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Neil Roberts 07a50012b9 egl: Only allow GLES2 context creation for the GLES2 driver
Previously, Cogl was advertising the GLES2 context feature whenever
the EGL winsys was used, even if the winsys was used with the GL
driver. This wasn't working because when the GL context is created the
API is set to GL with eglBindAPI and it is never changed back to GLES
when the GLES2 context is created. That meant that the created context
is actually GL not GLES2. Any rendering would then fail because the GL
context does not understand the precision statement.

It could be possible to fix it so that it will set the API correctly
before creating the context. It would then also need to reset the API
and unbind the previous context whenever switching between GLES2 and
GL contexts. If the context isn't unbound first then eglMakeCurrent
will actually try to bind both contexts at the same time and at least
Mesa detects this situation and reports that the two contexts
conflict. Presumably we would also need to do something more clever
when we retrieve the function pointers for the GLES2 context.
Currently we just copy them from the CoglContext but if the context is
using the GL driver then this would mean the functions came from libGL
not libGLESv2.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 624dea207cf76ae9ccd7f57c4ebd15d3bd65bff0)
2012-10-01 15:05:11 +01:00
build Clean up Visual C++ projects 2012-09-28 18:45:41 +08:00
cogl egl: Only allow GLES2 context creation for the GLES2 driver 2012-10-01 15:05:11 +01:00
cogl-gles2 cogl-gles2: Install headers in cogl/ instead of in cogl2/ 2012-08-16 16:36:34 +01:00
cogl-pango Mass rename CLUTTER_COMPILATION to COGL_COMPILATION 2012-08-06 14:27:45 +01:00
doc Fix the inclusion of the SDL integration documentation 2012-08-06 14:27:45 +01:00
examples build: remove duplicate cogl_info_SOURCES/LDADD lines 2012-09-03 15:55:14 +01:00
po [l10n] Updated Italian translation. 2012-09-29 18:02:19 +02:00
tests test-journal: Setup a UProf Mainloop timer 2012-09-03 15:51:45 +01:00
.gitignore Update .gitignore 2012-08-06 14:27:44 +01:00
.vimrc misc: Add a .vimrc file 2011-05-17 15:24:54 +01:00
autogen.sh Support building with automake 1.12.x 2012-08-15 13:46:25 +01:00
ChangeLog dist: Don't use elaborate script to gen Changelogs 2011-07-20 16:58:46 +01:00
cogl.doap Adds an initial cogl.doap file 2011-05-06 12:12:13 +01:00
config-custom.h configure: Force #undef of 'near' and 'far' on Windows 2011-06-14 12:14:02 +01:00
config.h.win32.in build: remove unneeded check for libdrm 2012-08-15 17:29:16 +01:00
configure.ac Post-release version bump to 1.12.1 2012-09-24 14:19:41 +01:00
COPYING Update the COPYING file 2011-09-05 19:02:05 +01:00
Makefile.am Adds libcogl-gles2 frontend GLES2 api 2012-08-06 14:27:42 +01:00
NEWS Updates NEWS for the 1.12.0 release 2012-09-24 13:46:01 +01:00
README.in docs: Update pointers to documentation 2012-09-03 15:55:14 +01:00

README for Cogl @COGL_1_VERSION@
===============================================================================

Note: This file is delimited with -- markers so it is possible to split
sections out for other purposes, such as for release notes.

--
DESCRIPTION
-------------------------------------------------------------------------------

Cogl is a small open source library for using 3D graphics hardware for
rendering. The API departs from the flat state machine style of OpenGL and is
designed to make it easy to write orthogonal components that can render without
stepping on each others toes.

As well as aiming for a nice API, we think having a single library as opposed
to an API specification like OpenGL has a few advantages too; like being
able to paper over the inconsistencies/bugs of different OpenGL
implementations in a centralized place, not to mention the myriad of OpenGL
extensions. It also means we are in a better position to provide utility
APIs that help software developers since they only need to be implemented
once and there is no risk of inconsistency between implementations.

Having other backends, besides OpenGL, such as drm, Gallium or D3D are
options we are interested in for the future.

--
REQUIREMENTS
-------------------------------------------------------------------------------

Cogl currently only requires:

  • GLib ≥ @GLIB_REQ_VERSION@
  • OpenGL ≥ 1.3 (or 1.2 + multitexturing), or OpenGL ES 2.0 (or 1.1)
  • GLX, AGL, WGL or an EGL implementation

Cogl also has optional dependencies:

  • GDK-Pixbuf ≥ @GDK_PIXBUF_REQ_VERSION@
     - for image loading
  • Cairo ≥ @CAIRO_REQ_VERSION@
     - for debugging texture atlasing (debug builds only)

The optional Cogl Pango library requires:
  • Cairo ≥ @CAIRO_REQ_VERSION@
  • PangoCairo ≥ @PANGOCAIRO_REQ_VERSION@

On X11, Cogl depends on the following extensions

  • XComposite ≥ @XCOMPOSITE_REQ_VERSION@
  • XDamage
  • XExt
  • XFixes ≥ @XFIXES_REQ_VERSION@

When running with OpenGL, Cogl requires at least version 1.3
or 1.2 with the multitexturing extension. However to build Cogl
you will need the latest GL headers which can be obtained from:

  http://www.khronos.org

If you are building the API reference you will also need:

  • GTK-Doc ≥ @GTK_DOC_REQ_VERSION@

If you are building the additional documentation you will also need:

  • xsltproc
  • jw (optional, for generating PDFs)

If you are building the Introspection data you will also need:

  • GObject-Introspection ≥ @GI_REQ_VERSION@

GObject-Introspection is available from:

  git://git.gnome.org/gobject-introspection

If you want support for profiling Cogl you will also need:

  • UProf ≥ @UPROF_REQ_VERSION@

UProf is available from:

  git://github.com/rib/UProf.git

--
DOCUMENTATION
-------------------------------------------------------------------------------

The 1.x stable API is documented here:

  http://developer.gnome.org/cogl/stable/

The 1.x development API is documented here:

  http://developer.gnome.org/cogl/1.$(COGL_1_MINOR_VERSION)

The experimental 2.0 API is currently not hosted online but can be built
by passing the --enable-gtk-doc option to ./configure when building
and the documentation can then be found under
doc/reference/cogl-2.0-experimental/html/index.html

--
LICENSE
-------------------------------------------------------------------------------

Most of Cogl is licensed under the terms of the GNU Lesser General Public
License, version 2.1 or (at your option) later. Some files are licensed under
more permissive licenses MIT or BSD style licenses though so please see
individual files for details.

--
BUILDING AND INSTALLATION
-------------------------------------------------------------------------------

Please refer to the INSTALL document.

--
BUGS
-------------------------------------------------------------------------------

Please report bugs here:

  http://bugzilla.gnome.org/enter_bug.cgi?product=cogl

You will need a Bugzilla account.

Please include the following in bug reports:

  • what system you're running Cogl on;
  • which version of Cogl you are using;
  • which version of GLib and OpenGL (or OpenGL ES) you are using;
  • which video card and which drivers you are using, including output of
    glxinfo and xdpyinfo (if applicable);
  • how to reproduce the bug.

If you cannot reproduce the bug with one of the tests that come with
Cogl's source code, it can help a lot to include a small test case
displaying the bad behaviour.

If the bug exposes a crash, the exact text printed out and a stack trace
obtained using gdb are greatly appreciated.

--
CONTRIBUTING
-------------------------------------------------------------------------------

The CODING_STYLE file describes the coding style we use throughout Cogl,
please try your best to conform to this style because the consistency
really helps keep the code maintainable.

We can accept contributions in several ways:
  • Either as patches attached to bugs on bugzilla
      - For this you may be interested in using git-bz.

        See http://git.fishsoup.net/man/git-bz.html for details
  • You can email us patches
      - For this we recommend using git-send-email

  • You can create a remote branch and ask us to pull from that for more
    substantial changes.
      - For this we recommend using github.

Ideally standalone patches should be created using git format-patch since
that makes it easiest to import the patch with a commit message into a
git repository.