<div class="refentry" title="glGetError"><a id="glGetError"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetError — return error information</p></div><div class="refsynopsisdiv" title="C Specification"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">GLenum <b class="fsfunc">glGetError</b>(</code></td><td><code>void)</code>;</td><td> </td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Description"><a id="description"></a><h2>Description</h2><p>

<code class="function">glGetError</code>

returns the value of the error flag. Each detectable error is

assigned a numeric code and symbolic name. When an error

occurs, the error flag is set to the appropriate error code

value. No other errors are recorded until

<code class="function">glGetError</code>

is called, the error code is returned, and the flag is reset to

<code class="constant">GL_NO_ERROR</code>. If a call to

<code class="function">glGetError</code>

returns <code class="constant">GL_NO_ERROR</code>,

there has been no detectable error since the last call to

<code class="function">glGetError</code>,

or since the GL was initialized.</p><p>To allow for distributed implementations, there may be

several error flags. If any single error flag has recorded an

error, the value of that flag is returned and that flag is

reset to <code class="constant">GL_NO_ERROR</code> when

<code class="function">glGetError</code>

is called. If more than one flag has recorded an error,

<code class="function">glGetError</code>

returns and clears an arbitrary error flag value. Thus,

<code class="function">glGetError</code>

should always be called in a loop, until it returns

<code class="constant">GL_NO_ERROR</code>,

if all error flags are to be reset.</p><p>Initially, all error flags are set to

<code class="constant">GL_NO_ERROR</code>.</p><p>The following errors are currently defined:</p><div class="variablelist"><dl><dt><span class="term">

<code class="constant">GL_NO_ERROR</code>

</span></dt><dd><p>No error has been recorded. The value of this

symbolic constant is guaranteed to be 0.</p></dd><dt><span class="term">

<code class="constant">GL_INVALID_ENUM</code>

</span></dt><dd><p>An unacceptable value is specified for an

enumerated argument. The offending command is ignored,

and has no other side effect than to set the error

flag.</p></dd><dt><span class="term">

<code class="constant">GL_INVALID_VALUE</code>

</span></dt><dd><p>A numeric argument is out of range. The offending

command is ignored, and has no other side effect than to

set the error flag.</p></dd><dt><span class="term">

<code class="constant">GL_INVALID_OPERATION</code>

</span></dt><dd><p>The specified operation is not allowed in the

current state. The offending command is ignored, and has

no other side effect than to set the error flag.</p></dd><dt><span class="term">

<code class="constant">GL_STACK_OVERFLOW</code>

</span></dt><dd><p>This command would cause a stack overflow. The

offending command is ignored, and has no other side

effect than to set the error flag.</p></dd><dt><span class="term">

<code class="constant">GL_STACK_UNDERFLOW</code>

</span></dt><dd><p>This command would cause a stack underflow. The

offending command is ignored, and has no other side

effect than to set the error flag.</p></dd><dt><span class="term">

<code class="constant">GL_OUT_OF_MEMORY</code>

</span></dt><dd><p>There is not enough memory left to execute the

command. The state of the GL is undefined, except for the

state of the error flags, after this error is

recorded.</p></dd></dl></div><p>When an error flag is set, results of a GL operation are

undefined only if <code class="constant">GL_OUT_OF_MEMORY</code>

has occurred. In all other cases, the command generating the

error is ignored and has no effect on the GL state or frame

buffer contents. If the generating command returns a value, it

returns 0. If <code class="function">glGetError</code>

itself generates an error, it returns 0.</p></div><div class="refsect1" title="Copyright"><a id="copyright"></a><h2>Copyright</h2><p>

Copyright <span class="trademark"></span>© 2003-2004

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>