// Circumcircle
// draws circumcircles for each selcted path
// Method:
// The major reason why I wrote this script is to draw a "circumcircle"
// for a star.
// So the method to find the center and the radius for the circumcircle
// is rather incertitude.
// 1. find out a perpendicular bisector for the line connecting
// 1st anchor and 2nd anchor
// 2. do the same for 1st anchor and 3rd anchor
// (if the path is a triangle, 2nd anchor and 3rd anchor)
// 3. find out intersection point of 1 and 2.
// for the center of the circumcircle to draw
// 4. find out the length of the line connecting the center and 1st
// anchor, then do the same for the center and 2nd anchor.
// define longer one as the radius of the circumcircle to draw.
var ver10 = (version.indexOf('10') == 0);
main();
function main(){
var sp = [];
getPathItemsInSelection(2, sp);
if(sp.length < 1) return;
activateEditableLayer(sp[0]);
var col = getGray(); // strokeColor
var p, arr1, arr2, mp, o, j, r, r1, rIdx, pi;
var err_fail_to_find_center = 0;
var err_radius_is_larget_than_artboard = 0;
for(var i = 0; i < sp.length; i++){
p = sp[i].pathPoints;
// find out the center of the circle to draw
arr1 = perpendicularBisector(p[0].anchor, p[2].anchor);
if(p.length==3){ // in case triangle
arr2 = perpendicularBisector(p[1].anchor, p[2].anchor);
} else {
arr2 = perpendicularBisector(p[1].anchor, p[3].anchor);
}
o = intersection(arr1, arr2);
if(o.length < 1){
err_fail_to_find_center = 1;
continue;
}
// find out the radius of the circle to draw
r = dist(p[0].anchor, o);
r1 = dist(p[1].anchor, o);
if(r >= r1){
rIdx = 0;
} else {
rIdx = 1;
r = r1;
}
// do not draw if the radius is larger than the artboard
with(activeDocument){
if(r==0 || r>Math.max(width, height)){
err_radius_is_larget_than_artboard = 1;
continue;
}
}
// draw a circle
pi = activeDocument.activeLayer.pathItems.ellipse(o[1] + r, o[0] - r, r * 2, r * 2);
with(pi){
filled = false;
stroked = true;
strokeColor = sp[i].stroked ? sp[i].strokeColor : col;
strokeWidth = sp[i].strokeWidth || 1;
}
}
if(err_fail_to_find_center == 1)
alert("Some circles hadn't been drawn because of fails in calculation.");
if(err_radius_is_larget_than_artboard == 1)
alert("Some circles hadn't been drawn because of too large diameters.");
}
// ------------------------------------------------
function perpendicularBisector(p1, p2){
var mp = getMidPnt(p1, p2);
var arr = defline([ mp[0] - (p1[1] - mp[1]), mp[1] + (p1[0] - mp[0]) ],
[ mp[0] - (p2[1] - mp[1]), mp[1] + (p2[0] - mp[0]) ]);
return arr;
}
// ------------------------------------------------
function getMidPnt(p1, p2){
return [ (p1[0] + p2[0]) / 2, (p1[1] + p2[1]) / 2 ];
}
// ------------------------------------------------
function dist(arr1, arr2) {
return Math.sqrt(Math.pow(arr1[0] - arr2[0], 2)
+ Math.pow(arr1[1] - arr2[1], 2));
}
// -----------------------------------------------
function defline(p1, p2){
var a = p1[1] - p2[1];
var b = p1[0] - p2[0];
return [a, -b, b * p1[1] - a * p1[0]];
}
// -----------------------------------------------
function intersection(p, q){
var d = p[0] * q[1] - p[1] * q[0];
if(d == 0) return [];
return [ (q[2] * p[1] - p[2] * q[1]) / d,
(p[2] * q[0] - q[2] * p[0]) / d ];
}
// -----------------------------------------------
function getGray(){
var col = new GrayColor();
col.gray = 100;
if(ver10){
var col2 = new Color();
col2.gray = col;
return col2;
}
return col;
}
// ------------------------------------------------
// extract PathItems from the selection which length of PathPoints
// is greater than "n"
function getPathItemsInSelection(n, pathes){
if(documents.length < 1) return;
var s = activeDocument.selection;
if (!(s instanceof Array) || s.length < 1) return;
extractPathes(s, n, pathes);
}
// --------------------------------------
// extract PathItems from "s" (Array of PageItems -- ex. selection),
// and put them into an Array "pathes". If "pp_length_limit" is specified,
// this function extracts PathItems which PathPoints length is greater
// than this number.
function extractPathes(s, pp_length_limit, pathes){
for(var i = 0; i < s.length; i++){
if(s[i].typename == "PathItem"
&& !s[i].guides && !s[i].clipping){
if(pp_length_limit
&& s[i].pathPoints.length <= pp_length_limit){
continue;
}
pathes.push(s[i]);
} else if(s[i].typename == "GroupItem"){
// search for PathItems in GroupItem, recursively
extractPathes(s[i].pageItems, pp_length_limit, pathes);
} else if(s[i].typename == "CompoundPathItem"){
// searches for pathitems in CompoundPathItem, recursively
// ( ### Grouped PathItems in CompoundPathItem are ignored ### )
extractPathes(s[i].pathItems, pp_length_limit , pathes);
}
}
}
// ----------------------------------------------
function activateEditableLayer(pi){
var lay = activeDocument.activeLayer;
if(lay.locked || !lay.visible) activeDocument.activeLayer = pi.layer;
}
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