[clinton/guile-figl.git] / upstream-doc / man3 / glGetTexLevelParameter.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="glGetTexLevelParameter">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glGetTexLevelParameter</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glGetTexLevelParameter</refname>
        <refpurpose>return texture parameter values for a specific level of detail</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glGetTexLevelParameterfv</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLint <parameter>level</parameter></paramdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLfloat * <parameter>params</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glGetTexLevelParameteriv</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLint <parameter>level</parameter></paramdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLint * <parameter>params</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 symbolic name of the target texture,
                    one of
                    <constant>GL_TEXTURE_1D</constant>,
                    <constant>GL_TEXTURE_2D</constant>,
                    <constant>GL_TEXTURE_3D</constant>,
                    <constant>GL_TEXTURE_1D_ARRAY</constant>,
                    <constant>GL_TEXTURE_2D_ARRAY</constant>,
                    <constant>GL_TEXTURE_RECTANGLE</constant>,
                    <constant>GL_TEXTURE_2D_MULTISAMPLE</constant>,
                    <constant>GL_TEXTURE_2D_MULTISAMPLE_ARRAY</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>,
                    <constant>GL_PROXY_TEXTURE_1D</constant>,
                    <constant>GL_PROXY_TEXTURE_2D</constant>,
                    <constant>GL_PROXY_TEXTURE_3D</constant>,
                    <constant>GL_PROXY_TEXTURE_1D_ARRAY</constant>,
                    <constant>GL_PROXY_TEXTURE_2D_ARRAY</constant>,
                    <constant>GL_PROXY_TEXTURE_RECTANGLE</constant>,
                    <constant>GL_PROXY_TEXTURE_2D_MULTISAMPLE</constant>,
                    <constant>GL_PROXY_TEXTURE_2D_MULTISAMPLE_ARRAY</constant>,
                    <constant>GL_PROXY_TEXTURE_CUBE_MAP</constant>, or
                    <constant>GL_TEXTURE_BUFFER</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>level</parameter></term>
            <listitem>
                <para>
                    Specifies the level-of-detail number of the desired image.
                    Level 0 is the base image level.
                    Level 
                    <inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
                    is the 
                    <inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>th
                    mipmap reduction image.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>pname</parameter></term>
            <listitem>
                <para>
                    Specifies the symbolic name of a texture parameter.
                    <constant>GL_TEXTURE_WIDTH</constant>,
                    <constant>GL_TEXTURE_HEIGHT</constant>,
                    <constant>GL_TEXTURE_DEPTH</constant>,
                    <constant>GL_TEXTURE_INTERNAL_FORMAT</constant>,
                    <constant>GL_TEXTURE_BORDER</constant>,
                    <constant>GL_TEXTURE_RED_SIZE</constant>,
                    <constant>GL_TEXTURE_GREEN_SIZE</constant>,
                    <constant>GL_TEXTURE_BLUE_SIZE</constant>,
                    <constant>GL_TEXTURE_ALPHA_SIZE</constant>,
                    <constant>GL_TEXTURE_DEPTH_SIZE</constant>,
                    <constant>GL_TEXTURE_COMPRESSED</constant>, and
                    <constant>GL_TEXTURE_COMPRESSED_IMAGE_SIZE</constant>
                     are accepted.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>params</parameter></term>
            <listitem>
                <para>
                    Returns the requested data.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glGetTexLevelParameter</function> returns in <parameter>params</parameter> texture parameter values for a specific
            level-of-detail value,
            specified as <parameter>level</parameter>.
            <parameter>target</parameter> defines the target texture,
            either <constant>GL_TEXTURE_1D</constant>, <constant>GL_TEXTURE_2D</constant>, <constant>GL_TEXTURE_3D</constant>,
            <constant>GL_PROXY_TEXTURE_1D</constant>,
            <constant>GL_PROXY_TEXTURE_2D</constant>,
            <constant>GL_PROXY_TEXTURE_3D</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>, or
            <constant>GL_PROXY_TEXTURE_CUBE_MAP</constant>.
        </para>
        <para>
            <constant>GL_MAX_TEXTURE_SIZE</constant>, and <constant>GL_MAX_3D_TEXTURE_SIZE</constant> are not really
            descriptive enough.
            It has to report the largest square texture image that can be
            accommodated with mipmaps and borders,
            but a long skinny texture, or a texture without mipmaps and borders, may
            easily fit in texture memory.
            The proxy targets allow the user to more accurately query
            whether the GL can accommodate a texture of a given configuration.
            If the texture cannot be accommodated, the texture state variables, which
            may be queried with <function>glGetTexLevelParameter</function>, are set to 0.  If the texture can be accommodated,
            the texture state values will be set as they would be set for a
            non-proxy target.
        </para>
        <para>
            <parameter>pname</parameter> specifies the texture parameter whose value or values
            will be returned.
        </para>
        <para>
            The accepted parameter names are as follows:
        </para>
        <variablelist>
            <varlistentry>
                <term><constant>GL_TEXTURE_WIDTH</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> returns a single value,
                        the width of the texture image.
                        This value includes the border of the texture image. The initial value is
                        0.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_HEIGHT</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> returns a single value,
                        the height of the texture image.
                        This value includes the border of the texture image. The initial value is
                        0.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_DEPTH</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> returns a single value,
                        the depth of the texture image.
                        This value includes the border of the texture image. The initial value is
                        0.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_INTERNAL_FORMAT</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> returns a single value,
                        the internal format of the texture image.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_RED_TYPE</constant>,</term>
                <listitem>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_GREEN_TYPE</constant>,</term>
                <listitem>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_BLUE_TYPE</constant>,</term>
                <listitem>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_ALPHA_TYPE</constant>,</term>
                <listitem>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_DEPTH_TYPE</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        The data type used to store the component.
                        The types <constant>GL_NONE</constant>, <constant>GL_SIGNED_NORMALIZED</constant>,
                        <constant>GL_UNSIGNED_NORMALIZED</constant>, <constant>GL_FLOAT</constant>,
                        <constant>GL_INT</constant>, and <constant>GL_UNSIGNED_INT</constant> may be returned
                        to indicate signed normalized fixed-point, unsigned normalized fixed-point, floating-point, integer unnormalized, and
                        unsigned integer unnormalized components, respectively.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_RED_SIZE</constant>,</term>
                <listitem>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_GREEN_SIZE</constant>,</term>
                <listitem>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_BLUE_SIZE</constant>,</term>
                <listitem>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_ALPHA_SIZE</constant>,</term>
                <listitem>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_DEPTH_SIZE</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        The internal storage resolution of an individual component.
                        The resolution chosen by the GL will be a close match for the resolution
                        requested by the user with the component argument of <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
                        <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>, and
                        <citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>. The initial value is 0.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_COMPRESSED</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> returns a single boolean value indicating if the texture image is
                        stored in a compressed internal format.  The initiali value is <constant>GL_FALSE</constant>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_COMPRESSED_IMAGE_SIZE</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> returns a single integer value, the number of unsigned bytes of the
                        compressed texture image that would be returned from
                        <citerefentry><refentrytitle>glGetCompressedTexImage</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            If an error is generated,
            no change is made to the contents of <parameter>params</parameter>.
        </para>
        <para>
            <function>glGetTexLevelParameter</function> returns the texture level parameters for the active texture unit.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> or <parameter>pname</parameter> is not an
            accepted value.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>level</parameter> is less than 0.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> may be generated if <parameter>level</parameter> is greater
            than 
            <inlineequation><mml:math>
                <!-- eqn: log sub 2: -->
                <mml:msub><mml:mi mathvariant="italic">log</mml:mi>
                <mml:mn>2</mml:mn>
                </mml:msub>
            </mml:math></inlineequation>
            <emphasis>max</emphasis>,
            where <emphasis>max</emphasis> is the returned value of <constant>GL_MAX_TEXTURE_SIZE</constant>.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>target</parameter> is <constant>GL_TEXTURE_BUFFER</constant>
            and <parameter>level</parameter> is not zero.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if
            <constant>GL_TEXTURE_COMPRESSED_IMAGE_SIZE</constant> is queried on texture images with an
            uncompressed internal format or on proxy targets.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glActiveTexture</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glGetTexParameter</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glCopyTexSubImage1D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glCopyTexSubImage2D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glCopyTexSubImage3D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexSubImage3D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 1991-2006
            Silicon Graphics, Inc. Copyright <trademark class="copyright"></trademark> 2010
            Khronos Group. This document is licensed under the SGI
            Free Software B License. For details, see
            <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
        </para>
    </refsect1>
</refentry>
Commit	Line	Data
7faf1d71 AW	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="glGetTexLevelParameter">
	5	<refmeta>
	6	<refmetainfo>
	7	<copyright>
f37e7e3d DH	8	<year>1991-2006</year>
f37e7e3d DH	9	<holder>Silicon Graphics, Inc.</holder>
7faf1d71 AW	10	</copyright>
	11	</refmetainfo>
	12	<refentrytitle>glGetTexLevelParameter</refentrytitle>
	13	<manvolnum>3G</manvolnum>
	14	</refmeta>
	15	<refnamediv>
	16	<refname>glGetTexLevelParameter</refname>
	17	<refpurpose>return texture parameter values for a specific level of detail</refpurpose>
	18	</refnamediv>
	19	<refsynopsisdiv><title>C Specification</title>
	20	<funcsynopsis>
	21	<funcprototype>
	22	<funcdef>void <function>glGetTexLevelParameterfv</function></funcdef>
	23	<paramdef>GLenum <parameter>target</parameter></paramdef>
	24	<paramdef>GLint <parameter>level</parameter></paramdef>
	25	<paramdef>GLenum <parameter>pname</parameter></paramdef>
	26	<paramdef>GLfloat * <parameter>params</parameter></paramdef>
	27	</funcprototype>
	28	</funcsynopsis>
	29	<funcsynopsis>
	30	<funcprototype>
	31	<funcdef>void <function>glGetTexLevelParameteriv</function></funcdef>
	32	<paramdef>GLenum <parameter>target</parameter></paramdef>
	33	<paramdef>GLint <parameter>level</parameter></paramdef>
	34	<paramdef>GLenum <parameter>pname</parameter></paramdef>
	35	<paramdef>GLint * <parameter>params</parameter></paramdef>
	36	</funcprototype>
	37	</funcsynopsis>
	38	</refsynopsisdiv>
	39	<!-- eqn: ignoring delim $$ -->
	40	<refsect1 id="parameters"><title>Parameters</title>
	41	<variablelist>
	42	<varlistentry>
	43	<term><parameter>target</parameter></term>
	44	<listitem>
	45	<para>
	46	Specifies the symbolic name of the target texture,
	47	one of
	48	<constant>GL_TEXTURE_1D</constant>,
	49	<constant>GL_TEXTURE_2D</constant>,
	50	<constant>GL_TEXTURE_3D</constant>,
	51	<constant>GL_TEXTURE_1D_ARRAY</constant>,
	52	<constant>GL_TEXTURE_2D_ARRAY</constant>,
	53	<constant>GL_TEXTURE_RECTANGLE</constant>,
	54	<constant>GL_TEXTURE_2D_MULTISAMPLE</constant>,
	55	<constant>GL_TEXTURE_2D_MULTISAMPLE_ARRAY</constant>,
	56	<constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>,
	57	<constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>,
	58	<constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>,
	59	<constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>,
	60	<constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>,
	61	<constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>,
	62	<constant>GL_PROXY_TEXTURE_1D</constant>,
	63	<constant>GL_PROXY_TEXTURE_2D</constant>,
	64	<constant>GL_PROXY_TEXTURE_3D</constant>,
	65	<constant>GL_PROXY_TEXTURE_1D_ARRAY</constant>,
	66	<constant>GL_PROXY_TEXTURE_2D_ARRAY</constant>,
	67	<constant>GL_PROXY_TEXTURE_RECTANGLE</constant>,
	68	<constant>GL_PROXY_TEXTURE_2D_MULTISAMPLE</constant>,
	69	<constant>GL_PROXY_TEXTURE_2D_MULTISAMPLE_ARRAY</constant>,
	70	<constant>GL_PROXY_TEXTURE_CUBE_MAP</constant>, or
	71	<constant>GL_TEXTURE_BUFFER</constant>.
	72	</para>
	73	</listitem>
74	</varlistentry>
75	<varlistentry>
76	<term><parameter>level</parameter></term>
77	<listitem>
78	<para>
79	Specifies the level-of-detail number of the desired image.
80	Level 0 is the base image level.
81	Level
82	<inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
83	is the
84	<inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>th
85	mipmap reduction image.
86	</para>
87	</listitem>
88	</varlistentry>
89	<varlistentry>
90	<term><parameter>pname</parameter></term>
91	<listitem>
92	<para>
93	Specifies the symbolic name of a texture parameter.
94	<constant>GL_TEXTURE_WIDTH</constant>,
95	<constant>GL_TEXTURE_HEIGHT</constant>,
96	<constant>GL_TEXTURE_DEPTH</constant>,
97	<constant>GL_TEXTURE_INTERNAL_FORMAT</constant>,
f37e7e3d	98	<constant>GL_TEXTURE_BORDER</constant>,
7faf1d71 AW	99	<constant>GL_TEXTURE_RED_SIZE</constant>,
	100	<constant>GL_TEXTURE_GREEN_SIZE</constant>,
	101	<constant>GL_TEXTURE_BLUE_SIZE</constant>,
	102	<constant>GL_TEXTURE_ALPHA_SIZE</constant>,
	103	<constant>GL_TEXTURE_DEPTH_SIZE</constant>,
	104	<constant>GL_TEXTURE_COMPRESSED</constant>, and
	105	<constant>GL_TEXTURE_COMPRESSED_IMAGE_SIZE</constant>
	106	are accepted.
	107	</para>
	108	</listitem>
	109	</varlistentry>
	110	<varlistentry>
	111	<term><parameter>params</parameter></term>
	112	<listitem>
	113	<para>
	114	Returns the requested data.
	115	</para>
	116	</listitem>
	117	</varlistentry>
	118	</variablelist>
	119	</refsect1>
	120	<refsect1 id="description"><title>Description</title>
	121	<para>
	122	<function>glGetTexLevelParameter</function> returns in <parameter>params</parameter> texture parameter values for a specific
	123	level-of-detail value,
	124	specified as <parameter>level</parameter>.
	125	<parameter>target</parameter> defines the target texture,
	126	either <constant>GL_TEXTURE_1D</constant>, <constant>GL_TEXTURE_2D</constant>, <constant>GL_TEXTURE_3D</constant>,
	127	<constant>GL_PROXY_TEXTURE_1D</constant>,
	128	<constant>GL_PROXY_TEXTURE_2D</constant>,
	129	<constant>GL_PROXY_TEXTURE_3D</constant>,
	130	<constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>,
	131	<constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>,
	132	<constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>,
	133	<constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>,
	134	<constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>,
	135	<constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>, or
	136	<constant>GL_PROXY_TEXTURE_CUBE_MAP</constant>.
	137	</para>
	138	<para>
	139	<constant>GL_MAX_TEXTURE_SIZE</constant>, and <constant>GL_MAX_3D_TEXTURE_SIZE</constant> are not really
	140	descriptive enough.
	141	It has to report the largest square texture image that can be
f37e7e3d DH	142	accommodated with mipmaps and borders,
f37e7e3d DH	143	but a long skinny texture, or a texture without mipmaps and borders, may
7faf1d71 AW	144	easily fit in texture memory.
	145	The proxy targets allow the user to more accurately query
	146	whether the GL can accommodate a texture of a given configuration.
	147	If the texture cannot be accommodated, the texture state variables, which
	148	may be queried with <function>glGetTexLevelParameter</function>, are set to 0. If the texture can be accommodated,
	149	the texture state values will be set as they would be set for a
	150	non-proxy target.
	151	</para>
	152	<para>
	153	<parameter>pname</parameter> specifies the texture parameter whose value or values
	154	will be returned.
	155	</para>
	156	<para>
	157	The accepted parameter names are as follows:
	158	</para>
	159	<variablelist>
	160	<varlistentry>
	161	<term><constant>GL_TEXTURE_WIDTH</constant></term>
	162	<listitem>
	163	<para>
	164	</para>
	165	<para>
	166	<parameter>params</parameter> returns a single value,
	167	the width of the texture image.
f37e7e3d DH	168	This value includes the border of the texture image. The initial value is
f37e7e3d DH	169	0.
7faf1d71 AW	170	</para>
	171	</listitem>
	172	</varlistentry>
	173	<varlistentry>
	174	<term><constant>GL_TEXTURE_HEIGHT</constant></term>
	175	<listitem>
	176	<para>
	177	</para>
	178	<para>
	179	<parameter>params</parameter> returns a single value,
	180	the height of the texture image.
f37e7e3d DH	181	This value includes the border of the texture image. The initial value is
f37e7e3d DH	182	0.
7faf1d71 AW	183	</para>
	184	</listitem>
	185	</varlistentry>
	186	<varlistentry>
	187	<term><constant>GL_TEXTURE_DEPTH</constant></term>
	188	<listitem>
	189	<para>
	190	</para>
	191	<para>
	192	<parameter>params</parameter> returns a single value,
	193	the depth of the texture image.
f37e7e3d DH	194	This value includes the border of the texture image. The initial value is
f37e7e3d DH	195	0.
7faf1d71 AW	196	</para>
	197	</listitem>
	198	</varlistentry>
	199	<varlistentry>
	200	<term><constant>GL_TEXTURE_INTERNAL_FORMAT</constant></term>
	201	<listitem>
	202	<para>
	203	</para>
	204	<para>
	205	<parameter>params</parameter> returns a single value,
	206	the internal format of the texture image.
	207	</para>
	208	</listitem>
	209	</varlistentry>
	210	<varlistentry>
	211	<term><constant>GL_TEXTURE_RED_TYPE</constant>,</term>
	212	<listitem>
	213	</listitem>
	214	</varlistentry>
	215	<varlistentry>
	216	<term><constant>GL_TEXTURE_GREEN_TYPE</constant>,</term>
	217	<listitem>
	218	</listitem>
	219	</varlistentry>
	220	<varlistentry>
	221	<term><constant>GL_TEXTURE_BLUE_TYPE</constant>,</term>
	222	<listitem>
	223	</listitem>
	224	</varlistentry>
	225	<varlistentry>
	226	<term><constant>GL_TEXTURE_ALPHA_TYPE</constant>,</term>
	227	<listitem>
	228	</listitem>
	229	</varlistentry>
	230	<varlistentry>
	231	<term><constant>GL_TEXTURE_DEPTH_TYPE</constant></term>
	232	<listitem>
	233	<para>
	234	</para>
	235	<para>
	236	The data type used to store the component.
	237	The types <constant>GL_NONE</constant>, <constant>GL_SIGNED_NORMALIZED</constant>,
	238	<constant>GL_UNSIGNED_NORMALIZED</constant>, <constant>GL_FLOAT</constant>,
	239	<constant>GL_INT</constant>, and <constant>GL_UNSIGNED_INT</constant> may be returned
	240	to indicate signed normalized fixed-point, unsigned normalized fixed-point, floating-point, integer unnormalized, and
	241	unsigned integer unnormalized components, respectively.
	242	</para>
	243	</listitem>
	244	</varlistentry>
	245	<varlistentry>
	246	<term><constant>GL_TEXTURE_RED_SIZE</constant>,</term>
	247	<listitem>
	248	</listitem>
	249	</varlistentry>
	250	<varlistentry>
	251	<term><constant>GL_TEXTURE_GREEN_SIZE</constant>,</term>
	252	<listitem>
	253	</listitem>
	254	</varlistentry>
	255	<varlistentry>
	256	<term><constant>GL_TEXTURE_BLUE_SIZE</constant>,</term>
	257	<listitem>
	258	</listitem>
	259	</varlistentry>
260	<varlistentry>
261	<term><constant>GL_TEXTURE_ALPHA_SIZE</constant>,</term>
262	<listitem>
263	</listitem>
264	</varlistentry>
265	<varlistentry>
266	<term><constant>GL_TEXTURE_DEPTH_SIZE</constant></term>
267	<listitem>
268	<para>
269	</para>
270	<para>
271	The internal storage resolution of an individual component.
272	The resolution chosen by the GL will be a close match for the resolution
273	requested by the user with the component argument of <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
274	<citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>, and
275	<citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>. The initial value is 0.
276	</para>
277	</listitem>
278	</varlistentry>
279	<varlistentry>
280	<term><constant>GL_TEXTURE_COMPRESSED</constant></term>
281	<listitem>
282	<para>
283	</para>
284	<para>
285	<parameter>params</parameter> returns a single boolean value indicating if the texture image is
286	stored in a compressed internal format. The initiali value is <constant>GL_FALSE</constant>.
287	</para>
288	</listitem>
289	</varlistentry>
290	<varlistentry>
291	<term><constant>GL_TEXTURE_COMPRESSED_IMAGE_SIZE</constant></term>
292	<listitem>
293	<para>
294	</para>
295	<para>
296	<parameter>params</parameter> returns a single integer value, the number of unsigned bytes of the
297	compressed texture image that would be returned from
298	<citerefentry><refentrytitle>glGetCompressedTexImage</refentrytitle></citerefentry>.
299	</para>
300	</listitem>
301	</varlistentry>
302	</variablelist>
303	</refsect1>
304	<refsect1 id="notes"><title>Notes</title>
305	<para>
306	If an error is generated,
307	no change is made to the contents of <parameter>params</parameter>.
308	</para>
309	<para>
310	<function>glGetTexLevelParameter</function> returns the texture level parameters for the active texture unit.
311	</para>
312	</refsect1>
313	<refsect1 id="errors"><title>Errors</title>
314	<para>
315	<constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> or <parameter>pname</parameter> is not an
316	accepted value.
317	</para>
318	<para>
319	<constant>GL_INVALID_VALUE</constant> is generated if <parameter>level</parameter> is less than 0.
320	</para>
321	<para>
322	<constant>GL_INVALID_VALUE</constant> may be generated if <parameter>level</parameter> is greater
323	than
324	<inlineequation><mml:math>
325	<!-- eqn: log sub 2: -->
326	<mml:msub><mml:mi mathvariant="italic">log</mml:mi>
327	<mml:mn>2</mml:mn>
328	</mml:msub>
329	</mml:math></inlineequation>
330	<emphasis>max</emphasis>,
331	where <emphasis>max</emphasis> is the returned value of <constant>GL_MAX_TEXTURE_SIZE</constant>.
332	</para>
333	<para>
334	<constant>GL_INVALID_VALUE</constant> is generated if <parameter>target</parameter> is <constant>GL_TEXTURE_BUFFER</constant>
335	and <parameter>level</parameter> is not zero.
336	</para>
337	<para>
338	<constant>GL_INVALID_OPERATION</constant> is generated if
339	<constant>GL_TEXTURE_COMPRESSED_IMAGE_SIZE</constant> is queried on texture images with an
340	uncompressed internal format or on proxy targets.
341	</para>
342	</refsect1>
343	<refsect1 id="seealso"><title>See Also</title>
344	<para>
345	<citerefentry><refentrytitle>glActiveTexture</refentrytitle></citerefentry>,
346	<citerefentry><refentrytitle>glGetTexParameter</refentrytitle></citerefentry>,
347	<citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>,
348	<citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>,
349	<citerefentry><refentrytitle>glCopyTexSubImage1D</refentrytitle></citerefentry>,
350	<citerefentry><refentrytitle>glCopyTexSubImage2D</refentrytitle></citerefentry>,
351	<citerefentry><refentrytitle>glCopyTexSubImage3D</refentrytitle></citerefentry>,
352	<citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
353	<citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
354	<citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>,
355	<citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>,
356	<citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>,
357	<citerefentry><refentrytitle>glTexSubImage3D</refentrytitle></citerefentry>,
358	<citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>
359	</para>
360	</refsect1>
361	<refsect1 id="Copyright"><title>Copyright</title>
362	<para>
363	Copyright <trademark class="copyright"></trademark> 1991-2006
f37e7e3d	364	Silicon Graphics, Inc. Copyright <trademark class="copyright"></trademark> 2010
7faf1d71 AW	365	Khronos Group. This document is licensed under the SGI
	366	Free Software B License. For details, see
	367	<ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
	368	</para>
	369	</refsect1>
	370	</refentry>