1 <?xml version=
"1.0" encoding=
"UTF-8"?>
2 <!DOCTYPE book PUBLIC
"-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
3 "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
4 <refentry id=
"gluPartialDisk">
9 <holder>Silicon Graphics, Inc.
</holder>
12 <refentrytitle>gluPartialDisk
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>gluPartialDisk
</refname>
17 <refpurpose>draw an arc of a disk
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>void
<function>gluPartialDisk
</function></funcdef>
23 <paramdef>GLUquadric*
<parameter>quad
</parameter></paramdef>
24 <paramdef>GLdouble
<parameter>inner
</parameter></paramdef>
25 <paramdef>GLdouble
<parameter>outer
</parameter></paramdef>
26 <paramdef>GLint
<parameter>slices
</parameter></paramdef>
27 <paramdef>GLint
<parameter>loops
</parameter></paramdef>
28 <paramdef>GLdouble
<parameter>start
</parameter></paramdef>
29 <paramdef>GLdouble
<parameter>sweep
</parameter></paramdef>
33 <!-- eqn: ignoring delim $$ -->
34 <refsect1 id=
"parameters"><title>Parameters
</title>
37 <term><parameter>quad
</parameter></term>
40 Specifies a quadrics object (created with
<citerefentry><refentrytitle>gluNewQuadric
</refentrytitle></citerefentry>).
45 <term><parameter>inner
</parameter></term>
48 Specifies the inner radius of the partial disk (can be
0).
53 <term><parameter>outer
</parameter></term>
56 Specifies the outer radius of the partial disk.
61 <term><parameter>slices
</parameter></term>
64 Specifies the number of subdivisions around the
<emphasis>z
</emphasis> axis.
69 <term><parameter>loops
</parameter></term>
72 Specifies the number of concentric rings about the origin into which
73 the partial disk is subdivided.
78 <term><parameter>start
</parameter></term>
81 Specifies the starting angle, in degrees, of the disk portion.
86 <term><parameter>sweep
</parameter></term>
89 Specifies the sweep angle, in degrees, of the disk portion.
95 <refsect1 id=
"description"><title>Description
</title>
97 <function>gluPartialDisk
</function> renders a partial disk on the
98 <inlineequation><mml:math>
101 <mml:mi mathvariant=
"italic">z
</mml:mi>
105 </mml:math></inlineequation>
106 plane. A partial disk is
107 similar to a full disk, except that only the subset of the disk from
108 <parameter>start
</parameter> through
<parameter>start
</parameter> +
<parameter>sweep
</parameter> is included (where
0 degrees is along the
110 90 degrees along the +
<emphasis>x
</emphasis> axis,
180 degrees along the \-
<emphasis>y
</emphasis> axis, and
111 270 degrees along the \-
<emphasis>x
</emphasis> axis).
114 The partial disk has a radius of
115 <parameter>outer
</parameter> and contains a concentric circular hole with a radius
116 of
<parameter>inner
</parameter>. If
<parameter>inner
</parameter> is
0, then no hole is generated. The partial disk is
117 subdivided around the
<emphasis>z
</emphasis> axis into slices (like pizza slices) and also
118 about the
<emphasis>z
</emphasis> axis into rings
119 (as specified by
<parameter>slices
</parameter> and
<parameter>loops
</parameter>, respectively).
122 With respect to orientation, the +
<emphasis>z
</emphasis>
123 side of the partial disk is considered to
124 be outside (see
<citerefentry><refentrytitle>gluQuadricOrientation
</refentrytitle></citerefentry>).
125 This means that if the
126 orientation is set to
<constant>GLU_OUTSIDE
</constant>, then any normals generated
127 point along the +
<emphasis>z
</emphasis> axis. Otherwise, they point along the \-
<emphasis>z
</emphasis>
131 If texturing is turned on (with
<citerefentry><refentrytitle>gluQuadricTexture
</refentrytitle></citerefentry>), texture
132 coordinates are generated
133 linearly such that where
134 <inlineequation><mml:math>
135 <!-- eqn: r = outer:-->
137 <mml:mi mathvariant=
"italic">r
</mml:mi>
139 <mml:mi mathvariant=
"italic">outer
</mml:mi>
141 </mml:math></inlineequation>,
142 the value at (
<emphasis>r
</emphasis>,
0,
0) is
143 (
1.0,
0.5), at (
0,
<emphasis>r
</emphasis>,
0) it is (
0.5,
1.0), at (\-
<emphasis>r
</emphasis>,
0,
0)
144 it is (
0.0,
0.5), and
145 at (
0, \-
<emphasis>r
</emphasis>,
0) it is (
0.5,
0.0).
148 <refsect1 id=
"seealso"><title>See Also
</title>
150 <citerefentry><refentrytitle>gluCylinder
</refentrytitle></citerefentry>,
151 <citerefentry><refentrytitle>gluDisk
</refentrytitle></citerefentry>,
152 <citerefentry><refentrytitle>gluNewQuadric
</refentrytitle></citerefentry>,
153 <citerefentry><refentrytitle>gluQuadricOrientation
</refentrytitle></citerefentry>,
154 <citerefentry><refentrytitle>gluQuadricTexture
</refentrytitle></citerefentry>,
155 <citerefentry><refentrytitle>gluSphere
</refentrytitle></citerefentry>
158 <refsect1 id=
"Copyright"><title>Copyright
</title>
160 Copyright
<trademark class=
"copyright"></trademark> 1991-
2006
161 Silicon Graphics, Inc. This document is licensed under the SGI
162 Free Software B License. For details, see
163 <ulink url=
"http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/
</ulink>.