Read-only mirror of https://gitlab.gnome.org/GNOME/mutter
df77e8565e
According to the EGL spec, eglGetProcAddress should only be used to retrieve extension functions. It also says that returning non-NULL does not mean the extension is available so you could interpret this as saying that the function is allowed to return garbage for core functions. This seems to happen at least for the Android implementation of EGL. To workaround this the winsys's are now passed down a flag to say whether the function is from the core API. This information is already in the gl-prototypes headers as the minimum core GL version and as a pair of flags to specify whether it is available in core GLES1 and GLES2. If the function is in core the EGL winsys will now avoid using eglGetProcAddress and always fallback to querying the library directly with the GModule API. The GLX winsys is left alone because glXGetProcAddress apparently supports querying core API and extension functions. The WGL winsys could ideally be changed because wglGetProcAddress should also only be used for extension functions but the situation is slightly different because WGL considers anything from GL > 1.1 to be an extension so it would need a bit more information to determine whether to query the function directly from the library. The SDL winsys is also left alone because it's not as easy to portably determine which GL library SDL has chosen to load in order to resolve the symbols directly. Reviewed-by: Robert Bragg <robert@linux.intel.com> (cherry picked from commit 72089730ad06ccdd38a344279a893965ae68cec1) Since we aren't able to break API on the 1.12 branch cogl_get_proc_address is still supported but isn't easily able to determine whether the given name corresponds to a core symbol or not. For now we just assume the symbol being queried isn't part of the core GL api and update the documentation accordingly. |
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cogl | ||
cogl-gles2 | ||
cogl-pango | ||
doc | ||
examples | ||
po | ||
tests | ||
.gitignore | ||
.vimrc | ||
autogen.sh | ||
ChangeLog | ||
cogl.doap | ||
config-custom.h | ||
config.h.win32.in | ||
configure.ac | ||
COPYING | ||
Makefile.am | ||
NEWS | ||
README.in |
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 API references for the latest stable release are available at: http://docs.clutter-project.org/docs/cogl/stable/ The experimental 2.0 API can be found here: http://docs.clutter-project.org/docs/cogl-2.0-experimental/stable/ Note: The confusing "stable" at the end refers to the overall Cogl release status, not the documentation specifically. -- 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.