GLUPARTIALDISK() MachTen Programmer’s Manual GLUPARTIALDISK()

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 )

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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 along the -y axis, and
270 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 sub-
divided 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 gluQuadricOrienta-
tion). 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), tex-
ture 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, gluQuadricOrienta-
tion, gluQuadricTexture, gluSphere

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