mirror of
https://github.com/Ryujinx/Opentk.git
synced 2024-12-26 08:25:38 +00:00
205 lines
13 KiB
XML
205 lines
13 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="glBeginQuery">
|
|
<refmeta>
|
|
<refmetainfo>
|
|
<copyright>
|
|
<year>2005</year>
|
|
<holder>Sams Publishing</holder>
|
|
</copyright>
|
|
</refmetainfo>
|
|
<refentrytitle>glBeginQuery</refentrytitle>
|
|
<manvolnum>3G</manvolnum>
|
|
</refmeta>
|
|
<refnamediv>
|
|
<refname>glBeginQuery</refname>
|
|
<refpurpose>delimit the boundaries of a query object</refpurpose>
|
|
</refnamediv>
|
|
<refsynopsisdiv><title>C Specification</title>
|
|
<funcsynopsis>
|
|
<funcprototype>
|
|
<funcdef>void <function>glBeginQuery</function></funcdef>
|
|
<paramdef>GLenum <parameter>target</parameter></paramdef>
|
|
<paramdef>GLuint <parameter>id</parameter></paramdef>
|
|
</funcprototype>
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
<!-- eqn: ignoring delim $$ -->
|
|
<refsect1 id="parameters"><title>Parameters</title>
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><parameter>target</parameter></term>
|
|
<listitem>
|
|
<para>
|
|
Specifies the target type of query object established between
|
|
<function>glBeginQuery</function> and the subsequent <citerefentry><refentrytitle>glEndQuery</refentrytitle></citerefentry>.
|
|
The symbolic constant must be one of <constant>GL_SAMPLES_PASSED</constant>, <constant>GL_ANY_SAMPLES_PASSED</constant>,
|
|
<constant>GL_PRIMITIVES_GENERATED</constant>, <constant>GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN</constant>, or
|
|
<constant>GL_TIME_ELAPSED</constant>.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>id</parameter></term>
|
|
<listitem>
|
|
<para>
|
|
Specifies the name of a query object.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
<refsynopsisdiv><title>C Specification</title>
|
|
<funcsynopsis>
|
|
<funcprototype>
|
|
<funcdef>void <function>glEndQuery</function></funcdef>
|
|
<paramdef>GLenum <parameter>target</parameter></paramdef>
|
|
</funcprototype>
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
<!-- eqn: ignoring delim $$ -->
|
|
<refsect1 id="parameters2"><title>Parameters</title>
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><parameter>target</parameter></term>
|
|
<listitem>
|
|
<para>
|
|
Specifies the target type of query object to be concluded.
|
|
The symbolic constant must be one of <constant>GL_SAMPLES_PASSED</constant>, <constant>GL_ANY_SAMPLES_PASSED</constant>,
|
|
<constant>GL_PRIMITIVES_GENERATED</constant>, <constant>GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN</constant>, or
|
|
<constant>GL_TIME_ELAPSED</constant>.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
<refsect1 id="description"><title>Description</title>
|
|
<para>
|
|
<function>glBeginQuery</function> and <citerefentry><refentrytitle>glEndQuery</refentrytitle></citerefentry> delimit the
|
|
boundaries of a query object. <parameter>query</parameter> must be a name previously returned from a call to
|
|
<citerefentry><refentrytitle>glGenQueries</refentrytitle></citerefentry>. If a query object with name <parameter>id</parameter>
|
|
does not yet exist it is created with the type determined by <parameter>target</parameter>. <parameter>target</parameter> must
|
|
be one of <constant>GL_SAMPLES_PASSED</constant>, <constant>GL_ANY_SAMPLES_PASSED</constant>, <constant>GL_PRIMITIVES_GENERATED</constant>,
|
|
<constant>GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN</constant>, or <constant>GL_TIME_ELAPSED</constant>. The behavior of the query
|
|
object depends on its type and is as follows.
|
|
</para>
|
|
<para>
|
|
If <parameter>target</parameter> is <constant>GL_SAMPLES_PASSED</constant>, <parameter>target</parameter> must be an unused name,
|
|
or the name of an existing occlusion query object.
|
|
When <function>glBeginQuery</function> is executed, the query object's samples-passed counter is reset to 0. Subsequent
|
|
rendering will increment the counter for every sample that passes the depth test. If the value of <constant>GL_SAMPLE_BUFFERS</constant>
|
|
is 0, then the samples-passed count is incremented by 1 for each fragment. If the value of <constant>GL_SAMPLE_BUFFERS</constant>
|
|
is 1, then the samples-passed count is incremented by the number of samples whose coverage bit is set. However, implementations, at their
|
|
discression may instead increase the samples-passed count by the value of <constant>GL_SAMPLES</constant> if any sample in the fragment
|
|
is covered. When <function>glEndQuery</function>
|
|
is executed, the samples-passed counter is assigned to the query object's result value. This value can be queried by
|
|
calling <citerefentry><refentrytitle>glGetQueryObject</refentrytitle></citerefentry> with <parameter>pname</parameter>
|
|
<constant>GL_QUERY_RESULT</constant>.
|
|
</para>
|
|
<para>
|
|
If <parameter>target</parameter> is <constant>GL_ANY_SAMPLES_PASSED</constant>, <parameter>target</parameter> must be an unused name,
|
|
or the name of an existing boolean occlusion query object.
|
|
When <function>glBeginQuery</function> is executed, the query object's samples-passed flag is reset to <constant>GL_FALSE</constant>.
|
|
Subsequent rendering causes the flag to be set to <constant>GL_TRUE</constant> if any sample passes the depth test. When
|
|
<function>glEndQuery</function> is executed, the samples-passed flag is assigned to the query object's result value. This value can
|
|
be queried by calling <citerefentry><refentrytitle>glGetQueryObject</refentrytitle></citerefentry> with <parameter>pname</parameter>
|
|
<constant>GL_QUERY_RESULT</constant>.
|
|
</para>
|
|
<para>
|
|
If <parameter>target</parameter> is <constant>GL_PRIMITIVES_GENERATED</constant>, <parameter>target</parameter> must be an unused
|
|
name, or the name of an existing primitive query object previously bound to the <constant>GL_PRIMITIVES_GENERATED</constant> query binding.
|
|
When <function>glBeginQuery</function> is executed, the query object's primitives-generated counter is reset to 0. Subsequent
|
|
rendering will increment the counter once for every vertex that is emitted from the geometry shader, or from the vertex shader if
|
|
no geometry shader is present. When <function>glEndQuery</function> is executed, the primitives-generated counter is assigned to
|
|
the query object's result value. This value can be queried by calling <citerefentry><refentrytitle>glGetQueryObject</refentrytitle></citerefentry> with <parameter>pname</parameter>
|
|
<constant>GL_QUERY_RESULT</constant>.
|
|
</para>
|
|
<para>
|
|
If <parameter>target</parameter> is <constant>GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN</constant>, <parameter>target</parameter> must be
|
|
an unused name, or the name of an existing primitive query object previously bound to the <constant>GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN</constant>
|
|
query binding. When <function>glBeginQuery</function> is executed, the query object's primitives-written counter is reset to 0. Subsequent
|
|
rendering will increment the counter once for every vertex that is written into the bound transform feedback buffer(s). If transform feedback
|
|
mode is not activated between the call to <function>glBeginQuery</function> and <function>glEndQuery</function>, the counter will not be
|
|
incremented. When <function>glEndQuery</function> is executed, the primitives-written counter is assigned to
|
|
the query object's result value. This value can be queried by calling <citerefentry><refentrytitle>glGetQueryObject</refentrytitle></citerefentry> with <parameter>pname</parameter>
|
|
<constant>GL_QUERY_RESULT</constant>.
|
|
</para>
|
|
<para>
|
|
If <parameter>target</parameter> is <constant>GL_TIME_ELAPSED</constant>, <parameter>target</parameter> must be
|
|
an unused name, or the name of an existing timer query object previously bound to the <constant>GL_TIME_ELAPSED</constant>
|
|
query binding. When <function>glBeginQuery</function> is executed, the query object's time counter is reset to 0. When <function>glEndQuery</function>
|
|
is executed, the elapsed server time that has passed since the call to <function>glBeginQuery</function> is written into the query object's
|
|
time counter. This value can be queried by calling <citerefentry><refentrytitle>glGetQueryObject</refentrytitle></citerefentry> with <parameter>pname</parameter>
|
|
<constant>GL_QUERY_RESULT</constant>.
|
|
</para>
|
|
<para>
|
|
Querying the <constant>GL_QUERY_RESULT</constant> implicitly flushes the GL pipeline until the rendering delimited by the
|
|
query object has completed and the result is available. <constant>GL_QUERY_RESULT_AVAILABLE</constant> can be queried to
|
|
determine if the result is immediately available or if the rendering is not yet complete.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="notes"><title>Notes</title>
|
|
<para>
|
|
If the query target's count exceeds the maximum value representable in the number of available bits, as reported by
|
|
<citerefentry><refentrytitle>glGetQueryiv</refentrytitle></citerefentry> with <parameter>target</parameter> set to the
|
|
appropriate query target and <parameter>pname</parameter>
|
|
<constant>GL_QUERY_COUNTER_BITS</constant>, the count becomes undefined.
|
|
</para>
|
|
<para>
|
|
An implementation may support 0 bits in its counter, in which case query results are always undefined
|
|
and essentially useless.
|
|
</para>
|
|
<para>
|
|
When <constant>GL_SAMPLE_BUFFERS</constant> is 0, the samples-passed counter of an occlusion query will increment once for each
|
|
fragment that passes the depth test. When <constant>GL_SAMPLE_BUFFERS</constant> is 1, an implementation may either increment
|
|
the samples-passed counter individually for each sample of a fragment that passes the depth test, or it may choose to increment
|
|
the counter for all samples of a fragment if any one of them passes the depth test.
|
|
</para>
|
|
<para>
|
|
The query targets <constant>GL_ANY_SAMPLES_PASSED</constant>, and <constant>GL_TIME_ELAPSED</constant> are availale only if
|
|
the GL version is 3.3 or higher.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="errors"><title>Errors</title>
|
|
<para>
|
|
<constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not one of the accepted tokens.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_OPERATION</constant> is generated if <function>glBeginQuery</function> is executed while
|
|
a query object of the same <parameter>target</parameter> is already active.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_OPERATION</constant> is generated if <citerefentry><refentrytitle>glEndQuery</refentrytitle></citerefentry>
|
|
is executed when a query object of the same <parameter>target</parameter> is not active.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_OPERATION</constant> is generated if <parameter>id</parameter> is 0.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_OPERATION</constant> is generated if <parameter>id</parameter> is the name of an already active query object.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_OPERATION</constant> is generated if <parameter>id</parameter> refers to an existing query object whose type
|
|
does not does not match <parameter>target</parameter>.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="seealso"><title>See Also</title>
|
|
<para>
|
|
<citerefentry><refentrytitle>glDeleteQueries</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glGenQueries</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glGetQueryiv</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glGetQueryObject</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glIsQuery</refentrytitle></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="Copyright"><title>Copyright</title>
|
|
<para>
|
|
Copyright <trademark class="copyright"></trademark> 2005 Addison-Wesley.
|
|
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>
|