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 <h1>OpenGL ES</h1> 11 12 <p>Mesa implements OpenGL ES 1.1 and OpenGL ES 2.0. More informations about 13 OpenGL ES can be found at <a href="http://www.khronos.org/opengles/" 14 target="_parent"> http://www.khronos.org/opengles/</a>.</p> 15 16 <p>OpenGL ES depends on a working EGL implementation. Please refer to 17 <a href="egl.html">Mesa EGL</a> for more information about EGL.</p> 18 19 <h2>Build the Libraries</h2> 20 <ol> 21 <li>Run <code>configure</code> with <code>--enable-gles1 --enable-gles2</code> and enable the Gallium driver for your hardware.</li> 22 <li>Build and install Mesa as usual.</li> 23 </ol> 24 25 Alternatively, if XCB-DRI2 is installed on the system, one can use 26 <code>egl_dri2</code> EGL driver with OpenGL|ES-enabled DRI drivers 27 28 <ol> 29 <li>Run <code>configure</code> with <code>--enable-gles1 --enable-gles2</code>.</li> 30 <li>Build and install Mesa as usual.</li> 31 </ol> 32 33 <p>Both methods will install libGLESv1_CM, libGLESv2, libEGL, and one or more 34 EGL drivers for your hardware.</p> 35 36 <h2>Run the Demos</h2> 37 38 <p>There are some demos in <code>mesa/demos</code> repository.</p> 39 40 <h2>Developers</h2> 41 42 <h3>Dispatch Table</h3> 43 44 <p>OpenGL ES has an additional indirection when dispatching fucntions</p> 45 46 <pre> 47 Mesa: glFoo() --> _mesa_Foo() 48 OpenGL ES: glFoo() --> _es_Foo() --> _mesa_Foo() 49 </pre> 50 51 <p>The indirection serves several purposes</p> 52 53 <ul> 54 <li>When a function is in Mesa and the type matches, it checks the arguments and calls the Mesa function.</li> 55 <li>When a function is in Mesa but the type mismatches, it checks and converts the arguments before calling the Mesa function.</li> 56 <li>When a function is not available in Mesa, or accepts arguments that are not available in OpenGL, it provides its own implementation.</li> 57 </ul> 58 59 <p>Other than the last case, OpenGL ES uses <code>APIspec.xml</code> to generate functions to check and/or converts the arguments.</p> 60 61 </body> 62 </html> 63
