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glCopyTexSubImage2D.xhtml
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glCopyTexSubImage2D.xhtml
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<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><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 class="citerefentry" href="glTexSubImage2D"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>).
</p><p>
The screen-aligned pixel rectangle with lower left corner at
<math overflow="scroll">
<mfenced open="(" close=")">
<mi mathvariant="italic">x</mi>
<mi mathvariant="italic">y</mi>
</mfenced>
</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
<math overflow="scroll">
<mrow>
<mi mathvariant="italic">xoffset</mi>
<mo>+</mo>
<mi mathvariant="italic">width</mi>
<mo>-</mo>
<mn>1</mn>
</mrow>
</math>,
inclusive, and y indices <em class="parameter"><code>yoffset</code></em> through
<math overflow="scroll">
<mrow>
<mi mathvariant="italic">yoffset</mi>
<mo>+</mo>
<mi mathvariant="italic">height</mi>
<mo>-</mo>
<mn>1</mn>
</mrow>
</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 class="citerefentry" href="glCopyPixels"><span class="citerefentry"><span class="refentrytitle">glCopyPixels</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
<math overflow="scroll">
<mfenced open="[" close="]">
<mn>0</mn>
<mn>1</mn>
</mfenced>
</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>,
<span class="emphasis"><em>height</em></span>, or <span class="emphasis"><em>border</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>
<code class="function">glCopyTexSubImage2D</code> is available only if the GL version is 1.1 or greater.
</p><p>
<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> are available only if the GL version is 1.3
or greater.
</p><p>
Texturing has no effect in color index mode.
</p><p>
<a class="citerefentry" href="glPixelStore"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a> and <a class="citerefentry" href="glPixelTransfer"><span class="citerefentry"><span class="refentrytitle">glPixelTransfer</span></span></a> modes affect texture images
in exactly the way they affect <a class="citerefentry" href="glDrawPixels"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>.
</p><p>
When the <code class="code">ARB_imaging</code> extension is supported, the RGBA components
read from the framebuffer may be processed by the imaging pipeline. See
<a class="citerefentry" href="glTexImage1D"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a> for specific details.
</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>, or
<code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</code>.
</p><p>
<code class="constant">GL_INVALID_OPERATION</code> is generated if the texture array has not been
defined by a previous <a class="citerefentry" href="glTexImage2D"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a> or <a class="citerefentry" href="glCopyTexImage2D"><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
<math overflow="scroll">
<mrow>
<mi mathvariant="italic">level</mi>
<mo>></mo>
<mrow>
<msub><mi mathvariant="italic">log</mi>
<mn>2</mn>
</msub>
<mo></mo>
<mfenced open="(" close=")">
<mi mathvariant="italic">max</mi>
</mfenced>
</mrow>
</mrow>
</math>,
where
<math overflow="scroll"><mi mathvariant="italic">max</mi></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
<math overflow="scroll">
<mrow>
<mi mathvariant="italic">xoffset</mi>
<mo><</mo>
<mrow>
<mo>-</mo>
<mi mathvariant="italic">b</mi>
</mrow>
</mrow>
</math>,
<math overflow="scroll">
<mrow>
<mfenced open="(" close=")">
<mrow>
<mi mathvariant="italic">xoffset</mi>
<mo>+</mo>
<mi mathvariant="italic">width</mi>
</mrow>
</mfenced>
<mo>></mo>
<mfenced open="(" close=")">
<mrow>
<mi mathvariant="italic">w</mi>
<mo>-</mo>
<mi mathvariant="italic">b</mi>
</mrow>
</mfenced>
</mrow>
</math>,
<math overflow="scroll">
<mrow>
<mi mathvariant="italic">yoffset</mi>
<mo><</mo>
<mrow>
<mo>-</mo>
<mi mathvariant="italic">b</mi>
</mrow>
</mrow>
</math>,
or
<math overflow="scroll">
<mrow>
<mfenced open="(" close=")">
<mrow>
<mi mathvariant="italic">yoffset</mi>
<mo>+</mo>
<mi mathvariant="italic">height</mi>
</mrow>
</mfenced>
<mo>></mo>
<mfenced open="(" close=")">
<mrow>
<mi mathvariant="italic">h</mi>
<mo>-</mo>
<mi mathvariant="italic">b</mi>
</mrow>
</mfenced>
</mrow>
</math>,
where
<math overflow="scroll"><mi mathvariant="italic">w</mi></math>
is the <code class="constant">GL_TEXTURE_WIDTH</code>,
<math overflow="scroll"><mi mathvariant="italic">h</mi></math>
is the <code class="constant">GL_TEXTURE_HEIGHT</code>,
and
<math overflow="scroll"><mi mathvariant="italic">b</mi></math>
is the <code class="constant">GL_TEXTURE_BORDER</code>
of the texture image being modified.
Note that
<math overflow="scroll"><mi mathvariant="italic">w</mi></math>
and
<math overflow="scroll"><mi mathvariant="italic">h</mi></math>
include twice the border width.
</p><p>
<code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glCopyTexSubImage2D</code> is executed
between the execution of <a class="citerefentry" href="glBegin"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding
execution of <a class="citerefentry" href="glEnd"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
<a class="citerefentry" href="glGetTexImage"><span class="citerefentry"><span class="refentrytitle">glGetTexImage</span></span></a>
</p><p>
<a class="citerefentry" href="glIsEnabled"><span class="citerefentry"><span class="refentrytitle">glIsEnabled</span></span></a> with argument <code class="constant">GL_TEXTURE_2D</code>
</p></div>
{$pipelinestall}{$examples}
<div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
<a class="citerefentry" href="glCopyPixels"><span class="citerefentry"><span class="refentrytitle">glCopyPixels</span></span></a>,
<a class="citerefentry" href="glCopyTexImage1D"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>,
<a class="citerefentry" href="glCopyTexImage2D"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>,
<a class="citerefentry" href="glCopyTexSubImage1D"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage1D</span></span></a>,
<a class="citerefentry" href="glCopyTexSubImage3D"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage3D</span></span></a>,
<a class="citerefentry" href="glPixelStore"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
<a class="citerefentry" href="glPixelTransfer"><span class="citerefentry"><span class="refentrytitle">glPixelTransfer</span></span></a>,
<a class="citerefentry" href="glReadBuffer"><span class="citerefentry"><span class="refentrytitle">glReadBuffer</span></span></a>,
<a class="citerefentry" href="glTexEnv"><span class="citerefentry"><span class="refentrytitle">glTexEnv</span></span></a>,
<a class="citerefentry" href="glTexGen"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a>,
<a class="citerefentry" href="glTexImage1D"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
<a class="citerefentry" href="glTexImage2D"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
<a class="citerefentry" href="glTexImage3D"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
<a class="citerefentry" href="glTexParameter"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>,
<a class="citerefentry" href="glTexSubImage1D"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
<a class="citerefentry" href="glTexSubImage2D"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,
<a class="citerefentry" href="glTexSubImage3D"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>
</p></div><div class="refsect1" lang="en" xml:lang="en"><div id="Copyright"><h2>Copyright</h2><p>
Copyright © 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
<a class="ulink" href="https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/" target="_top">https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/</a>.
</p></div></div></div>