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<title>Graphics/Rendering/OpenGL/GL/Extensions.hs</title>
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<pre><a name="line-1"></a><span class='hs-comment'>-- #hide</span>
<a name="line-2"></a><span class='hs-comment'>--------------------------------------------------------------------------------</span>
<a name="line-3"></a><span class='hs-comment'>-- |</span>
<a name="line-4"></a><span class='hs-comment'>-- Module : Graphics.Rendering.OpenGL.GL.Extensions</span>
<a name="line-5"></a><span class='hs-comment'>-- Copyright : (c) Sven Panne 2002-2009</span>
<a name="line-6"></a><span class='hs-comment'>-- License : BSD-style (see the file libraries/OpenGL/LICENSE)</span>
<a name="line-7"></a><span class='hs-comment'>-- </span>
<a name="line-8"></a><span class='hs-comment'>-- Maintainer : sven.panne@aedion.de</span>
<a name="line-9"></a><span class='hs-comment'>-- Stability : stable</span>
<a name="line-10"></a><span class='hs-comment'>-- Portability : portable</span>
<a name="line-11"></a><span class='hs-comment'>--</span>
<a name="line-12"></a><span class='hs-comment'>-- This is a purely internal module for handling the OpenGL extension</span>
<a name="line-13"></a><span class='hs-comment'>-- mechanism.</span>
<a name="line-14"></a><span class='hs-comment'>--</span>
<a name="line-15"></a><span class='hs-comment'>--------------------------------------------------------------------------------</span>
<a name="line-16"></a>
<a name="line-17"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Graphics</span><span class='hs-varop'>.</span><span class='hs-conid'>Rendering</span><span class='hs-varop'>.</span><span class='hs-conid'>OpenGL</span><span class='hs-varop'>.</span><span class='hs-conid'>GL</span><span class='hs-varop'>.</span><span class='hs-conid'>Extensions</span> <span class='hs-layout'>(</span>
<a name="line-18"></a> <span class='hs-conid'>FunPtr</span><span class='hs-layout'>,</span> <span class='hs-varid'>unsafePerformIO</span><span class='hs-layout'>,</span>
<a name="line-19"></a> <span class='hs-conid'>Invoker</span><span class='hs-layout'>,</span> <span class='hs-varid'>getProcAddress</span> <span class='hs-comment'>-- used only internally</span>
<a name="line-20"></a><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-21"></a>
<a name="line-22"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Foreign</span><span class='hs-varop'>.</span><span class='hs-conid'>C</span><span class='hs-varop'>.</span><span class='hs-conid'>String</span> <span class='hs-layout'>(</span> <span class='hs-conid'>CString</span><span class='hs-layout'>,</span> <span class='hs-varid'>withCString</span> <span class='hs-layout'>)</span>
<a name="line-23"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Foreign</span><span class='hs-varop'>.</span><span class='hs-conid'>Ptr</span> <span class='hs-layout'>(</span> <span class='hs-conid'>FunPtr</span><span class='hs-layout'>,</span> <span class='hs-varid'>nullFunPtr</span> <span class='hs-layout'>)</span>
<a name="line-24"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span><span class='hs-varop'>.</span><span class='hs-conid'>Unsafe</span> <span class='hs-layout'>(</span> <span class='hs-varid'>unsafePerformIO</span> <span class='hs-layout'>)</span>
<a name="line-25"></a>
<a name="line-26"></a><span class='hs-cpp'>#ifdef __HUGS__</span>
<a name="line-27"></a><span class='hs-comment'>{-# CFILES cbits/HsOpenGL.c #-}</span>
<a name="line-28"></a><span class='hs-cpp'>#endif</span>
<a name="line-29"></a>
<a name="line-30"></a><span class='hs-comment'>--------------------------------------------------------------------------------</span>
<a name="line-31"></a>
<a name="line-32"></a><a name="Invoker"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>Invoker</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>FunPtr</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-33"></a>
<a name="line-34"></a><a name="getProcAddress"></a><span class='hs-definition'>getProcAddress</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>FunPtr</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-35"></a><span class='hs-definition'>getProcAddress</span> <span class='hs-varid'>ext</span> <span class='hs-varid'>call</span> <span class='hs-keyglyph'>=</span>
<a name="line-36"></a> <span class='hs-varid'>throwIfNull</span> <span class='hs-layout'>(</span><span class='hs-str'>"unknown OpenGL call "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>call</span> <span class='hs-varop'>++</span> <span class='hs-str'>", check for "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>ext</span><span class='hs-layout'>)</span> <span class='hs-varop'>$</span>
<a name="line-37"></a> <span class='hs-varid'>withCString</span> <span class='hs-varid'>call</span> <span class='hs-varid'>hs_OpenGL_getProcAddress</span>
<a name="line-38"></a>
<a name="line-39"></a><a name="throwIfNull"></a><span class='hs-definition'>throwIfNull</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>FunPtr</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>FunPtr</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-40"></a><span class='hs-definition'>throwIfNull</span> <span class='hs-varid'>msg</span> <span class='hs-varid'>act</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-41"></a> <span class='hs-varid'>res</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>act</span>
<a name="line-42"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>res</span> <span class='hs-varop'>==</span> <span class='hs-varid'>nullFunPtr</span>
<a name="line-43"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>ioError</span> <span class='hs-layout'>(</span><span class='hs-varid'>userError</span> <span class='hs-varid'>msg</span><span class='hs-layout'>)</span>
<a name="line-44"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>return</span> <span class='hs-varid'>res</span>
<a name="line-45"></a>
<a name="line-46"></a><span class='hs-keyword'>foreign</span> <span class='hs-keyword'>import</span> <span class='hs-keyword'>ccall</span> <span class='hs-keyword'>unsafe</span> <span class='hs-str'>"hs_OpenGL_getProcAddress"</span> <span class='hs-varid'>hs_OpenGL_getProcAddress</span>
<a name="line-47"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>FunPtr</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
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