NAME¶

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 +yaxis, 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 $r=\mathrm{outer}$ , 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(3G), gluDisk(3G), gluNewQuadric(3G), gluQuadricOrientation(3G), gluQuadricTexture(3G), gluSphere(3G)