**gluPartialDisk**

### NAME

**gluPartialDisk** -- draw an arc of a disk
### C SPECIFICATION

void **gluPartialDisk**(GLUquadricObj **qobj*,
GLdouble *innerRadius*,
GLdouble *outerRadius*,
GLint *slices*,
GLint *loops*,
GLdouble *startAngle*,
GLdouble *sweepAngle*)

### PARAMETERS

*qobj*-
Specifies a quadrics object (created with
**gluNewQuadric**).

*innerRadius*-
Specifies the inner radius of the partial disk (can be zero).

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

*slices*-
Specfies 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.

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

*sweepAngle*-
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 *startAngle* through *startAngle* + *sweepAngle* is
included (where 0 degrees is along the +*y* axis, 90 degrees along the
+*x* axis, 180 along the -*y* axis, and 270 along the -*x*
axis).
The partial disk has a radius of *outerRadius*, and contains a concentric
circular hole with a radius of *innerRadius*. If *innerRadius* is
zero, 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* =
*outerRadius*, the value at (*r*, 0, 0) is (1, 0.5), at
(0, *r*, 0) it is (0.5, 1), at (-*r*, 0, 0) it is (0, 0.5), and at
(0, -*r*, 0) it is (0.5, 0).

### SEE ALSO

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

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© *1995 Uwe Behrens All rights reserved*