<div class="refentry"><a id="glBindVertexArray"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBlitFramebuffer — copy a block of pixels from the read framebuffer to the draw framebuffer</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table class="funcprototype-table" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glBlitFramebuffer</strong>(</code></td><td>GLint <var class="pdparam">srcX0</var>, </td></tr><tr><td> </td><td>GLint <var class="pdparam">srcY0</var>, </td></tr><tr><td> </td><td>GLint <var class="pdparam">srcX1</var>, </td></tr><tr><td> </td><td>GLint <var class="pdparam">srcY1</var>, </td></tr><tr><td> </td><td>GLint <var class="pdparam">dstX0</var>, </td></tr><tr><td> </td><td>GLint <var class="pdparam">dstY0</var>, </td></tr><tr><td> </td><td>GLint <var class="pdparam">dstX1</var>, </td></tr><tr><td> </td><td>GLint <var class="pdparam">dstY1</var>, </td></tr><tr><td> </td><td>GLbitfield <var class="pdparam">mask</var>, </td></tr><tr><td> </td><td>GLenum <var class="pdparam">filter</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>srcX0</code></em>, </span><span class="term"><em class="parameter"><code>srcY0</code></em>, </span><span class="term"><em class="parameter"><code>srcX1</code></em>, </span><span class="term"><em class="parameter"><code>srcY1</code></em></span></dt><dd><p>

Specify the bounds of the source rectangle within the read buffer of the read framebuffer.

</p></dd><dt><span class="term"><em class="parameter"><code>dstX0</code></em>, </span><span class="term"><em class="parameter"><code>dstY0</code></em>, </span><span class="term"><em class="parameter"><code>dstX1</code></em>, </span><span class="term"><em class="parameter"><code>dstY1</code></em></span></dt><dd><p>

Specify the bounds of the destination rectangle within the write buffer of the write framebuffer.

</p></dd><dt><span class="term"><em class="parameter"><code>mask</code></em></span></dt><dd><p>

The bitwise OR of the flags indicating which buffers are to be copied. The allowed flags are

<code class="constant">GL_COLOR_BUFFER_BIT</code>, <code class="constant">GL_DEPTH_BUFFER_BIT</code> and <code class="constant">GL_STENCIL_BUFFER_BIT</code>.

</p></dd><dt><span class="term"><em class="parameter"><code>filter</code></em></span></dt><dd><p>

Specifies the interpolation to be applied if the image is stretched. Must be <code class="constant">GL_NEAREST</code> or <code class="constant">GL_LINEAR</code>.

</p></dd></dl></div></div><div class="refsect1"><a id="description"></a><h2>Description</h2><p>

<code class="function">glBlitFramebuffer</code> transfers a rectangle of pixel values from one region of the read framebuffer to another region in

the draw framebuffer. <em class="parameter"><code>mask</code></em> is the bitwise OR of a number of values indicating which buffers are

to be copied. The values are <code class="constant">GL_COLOR_BUFFER_BIT</code>, <code class="constant">GL_DEPTH_BUFFER_BIT</code>, and

<code class="constant">GL_STENCIL_BUFFER_BIT</code>. The pixels corresponding to these buffers are copied from the source rectangle bounded by the

locations (<em class="parameter"><code>srcX0</code></em>; <em class="parameter"><code>srcY0</code></em>) and (<em class="parameter"><code>srcX1</code></em>; <em class="parameter"><code>srcY1</code></em>)

to the destination rectangle bounded by the locations (<em class="parameter"><code>dstX0</code></em>; <em class="parameter"><code>dstY0</code></em>) and

(<em class="parameter"><code>dstX1</code></em>; <em class="parameter"><code>dstY1</code></em>). The lower bounds of the rectangle are inclusive, while the upper

bounds are exclusive.

</p><p>

The actual region taken from the read framebuffer is limited to the intersection of the source buffers being transferred, which may

include the color buffer selected by the read buffer, the depth buffer, and/or the stencil buffer depending on mask. The actual region

written to the draw framebuffer is limited to the intersection of the destination buffers being written, which may include multiple draw

buffers, the depth buffer, and/or the stencil buffer depending on mask. Whether or not the source or destination regions are altered due

to these limits, the scaling and offset applied to pixels being transferred is performed as though no such limits were present.

</p><p>

If the sizes of the source and destination rectangles are not equal, <em class="parameter"><code>filter</code></em> specifies the interpolation method that

will be applied to resize the source image , and must be <code class="constant">GL_NEAREST</code> or <code class="constant">GL_LINEAR</code>.

<code class="constant">GL_LINEAR</code> is only a valid interpolation method for the color buffer. If <em class="parameter"><code>filter</code></em> is not

<code class="constant">GL_NEAREST</code> and <em class="parameter"><code>mask</code></em> includes <code class="constant">GL_DEPTH_BUFFER_BIT</code> or

<code class="constant">GL_STENCIL_BUFFER_BIT</code>, no data is transferred and a <code class="constant">GL_INVALID_OPERATION</code> error is generated.

</p><p>

If <em class="parameter"><code>filter</code></em> is <code class="constant">GL_LINEAR</code> and the source rectangle would require sampling outside the bounds of

the source framebuffer, values are read as if the <code class="constant">GL_CLAMP_TO_EDGE</code> texture wrapping mode were applied.

</p><p>

When the color buffer is transferred, values are taken from the read buffer of the read framebuffer and written to each of the draw

buffers of the draw framebuffer.

</p><p>

If the source and destination rectangles overlap or are the same, and the read and draw buffers are the same, the result of the operation

is undefined.

</p></div><div class="refsect1"><a id="errors"></a><h2>Errors</h2><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>mask</code></em> contains any of the <code class="constant">GL_DEPTH_BUFFER_BIT</code>

or <code class="constant">GL_STENCIL_BUFFER_BIT</code> and <em class="parameter"><code>filter</code></em> is not <code class="constant">GL_NEAREST</code>.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>mask</code></em> contains <code class="constant">GL_COLOR_BUFFER_BIT</code>

and any of the following conditions hold:

</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>The read buffer contains fixed-point or floating-point values and any draw buffer contains

neither fixed-point nor floating-point values.</p></li><li class="listitem"><p>The read buffer contains unsigned integer values and any draw buffer does not contain unsigned

integer values.</p></li><li class="listitem"><p>The read buffer contains signed integer values and any draw buffer does not contain signed integer values.</p></li></ul></div><p>

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>mask</code></em> contains <code class="constant">GL_DEPTH_BUFFER_BIT</code> or

<code class="constant">GL_STENCIL_BUFFER_BIT</code> and the source and destination depth and stencil formats do not match.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>filter</code></em> is <code class="constant">GL_LINEAR</code> and the read buffer

contains integer data.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if the value of <em class="parameter"><code>GL_SAMPLES</code></em> for the read and draw buffers is

not identical.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>GL_SAMPLE_BUFFERS</code></em> for both read and draw buffers greater than

zero and the dimensions of the source and destination rectangles is not identical.

</p><p>

<code class="constant">GL_INVALID_FRAMEBUFFER_OPERATION</code> is generated if the objects bound to <code class="constant">GL_DRAW_FRAMEBUFFER_BINDING</code>

or <code class="constant">GL_READ_FRAMEBUFFER_BINDING</code> are not framebuffer complete.

</p></div>

{$pipelinestall}{$examples}

<div class="refsect1"><a id="seealso"></a><h2>See Also</h2><p>

<a class="citerefentry" href="glReadPixels"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a>

<a class="citerefentry" href="glCheckFramebufferStatus"><span class="citerefentry"><span class="refentrytitle">glCheckFramebufferStatus</span></span></a>,

<a class="citerefentry" href="glGenFramebuffers"><span class="citerefentry"><span class="refentrytitle">glGenFramebuffers</span></span></a>

<a class="citerefentry" href="glBindFramebuffer"><span class="citerefentry"><span class="refentrytitle">glBindFramebuffer</span></span></a>

<a class="citerefentry" href="glDeleteFramebuffers"><span class="citerefentry"><span class="refentrytitle">glDeleteFramebuffers</span></span></a>

</p></div><div class="refsect1"><div id="Copyright"><h2>Copyright</h2><p>

Copyright © 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 class="ulink" href="https://opencontent.org/openpub/" target="_top">https://opencontent.org/openpub/</a>.

</p></div></div></div>