Reticle paths
Goal of this article: draw the shapes the other element types cannot — anything with a corner or a curve that is not a whole circle.
A path is a single element made of a sequence of pen movements. One line width, one style, one colour and one fill setting apply to the whole thing, and the sequence decides the shape. Chevrons, horseshoes, tapered posts, the outline of an aperture field, a bracket around a target box: all paths.
Choose Path in the type dropdown and press New (or Edit an existing one) and you get a dialog that
is a small editor in its own right.
The dialog
| Section | What it holds |
|---|---|
| Path Parameters | Line width, style (Solid / Dashed / Dotted), colour, and Fill — for the path as a whole |
| Elements | The sequence of pen movements, in order, with Move To / Line To / Arc to add one and Edit / Delete / Up / Down to work on the selection |
| Preview | The reticle with this path in it, redrawn after every change |
| Buttons | OK, Cancel, Revert |
Revert puts the path back to exactly how it was when the dialog opened — parameters and the whole sequence — without closing. It is there because the dialog edits the real element as you go, so Revert is your undo. Cancel does the same thing and then closes, so a cancelled path edit leaves nothing behind.
The three movements
Think of a pen on paper. There is a current point; each entry either moves it without drawing or draws to a new place.
Move To
Position X / Y. Lifts the pen and puts it down somewhere. A path should begin with one — otherwise the first drawing operation starts from an undefined point — and a later Move To in the middle of a path starts a new disconnected sub-shape within the same element. That is how a reticle draws two mirrored marks as one path.
Line To
Position X / Y. A straight segment from the current point to there. The current point becomes the end.
Arc
| Field | Notes |
|---|---|
| End Position X / Y | Where the arc finishes |
| Radius | The radius of the circle the arc is a piece of |
| Clockwise | Which way round it sweeps |
| Major Arc | The long way round instead of the short way |
An arc is defined by where it ends and how curved it is, not by its centre. Given a start point, an end point and a radius there are four arcs that fit — two circles of that radius pass through both points, and each offers a short way and a long way round. The two checkboxes pick between them: Clockwise chooses the sweep direction and Major Arc chooses the long way. If an arc comes out mirrored or bulging the wrong side, one of those two boxes is the fix; try them in turn rather than recomputing geometry.
The radius has to be at least half the distance between the two points — no circle smaller than that can touch both. Keep the radius comfortably above that limit and arcs behave predictably.
Order is the whole shape
The list is the pen’s itinerary, so Up and Down do not tidy the list, they redraw the shape. Moving a Line To earlier changes which point it starts from and which point the next entry starts from. If a path comes out looking like a scribble, the sequence is wrong rather than the coordinates.
Fill
Fill treats the path as an enclosed region and paints it. Without it you get an outline of the given line width.
Two things follow:
- A filled path does not need to be closed by hand. The region between the last point and the first is filled as though it were.
- A filled path covers what is under it, and paths are usually large, so watch its position in the element list — see draw order.
A worked example: a chevron
A chevron with its point on the aiming point, 1 mil wide each side and 1.5 mil tall:
| # | Entry | Position |
|---|---|---|
| 1 | Move To | −1, 1.5 |
| 2 | Line To | 0, 0 |
| 3 | Line To | 1, 1.5 |
Three entries, no fill: a V with its apex exactly on the crosshair. Set the line width to taste — 0.1 mil
for a fine mark, 0.3 mil for something visible against clutter.
To make it a solid triangle instead, tick Fill: the open top closes and the shape becomes a filled
wedge. To make it a hollow outline of a thick chevron, extend the sequence back along the inside — five more
Line To entries — and fill that instead.
Next
Choosing a drag model — where the application’s accuracy actually comes from, and the part of the manual that is also its argument.