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).

QuickInfo

  Windows NT: Use version 3.5 and later.
  Windows: Use Windows 95 and later.
  Windows CE: Unsupported.
  Header: Declared in glu.h.
  Import Library: Link with glu32.lib.

See Also

gluCylinder, gluDisk, gluNewQuadric, gluQuadricOrientation, gluQuadricTexture, gluSphere