glupartialdisk
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gluPartialDisk(3G) OpenGL Reference gluPartialDisk(3G)
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 zero).
outer 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.
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 +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 outer, and contains a concentric
circular hole with a radius of inner. If inner 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=outer, 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
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gluPartialDisk(3G) OpenGL Reference gluPartialDisk(3G)
at (0, -r, 0) it is (0.5, 0).
SEE ALSO
gluCylinder, gluDisk, gluNewQuadric, gluQuadricOrientation,
gluQuadricTexture, gluSphere
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