathPoints[h].pointType;
HintenRight = theItems.pathPoints[h].rightDirection;
theItems.pathPoints[h].anchor = theItems.pathPoints[k].anchor;
theItems.pathPoints[h].leftDirection = theItems.pathPoints[k].rightDirection;
theItems.pathPoints[h].pointType = theItems.pathPoints[k].pointType;
theItems.pathPoints[h].rightDirection = theItems.pathPoints[k].leftDirection;
theItems.pathPoints[k].anchor = HintenAnchor;
theItems.pathPoints[k].leftDirection = HintenRight;
theItems.pathPoints[k].pointType = HintenType;
theItems.pathPoints[k].rightDirection = HintenLeft;
}
}
}
var allPaths = []; // Grab every line in the document
for (var i = 0; i < documents[0].pathItems.length; i++) {
allPaths.push(documents[0].pathItems[i]);
// This could be better changed to the selected objects, or to filter only objects below a certain
// stroke weight so that raster paths are not affected, but cut paths are.
}
Optimize(allPaths); // Feed all paths in the document into the optimize function.
}
main(); // Call the main function, executing the above code.
