Arc Items

Items of type arc appear on the display as arc-shaped regions. An arc is a section of an oval delimited by two angles (specified by the #:start and #:extent options) and displayed in one of several ways (specified by the #:style option). Arcs are created with widget commands of the following form:

(#<widget> 'create 'arc x1 y1 x2 y2 ?option value option value ...?)
(#<widget> 'create 'arc coordList ?option value option value ...?)

The arguments x1, y1, x2, and y2 or coordList give the coordinates of two diagonally opposite corners of a rectangular region enclosing the oval that defines the arc. After the coordinates there may be any number of option-value pairs, each of which sets one of the configuration options for the item. These same option-value pairs may be used in itemconfigure widget commands to change the item's configuration.

The following standard options are supported by arcs:

#:dash
#:activedash
#:disableddash
#:dashoffset
#:fill
#:activefill
#:disabledfill
#:offset
#:outline
#:activeoutline
#:disabledoutline
#:outlinestipple
#:activeoutlinestipple
#:disabledoutlinestipple
#:stipple
#:activestipple
#:disabledstipple
#:state
#:tags
#:width
#:activewidth
#:disabledwidth

The following extra options are supported for arcs:

#:extent degrees
Specifies the size of the angular range occupied by the arc. The arc's range extends for degrees degrees counter-clockwise from the starting angle given by the #:start option. Degrees may be negative. If it is greater than 360 or less than -360, then degrees modulo 360 is used as the extent.
#:start degrees
Specifies the beginning of the angular range occupied by the arc. Degrees is given in units of degrees measured counter-clockwise from the 3-o'clock position; it may be either positive or negative.
#:style type
Specifies how to draw the arc. If type is pieslice (the default) then the arc's region is defined by a section of the oval's perimeter plus two line segments, one between the center of the oval and each end of the perimeter section. If type is chord then the arc's region is defined by a section of the oval's perimeter plus a single line segment connecting the two end points of the perimeter section. If type is arc then the arc's region consists of a section of the perimeter alone. In this last case the #:fill option is ignored.

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