1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html lang="en"> 3<head> 4 <meta http-equiv="content-type" content="text/html; charset=utf-8"> 5 <title>OpenGL ES</title> 6 <link rel="stylesheet" type="text/css" href="mesa.css"> 7</head> 8<body> 9 10<div class="header"> 11 <h1>The Mesa 3D Graphics Library</h1> 12</div> 13 14<iframe src="contents.html"></iframe> 15<div class="content"> 16 17<h1>OpenGL ES</h1> 18 19<p>Mesa implements OpenGL ES 1.1 and OpenGL ES 2.0. More information about 20OpenGL ES can be found at <a href="https://www.khronos.org/opengles/"> 21https://www.khronos.org/opengles/</a>.</p> 22 23<p>OpenGL ES depends on a working EGL implementation. Please refer to 24<a href="egl.html">Mesa EGL</a> for more information about EGL.</p> 25 26<h2>Build the Libraries</h2> 27<ol> 28<li>Run <code>configure</code> with <code>--enable-gles1 --enable-gles2</code> and enable the Gallium driver for your hardware.</li> 29<li>Build and install Mesa as usual.</li> 30</ol> 31 32Alternatively, if XCB-DRI2 is installed on the system, one can use 33<code>egl_dri2</code> EGL driver with OpenGL|ES-enabled DRI drivers 34 35<ol> 36<li>Run <code>configure</code> with <code>--enable-gles1 --enable-gles2</code>.</li> 37<li>Build and install Mesa as usual.</li> 38</ol> 39 40<p>Both methods will install libGLESv1_CM, libGLESv2, libEGL, and one or more 41EGL drivers for your hardware.</p> 42 43<h2>Run the Demos</h2> 44 45<p>There are some demos in <code>mesa/demos</code> repository.</p> 46 47<h2>Developers</h2> 48 49<h3>Dispatch Table</h3> 50 51<p>OpenGL ES has an additional indirection when dispatching functions</p> 52 53<pre> 54 Mesa: glFoo() --> _mesa_Foo() 55 OpenGL ES: glFoo() --> _es_Foo() --> _mesa_Foo() 56</pre> 57 58<p>The indirection serves several purposes</p> 59 60<ul> 61<li>When a function is in Mesa and the type matches, it checks the arguments and calls the Mesa function.</li> 62<li>When a function is in Mesa but the type mismatches, it checks and converts the arguments before calling the Mesa function.</li> 63<li>When a function is not available in Mesa, or accepts arguments that are not available in OpenGL, it provides its own implementation.</li> 64</ul> 65 66<p>Other than the last case, OpenGL ES uses <code>APIspec.xml</code> to generate functions to check and/or converts the arguments.</p> 67 68</div> 69</body> 70</html> 71