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+<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glGetTexLevelParameter</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetTexLevelParameter"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetTexLevelParameter — return texture parameter values for a specific level of detail</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetTexLevelParameterfv</b>(</code></td><td>GLenum </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLint </td><td><var class="pdparam">level</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLfloat * </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetTexLevelParameteriv</b>(</code></td><td>GLenum </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLint </td><td><var class="pdparam">level</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLint * </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>target</code></em></span></dt><dd><p>
+ Specifies the symbolic name of the target texture,
+ one of
+ <code class="constant">GL_TEXTURE_1D</code>,
+ <code class="constant">GL_TEXTURE_2D</code>,
+ <code class="constant">GL_TEXTURE_3D</code>,
+ <code class="constant">GL_TEXTURE_1D_ARRAY</code>,
+ <code class="constant">GL_TEXTURE_2D_ARRAY</code>,
+ <code class="constant">GL_TEXTURE_RECTANGLE</code>,
+ <code class="constant">GL_TEXTURE_2D_MULTISAMPLE</code>,
+ <code class="constant">GL_TEXTURE_2D_MULTISAMPLE_ARRAY</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_X</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_X</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Y</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Z</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</code>,
+ <code class="constant">GL_PROXY_TEXTURE_1D</code>,
+ <code class="constant">GL_PROXY_TEXTURE_2D</code>,
+ <code class="constant">GL_PROXY_TEXTURE_3D</code>,
+ <code class="constant">GL_PROXY_TEXTURE_1D_ARRAY</code>,
+ <code class="constant">GL_PROXY_TEXTURE_2D_ARRAY</code>,
+ <code class="constant">GL_PROXY_TEXTURE_RECTANGLE</code>,
+ <code class="constant">GL_PROXY_TEXTURE_2D_MULTISAMPLE</code>,
+ <code class="constant">GL_PROXY_TEXTURE_2D_MULTISAMPLE_ARRAY</code>,
+ <code class="constant">GL_PROXY_TEXTURE_CUBE_MAP</code>, or
+ <code class="constant">GL_TEXTURE_BUFFER</code>.
+ </p></dd><dt><span class="term"><em class="parameter"><code>level</code></em></span></dt><dd><p>
+ Specifies the level-of-detail number of the desired image.
+ Level 0 is the base image level.
+ Level
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>
+ is the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>th
+ mipmap reduction image.
+ </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
+ Specifies the symbolic name of a texture parameter.
+ <code class="constant">GL_TEXTURE_WIDTH</code>,
+ <code class="constant">GL_TEXTURE_HEIGHT</code>,
+ <code class="constant">GL_TEXTURE_DEPTH</code>,
+ <code class="constant">GL_TEXTURE_INTERNAL_FORMAT</code>,
+ <code class="constant">GL_TEXTURE_BORDER</code>,
+ <code class="constant">GL_TEXTURE_RED_SIZE</code>,
+ <code class="constant">GL_TEXTURE_GREEN_SIZE</code>,
+ <code class="constant">GL_TEXTURE_BLUE_SIZE</code>,
+ <code class="constant">GL_TEXTURE_ALPHA_SIZE</code>,
+ <code class="constant">GL_TEXTURE_DEPTH_SIZE</code>,
+ <code class="constant">GL_TEXTURE_COMPRESSED</code>, and
+ <code class="constant">GL_TEXTURE_COMPRESSED_IMAGE_SIZE</code>
+ are accepted.
+ </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
+ Returns the requested data.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
+ <code class="function">glGetTexLevelParameter</code> returns in <em class="parameter"><code>params</code></em> texture parameter values for a specific
+ level-of-detail value,
+ specified as <em class="parameter"><code>level</code></em>.
+ <em class="parameter"><code>target</code></em> defines the target texture,
+ either <code class="constant">GL_TEXTURE_1D</code>, <code class="constant">GL_TEXTURE_2D</code>, <code class="constant">GL_TEXTURE_3D</code>,
+ <code class="constant">GL_PROXY_TEXTURE_1D</code>,
+ <code class="constant">GL_PROXY_TEXTURE_2D</code>,
+ <code class="constant">GL_PROXY_TEXTURE_3D</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_X</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_X</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Y</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Z</code>,
+ <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</code>, or
+ <code class="constant">GL_PROXY_TEXTURE_CUBE_MAP</code>.
+ </p><p>
+ <code class="constant">GL_MAX_TEXTURE_SIZE</code>, and <code class="constant">GL_MAX_3D_TEXTURE_SIZE</code> 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 <code class="function">glGetTexLevelParameter</code>, 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.
+ </p><p>
+ <em class="parameter"><code>pname</code></em> specifies the texture parameter whose value or values
+ will be returned.
+ </p><p>
+ The accepted parameter names are as follows:
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_WIDTH</code></span></dt><dd><p>
+ </p><p>
+ <em class="parameter"><code>params</code></em> returns a single value,
+ the width of the texture image.
+ This value includes the border of the texture image. The initial value is
+ 0.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_HEIGHT</code></span></dt><dd><p>
+ </p><p>
+ <em class="parameter"><code>params</code></em> returns a single value,
+ the height of the texture image.
+ This value includes the border of the texture image. The initial value is
+ 0.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_DEPTH</code></span></dt><dd><p>
+ </p><p>
+ <em class="parameter"><code>params</code></em> returns a single value,
+ the depth of the texture image.
+ This value includes the border of the texture image. The initial value is
+ 0.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_INTERNAL_FORMAT</code></span></dt><dd><p>
+ </p><p>
+ <em class="parameter"><code>params</code></em> returns a single value,
+ the internal format of the texture image.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_RED_TYPE</code>,</span></dt><dd></dd><dt><span class="term"><code class="constant">GL_TEXTURE_GREEN_TYPE</code>,</span></dt><dd></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BLUE_TYPE</code>,</span></dt><dd></dd><dt><span class="term"><code class="constant">GL_TEXTURE_ALPHA_TYPE</code>,</span></dt><dd></dd><dt><span class="term"><code class="constant">GL_TEXTURE_DEPTH_TYPE</code></span></dt><dd><p>
+ </p><p>
+ The data type used to store the component.
+ The types <code class="constant">GL_NONE</code>, <code class="constant">GL_SIGNED_NORMALIZED</code>,
+ <code class="constant">GL_UNSIGNED_NORMALIZED</code>, <code class="constant">GL_FLOAT</code>,
+ <code class="constant">GL_INT</code>, and <code class="constant">GL_UNSIGNED_INT</code> may be returned
+ to indicate signed normalized fixed-point, unsigned normalized fixed-point, floating-point, integer unnormalized, and
+ unsigned integer unnormalized components, respectively.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_RED_SIZE</code>,</span></dt><dd></dd><dt><span class="term"><code class="constant">GL_TEXTURE_GREEN_SIZE</code>,</span></dt><dd></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BLUE_SIZE</code>,</span></dt><dd></dd><dt><span class="term"><code class="constant">GL_TEXTURE_ALPHA_SIZE</code>,</span></dt><dd></dd><dt><span class="term"><code class="constant">GL_TEXTURE_DEPTH_SIZE</code></span></dt><dd><p>
+ </p><p>
+ 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 <a href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
+ <a href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>, <a href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>, <a href="glCopyTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>, and
+ <a href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>. The initial value is 0.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPRESSED</code></span></dt><dd><p>
+ </p><p>
+ <em class="parameter"><code>params</code></em> returns a single boolean value indicating if the texture image is
+ stored in a compressed internal format. The initiali value is <code class="constant">GL_FALSE</code>.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPRESSED_IMAGE_SIZE</code></span></dt><dd><p>
+ </p><p>
+ <em class="parameter"><code>params</code></em> returns a single integer value, the number of unsigned bytes of the
+ compressed texture image that would be returned from
+ <a href="glGetCompressedTexImage.xml"><span class="citerefentry"><span class="refentrytitle">glGetCompressedTexImage</span></span></a>.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
+ If an error is generated,
+ no change is made to the contents of <em class="parameter"><code>params</code></em>.
+ </p><p>
+ <code class="function">glGetTexLevelParameter</code> returns the texture level parameters for the active texture unit.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
+ <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> or <em class="parameter"><code>pname</code></em> is not an
+ accepted value.
+ </p><p>
+ <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>level</code></em> is less than 0.
+ </p><p>
+ <code class="constant">GL_INVALID_VALUE</code> may be generated if <em class="parameter"><code>level</code></em> is greater
+ than
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">log</mml:mi>
+ <mml:mn>2</mml:mn>
+ </mml:msub>
+ </mml:math>
+ <span class="emphasis"><em>max</em></span>,
+ where <span class="emphasis"><em>max</em></span> is the returned value of <code class="constant">GL_MAX_TEXTURE_SIZE</code>.
+ </p><p>
+ <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>target</code></em> is <code class="constant">GL_TEXTURE_BUFFER</code>
+ and <em class="parameter"><code>level</code></em> is not zero.
+ </p><p>
+ <code class="constant">GL_INVALID_OPERATION</code> is generated if
+ <code class="constant">GL_TEXTURE_COMPRESSED_IMAGE_SIZE</code> is queried on texture images with an
+ uncompressed internal format or on proxy targets.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
+ <a href="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>,
+ <a href="glGetTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexParameter</span></span></a>,
+ <a href="glCopyTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>,
+ <a href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>,
+ <a href="glCopyTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage1D</span></span></a>,
+ <a href="glCopyTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage2D</span></span></a>,
+ <a href="glCopyTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage3D</span></span></a>,
+ <a href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
+ <a href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
+ <a href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
+ <a href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
+ <a href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,
+ <a href="glTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>,
+ <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
+ Copyright <span class="trademark"></span>© 1991-2006
+ Silicon Graphics, Inc. Copyright <span class="trademark"></span>© 2010
+ Khronos Group. This document is licensed under the SGI
+ Free Software B License. For details, see
+ <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
+ </p></div></div></body></html>
HCoop / clinton / guile-figl.git / blobdiff