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<div class="header">
  <div class="summary">
<a href="#typedef-members">Typedefs</a> &#124;
<a href="#func-members">Functions</a>  </div>
  <div class="headertitle">
<div class="title">Context reference</div>  </div>
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<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="typedef-members"></a>
Typedefs</h2></td></tr>
<tr class="memitem:ga3d47c2d2fbe0be9c505d0e04e91a133c"><td class="memItemLeft" align="right" valign="top">typedef void(*&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__context.html#ga3d47c2d2fbe0be9c505d0e04e91a133c">GLFWglproc</a>) (void)</td></tr>
<tr class="memdesc:ga3d47c2d2fbe0be9c505d0e04e91a133c"><td class="mdescLeft">&#160;</td><td class="mdescRight">Client API function pointer type.  <a href="#ga3d47c2d2fbe0be9c505d0e04e91a133c">More...</a><br /></td></tr>
<tr class="separator:ga3d47c2d2fbe0be9c505d0e04e91a133c"><td class="memSeparator" colspan="2">&#160;</td></tr>
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<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:ga1c04dc242268f827290fe40aa1c91157"><td class="memItemLeft" align="right" valign="top">void&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__context.html#ga1c04dc242268f827290fe40aa1c91157">glfwMakeContextCurrent</a> (<a class="el" href="group__window.html#ga3c96d80d363e67d13a41b5d1821f3242">GLFWwindow</a> *window)</td></tr>
<tr class="memdesc:ga1c04dc242268f827290fe40aa1c91157"><td class="mdescLeft">&#160;</td><td class="mdescRight">Makes the context of the specified window current for the calling thread.  <a href="#ga1c04dc242268f827290fe40aa1c91157">More...</a><br /></td></tr>
<tr class="separator:ga1c04dc242268f827290fe40aa1c91157"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:gac84759b1f6c2d271a4fea8ae89ec980d"><td class="memItemLeft" align="right" valign="top"><a class="el" href="group__window.html#ga3c96d80d363e67d13a41b5d1821f3242">GLFWwindow</a> *&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__context.html#gac84759b1f6c2d271a4fea8ae89ec980d">glfwGetCurrentContext</a> (void)</td></tr>
<tr class="memdesc:gac84759b1f6c2d271a4fea8ae89ec980d"><td class="mdescLeft">&#160;</td><td class="mdescRight">Returns the window whose context is current on the calling thread.  <a href="#gac84759b1f6c2d271a4fea8ae89ec980d">More...</a><br /></td></tr>
<tr class="separator:gac84759b1f6c2d271a4fea8ae89ec980d"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga6d4e0cdf151b5e579bd67f13202994ed"><td class="memItemLeft" align="right" valign="top">void&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__context.html#ga6d4e0cdf151b5e579bd67f13202994ed">glfwSwapInterval</a> (int interval)</td></tr>
<tr class="memdesc:ga6d4e0cdf151b5e579bd67f13202994ed"><td class="mdescLeft">&#160;</td><td class="mdescRight">Sets the swap interval for the current context.  <a href="#ga6d4e0cdf151b5e579bd67f13202994ed">More...</a><br /></td></tr>
<tr class="separator:ga6d4e0cdf151b5e579bd67f13202994ed"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga87425065c011cef1ebd6aac75e059dfa"><td class="memItemLeft" align="right" valign="top">int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__context.html#ga87425065c011cef1ebd6aac75e059dfa">glfwExtensionSupported</a> (const char *extension)</td></tr>
<tr class="memdesc:ga87425065c011cef1ebd6aac75e059dfa"><td class="mdescLeft">&#160;</td><td class="mdescRight">Returns whether the specified extension is available.  <a href="#ga87425065c011cef1ebd6aac75e059dfa">More...</a><br /></td></tr>
<tr class="separator:ga87425065c011cef1ebd6aac75e059dfa"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga35f1837e6f666781842483937612f163"><td class="memItemLeft" align="right" valign="top"><a class="el" href="group__context.html#ga3d47c2d2fbe0be9c505d0e04e91a133c">GLFWglproc</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__context.html#ga35f1837e6f666781842483937612f163">glfwGetProcAddress</a> (const char *procname)</td></tr>
<tr class="memdesc:ga35f1837e6f666781842483937612f163"><td class="mdescLeft">&#160;</td><td class="mdescRight">Returns the address of the specified function for the current context.  <a href="#ga35f1837e6f666781842483937612f163">More...</a><br /></td></tr>
<tr class="separator:ga35f1837e6f666781842483937612f163"><td class="memSeparator" colspan="2">&#160;</td></tr>
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<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2>
<p>This is the reference documentation for OpenGL and OpenGL ES context related functions. For more task-oriented information, see the <a class="el" href="context_guide.html">Context guide</a>. </p>
<h2 class="groupheader">Typedef Documentation</h2>
<a class="anchor" id="ga3d47c2d2fbe0be9c505d0e04e91a133c"></a>
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          <td class="memname">typedef void(* GLFWglproc) (void)</td>
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<p>Generic function pointer used for returning client API function pointers without forcing a cast from a regular pointer.</p>
<dl class="section see"><dt>See also</dt><dd><a class="el" href="context_guide.html#context_glext">OpenGL and OpenGL ES extensions</a> </dd>
<dd>
<a class="el" href="group__context.html#ga35f1837e6f666781842483937612f163" title="Returns the address of the specified function for the current context. ">glfwGetProcAddress</a></dd></dl>
<dl class="section since"><dt>Since</dt><dd>Added in version 3.0. </dd></dl>

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<h2 class="groupheader">Function Documentation</h2>
<a class="anchor" id="ga87425065c011cef1ebd6aac75e059dfa"></a>
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          <td class="memname">int glfwExtensionSupported </td>
          <td>(</td>
          <td class="paramtype">const char *&#160;</td>
          <td class="paramname"><em>extension</em></td><td>)</td>
          <td></td>
        </tr>
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<p>This function returns whether the specified <a class="el" href="context_guide.html#context_glext">API extension</a> is supported by the current OpenGL or OpenGL ES context. It searches both for client API extension and context creation API extensions.</p>
<p>A context must be current on the calling thread. Calling this function without a current context will cause a <a class="el" href="group__errors.html#gaa8290386e9528ccb9e42a3a4e16fc0d0">GLFW_NO_CURRENT_CONTEXT</a> error.</p>
<p>As this functions retrieves and searches one or more extension strings each call, it is recommended that you cache its results if it is going to be used frequently. The extension strings will not change during the lifetime of a context, so there is no danger in doing this.</p>
<p>This function does not apply to Vulkan. If you are using Vulkan, see <a class="el" href="group__vulkan.html#ga1abcbe61033958f22f63ef82008874b1">glfwGetRequiredInstanceExtensions</a>, <code>vkEnumerateInstanceExtensionProperties</code> and <code>vkEnumerateDeviceExtensionProperties</code> instead.</p>
<dl class="params"><dt>Parameters</dt><dd>
  <table class="params">
    <tr><td class="paramdir">[in]</td><td class="paramname">extension</td><td>The ASCII encoded name of the extension. </td></tr>
  </table>
  </dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd><code>GLFW_TRUE</code> if the extension is available, or <code>GLFW_FALSE</code> otherwise.</dd></dl>
<dl class="section user"><dt>Errors</dt><dd>Possible errors include <a class="el" href="group__errors.html#ga2374ee02c177f12e1fa76ff3ed15e14a">GLFW_NOT_INITIALIZED</a>, <a class="el" href="group__errors.html#gaa8290386e9528ccb9e42a3a4e16fc0d0">GLFW_NO_CURRENT_CONTEXT</a>, <a class="el" href="group__errors.html#gaaf2ef9aa8202c2b82ac2d921e554c687">GLFW_INVALID_VALUE</a> and <a class="el" href="group__errors.html#gad44162d78100ea5e87cdd38426b8c7a1">GLFW_PLATFORM_ERROR</a>.</dd></dl>
<dl class="section user"><dt>Thread safety</dt><dd>This function may be called from any thread.</dd></dl>
<dl class="section see"><dt>See also</dt><dd><a class="el" href="context_guide.html#context_glext">OpenGL and OpenGL ES extensions</a> </dd>
<dd>
<a class="el" href="group__context.html#ga35f1837e6f666781842483937612f163" title="Returns the address of the specified function for the current context. ">glfwGetProcAddress</a></dd></dl>
<dl class="section since"><dt>Since</dt><dd>Added in version 1.0. </dd></dl>

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<a class="anchor" id="gac84759b1f6c2d271a4fea8ae89ec980d"></a>
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          <td class="memname"><a class="el" href="group__window.html#ga3c96d80d363e67d13a41b5d1821f3242">GLFWwindow</a>* glfwGetCurrentContext </td>
          <td>(</td>
          <td class="paramtype">void&#160;</td>
          <td class="paramname"></td><td>)</td>
          <td></td>
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<p>This function returns the window whose OpenGL or OpenGL ES context is current on the calling thread.</p>
<dl class="section return"><dt>Returns</dt><dd>The window whose context is current, or <code>NULL</code> if no window's context is current.</dd></dl>
<dl class="section user"><dt>Errors</dt><dd>Possible errors include <a class="el" href="group__errors.html#ga2374ee02c177f12e1fa76ff3ed15e14a">GLFW_NOT_INITIALIZED</a>.</dd></dl>
<dl class="section user"><dt>Thread safety</dt><dd>This function may be called from any thread.</dd></dl>
<dl class="section see"><dt>See also</dt><dd><a class="el" href="context_guide.html#context_current">Current context</a> </dd>
<dd>
<a class="el" href="group__context.html#ga1c04dc242268f827290fe40aa1c91157" title="Makes the context of the specified window current for the calling thread. ">glfwMakeContextCurrent</a></dd></dl>
<dl class="section since"><dt>Since</dt><dd>Added in version 3.0. </dd></dl>

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          <td class="memname"><a class="el" href="group__context.html#ga3d47c2d2fbe0be9c505d0e04e91a133c">GLFWglproc</a> glfwGetProcAddress </td>
          <td>(</td>
          <td class="paramtype">const char *&#160;</td>
          <td class="paramname"><em>procname</em></td><td>)</td>
          <td></td>
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<p>This function returns the address of the specified OpenGL or OpenGL ES <a class="el" href="context_guide.html#context_glext">core or extension function</a>, if it is supported by the current context.</p>
<p>A context must be current on the calling thread. Calling this function without a current context will cause a <a class="el" href="group__errors.html#gaa8290386e9528ccb9e42a3a4e16fc0d0">GLFW_NO_CURRENT_CONTEXT</a> error.</p>
<p>This function does not apply to Vulkan. If you are rendering with Vulkan, see <a class="el" href="group__vulkan.html#gadf228fac94c5fd8f12423ec9af9ff1e9">glfwGetInstanceProcAddress</a>, <code>vkGetInstanceProcAddr</code> and <code>vkGetDeviceProcAddr</code> instead.</p>
<dl class="params"><dt>Parameters</dt><dd>
  <table class="params">
    <tr><td class="paramdir">[in]</td><td class="paramname">procname</td><td>The ASCII encoded name of the function. </td></tr>
  </table>
  </dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>The address of the function, or <code>NULL</code> if an <a class="el" href="intro_guide.html#error_handling">error</a> occurred.</dd></dl>
<dl class="section user"><dt>Errors</dt><dd>Possible errors include <a class="el" href="group__errors.html#ga2374ee02c177f12e1fa76ff3ed15e14a">GLFW_NOT_INITIALIZED</a>, <a class="el" href="group__errors.html#gaa8290386e9528ccb9e42a3a4e16fc0d0">GLFW_NO_CURRENT_CONTEXT</a> and <a class="el" href="group__errors.html#gad44162d78100ea5e87cdd38426b8c7a1">GLFW_PLATFORM_ERROR</a>.</dd></dl>
<dl class="section remark"><dt>Remarks</dt><dd>The address of a given function is not guaranteed to be the same between contexts.</dd>
<dd>
This function may return a non-<code>NULL</code> address despite the associated version or extension not being available. Always check the context version or extension string first.</dd></dl>
<dl class="section user"><dt>Pointer lifetime</dt><dd>The returned function pointer is valid until the context is destroyed or the library is terminated.</dd></dl>
<dl class="section user"><dt>Thread safety</dt><dd>This function may be called from any thread.</dd></dl>
<dl class="section see"><dt>See also</dt><dd><a class="el" href="context_guide.html#context_glext">OpenGL and OpenGL ES extensions</a> </dd>
<dd>
<a class="el" href="group__context.html#ga87425065c011cef1ebd6aac75e059dfa" title="Returns whether the specified extension is available. ">glfwExtensionSupported</a></dd></dl>
<dl class="section since"><dt>Since</dt><dd>Added in version 1.0. </dd></dl>

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          <td class="memname">void glfwMakeContextCurrent </td>
          <td>(</td>
          <td class="paramtype"><a class="el" href="group__window.html#ga3c96d80d363e67d13a41b5d1821f3242">GLFWwindow</a> *&#160;</td>
          <td class="paramname"><em>window</em></td><td>)</td>
          <td></td>
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<p>This function makes the OpenGL or OpenGL ES context of the specified window current on the calling thread. A context can only be made current on a single thread at a time and each thread can have only a single current context at a time.</p>
<p>By default, making a context non-current implicitly forces a pipeline flush. On machines that support <code>GL_KHR_context_flush_control</code>, you can control whether a context performs this flush by setting the <a class="el" href="window_guide.html#window_hints_ctx">GLFW_CONTEXT_RELEASE_BEHAVIOR</a> window hint.</p>
<p>The specified window must have an OpenGL or OpenGL ES context. Specifying a window without a context will generate a <a class="el" href="group__errors.html#gacff24d2757da752ae4c80bf452356487">GLFW_NO_WINDOW_CONTEXT</a> error.</p>
<dl class="params"><dt>Parameters</dt><dd>
  <table class="params">
    <tr><td class="paramdir">[in]</td><td class="paramname">window</td><td>The window whose context to make current, or <code>NULL</code> to detach the current context.</td></tr>
  </table>
  </dd>
</dl>
<dl class="section user"><dt>Errors</dt><dd>Possible errors include <a class="el" href="group__errors.html#ga2374ee02c177f12e1fa76ff3ed15e14a">GLFW_NOT_INITIALIZED</a>, <a class="el" href="group__errors.html#gacff24d2757da752ae4c80bf452356487">GLFW_NO_WINDOW_CONTEXT</a> and <a class="el" href="group__errors.html#gad44162d78100ea5e87cdd38426b8c7a1">GLFW_PLATFORM_ERROR</a>.</dd></dl>
<dl class="section user"><dt>Thread safety</dt><dd>This function may be called from any thread.</dd></dl>
<dl class="section see"><dt>See also</dt><dd><a class="el" href="context_guide.html#context_current">Current context</a> </dd>
<dd>
<a class="el" href="group__context.html#gac84759b1f6c2d271a4fea8ae89ec980d" title="Returns the window whose context is current on the calling thread. ">glfwGetCurrentContext</a></dd></dl>
<dl class="section since"><dt>Since</dt><dd>Added in version 3.0. </dd></dl>

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          <td class="memname">void glfwSwapInterval </td>
          <td>(</td>
          <td class="paramtype">int&#160;</td>
          <td class="paramname"><em>interval</em></td><td>)</td>
          <td></td>
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<p>This function sets the swap interval for the current OpenGL or OpenGL ES context, i.e. the number of screen updates to wait from the time <a class="el" href="group__window.html#ga15a5a1ee5b3c2ca6b15ca209a12efd14">glfwSwapBuffers</a> was called before swapping the buffers and returning. This is sometimes called <em>vertical synchronization</em>, <em>vertical retrace synchronization</em> or just <em>vsync</em>.</p>
<p>Contexts that support either of the <code>WGL_EXT_swap_control_tear</code> and <code>GLX_EXT_swap_control_tear</code> extensions also accept negative swap intervals, which allow the driver to swap even if a frame arrives a little bit late. You can check for the presence of these extensions using <a class="el" href="group__context.html#ga87425065c011cef1ebd6aac75e059dfa">glfwExtensionSupported</a>. For more information about swap tearing, see the extension specifications.</p>
<p>A context must be current on the calling thread. Calling this function without a current context will cause a <a class="el" href="group__errors.html#gaa8290386e9528ccb9e42a3a4e16fc0d0">GLFW_NO_CURRENT_CONTEXT</a> error.</p>
<p>This function does not apply to Vulkan. If you are rendering with Vulkan, see the present mode of your swapchain instead.</p>
<dl class="params"><dt>Parameters</dt><dd>
  <table class="params">
    <tr><td class="paramdir">[in]</td><td class="paramname">interval</td><td>The minimum number of screen updates to wait for until the buffers are swapped by <a class="el" href="group__window.html#ga15a5a1ee5b3c2ca6b15ca209a12efd14">glfwSwapBuffers</a>.</td></tr>
  </table>
  </dd>
</dl>
<dl class="section user"><dt>Errors</dt><dd>Possible errors include <a class="el" href="group__errors.html#ga2374ee02c177f12e1fa76ff3ed15e14a">GLFW_NOT_INITIALIZED</a>, <a class="el" href="group__errors.html#gaa8290386e9528ccb9e42a3a4e16fc0d0">GLFW_NO_CURRENT_CONTEXT</a> and <a class="el" href="group__errors.html#gad44162d78100ea5e87cdd38426b8c7a1">GLFW_PLATFORM_ERROR</a>.</dd></dl>
<dl class="section remark"><dt>Remarks</dt><dd>This function is not called during context creation, leaving the swap interval set to whatever is the default on that platform. This is done because some swap interval extensions used by GLFW do not allow the swap interval to be reset to zero once it has been set to a non-zero value.</dd>
<dd>
Some GPU drivers do not honor the requested swap interval, either because of a user setting that overrides the application's request or due to bugs in the driver.</dd></dl>
<dl class="section user"><dt>Thread safety</dt><dd>This function may be called from any thread.</dd></dl>
<dl class="section see"><dt>See also</dt><dd><a class="el" href="window_guide.html#buffer_swap">Buffer swapping</a> </dd>
<dd>
<a class="el" href="group__window.html#ga15a5a1ee5b3c2ca6b15ca209a12efd14" title="Swaps the front and back buffers of the specified window. ">glfwSwapBuffers</a></dd></dl>
<dl class="section since"><dt>Since</dt><dd>Added in version 1.0. </dd></dl>

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Last update on Thu Aug 18 2016 for GLFW 3.2.1
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