PtArc

Gamma/Photon: Using Gamma™ with the Photon microGUIŽ, Version 4.0
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# `PtArc`

`PtArc` -- An elliptical arc.

## Synopsis

    class PtArc PtGraphic
    {
        arc_end;      // unsigned short  (Pt_ARG_ARC_END)
        arc_start;    // unsigned short  (Pt_ARG_ARC_START)
        arc_type;     // unsigned short  (Pt_ARG_ARC_TYPE)
    }

## Base Classes

`PtWidget` <-- `PtBasic` <-- `PtGraphic` <-- `PtArc`

## Description

This widget is an arc of an ellipse, defined by its point of origin, bounding rectangle, and start and end angles.

The point of origin accesses the inherited `origin` variable, which is a single `PtPoint`. The bounding rectangle is determined by two `PtPoints` (relative to the origin), or by the values of the inherited `dim` variable. The default arc is a full circle with start and end points at the same point: 0 degrees, the point horizontal to the centroid of the ellipse.

There are three types of fill: empty (open curve), chord, or pie-shaped, specified by their respective variables as explained below.

| For detailed information, please refer to PtArc in the Photon documentation.

## Instance Variables

arc_end

  A number specifying the end angle of the arc, in tenths of degrees.

arc_start

  A number specifying the start angle of the arc, in tenths of degrees.

arc_type

  A constant that controls the type of arc: open curve, closed pie-shaped, or closed with a chord. Default is `Pt_ARC_CURVE`.

  This instance variable may have one of the following values:

  Constant | Description
  --- | ---
  `Pt_ARC_CURVE` | An unclosed, unfilled curve; the default.
  `Pt_ARC_PIE` | A curve closed by two lines that connect the end points to the centroid of the arc, like a piece of pie.
  `Pt_ARC_CHORD` | A curve closed by a line connecting the two end points.

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