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Arc `objects`

are specified by center position, radius, and start
and end angles. They are purely graphical with no electrical
meaning. They can be drawn in different colors, and with various
stroke settings.

- Function:
**arc?***object* Returns ‘

`#t`’ if and only if`object`is an arc`object`

.

- Function:
**make-arc***center radius start-angle end-angle [color]* Creates and returns a new arc

`object`

.`center`is the position of the center of the new arc in the form`(x . y)`

, and`radius`is the integer radius of the arc.`start-angle`and`end-angle`are the angles at which to start and end the arc, in degrees. If`color`is specified, it should be the integer color map index of the color with which to draw the arc. If`color`is not specified, the default arc color is used.

- Function:
**set-arc!***arc center radius start-angle end-angle [color]* Sets the parameters of

`arc`. The arguments are the same as to`make-arc`

. Returns`arc`.

- Function:
**arc-info***arc* Returns the parameters of

`arc`as a list of the form:((center-x . center-y) radius start-angle end-angle color)

- Function:
**arc-center***arc* Returns the position of the center of

`arc`in the form`(x . y)`

.

- Function:
**arc-radius***arc* Returns the radius of

`arc`as an integer.

- Function:
**arc-start-angle***arc* Returns the start angle of

`arc`as an integer number of degrees.

- Function:
**arc-end-angle***arc* Returns the end angle of

`arc`as an integer number of degrees.

Next: Paths, Previous: Circles, Up: Core object functions [Contents][Index]