upstream-doc/man2/glPointParameter.xml

   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="glPointParameter">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glPointParameter</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glPointParameter</refname>
  17         <refpurpose>specify point parameters</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glPointParameterf</function></funcdef>
  23                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  24                 <paramdef>GLfloat <parameter>param</parameter></paramdef>
  25             </funcprototype>
  26         </funcsynopsis>
  27         <para></para>
  28         <funcsynopsis>
  29             <funcprototype>
  30                 <funcdef>void <function>glPointParameteri</function></funcdef>
  31                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  32                 <paramdef>GLint <parameter>param</parameter></paramdef>
  33             </funcprototype>
  34         </funcsynopsis>
  35     </refsynopsisdiv>
  36     <!-- eqn: ignoring delim $$ -->
  37     <refsect1 id="parameters"><title>Parameters</title>
  38         <variablelist>
  39         <varlistentry>
  40             <term><parameter>pname</parameter></term>
  41             <listitem>
  42                 <para>
  43                     Specifies a single-valued point parameter.
  44                     <constant>GL_POINT_SIZE_MIN</constant>,
  45                     <constant>GL_POINT_SIZE_MAX</constant>,
  46                     <constant>GL_POINT_FADE_THRESHOLD_SIZE</constant>, and
  47                     <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant>
  48                     are accepted.
  49                 </para>
  50             </listitem>
  51         </varlistentry>
  52         <varlistentry>
  53             <term><parameter>param</parameter></term>
  54             <listitem>
  55                 <para>
  56                     Specifies the value that <parameter>pname</parameter> will be set to.
  57                 </para>
  58             </listitem>
  59         </varlistentry>
  60         </variablelist>
  61     </refsect1>
  62     <refsynopsisdiv><title>C Specification</title>
  63         <funcsynopsis>
  64             <funcprototype>
  65                 <funcdef>void <function>glPointParameterfv</function></funcdef>
  66                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  67                 <paramdef>const GLfloat * <parameter>params</parameter></paramdef>
  68             </funcprototype>
  69         </funcsynopsis>
  70         <para></para>
  71         <funcsynopsis>
  72             <funcprototype>
  73                 <funcdef>void <function>glPointParameteriv</function></funcdef>
  74                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  75                 <paramdef>const GLint * <parameter>params</parameter></paramdef>
  76             </funcprototype>
  77         </funcsynopsis>
  78     </refsynopsisdiv>
  79     <refsect1 id="parameters2"><title>Parameters</title>
  80         <variablelist>
  81         <varlistentry>
  82             <term><parameter>pname</parameter></term>
  83             <listitem>
  84                 <para>
  85                     Specifies a point parameter.
  86                     <constant>GL_POINT_SIZE_MIN</constant>,
  87                     <constant>GL_POINT_SIZE_MAX</constant>,
  88                     <constant>GL_POINT_DISTANCE_ATTENUATION</constant>,
  89                     <constant>GL_POINT_FADE_THRESHOLD_SIZE</constant>, and
  90                     <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant>
  91                     are accepted.
  92                 </para>
  93             </listitem>
  94         </varlistentry>
  95         <varlistentry>
  96             <term><parameter>params</parameter></term>
  97             <listitem>
  98                 <para>
  99                     Specifies the value or values to be assigned to <parameter>pname</parameter>.
 100                     <constant>GL_POINT_DISTANCE_ATTENUATION</constant> requires an array of three values.
 101                     All other parameters accept an array containing only a single value.
 102                 </para>
 103             </listitem>
 104         </varlistentry>
 105         </variablelist>
 106     </refsect1>
 107     <refsect1 id="description"><title>Description</title>
 108         <para>
 109             The following values are accepted for <parameter>pname</parameter>:
 110         </para>
 111         <variablelist>
 112             <varlistentry>
 113                 <term><constant>GL_POINT_SIZE_MIN</constant></term>
 114                 <listitem>
 115                     <para>
 116                     </para>
 117                     <para>
 118                         <parameter>params</parameter> is a single floating-point value that specifies the minimum point size.  The default value is 0.0.
 119                     </para>
 120                 </listitem>
 121             </varlistentry>
 122             <varlistentry>
 123                 <term><constant>GL_POINT_SIZE_MAX</constant></term>
 124                 <listitem>
 125                     <para>
 126                     </para>
 127                     <para>
 128                         <parameter>params</parameter> is a single floating-point value that specifies the maximum point size.  The default value is 1.0.
 129                     </para>
 130                 </listitem>
 131             </varlistentry>
 132             <varlistentry>
 133                 <term><constant>GL_POINT_FADE_THRESHOLD_SIZE</constant></term>
 134                 <listitem>
 135                     <para>
 136                     </para>
 137                     <para>
 138                         <parameter>params</parameter> is a single floating-point value that specifies the threshold value
 139                         to which point sizes are clamped if they exceed the specified value.  The
 140                         default value is 1.0.
 141                     </para>
 142                 </listitem>
 143             </varlistentry>
 144             <varlistentry>
 145                 <term><constant>GL_POINT_DISTANCE_ATTENUATION</constant></term>
 146                 <listitem>
 147                     <para>
 148                     </para>
 149                     <para>
 150                         <parameter>params</parameter> is an array of three floating-point values that specify the
 151                         coefficients used for scaling the computed point size.  The default values
 152                         are
 153                         <inlineequation><mml:math>
 154                             <!-- eqn: (1,  0,  0):-->
 155                             <mml:mfenced open="(" close=")">
 156                                 <mml:mn>1</mml:mn>
 157                                 <mml:mn>0</mml:mn>
 158                                 <mml:mn>0</mml:mn>
 159                             </mml:mfenced>
 160                         </mml:math></inlineequation>.
 161                     </para>
 162                 </listitem>
 163             </varlistentry>
 164             <varlistentry>
 165                 <term><constant>GL_POINT_SPRITE_COORD_ORIGIN</constant></term>
 166                 <listitem>
 167                     <para>
 168                     </para>
 169                     <para>
 170                         <parameter>params</parameter> is a single enum specifying the point sprite texture coordinate origin, either <constant>GL_LOWER_LEFT</constant> or <constant>GL_UPPER_LEFT</constant>.
 171                         The default value is <constant>GL_UPPER_LEFT</constant>.
 172                     </para>
 173                 </listitem>
 174             </varlistentry>
 175         </variablelist>
 176     </refsect1>
 177     <refsect1 id="notes"><title>Notes</title>
 178         <para>
 179             <function>glPointParameter</function> is available only if the GL version is 1.4 or greater.
 180         </para>
 181         <para>
 182             <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant> is available only if the GL version is 2.0 or greater.
 183         </para>
 184     </refsect1>
 185     <refsect1 id="errors"><title>Errors</title>
 186         <para>
 187             <constant>GL_INVALID_VALUE</constant> is generated If the value specified for
 188             <constant>GL_POINT_SIZE_MIN</constant>, <constant>GL_POINT_SIZE_MAX</constant>, or
 189             <constant>GL_POINT_FADE_THRESHOLD_SIZE</constant> is less than zero.
 190         </para>
 191         <para>
 192             <constant>GL_INVALID_ENUM</constant> is generated If the value specified for
 193             <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant> is not <constant>GL_LOWER_LEFT</constant> or <constant>GL_UPPER_LEFT</constant>.
 194         </para>
 195         <para>
 196             If the value for <constant>GL_POINT_SIZE_MIN</constant> is greater than
 197             <constant>GL_POINT_SIZE_MAX</constant>, the point size after clamping is undefined, but no
 198             error is generated.
 199         </para>
 200         <para>
 201         </para>
 202     </refsect1>
 203     <refsect1 id="associatedgets"><title>Associated Gets</title>
 204         <para>
 205             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_SIZE_MIN</constant>
 206         </para>
 207         <para>
 208             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_SIZE_MAX</constant>
 209         </para>
 210         <para>
 211             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_FADE_THRESHOLD_SIZE</constant>
 212         </para>
 213         <para>
 214             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_DISTANCE_ATTENUATION</constant>
 215         </para>
 216         <para>
 217             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant>
 218         </para>
 219     </refsect1>
 220     <refsect1 id="seealso"><title>See Also</title>
 221         <para>
 222             <citerefentry><refentrytitle>glPointSize</refentrytitle></citerefentry>
 223         </para>
 224     </refsect1>
 225     <refsect1 id="Copyright"><title>Copyright</title>
 226         <para>
 227             Copyright <trademark class="copyright"></trademark> 1991-2006
 228             Silicon Graphics, Inc. This document is licensed under the SGI
 229             Free Software B License. For details, see
 230             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 231         </para>
 232     </refsect1>
 233 </refentry>