# gluPartialDisk

The **gluPartialDisk** function draws an arc of a disk.

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

#### Parameters

*qobj*- A quadric object (created with
**gluNewQuadric**). *innerRadius*- The inner radius of the partial disk (can be zero).
*outerRadius*- The outer radius of the partial disk.
*slices*- The number of subdivisions around the z-axis.
*loops*- The number of concentric rings about the origin into which the partial disk is subdivided.
*startAngle*- The starting angle, in degrees, of the disk portion.
*sweepAngle*- The sweep angle, in degrees, of the disk portion.

#### Remarks

The **gluPartialDisk** function 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 positive y-axis, 90 degrees is along the positive x-axis, 180 degrees is along the negative y-axis, and 270 degrees is along the negative 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 positive 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 positive z-axis.

If you have turned on texturing (with **gluQuadricTexture**), **gluPartialDisk **generates texture coordinates 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).

#### Requirements

** Windows NT/2000: **Requires Windows NT 3.5 or later.

** Windows 95/98: **Requires Windows 95 or later. Available as a redistributable for Windows 95.

** Header: **Declared in Glu.h.

** Library: **Use Glu32.lib.

#### See Also

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