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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" /><title>glMaterial</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glMaterial"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glMaterial — specify material parameters for the lighting model</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">glMaterialf</b>(</code></td><td>GLenum </td><td><var class="pdparam">face</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">glMateriali</b>(</code></td><td>GLenum </td><td><var class="pdparam">face</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>face</code></em></span></dt><dd><p>
+ Specifies which face or faces are being updated.
+ Must be one of
+ <code class="constant">GL_FRONT</code>,
+ <code class="constant">GL_BACK</code>, or
+ <code class="constant">GL_FRONT_AND_BACK</code>.
+ </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
+ Specifies the single-valued material parameter of the face or faces
+ that is being updated.
+ Must be <code class="constant">GL_SHININESS</code>.
+ </p></dd><dt><span class="term"><em class="parameter"><code>param</code></em></span></dt><dd><p>
+ Specifies the value that parameter <code class="constant">GL_SHININESS</code> will be set to.
+ </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">glMaterialfv</b>(</code></td><td>GLenum </td><td><var class="pdparam">face</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">glMaterialiv</b>(</code></td><td>GLenum </td><td><var class="pdparam">face</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><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>face</code></em></span></dt><dd><p>
+ Specifies which face or faces are being updated.
+ Must be one of
+ <code class="constant">GL_FRONT</code>,
+ <code class="constant">GL_BACK</code>, or
+ <code class="constant">GL_FRONT_AND_BACK</code>.
+ </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
+ Specifies the material parameter of the face or faces that is being updated.
+ Must be one of
+ <code class="constant">GL_AMBIENT</code>,
+ <code class="constant">GL_DIFFUSE</code>,
+ <code class="constant">GL_SPECULAR</code>,
+ <code class="constant">GL_EMISSION</code>,
+ <code class="constant">GL_SHININESS</code>,
+ <code class="constant">GL_AMBIENT_AND_DIFFUSE</code>, or
+ <code class="constant">GL_COLOR_INDEXES</code>.
+ </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
+ Specifies a pointer to the value or values that <em class="parameter"><code>pname</code></em> will be set to.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
+ <code class="function">glMaterial</code> assigns values to material parameters.
+ There are two matched sets of material parameters.
+ One,
+ the <span class="emphasis"><em>front-facing</em></span> set,
+ is used to shade points,
+ lines,
+ bitmaps,
+ and all polygons
+ (when two-sided lighting is disabled),
+ or just front-facing polygons
+ (when two-sided lighting is enabled).
+ The other set,
+ <span class="emphasis"><em>back-facing</em></span>,
+ is used to shade back-facing polygons only when two-sided lighting is enabled.
+ Refer to the <a class="citerefentry" href="glLightModel.xml"><span class="citerefentry"><span class="refentrytitle">glLightModel</span></span></a> reference page for details concerning one- and
+ two-sided lighting calculations.
+ </p><p>
+ <code class="function">glMaterial</code> takes three arguments.
+ The first,
+ <em class="parameter"><code>face</code></em>,
+ specifies whether the
+ <code class="constant">GL_FRONT</code> materials, the
+ <code class="constant">GL_BACK</code> materials, or both
+ <code class="constant">GL_FRONT_AND_BACK</code> materials will be modified.
+ The second,
+ <em class="parameter"><code>pname</code></em>,
+ specifies which of several parameters in one or both sets will be modified.
+ The third,
+ <em class="parameter"><code>params</code></em>,
+ specifies what value or values will be assigned to the specified parameter.
+ </p><p>
+ Material parameters are used in the lighting equation that is optionally
+ applied to each vertex.
+ The equation is discussed in the <a class="citerefentry" href="glLightModel.xml"><span class="citerefentry"><span class="refentrytitle">glLightModel</span></span></a> reference page.
+ The parameters that can be specified using <code class="function">glMaterial</code>,
+ and their interpretations by the lighting equation, are as follows:
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_AMBIENT</code></span></dt><dd><p>
+ <em class="parameter"><code>params</code></em> contains four integer or floating-point values that specify
+ the ambient RGBA reflectance of the material.
+ Integer values are mapped linearly such that the most positive representable
+ value maps to 1.0,
+ and the most negative representable value maps to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mn>-1.0</mml:mn>
+ </mml:math>.
+ Floating-point values are mapped directly.
+ Neither integer nor floating-point values are clamped.
+ The initial ambient reflectance for both front- and back-facing materials
+ is (0.2, 0.2, 0.2, 1.0).
+ </p></dd><dt><span class="term"><code class="constant">GL_DIFFUSE</code></span></dt><dd><p>
+ <em class="parameter"><code>params</code></em> contains four integer or floating-point values that specify
+ the diffuse RGBA reflectance of the material.
+ Integer values are mapped linearly such that the most positive representable
+ value maps to 1.0,
+ and the most negative representable value maps to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mn>-1.0</mml:mn>
+ </mml:math>.
+ Floating-point values are mapped directly.
+ Neither integer nor floating-point values are clamped.
+ The initial diffuse reflectance for both front- and back-facing materials
+ is (0.8, 0.8, 0.8, 1.0).
+ </p></dd><dt><span class="term"><code class="constant">GL_SPECULAR</code></span></dt><dd><p>
+ <em class="parameter"><code>params</code></em> contains four integer or floating-point values that specify
+ the specular RGBA reflectance of the material.
+ Integer values are mapped linearly such that the most positive representable
+ value maps to 1.0,
+ and the most negative representable value maps to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mn>-1.0</mml:mn>
+ </mml:math>.
+ Floating-point values are mapped directly.
+ Neither integer nor floating-point values are clamped.
+ The initial specular reflectance for both front- and back-facing materials
+ is (0, 0, 0, 1).
+ </p></dd><dt><span class="term"><code class="constant">GL_EMISSION</code></span></dt><dd><p>
+ <em class="parameter"><code>params</code></em> contains four integer or floating-point values that specify
+ the RGBA emitted light intensity of the material.
+ Integer values are mapped linearly such that the most positive representable
+ value maps to 1.0,
+ and the most negative representable value maps to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mn>-1.0</mml:mn>
+ </mml:math>.
+ Floating-point values are mapped directly.
+ Neither integer nor floating-point values are clamped.
+ The initial emission intensity for both front- and back-facing materials
+ is (0, 0, 0, 1).
+ </p></dd><dt><span class="term"><code class="constant">GL_SHININESS</code></span></dt><dd><p>
+ <em class="parameter"><code>params</code></em> is a single integer or floating-point value that specifies
+ the RGBA specular exponent of the material.
+ Integer and floating-point values are mapped directly.
+ Only values in the range
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close="]">
+ <mml:mn>0</mml:mn>
+ <mml:mn>128</mml:mn>
+ </mml:mfenced>
+ </mml:math>
+ are accepted.
+ The initial specular exponent for both front- and back-facing materials
+ is 0.
+ </p></dd><dt><span class="term"><code class="constant">GL_AMBIENT_AND_DIFFUSE</code></span></dt><dd><p>
+ Equivalent to calling <code class="function">glMaterial</code> twice with the same parameter values,
+ once with <code class="constant">GL_AMBIENT</code> and once with <code class="constant">GL_DIFFUSE</code>.
+ </p></dd><dt><span class="term"><code class="constant">GL_COLOR_INDEXES</code></span></dt><dd><p>
+ <em class="parameter"><code>params</code></em> contains three integer or floating-point values specifying
+ the color indices for ambient,
+ diffuse,
+ and specular lighting.
+ These three values,
+ and <code class="constant">GL_SHININESS</code>,
+ are the only material values used by the color index mode lighting equation.
+ Refer to the <a class="citerefentry" href="glLightModel.xml"><span class="citerefentry"><span class="refentrytitle">glLightModel</span></span></a> reference page for a discussion
+ of color index lighting.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
+ The material parameters can be updated at any time.
+ In particular,
+ <code class="function">glMaterial</code> can be called between a call to <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding
+ call to <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
+ If only a single material parameter is to be changed per vertex,
+ however,
+ <a class="citerefentry" href="glColorMaterial.xml"><span class="citerefentry"><span class="refentrytitle">glColorMaterial</span></span></a> is preferred over <code class="function">glMaterial</code>
+ (see <a class="citerefentry" href="glColorMaterial.xml"><span class="citerefentry"><span class="refentrytitle">glColorMaterial</span></span></a>).
+ </p><p>
+ While the ambient, diffuse, specular and emission material parameters
+ all have alpha components, only the diffuse alpha component is used in
+ the lighting computation.
+ </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 either <em class="parameter"><code>face</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 a specular exponent outside the range
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close="]">
+ <mml:mn>0</mml:mn>
+ <mml:mn>128</mml:mn>
+ </mml:mfenced>
+ </mml:math>
+ is specified.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
+ <a class="citerefentry" href="glGetMaterial.xml"><span class="citerefentry"><span class="refentrytitle">glGetMaterial</span></span></a>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
+ <a class="citerefentry" href="glColorMaterial.xml"><span class="citerefentry"><span class="refentrytitle">glColorMaterial</span></span></a>,
+ <a class="citerefentry" href="glLight.xml"><span class="citerefentry"><span class="refentrytitle">glLight</span></span></a>,
+ <a class="citerefentry" href="glLightModel.xml"><span class="citerefentry"><span class="refentrytitle">glLightModel</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. This document is licensed under the SGI
+ Free Software B License. For details, see
+ <a class="ulink" 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