From 2e3c4e47842905bc7f3d506e865cc77f7463166b Mon Sep 17 00:00:00 2001 From: Chia-I Wu Date: Fri, 7 May 2010 14:13:08 +0800 Subject: docs: Update EGL and OpenGL ES docs. Update to reflect recent gles and mapi works. --- docs/opengles.html | 69 +++++++++++++++++++++++++++--------------------------- 1 file changed, 35 insertions(+), 34 deletions(-) (limited to 'docs/opengles.html') diff --git a/docs/opengles.html b/docs/opengles.html index fc41e6771c..9984a79b1b 100644 --- a/docs/opengles.html +++ b/docs/opengles.html @@ -1,68 +1,69 @@ -OpenGL ES State Trackers +OpenGL ES -

OpenGL ES State Trackers

OpenGL ES

The current version of the OpenGL ES state trackers implement OpenGL ES 1.1 and OpenGL ES 2.0. -More informations about OpenGL ES can be found at - -http://www.khronos.org/opengles/.

- -

The OpenGL ES state trackers depends on the Gallium architecture and a -working EGL implementation. Please refer to Mesa EGL -for more information about EGL.

Mesa implements OpenGL ES 1.1 and OpenGL ES 2.0. More informations about +OpenGL ES can be found at http://www.khronos.org/opengles/.

OpenGL ES depends on a working EGL implementation. Please refer to +Mesa EGL for more information about EGL.

Build the Libraries

Run configure with --with-state-trackers=egl,es and enable the Gallium driver for your hardware.
Run configure with --enable-gles-overlay and enable the Gallium driver for your hardware.
Build and install Mesa as usual.

+ +Alternatively, if XCB-DRI2 is installed on the system, one can use +egl_dri2 EGL driver with OpenGL|ES-enabled DRI drivers + +

Run configure with --enable-gles1 --enable-gles2.
Build and install Mesa as usual.

It will install libGLESv1_CM, libGLESv2, libEGL, and one or more EGL drivers for your hardware.

Both methods will install libGLESv1_CM, libGLESv2, libEGL, and one or more +EGL drivers for your hardware.

Run the Demos

There are some demos in progs/es1/ and progs/es2/. You can use them to test your build. For example,

There are some demos in progs/egl/. You can use them to test +your build. For example,

-  $ cd progs/es1/xegl
+  $ cd progs/egl/eglut
+  $ make
+  $ cd ../opengles1
   $ make
-  $ ./torus
+  $ ./torus_x11

Developers

The core of OpenGL ES state trackers is the ES overlay. It is located in -src/mesa/es/.

- -

Structure

Internal Libraries

The ES overlay uses as much code as possible from Mesa. It has its own glapi XMLs to describe the APIs of OpenGL ES. The ES overlay can be built parallelly with Mesa, and they will give

- - - - - - - - - +

Library Name	Usage	Source
libmesagallium.a	OpenGL state tracker	Mesa
libes1gallium.a	OpenGL ES 1.x state tracker	ES overlay
libes2gallium.a	OpenGL ES 2.x state tracker	ES overlay
libglapi.a	OpenGL API	Mesa
libes1api.a	OpenGL ES 1.x API	ES overlay
libes2api.a	OpenGL ES 2.x API	ES overlay

+ + + + +

Library Name	Used By	Enabled	OpenGL	OpenGL ES 1.x	OpenGL ES 2.x
`src/mesa/libmesa.a`	Classic DRI drivers	y	y	--enable-gles1	--enable-gles2
`src/mesa/libmesagallium.a`	Gallium EGL and DRI drivers	y	y	--enable-gles1	--enable-gles2
`src/mesa/es/libes1gallium.a`	Gallium EGL drivers	--enable-gles-overlay	n	y	n
`src/mesa/es/libes2gallium.a`	Gallium EGL drivers	--enable-gles-overlay	n	n	y

The OpenGL ES state trackers and APIs are then used by src/gallium/state_trackers/es/ to create the final libraries.

Dispatch Table

The ES overlay uses an additional indirection when dispatching fucntions

OpenGL ES has an additional indirection when dispatching fucntions

   Mesa:       glFoo() --> _mesa_Foo()
-  ES overlay: glFoo() --> _es_Foo() --> _mesa_Foo()
+  OpenGL ES:  glFoo() --> _es_Foo() --> _mesa_Foo()

The indirection serves several purposes

@@ -73,7 +74,7 @@ for more information about EGL.

When a function is not available in Mesa, or accepts arguments that are not available in OpenGL, it provides its own implementation.

Other than the last case, the ES overlay uses APIspec.xml to generate functions to check and/or converts the arguments.

Other than the last case, OpenGL ES uses APIspec.xml to generate functions to check and/or converts the arguments.

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