| 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> |