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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>glCopyTexSubImage2D - 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="glCopyTexSubImage2D"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glCopyTexSubImage2D — copy a two-dimensional texture subimage</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">glCopyTexSubImage2D</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>GLint  </td><td><var class="pdparam">xoffset</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">yoffset</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">x</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">y</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">width</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">height</var><code>)</code>;</td></tr></table></div></div><p>
    </p><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 target texture.
                    Must be <code class="constant">GL_TEXTURE_2D</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>, or
                    <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>level</code></em></span></dt><dd><p>
                    Specifies the level-of-detail number.
                    Level 0 is the base image level.
                    Level <span class="emphasis"><em>n</em></span> is the <span class="emphasis"><em>n</em></span>th mipmap reduction image.
                </p></dd><dt><span class="term"><em class="parameter"><code>xoffset</code></em></span></dt><dd><p>
                    Specifies a texel offset in the x direction within the texture array.
                </p></dd><dt><span class="term"><em class="parameter"><code>yoffset</code></em></span></dt><dd><p>
                    Specifies a texel offset in the y direction within the texture array.
                </p></dd><dt><span class="term"><em class="parameter"><code>x</code></em>, </span><span class="term"><em class="parameter"><code>y</code></em></span></dt><dd><p>
                    Specify the window coordinates of the lower left corner
                    of the rectangular region of pixels to be copied.
                </p></dd><dt><span class="term"><em class="parameter"><code>width</code></em></span></dt><dd><p>
                    Specifies the width of the texture subimage.
                </p></dd><dt><span class="term"><em class="parameter"><code>height</code></em></span></dt><dd><p>
                    Specifies the height of the texture subimage.
                </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glCopyTexSubImage2D</code> replaces a rectangular portion of a two-dimensional texture image or
            cube-map texture image with pixels from the current <code class="constant">GL_READ_BUFFER</code>
            (rather than from main memory, as is the case for <a href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>).
        </p><p>
            The screen-aligned pixel rectangle with lower left corner at
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mfenced open="(" close=")">
                    <mml:mi mathvariant="italic">x</mml:mi>
                    <mml:mi mathvariant="italic">y</mml:mi>
                </mml:mfenced>
            </mml:math>
            and with
            width <em class="parameter"><code>width</code></em> and height <em class="parameter"><code>height</code></em> replaces the portion of the
            texture array with x indices <em class="parameter"><code>xoffset</code></em> through 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mi mathvariant="italic">xoffset</mml:mi>
                    <mml:mo>+</mml:mo>
                    <mml:mi mathvariant="italic">width</mml:mi>
                    <mml:mo>-</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math>,
            inclusive, and y indices <em class="parameter"><code>yoffset</code></em> through 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mi mathvariant="italic">yoffset</mml:mi>
                    <mml:mo>+</mml:mo>
                    <mml:mi mathvariant="italic">height</mml:mi>
                    <mml:mo>-</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math>,
            inclusive, at the mipmap level specified by <em class="parameter"><code>level</code></em>.
        </p><p>
            The pixels in the rectangle are processed exactly as if
            <a href="glReadPixels.xml"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a> had been called, but the process stops just before
            final conversion.
            At this point, all pixel component values are clamped to 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>1</mml:mn>
                </mml:mfenced>
            </mml:math>
            and then converted to the texture's internal format for storage in the texel
            array.
        </p><p>
            The destination rectangle in the texture array may not include any texels
            outside the texture array as it was originally specified.
            It is not an error to specify a subtexture with zero width or height, but
            such a specification has no effect.
        </p><p>
            If any of the pixels within the specified rectangle of the current
            <code class="constant">GL_READ_BUFFER</code> are outside the read window associated with the current
            rendering context, then the values obtained for those pixels are undefined.
        </p><p>
            No change is made to the <span class="emphasis"><em>internalformat</em></span>, <span class="emphasis"><em>width</em></span> or
            <span class="emphasis"><em>height</em></span> parameters of the specified texture
            array or to texel values outside the specified subregion.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
            <a href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a> modes affect texture images.
        </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> is not <code class="constant">GL_TEXTURE_2D</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_TEXTURE_1D_ARRAY</code>.
        </p><p>
            <code class="constant">GL_INVALID_OPERATION</code> is generated if the texture array has not been
            defined by a previous <a href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a> or <a href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a> operation.
        </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 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mi mathvariant="italic">level</mml:mi>
                    <mml:mo>&gt;</mml:mo>
                    <mml:mrow>
                        <mml:msub><mml:mi mathvariant="italic">log</mml:mi>
                        <mml:mn>2</mml:mn>
                        </mml:msub>
                        <mml:mo>⁡</mml:mo>
                        <mml:mfenced open="(" close=")">
                            <mml:mi mathvariant="italic">max</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:mi mathvariant="italic">max</mml:mi></mml:math>
            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 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mi mathvariant="italic">xoffset</mml:mi>
                    <mml:mo>&lt;</mml:mo>
                    <mml:mn>0</mml:mn>
                </mml:mrow>
            </mml:math>,
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mfenced open="(" close=")">
                        <mml:mrow>
                            <mml:mi mathvariant="italic">xoffset</mml:mi>
                            <mml:mo>+</mml:mo>
                            <mml:mi mathvariant="italic">width</mml:mi>
                        </mml:mrow>
                    </mml:mfenced>
                    <mml:mo>&gt;</mml:mo>
                    <mml:mrow>
                        <mml:mi mathvariant="italic">w</mml:mi>
                    </mml:mrow>
                </mml:mrow>
            </mml:math>,
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mi mathvariant="italic">yoffset</mml:mi>
                    <mml:mo>&lt;</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:mfenced open="(" close=")">
                        <mml:mrow>
                            <mml:mi mathvariant="italic">yoffset</mml:mi>
                            <mml:mo>+</mml:mo>
                            <mml:mi mathvariant="italic">height</mml:mi>
                        </mml:mrow>
                    </mml:mfenced>
                    <mml:mo>&gt;</mml:mo>
                    <mml:mi mathvariant="italic">h</mml:mi>
                </mml:mrow>
            </mml:math>,
            where 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">w</mml:mi></mml:math>
            is the <code class="constant">GL_TEXTURE_WIDTH</code>, and
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">h</mml:mi></mml:math>
            is the <code class="constant">GL_TEXTURE_HEIGHT</code>
            of the texture image being modified.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
            <a href="glGetTexImage.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexImage</span></span></a>
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
            <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="glCopyTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage3D</span></span></a>,
            <a href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
            <a href="glReadBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glReadBuffer</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="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</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>
        </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 href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
        </p></div></div></body></html>
