Geometric test functions

[femkeblanco]

Testing whether a selected path intersects() a selected path:

var intersects = function() {
    if (app.selection.length == 1) {
        return false;
    }
    app.executeMenuCommand("group");
    app.executeMenuCommand("Live Pathfinder Intersect");
    app.executeMenuCommand("expandStyle");
    app.executeMenuCommand("ungroup");
    var a = app.selection.length;
    app.redraw();
    app.undo();
    return a == 1;
}
alert( intersects() );

Testing whether a selected path contains() a selected path:

var contains = function() {
    app.executeMenuCommand("group");
    app.executeMenuCommand("Live Pathfinder Subtract");
    app.executeMenuCommand("expandStyle");
    app.executeMenuCommand("ungroup");
    var a = app.selection[0].typename;
    var b = app.selection.length;
    app.redraw();
    app.undo();
    return a == "CompoundPathItem" || b == 2;
    // if a front path totally eclipsing a back path shouldn't count as contains()
    // then remove the b == 2 part of the expression
}
alert( contains() );

Whether a path contains() a point can be tested by first converting the point to a path with the same coordinates:

var convertPointToPath = function (x, y) {
    var path1 = app.activeDocument.pathItems.add();
    path1.setEntirePath([ [x, y], [x, y] ]);
    return path1;
}
// e.g.
var w = app.activeDocument.width;
var h = - app.activeDocument.height;
var tempPoint = convertPointToPath(w/2, h/2);

1. Feedback is appreciated.
2. Is there any way to do away with redraw()?  Presently, without redraw(), undo() undos the script and a step before. 

Thanks in advance. 

[CarlosCanto]

I would rather work with a duplicate than redrawing and/or undoing.

[femkeblanco · Accepted solution]

I would rather work with a duplicate than redrawing and/or undoing.

By @CarlosCanto

That sounds better. 

How about

var intersects = function() {
    if (app.selection.length != 2) {
        return false;
    }
    var path1 = app.selection[0].duplicate(),
    path2 = app.selection[1].duplicate();
    app.selection = null;
    path1.selected = true;
    path2.selected = true;
    app.executeMenuCommand("group");
    app.executeMenuCommand("Live Pathfinder Intersect");
    app.executeMenuCommand("expandStyle");
    app.executeMenuCommand("ungroup");
    var a = app.selection.length;
    for (var i = app.selection.length - 1; i > -1; i--) {
        app.selection[i].remove();
    }
    return a == 1;
}
alert( intersects() );

var contains = function() {
    if (app.selection.length != 2) {
        return false;
    }
    var path1 = app.selection[0].duplicate(),
    path2 = app.selection[1].duplicate();
    app.selection = null;
    path1.selected = true;
    path2.selected = true;
    app.executeMenuCommand("group");
    app.executeMenuCommand("Live Pathfinder Subtract");
    app.executeMenuCommand("expandStyle");
    app.executeMenuCommand("ungroup");
    var a = app.selection[0].typename,
    b = app.selection.length;
    for (var i = app.selection.length - 1; i > -1; i--) {
        app.selection[i].remove();
    }
    return a == "CompoundPathItem" || b == 2;
}
alert( contains() );

[CarlosCanto]

the script works great, but one small circle fully inside a bigger circle but not touching should be "false" (not intersecting), no?

[CarlosCanto]

same as these two objects, intersecting returns "true"

[femkeblanco]

Thanks @CarlosCanto .

The intention was that if there was "overlap", whether in part or in whole, "intersect" would be true. May be "intersect" was a poor choice of word; "overlap" would have been better.

And I was thinking of closed paths or semi-closed paths. I have wanted to do a function which returns the point(s) where lines intersect, but I left that for later.

[Disposition_Dev]

i don't think intersect is the wrong word. if the paths were filled instead of stroked then they would indeed intersect. i think intersection means that the outer limits of two shapes share at least some real estate.

cool stuff

[CarlosCanto]

I see, the Bounding Boxes do intersect.