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=
"glDrawElementsBaseVertex">
9 <holder>Khronos Group
</holder>
12 <refentrytitle>glDrawElementsBaseVertex
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>glDrawElementsBaseVertex
</refname>
17 <refpurpose>render primitives from array data with a per-element offset
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>void
<function>glDrawElementsBaseVertex
</function></funcdef>
23 <paramdef>GLenum
<parameter>mode
</parameter></paramdef>
24 <paramdef>GLsizei
<parameter>count
</parameter></paramdef>
25 <paramdef>GLenum
<parameter>type
</parameter></paramdef>
26 <paramdef>GLvoid *
<parameter>indices
</parameter></paramdef>
27 <paramdef>GLint
<parameter>basevertex
</parameter></paramdef>
31 <!-- eqn: ignoring delim $$ -->
32 <refsect1 id=
"parameters"><title>Parameters
</title>
35 <term><parameter>mode
</parameter></term>
38 Specifies what kind of primitives to render.
40 <constant>GL_POINTS
</constant>,
<constant>GL_LINE_STRIP
</constant>,
<constant>GL_LINE_LOOP
</constant>,
41 <constant>GL_LINES
</constant>,
<constant>GL_TRIANGLE_STRIP
</constant>,
<constant>GL_TRIANGLE_FAN
</constant>,
42 <constant>GL_TRIANGLES
</constant>,
<constant>GL_LINES_ADJACENCY
</constant>,
<constant>GL_LINE_STRIP_ADJACENCY
</constant>,
43 <constant>GL_TRIANGLES_ADJACENCY
</constant>,
<constant>GL_TRIANGLE_STRIP_ADJACENCY
</constant> and
<constant>GL_PATCHES
</constant> are accepted.
48 <term><parameter>count
</parameter></term>
51 Specifies the number of elements to be rendered.
56 <term><parameter>type
</parameter></term>
59 Specifies the type of the values in indices. Must be one of
<constant>GL_UNSIGNED_BYTE
</constant>,
60 <constant>GL_UNSIGNED_SHORT
</constant>, or
<constant>GL_UNSIGNED_INT
</constant>.
65 <term><parameter>indices
</parameter></term>
68 Specifies a pointer to the location where the indices are stored.
73 <term><parameter>basevertex
</parameter></term>
76 Specifies a constant that should be added to each element of
<parameter>indices
</parameter>
77 when chosing elements from the enabled vertex arrays.
83 <refsect1 id=
"description"><title>Description
</title>
85 <function>glDrawElementsBaseVertex
</function> behaves identically to
86 <citerefentry><refentrytitle>glDrawElements
</refentrytitle></citerefentry> except that the
<emphasis>i
</emphasis>th element
87 transferred by the corresponding draw call will be taken from element
<parameter>indices
</parameter>[i] +
<parameter>basevertex
</parameter>
88 of each enabled array. If the resulting value is larger than the maximum value representable by
<parameter>type
</parameter>,
89 it is as if the calculation were upconverted to
32-bit unsigned integers (with wrapping on overflow conditions).
90 The operation is undefined if the sum would be negative.
93 <refsect1 id=
"notes"><title>Notes
</title>
94 <function>glDrawElementsBaseVertex
</function> is only supported if the GL version is
3.2 or greater, or if
95 the
<code>ARB_draw_elements_base_vertex
</code> extension is supported.
97 <refsect1 id=
"errors"><title>Errors
</title>
99 <constant>GL_INVALID_ENUM
</constant> is generated if
<parameter>mode
</parameter> is not an accepted value.
102 <constant>GL_INVALID_VALUE
</constant> is generated if
<parameter>count
</parameter> is negative.
105 <constant>GL_INVALID_OPERATION
</constant> is generated if a geometry shader is active and
<parameter>mode
</parameter>
106 is incompatible with the input primitive type of the geometry shader in the currently installed program object.
109 <constant>GL_INVALID_OPERATION
</constant> is generated if a non-zero buffer object name is bound to an
110 enabled array or the element array and the buffer object's data store is currently mapped.
113 <refsect1 id=
"seealso"><title>See Also
</title>
115 <citerefentry><refentrytitle>glDrawElements
</refentrytitle></citerefentry>,
116 <citerefentry><refentrytitle>glDrawRangeElements
</refentrytitle></citerefentry>,
117 <citerefentry><refentrytitle>glDrawRangeElementsBaseVertex
</refentrytitle></citerefentry>,
118 <citerefentry><refentrytitle>glDrawElementsInstanced
</refentrytitle></citerefentry>,
119 <citerefentry><refentrytitle>glDrawElementsInstancedBaseVertex
</refentrytitle></citerefentry>
122 <refsect1 id=
"Copyright"><title>Copyright
</title>
124 Copyright
<trademark class=
"copyright"></trademark> 2010 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>.