mirror of
https://github.com/Ryujinx/Opentk.git
synced 2024-12-26 12:15:46 +00:00
163 lines
8 KiB
XML
163 lines
8 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
|
|
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
|
|
"http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
|
|
<refentry id="glDrawArraysIndirect">
|
|
<refmeta>
|
|
<refmetainfo>
|
|
<copyright>
|
|
<year>2010</year>
|
|
<holder>Khronos Group.</holder>
|
|
</copyright>
|
|
</refmetainfo>
|
|
<refentrytitle>glDrawElementsIndirect</refentrytitle>
|
|
<manvolnum>3G</manvolnum>
|
|
</refmeta>
|
|
<refnamediv>
|
|
<refname>glDrawElementsIndirect</refname>
|
|
<refpurpose>render indexed primitives from array data, taking parameters from memory</refpurpose>
|
|
</refnamediv>
|
|
<refsynopsisdiv><title>C Specification</title>
|
|
<funcsynopsis>
|
|
<funcprototype>
|
|
<funcdef>void <function>glDrawElementsIndirect</function></funcdef>
|
|
<paramdef>GLenum <parameter>mode</parameter></paramdef>
|
|
<paramdef>GLenum <parameter>type</parameter></paramdef>
|
|
<paramdef>const void *<parameter>indirect</parameter></paramdef>
|
|
</funcprototype>
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
<!-- eqn: ignoring delim $$ -->
|
|
<refsect1 id="parameters"><title>Parameters</title>
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><parameter>mode</parameter></term>
|
|
<listitem>
|
|
<para>
|
|
Specifies what kind of primitives to render.
|
|
Symbolic constants
|
|
<constant>GL_POINTS</constant>,
|
|
<constant>GL_LINE_STRIP</constant>,
|
|
<constant>GL_LINE_LOOP</constant>,
|
|
<constant>GL_LINES</constant>,
|
|
<constant>GL_LINE_STRIP_ADJACENCY</constant>,
|
|
<constant>GL_LINES_ADJACENCY</constant>,
|
|
<constant>GL_TRIANGLE_STRIP</constant>,
|
|
<constant>GL_TRIANGLE_FAN</constant>,
|
|
<constant>GL_TRIANGLES</constant>,
|
|
<constant>GL_TRIANGLE_STRIP_ADJACENCY</constant>,
|
|
<constant>GL_TRIANGLES_ADJACENCY</constant>, and
|
|
<constant>GL_PATCHES</constant>
|
|
are accepted.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>type</parameter></term>
|
|
<listitem>
|
|
<para>
|
|
Specifies the type of data in the buffer bound to the <constant>GL_ELEMENT_ARRAY_BUFFER</constant> binding.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>indirect</parameter></term>
|
|
<listitem>
|
|
<para>
|
|
Specifies the address of a structure containing the draw parameters.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
<refsect1 id="description"><title>Description</title>
|
|
<para>
|
|
<function>glDrawElementsIndirect</function> specifies multiple indexed geometric primitives
|
|
with very few subroutine calls. <function>glDrawElementsIndirect</function> behaves
|
|
similarly to <citerefentry><refentrytitle>glDrawElementsInstancedBaseVertex</refentrytitle></citerefentry>,
|
|
execpt that the parameters to <citerefentry><refentrytitle>glDrawElementsInstancedBaseVertex</refentrytitle></citerefentry>
|
|
are stored in memory at the address given by <parameter>indirect</parameter>.
|
|
</para>
|
|
<para>
|
|
The parameters addressed by <parameter>indirect</parameter> are packed into a structure
|
|
that takes the form (in C):
|
|
<programlisting><![CDATA[ typedef struct {
|
|
uint count;
|
|
uint primCount;
|
|
uint firstIndex;
|
|
uint baseVertex;
|
|
uint reservedMustBeZero;
|
|
} DrawElementsIndirectCommand;]]></programlisting>
|
|
<para>
|
|
<function>glDrawElementsIndirect</function> is equivalent to:
|
|
</para>
|
|
<programlisting><![CDATA[ void glDrawElementsIndirect(GLenum mode, GLenum type, const void * indirect)
|
|
{
|
|
const DrawElementsIndirectCommand *cmd = (const DrawElementsIndirectCommand *)indirect;
|
|
glDrawElementsInstancedBaseVertex(mode,
|
|
cmd->count,
|
|
type,
|
|
cmd->firstIndex + size-of-type,
|
|
cmd->primCount,
|
|
cmd->baseVertex);
|
|
}]]></programlisting>
|
|
</para>
|
|
<para>
|
|
If a buffer is bound to the <constant>GL_INDIRECT_BUFFER</constant> binding at the time
|
|
of a call to <function>glDrawElementsIndirect</function>, <parameter>indirect</parameter>
|
|
is interpreted as an offset, in basic machine units, into that buffer and the parameter
|
|
data is read from the buffer rather than from client memory.
|
|
</para>
|
|
<para>
|
|
Note that indices stored in client memory are not supported. If no buffer is bound to the
|
|
<constant>GL_ELEMENT_ARRAY_BUFFER</constant> binding, an error will be generated.
|
|
</para>
|
|
<para>
|
|
The results of the operation are undefined if the <code>reservedMustBeZero</code> member
|
|
of the parameter structure is non-zero. However, no error is generated in this case.
|
|
</para>
|
|
<para>
|
|
Vertex attributes that are modified by <function>glDrawElementsIndirect</function> have an
|
|
unspecified value after <function>glDrawElementsIndirect</function> returns. Attributes that aren't
|
|
modified remain well defined.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="errors"><title>Errors</title>
|
|
<para>
|
|
<constant>GL_INVALID_ENUM</constant> is generated if <parameter>mode</parameter> is not an accepted value.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_OPERATION</constant> is generated if no buffer is bound to the <constant>GL_ELEMENT_ARRAY_BUFFER</constant>
|
|
binding, or if such a buffer's data store is currently mapped.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to an
|
|
enabled array or to the <constant>GL_INDIRECT_BUFFER</constant> binding and the buffer object's data store is currently mapped.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_OPERATION</constant> is generated if a geometry shader is active and <parameter>mode</parameter>
|
|
is incompatible with the input primitive type of the geometry shader in the currently installed program object.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_OPERATION</constant> is generated if <parameter>mode</parameter> is <constant>GL_PATCHES</constant>
|
|
and no tessellation control shader is active.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="seealso"><title>See Also</title>
|
|
<para>
|
|
<citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glDrawArraysInstanced</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glDrawArraysIndirect</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="Copyright"><title>Copyright</title>
|
|
<para>
|
|
Copyright <trademark class="copyright"></trademark> 2010 Khronos Group.
|
|
This material may be distributed subject to the terms and conditions set forth in
|
|
the Open Publication License, v 1.0, 8 June 1999.
|
|
<ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
|
|
</para>
|
|
</refsect1>
|
|
</refentry>
|