<?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="glDrawTransformFeedbackStream"> <refmeta> <refmetainfo> <copyright> <year>2010</year> <holder>Khronos Group.</holder> </copyright> </refmetainfo> <refentrytitle>glDrawTransformFeedbackStream</refentrytitle> <manvolnum>3G</manvolnum> </refmeta> <refnamediv> <refname>glDrawTransformFeedbackStream</refname> <refpurpose>render primitives using a count derived from a specifed stream of a transform feedback object</refpurpose> </refnamediv> <refsynopsisdiv><title>C Specification</title> <funcsynopsis> <funcprototype> <funcdef>void <function>glDrawTransformFeedbackStream</function></funcdef> <paramdef>GLenum <parameter>mode</parameter></paramdef> <paramdef>GLuint <parameter>id</parameter></paramdef> <paramdef>GLuint <parameter>stream</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>id</parameter></term> <listitem> <para> Specifies the name of a transform feedback object from which to retrieve a primitive count. </para> </listitem> </varlistentry> <varlistentry> <term><parameter>stream</parameter></term> <listitem> <para> Specifies the index of the transform feedback stream from which to retrieve a primitive count. </para> </listitem> </varlistentry> </variablelist> </refsect1> <refsect1 id="description"><title>Description</title> <para> <function>glDrawTransformFeedbackStream</function> draws primitives of a type specified by <parameter>mode</parameter> using a count retrieved from the transform feedback stream specified by <parameter>stream</parameter> of the transform feedback object specified by <parameter>id</parameter>. Calling <function>glDrawTransformFeedbackStream</function> is equivalent to calling <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry> with <parameter>mode</parameter> as specified, <parameter>first</parameter> set to zero, and <parameter>count</parameter> set to the number of vertices captured on vertex stream <parameter>stream</parameter> the last time transform feedback was active on the transform feedback object named by <parameter>id</parameter>. </para> <para> Calling <citerefentry>glDrawTransformFeedback</citerefentry> is equivalent to calling <function>glDrawTransformFeedbackStream</function> with <parameter>stream</parameter> set to zero. </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_VALUE</constant> is generated if <parameter>id</parameter> is not the name of a transform feedback object. </para> <para> <constant>GL_INVALID_VALUE</constant> is generated if <parameter>stream</parameter> is greater than or equal to the value of <constant>GL_MAX_VERTEX_STREAMS</constant>. </para> <para> <constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to an enabled array 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> <para> <constant>GL_INVALID_OPERATION</constant> is generated if <citerefentry><refentrytitle>glEndTransformFeedback</refentrytitle></citerefentry> has never been called while the transform feedback object named by <parameter>id</parameter> was bound. </para> </refsect1> <refsect1 id="seealso"><title>See Also</title> <para> <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawArraysInstanced</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawTransformFeedback</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>