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+ <h1>The Mesa 3D Graphics Library</h1>
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<h1>GL Dispatch in Mesa</h1>
<p>Several factors combine to make efficient dispatch of OpenGL functions
<h2>1. Complexity of GL Dispatch</h2>
<p>Every GL application has at least one object called a GL <em>context</em>.
-This object, which is an implicit parameter to ever GL function, stores all
+This object, which is an implicit parameter to every GL function, stores all
of the GL related state for the application. Every texture, every buffer
object, every enable, and much, much more is stored in the context. Since
an application can have more than one context, the context to be used is
or not fog is enabled.</p>
<p>In multi-threaded environments, it is possible for each thread to have a
-differnt GL context current. This means that poor old <tt>glVertex3fv</tt>
+different GL context current. This means that poor old <tt>glVertex3fv</tt>
has to know which GL context is current in the thread where it is being
called.</p>
few preprocessor defines.</p>
<ul>
-<li>If <tt>GLX_USE_TLS</tt> is defined, method #4 is used.</li>
-<li>If <tt>PTHREADS</tt> is defined, method #3 is used.</li>
-<li>If <tt>WIN32_THREADS</tt> is defined, method #2 is used.</li>
-<li>If none of the preceeding are defined, method #1 is used.</li>
+<li>If <tt>GLX_USE_TLS</tt> is defined, method #3 is used.</li>
+<li>If <tt>HAVE_PTHREAD</tt> is defined, method #2 is used.</li>
+<li>If none of the preceding are defined, method #1 is used.</li>
</ul>
<p>Two different techniques are used to handle the various different cases.
On x86 and SPARC, a macro called <tt>GL_STUB</tt> is used. In the preamble
of the assembly source file different implementations of the macro are
-selected based on the defined preprocessor variables. The assmebly code
+selected based on the defined preprocessor variables. The assembly code
then consists of a series of invocations of the macros such as:
<blockquote>
implementation of each function. This makes the assembly file considerably
larger (e.g., 29,332 lines for <tt>glapi_x86-64.S</tt> versus 1,155 lines for
<tt>glapi_x86.S</tt>) and causes simple changes to the function
-implementation to generate many lines of diffs. Since the assmebly files
+implementation to generate many lines of diffs. Since the assembly files
are typically generated by scripts (see <a href="#autogen">below</a>), this
isn't a significant problem.</p>
<h2 id="autogen">4. Automatic Generation of Dispatch Stubs</h2>
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