Sketcher ConstrainPerpendicular/it

Descrizione
Il vincolo Perpendicolare fa sì che due linee siano perpendicolari tra loro, o che due curve siano perpendicolari al loro incrocio. Le linee sono considerate infinite, e gli archi sono considerati cerchi completi o ellissi complete. Il vincolo è anche in grado di collegare due curve, costringendole perpendicolari nel punto di unione, in modo simile al vincolo Tangente.

Uso
Ci sono quattro modi diversi per applicare il vincolo:
 * 1) tra due curve (non disponibile per tutte le curve)
 * 2) tra due punti finali di curve
 * 3) tra una curva e il punto finale di un'altra curva
 * 4) tra due curve in un punto definito dall'utente

Per applicare il vincolo perpendicolare, si dovrebbe usare la seguente procedura:
 * Selezionare due o tre entità nello schizzo.
 * Invocare il vincolo facendo clic sull'icona nella barra degli strumenti, oppure selezionando la voce del menu, oppure usando la scorciatoia da tastiera.

Tra due curve (perpendicolarità diretta)


Two curves will be made perpendicular at point of their intersection (either real, or of curves' extensions), and the point of intersection will be implicit. This mode is applied if two curves were selected.

Accepted selection: If direct perpendicularity between selected curves is not supported (e.g. between a line and an ellipse), a helper point will be added to sketch automatically, and perpendicular-via-point will be applied.
 * line +  line, circle, arc
 * circle, arc +  circle, arc

Unlike for tangency, it is perfectly fine to reconstruct the point of perpendicularity by creating a point and constraining it to lie on both curves (thus constraining the point to the intersection).

Between two endpoints (point-to-point perpendicularity)


In this mode, the endpoints are made coincident, and the joint is made to be right angle. This mode is applied when two endpoints of two curves were selected.

Accepted selection:
 * endpoint of line/arc/arc-of-ellipse +  endpoint of line/arc/arc-of-ellipse (i.e., two endpoints of any two curves)

Between curve and endpoint (point-to-curve perpendicularity)


In this mode, an endpoint of one curve is constrained to lie on the other curve, and the curves are forced perpendicular at the point. This mode is applied when a curve and an endpoint of another curve were selected.

Accepted selection:
 * line, circle, arc, ellipse, arc-of-ellipse +  endpoint of line/arc/arc-of-ellipse (i.e., any curve  +  endpoint of any curve)

Between two curves at point (perpendicular-via-point) (v0.15)


In this mode, two curves are made perpendicular, and the point of perpendicularity is tracked. This mode is applied when two curves and a point were selected.

Accepted selection: "Any point" can be a lone point, or a point of something, e.g. a center of a circle, an endpoint of an arc, or the origin.
 * any line/curve +  any line/curve  +  any point

For the constraint to work correctly, the point must be on both curves. So, as the constraint is invoked, the point will be automatically constrained onto both curves (helper constraints will be added, if necessary), and the curves will be forced perpendicular at the point. These helper constraints are plain regular constraints. They can be added manually, or deleted.

Compared to direct perpendicular, this constraint is slower, because there are mode degrees of freedom involved, but it supports ellipses.

The placement of the point before the constraint is applied is a hint for the solver for where the perpendicularity should be.

Scripting
Perpendicular Constraint can be created from macros and from the python console by using the following:

where:
 * Sketch is a sketch object
 * icurve1, icurve2 are two integers identifying the curves to be made perpendicular. The integers are indexes in the sketch (the value, returned by Sketch.addGeometry).
 * pointpos1, pointpos2 should be 1 for start point and 2 for end point.
 * geoidpoint and pointpos in PerpendicularViaPoint are the indexes specifying the point of perpendicularity.