--- /dev/null
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
+<!-- saved from url=(0013)about:internet -->
+<?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>glSamplerParameter - OpenGL 3.3 Reference Pages</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glSamplerParameter"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glSamplerParameter — set sampler parameters</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">glSamplerParameterf</b>(</code></td><td>GLuint </td><td><var class="pdparam">sampler</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">param</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">glSamplerParameteri</b>(</code></td><td>GLuint </td><td><var class="pdparam">sampler</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">param</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>sampler</code></em></span></dt><dd><p>
+ Specifies the sampler object whose parameter to modify.
+ </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
+ Specifies the symbolic name of a single-valued sampler parameter.
+ <em class="parameter"><code>pname</code></em> can be one of the following:
+ <code class="constant">GL_TEXTURE_WRAP_S</code>,
+ <code class="constant">GL_TEXTURE_WRAP_T</code>,
+ <code class="constant">GL_TEXTURE_WRAP_R</code>,
+ <code class="constant">GL_TEXTURE_MIN_FILTER</code>,
+ <code class="constant">GL_TEXTURE_MAG_FILTER</code>,
+ <code class="constant">GL_TEXTURE_MIN_LOD</code>,
+ <code class="constant">GL_TEXTURE_MAX_LOD</code>,
+ <code class="constant">GL_TEXTURE_LOD_BIAS</code>
+ <code class="constant">GL_TEXTURE_COMPARE_MODE</code>, or
+ <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>.
+ </p></dd><dt><span class="term"><em class="parameter"><code>param</code></em></span></dt><dd><p>
+ Specifies the value of <em class="parameter"><code>pname</code></em>.
+ </p></dd></dl></div></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">glSamplerParameterfv</b>(</code></td><td>GLuint </td><td><var class="pdparam">sampler</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>const 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">glSamplerParameteriv</b>(</code></td><td>GLuint </td><td><var class="pdparam">sampler</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>const GLint * </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">glSamplerParameterIiv</b>(</code></td><td>GLuint </td><td><var class="pdparam">sampler</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>const GLint * </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">glSamplerParameterIuiv</b>(</code></td><td>GLuint </td><td><var class="pdparam">sampler</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>const GLuint * </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters2"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>sampler</code></em></span></dt><dd><p>
+ Specifies the sampler object whose parameter to modify.
+ </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
+ Specifies the symbolic name of a sampler parameter.
+ <em class="parameter"><code>pname</code></em> can be one of the following:
+ <code class="constant">GL_TEXTURE_WRAP_S</code>,
+ <code class="constant">GL_TEXTURE_WRAP_T</code>,
+ <code class="constant">GL_TEXTURE_WRAP_R</code>,
+ <code class="constant">GL_TEXTURE_MIN_FILTER</code>,
+ <code class="constant">GL_TEXTURE_MAG_FILTER</code>,
+ <code class="constant">GL_TEXTURE_BORDER_COLOR</code>,
+ <code class="constant">GL_TEXTURE_MIN_LOD</code>,
+ <code class="constant">GL_TEXTURE_MAX_LOD</code>,
+ <code class="constant">GL_TEXTURE_LOD_BIAS</code>
+ <code class="constant">GL_TEXTURE_COMPARE_MODE</code>, or
+ <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>.
+ </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
+ Specifies a pointer to an array where the value or values of <em class="parameter"><code>pname</code></em>
+ are stored.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
+ <code class="function">glSamplerParameter</code> assigns the value or values in <em class="parameter"><code>params</code></em> to the sampler parameter
+ specified as <em class="parameter"><code>pname</code></em>.
+ <em class="parameter"><code>sampler</code></em> specifies the sampler object to be modified, and must be the name of a sampler object previously
+ returned from a call to <a href="glGenSamplers.xml"><span class="citerefentry"><span class="refentrytitle">glGenSamplers</span></span></a>.
+ The following symbols are accepted in <em class="parameter"><code>pname</code></em>:
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_FILTER</code></span></dt><dd><p>
+ The texture minifying function is used whenever the pixel being textured
+ maps to an area greater than one texture element.
+ There are six defined minifying functions.
+ Two of them use the nearest one or nearest four texture elements
+ to compute the texture value.
+ The other four use mipmaps.
+ </p><p>
+ A mipmap is an ordered set of arrays representing the same image
+ at progressively lower resolutions.
+ If the texture has dimensions
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mi mathvariant="italic">n</mml:mi>
+ </mml:msup>
+ <mml:mo>×</mml:mo>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mi mathvariant="italic">m</mml:mi>
+ </mml:msup>
+ </mml:mrow>
+ </mml:math>,
+ there are
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">max</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mi mathvariant="italic">n</mml:mi>
+ <mml:mi mathvariant="italic">m</mml:mi>
+ </mml:mfenced>
+ </mml:mrow>
+ <mml:mo>+</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:math>
+ mipmaps.
+ The first mipmap is the original texture,
+ with dimensions
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mi mathvariant="italic">n</mml:mi>
+ </mml:msup>
+ <mml:mo>×</mml:mo>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mi mathvariant="italic">m</mml:mi>
+ </mml:msup>
+ </mml:mrow>
+ </mml:math>.
+ Each subsequent mipmap has dimensions
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mfenced open="" close="">
+ <mml:mrow>
+ <mml:mi mathvariant="italic">k</mml:mi>
+ <mml:mo>-</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:msup>
+ <mml:mo>×</mml:mo>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mfenced open="" close="">
+ <mml:mrow>
+ <mml:mi mathvariant="italic">l</mml:mi>
+ <mml:mo>-</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:msup>
+ </mml:mrow>
+ </mml:math>,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mi mathvariant="italic">k</mml:mi>
+ </mml:msup>
+ <mml:mo>×</mml:mo>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mi mathvariant="italic">l</mml:mi>
+ </mml:msup>
+ </mml:mrow>
+ </mml:math>
+ are the dimensions of the previous mipmap,
+ until either
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">k</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mn>0</mml:mn>
+ </mml:mrow>
+ </mml:math>
+ or
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">l</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mn>0</mml:mn>
+ </mml:mrow>
+ </mml:math>.
+ At that point,
+ subsequent mipmaps have dimension
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mn>1</mml:mn>
+ <mml:mo>×</mml:mo>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mfenced open="" close="">
+ <mml:mrow>
+ <mml:mi mathvariant="italic">l</mml:mi>
+ <mml:mo>-</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:msup>
+ </mml:mrow>
+ </mml:math>
+ or
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:msup><mml:mn>2</mml:mn>
+ <mml:mfenced open="" close="">
+ <mml:mrow>
+ <mml:mi mathvariant="italic">k</mml:mi>
+ <mml:mo>-</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:msup>
+ <mml:mo>×</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:math>
+ until the final mipmap,
+ which has dimension
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mn>1</mml:mn>
+ <mml:mo>×</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:math>.
+ To define the mipmaps, call <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>, or <a href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>
+ with the <span class="emphasis"><em>level</em></span> argument indicating the order of the mipmaps.
+ Level 0 is the original texture;
+ level
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">max</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mi mathvariant="italic">n</mml:mi>
+ <mml:mi mathvariant="italic">m</mml:mi>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:math>
+ is the final
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mn>1</mml:mn>
+ <mml:mo>×</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:math>
+ mipmap.
+ </p><p>
+ <em class="parameter"><code>params</code></em> supplies a function for minifying the texture as one of the
+ following:
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_NEAREST</code></span></dt><dd><p>
+ Returns the value of the texture element that is nearest
+ (in Manhattan distance)
+ to the center of the pixel being textured.
+ </p></dd><dt><span class="term"><code class="constant">GL_LINEAR</code></span></dt><dd><p>
+ Returns the weighted average of the four texture elements
+ that are closest to the center of the pixel being textured.
+ These can include border texture elements,
+ depending on the values of <code class="constant">GL_TEXTURE_WRAP_S</code> and <code class="constant">GL_TEXTURE_WRAP_T</code>,
+ and on the exact mapping.
+ </p></dd><dt><span class="term"><code class="constant">GL_NEAREST_MIPMAP_NEAREST</code></span></dt><dd><p>
+ Chooses the mipmap that most closely matches the size of the pixel
+ being textured and uses the <code class="constant">GL_NEAREST</code> criterion
+ (the texture element nearest to the center of the pixel)
+ to produce a texture value.
+ </p></dd><dt><span class="term"><code class="constant">GL_LINEAR_MIPMAP_NEAREST</code></span></dt><dd><p>
+ Chooses the mipmap that most closely matches the size of the pixel
+ being textured and uses the <code class="constant">GL_LINEAR</code> criterion
+ (a weighted average of the four texture elements that are closest
+ to the center of the pixel)
+ to produce a texture value.
+ </p></dd><dt><span class="term"><code class="constant">GL_NEAREST_MIPMAP_LINEAR</code></span></dt><dd><p>
+ Chooses the two mipmaps that most closely match the size of the pixel
+ being textured and uses the <code class="constant">GL_NEAREST</code> criterion
+ (the texture element nearest to the center of the pixel)
+ to produce a texture value from each mipmap.
+ The final texture value is a weighted average of those two values.
+ </p></dd><dt><span class="term"><code class="constant">GL_LINEAR_MIPMAP_LINEAR</code></span></dt><dd><p>
+ Chooses the two mipmaps that most closely match the size of the pixel
+ being textured and uses the <code class="constant">GL_LINEAR</code> criterion
+ (a weighted average of the four texture elements that are closest
+ to the center of the pixel)
+ to produce a texture value from each mipmap.
+ The final texture value is a weighted average of those two values.
+ </p></dd></dl></div><p>
+ </p><p>
+ As more texture elements are sampled in the minification process,
+ fewer aliasing artifacts will be apparent.
+ While the <code class="constant">GL_NEAREST</code> and <code class="constant">GL_LINEAR</code> minification functions can be
+ faster than the other four,
+ they sample only one or four texture elements to determine the texture value
+ of the pixel being rendered and can produce moire patterns
+ or ragged transitions.
+ The initial value of <code class="constant">GL_TEXTURE_MIN_FILTER</code> is
+ <code class="constant">GL_NEAREST_MIPMAP_LINEAR</code>.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAG_FILTER</code></span></dt><dd><p>
+ The texture magnification function is used when the pixel being textured
+ maps to an area less than or equal to one texture element.
+ It sets the texture magnification function to either <code class="constant">GL_NEAREST</code>
+ or <code class="constant">GL_LINEAR</code> (see below). <code class="constant">GL_NEAREST</code> is generally faster
+ than <code class="constant">GL_LINEAR</code>,
+ but it can produce textured images with sharper edges
+ because the transition between texture elements is not as smooth.
+ The initial value of <code class="constant">GL_TEXTURE_MAG_FILTER</code> is <code class="constant">GL_LINEAR</code>.
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_NEAREST</code></span></dt><dd><p>
+ Returns the value of the texture element that is nearest
+ (in Manhattan distance)
+ to the center of the pixel being textured.
+ </p></dd><dt><span class="term"><code class="constant">GL_LINEAR</code></span></dt><dd><p>
+ Returns the weighted average of the four texture elements
+ that are closest to the center of the pixel being textured.
+ These can include border texture elements,
+ depending on the values of <code class="constant">GL_TEXTURE_WRAP_S</code> and <code class="constant">GL_TEXTURE_WRAP_T</code>,
+ and on the exact mapping.
+ </p></dd></dl></div><p>
+ </p><p>
+ </p><p>
+ </p></dd></dl></div><p>
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_LOD</code></span></dt><dd><p>
+ Sets the minimum level-of-detail parameter. This floating-point value
+ limits the selection of highest resolution mipmap (lowest mipmap
+ level). The initial value is -1000.
+ </p></dd></dl></div><p>
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LOD</code></span></dt><dd><p>
+ Sets the maximum level-of-detail parameter. This floating-point value
+ limits the selection of the lowest resolution mipmap (highest mipmap
+ level). The initial value is 1000.
+ </p></dd></dl></div><p>
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_S</code></span></dt><dd><p>
+ Sets the wrap parameter for texture coordinate
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ to either <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_MIRRORED_REPEAT</code>, or
+ <code class="constant">GL_REPEAT</code>. <code class="constant">GL_CLAMP_TO_BORDER</code> causes the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ coordinate to be clamped to the range
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close="]">
+ <mml:mfenced open="" close="">
+ <mml:mrow>
+ <mml:mfrac>
+ <mml:mn>-1</mml:mn>
+ <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
+ </mml:mfrac>
+ </mml:mrow>
+ </mml:mfenced>
+ <mml:mrow>
+ <mml:mn>1</mml:mn>
+ <mml:mo>+</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:mrow>
+ <mml:mfrac>
+ <mml:mn>1</mml:mn>
+ <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
+ </mml:mfrac>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:math>,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">N</mml:mi></mml:math>
+ is the size of the texture in the direction of
+ clamping.<code class="constant">GL_CLAMP_TO_EDGE</code> causes
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ coordinates to be clamped to the
+ range
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close="]">
+ <mml:mfenced open="" close="">
+ <mml:mrow>
+ <mml:mfrac>
+ <mml:mn>1</mml:mn>
+ <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
+ </mml:mfrac>
+ </mml:mrow>
+ </mml:mfenced>
+ <mml:mrow>
+ <mml:mn>1</mml:mn>
+ <mml:mo>-</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:mrow>
+ <mml:mfrac>
+ <mml:mn>1</mml:mn>
+ <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
+ </mml:mfrac>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:math>,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">N</mml:mi></mml:math>
+ is the size
+ of the texture in the direction of clamping. <code class="constant">GL_REPEAT</code> causes the
+ integer part of the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ coordinate to be ignored; the GL uses only the
+ fractional part, thereby creating a repeating pattern.
+ <code class="constant">GL_MIRRORED_REPEAT</code> causes the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ coordinate to be set to the
+ fractional part of the texture coordinate if the integer part of
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ is
+ even; if the integer part of
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ is odd, then the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ texture coordinate is
+ set to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mn>1</mml:mn>
+ <mml:mo>-</mml:mo>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">frac</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math>,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">frac</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:math>
+ represents the fractional part of
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>.
+ Initially, <code class="constant">GL_TEXTURE_WRAP_S</code> is set to <code class="constant">GL_REPEAT</code>.
+ </p></dd></dl></div><p>
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_T</code></span></dt><dd><p>
+ Sets the wrap parameter for texture coordinate
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">t</mml:mi></mml:math>
+ to either <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_MIRRORED_REPEAT</code>, or
+ <code class="constant">GL_REPEAT</code>. See the discussion under <code class="constant">GL_TEXTURE_WRAP_S</code>.
+ Initially, <code class="constant">GL_TEXTURE_WRAP_T</code> is set to <code class="constant">GL_REPEAT</code>.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_R</code></span></dt><dd><p>
+ Sets the wrap parameter for texture coordinate
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>
+ to either <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_MIRRORED_REPEAT</code>, or
+ <code class="constant">GL_REPEAT</code>. See the discussion under <code class="constant">GL_TEXTURE_WRAP_S</code>.
+ Initially, <code class="constant">GL_TEXTURE_WRAP_R</code> is set to <code class="constant">GL_REPEAT</code>.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BORDER_COLOR</code></span></dt><dd><p>
+ The data in <em class="parameter"><code>params</code></em> specifies four values that define the border values that
+ should be used for border texels. If a texel is sampled from the border of the texture, the
+ values of <code class="constant">GL_TEXTURE_BORDER_COLOR</code> are interpreted as an RGBA color to match the
+ texture's internal format and substituted for the non-existent texel data. If the texture contains depth
+ components, the first component of <code class="constant">GL_TEXTURE_BORDER_COLOR</code> is interpreted as a depth value.
+ The initial value is
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+ <mml:mrow>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:mn>0.0</mml:mn>, <mml:mn>0.0</mml:mn>, <mml:mn>0.0</mml:mn>, <mml:mn>0.0</mml:mn>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:math>.
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_MODE</code></span></dt><dd><p>
+ Specifies the texture comparison mode for currently bound textures.
+ That is, a texture whose internal format is <code class="constant">GL_DEPTH_COMPONENT_*</code>; see
+ <a href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>)
+ Permissible values are:
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_COMPARE_REF_TO_TEXTURE</code></span></dt><dd><p>
+ Specifies that the interpolated and clamped
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>
+ texture coordinate should
+ be compared to the value in the currently bound texture. See the
+ discussion of <code class="constant">GL_TEXTURE_COMPARE_FUNC</code> for details of how the comparison
+ is evaluated. The result of the comparison is assigned to the red channel.
+ </p></dd><dt><span class="term"><code class="constant">GL_NONE</code></span></dt><dd><p>
+ Specifies that the red channel should be assigned the
+ appropriate value from the currently bound texture.
+ </p></dd></dl></div><p>
+ </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_FUNC</code></span></dt><dd><p>
+ Specifies the comparison operator used when <code class="constant">GL_TEXTURE_COMPARE_MODE</code> is
+ set to <code class="constant">GL_COMPARE_REF_TO_TEXTURE</code>. Permissible values are:
+ </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="left" /></colgroup><thead><tr><th align="left"><span class="bold"><strong>
+ Texture Comparison Function
+ </strong></span></th><th align="left"><span class="bold"><strong>
+ Computed result
+ </strong></span></th></tr></thead><tbody><tr><td align="left">
+ <code class="constant">GL_LEQUAL</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">result</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mfenced open="{" close="">
+ <mml:mrow>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mn>1.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mn>0.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ <mml:mo> </mml:mo>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo><=</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo>></mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_GEQUAL</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">result</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mfenced open="{" close="">
+ <mml:mrow>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mn>1.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mn>0.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ <mml:mo> </mml:mo>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo>>=</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo><</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_LESS</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">result</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mfenced open="{" close="">
+ <mml:mrow>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mn>1.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mn>0.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ <mml:mo> </mml:mo>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo><</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo>>=</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_GREATER</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">result</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mfenced open="{" close="">
+ <mml:mrow>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mn>1.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mn>0.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ <mml:mo> </mml:mo>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo>></mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo><=</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_EQUAL</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">result</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mfenced open="{" close="">
+ <mml:mrow>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mn>1.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mn>0.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ <mml:mo> </mml:mo>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo>≠</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_NOTEQUAL</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">result</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mfenced open="{" close="">
+ <mml:mrow>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mn>1.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mn>0.0</mml:mn>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ <mml:mo> </mml:mo>
+ <mml:mtable>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo>≠</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ <mml:mtr><mml:mtd>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mfenced open="" close="">
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mtd></mml:mtr>
+ </mml:mtable>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_ALWAYS</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+ <mml:mrow>
+ <mml:mi mathvariant="italic">result</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mi>1.0</mml:mi>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_NEVER</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+ <mml:mrow>
+ <mml:mi mathvariant="italic">result</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mi>0.0</mml:mi>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr></tbody></table></div><p>
+ where <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>
+ is the current interpolated texture coordinate, and
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:math>
+ is the texture value sampled from the currently bound texture.
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">result</mml:mi></mml:math>
+ is assigned to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">t</mml:mi>
+ </mml:msub>
+ </mml:math>.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
+ <code class="function">glSamplerParameter</code> is available only if the GL version is 3.3 or higher.
+ </p><p>
+ If a sampler object is bound to a texture unit and that unit is used to sample from a texture, the parameters in the sampler
+ are used to sample from the texture, rather than the equivalent parameters in the texture object bound to that unit. This
+ introduces the possibility of sampling from the same texture object with different sets of sampler state, which may lead to
+ a condition where a texture is <span class="emphasis"><em>incomplete</em></span> with respect to one sampler object and not with respect to
+ another. Thus, completeness can be considered a function of a sampler object and a texture object bound to a single
+ texture unit, rather than a property of the texture object itself.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
+ <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>sampler</code></em> is not the name of a sampler object previously
+ returned from a call to <a href="glGenSamplers.xml"><span class="citerefentry"><span class="refentrytitle">glGenSamplers</span></span></a>.
+ </p><p>
+ <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>params</code></em> should have a defined
+ constant value (based on the value of <em class="parameter"><code>pname</code></em>) and does not.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
+ <a href="glGetSamplerParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetSamplerParameter</span></span></a>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
+ <a href="glGenSamplers.xml"><span class="citerefentry"><span class="refentrytitle">glGenSamplers</span></span></a>,
+ <a href="glBindSampler.xml"><span class="citerefentry"><span class="refentrytitle">glBindSampler</span></span></a>,
+ <a href="glDeleteSamplers.xml"><span class="citerefentry"><span class="refentrytitle">glDeleteSamplers</span></span></a>,
+ <a href="glIsSampler.xml"><span class="citerefentry"><span class="refentrytitle">glIsSampler</span></span></a>,
+ <a href="glBindTexture.xml"><span class="citerefentry"><span class="refentrytitle">glBindTexture</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>© 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.
+ <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
+ </p></div></div></body></html>
HCoop / clinton / guile-figl.git / blobdiff