Blame - docs/opengles.html - platform/external/mesa3d

blob: d02482589e9fe1cdaadd73b51740346b45d07262 [file] [log] [blame]

Andreas Boll	ecd5c7c	2012-06-12 09:05:03 +0200	[diff] [blame^]	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>
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	8	<body>
				9
Chia-I Wu	2e3c4e4	2010-05-07 14:13:08 +0800	[diff] [blame]	10	<h1>OpenGL ES</h1>
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	11
Chia-I Wu	2e3c4e4	2010-05-07 14:13:08 +0800	[diff] [blame]	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>
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	15
Chia-I Wu	2e3c4e4	2010-05-07 14:13:08 +0800	[diff] [blame]	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>
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	18
				19	<h2>Build the Libraries</h2>
				20	<ol>
Chia-I Wu	1258317	2011-01-07 17:24:16 +0800	[diff] [blame]	21	<li>Run <code>configure</code> with <code>--enable-gles1 --enable-gles2</code> and enable the Gallium driver for your hardware.</li>
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	22	<li>Build and install Mesa as usual.</li>
				23	</ol>
				24
Chia-I Wu	2e3c4e4	2010-05-07 14:13:08 +0800	[diff] [blame]	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
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	36	<h2>Run the Demos</h2>
				37
Chia-I Wu	8eea050	2011-06-20 11:14:56 +0900	[diff] [blame]	38	<p>There are some demos in <code>mesa/demos</code> repository.</p>
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	39
				40	<h2>Developers</h2>
				41
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	42	<h3>Dispatch Table</h3>
				43
Chia-I Wu	2e3c4e4	2010-05-07 14:13:08 +0800	[diff] [blame]	44	<p>OpenGL ES has an additional indirection when dispatching fucntions</p>
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	45
				46	<pre>
				47	Mesa: glFoo() --> _mesa_Foo()
Chia-I Wu	2e3c4e4	2010-05-07 14:13:08 +0800	[diff] [blame]	48	OpenGL ES: glFoo() --> _es_Foo() --> _mesa_Foo()
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	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
Chia-I Wu	2e3c4e4	2010-05-07 14:13:08 +0800	[diff] [blame]	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>
Chia-I Wu	d8299af	2010-01-11 18:25:03 +0800	[diff] [blame]	60
				61	</body>
				62	</html>