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=
"gl_PointCoord">
9 <holder>Khronos Group
</holder>
12 <refentrytitle>gl_PointCoord
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>gl_PointCoord
</refname>
17 <refpurpose>contains the coordinate of a fragment within a point
</refpurpose>
19 <refsynopsisdiv><title>Declaration
</title>
21 <function>in vec2 gl_PointCoord;
</function>
24 <refsect1 id=
"description"><title>Description
</title>
26 <function>gl_PointCoord
</function> is a fragment language input variable that contains
27 the two-dimensional coordinates indicating where within a point primitive the current
28 fragment is located. If the current primitive is not a point, then values read
29 from
<function>gl_PointCoord
</function> are undefined.
32 <function>gl_PointCoord.s
</function> ranges from
0.0 to
1.0 across the point horizontally
33 from left to right. If
<constant>GL_POINT_SPRITE_COORD_ORIGIN
</constant> is
34 <constant>GL_LOWER_LEFT
</constant>,
<function>gl_PointCoord.t
</function> varies
35 from
0.0 to
1.0 vertically from bottom to top. Otherwise, if
<constant>GL_POINT_SPRITE_COORD_ORIGIN
</constant>
36 is
<constant>GL_UPPER_LEFT
</constant> then
<function>gl_PointCoord.t
</function> varies
37 from
0.0 to
1.0 vertically from top to bottom. The default value of
<constant>GL_POINT_SPRITE_COORD_ORIGIN
</constant>
38 is
<constant>GL_UPPER_LEFT
</constant>.
41 <refsect1 id=
"versions"><title>Version Support
</title>
42 <informaltable frame=
"topbot">
43 <tgroup cols=
"3" align=
"left">
44 <colspec colwidth=
"1.1*" />
45 <colspec colwidth=
"1*" align=
"center" />
46 <colspec colwidth=
"1*" align=
"center" />
47 <colspec colwidth=
"1*" align=
"center" />
48 <colspec colwidth=
"1*" align=
"center" />
49 <colspec colwidth=
"1*" align=
"center" />
50 <colspec colwidth=
"1*" align=
"center" />
51 <colspec colwidth=
"1*" align=
"center" />
52 <colspec colwidth=
"1*" align=
"center" />
55 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
58 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
61 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
64 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
67 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
70 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
73 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
76 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
79 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
88 <emphasis>Y
</emphasis>
91 <emphasis>Y
</emphasis>
94 <emphasis>Y
</emphasis>
97 <emphasis>Y
</emphasis>
100 <emphasis>Y
</emphasis>
103 <emphasis>Y
</emphasis>
106 <emphasis>Y
</emphasis>
109 <emphasis>Y
</emphasis>
116 <refsect1 id=
"seealso"><title>See Also
</title>
118 <citerefentry><refentrytitle>gl_FragCoord
</refentrytitle></citerefentry>,
119 <citerefentry><refentrytitle>gl_FragDepth
</refentrytitle></citerefentry>
122 <refsect1 id=
"Copyright"><title>Copyright
</title>
124 Copyright
<trademark class=
"copyright"></trademark> 2011 Khronos Group.
125 This material may be distributed subject to the terms and conditions set forth in
126 the Open Publication License, v
1.0,
8 June
1999.
127 <ulink url=
"http://opencontent.org/openpub/">http://opencontent.org/openpub/
</ulink>.