# gluPartialDisk.3G man page

gluPartialDisk — draw an arc of a disk

## C Specification

**void gluPartialDisk(GLUquadric*** *quad***, GLdouble** *inner***, GLdouble** *outer***, GLint** *slices***, GLint** *loops***, GLdouble** *start***, GLdouble** *sweep***);**

## Parameters

*quad*Specifies a quadrics object (created with

**gluNewQuadric**()).*inner*Specifies the inner radius of the partial disk (can be 0).

*outer*Specifies the outer radius of the partial disk.

*slices*Specifies the number of subdivisions around the

*z*axis.*loops*Specifies the number of concentric rings about the origin into which the partial disk is subdivided.

*start*Specifies the starting angle, in degrees, of the disk portion.

*sweep*Specifies the sweep angle, in degrees, of the disk portion.

## Description

**gluPartialDisk** renders a partial disk on the z = 0 plane. A partial disk is similar to a full disk, except that only the subset of the disk from *start* through *start* + *sweep* is included (where 0 degrees is along the +\f2y\f axis, 90 degrees along the +*x* axis, 180 degrees along the \-*y* axis, and 270 degrees along the \-*x* axis).

The partial disk has a radius of *outer* and contains a concentric circular hole with a radius of *inner*. If *inner* is 0, then no hole is generated. The partial disk is subdivided around the *z* axis into slices (like pizza slices) and also about the *z* axis into rings (as specified by *slices* and *loops*, respectively).

With respect to orientation, the +*z* side of the partial disk is considered to be outside (see **gluQuadricOrientation**()). This means that if the orientation is set to **GLU_OUTSIDE**, then any normals generated point along the +*z* axis. Otherwise, they point along the \-*z* axis.

If texturing is turned on (with **gluQuadricTexture**()), texture coordinates are generated linearly such that where r = outer, the value at (*r*, 0, 0) is (1.0, 0.5), at (0, *r*, 0) it is (0.5, 1.0), at (\-*r*, 0, 0) it is (0.0, 0.5), and at (0, \-*r*, 0) it is (0.5, 0.0).

## See Also

**gluCylinder**(), **gluDisk**(), **gluNewQuadric**(), **gluQuadricOrientation**(), **gluQuadricTexture**(), **gluSphere**()

## Copyright

Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

## Authors

**opengl.org**