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Neil Roberts 2933423ca7 Don't generate GLSL for the point size for default pipelines
Previously on GLES2 where there is no builtin point size uniform then
we would always add a line to the vertex shader to write to the
builtin point size output because when generating the shader it is not
possible to determine if the pipeline will be used to draw points or
not. This patch changes it so that the default point size is 0.0f
which is documented to have undefined results when drawing points.
That way we can avoid adding the point size code to the shader in that
case. The assumption is that any application that is drawing points
will probably have explicitly set the point size on the pipeline
anyway so it is not a big deal to change the default size from 1.0f.

This adds a new pipeline state flag to track whether the point size is
non-zero. This needs to be its own state because altering it needs to
cause a different shader to be added to the pipeline cache. The state
flags that affect the vertex shader have been changed from a constant
to a runtime function because they will be different depending on
whether there is a builtin point size uniform.

There is also a unit test to ensure that changing the point size does
or doesn't generate a new shader depending on the values.

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

(cherry picked from commit b2eba06e16b587acbf5c57944a70ceccecb4f175)

Conflicts:
	cogl/cogl-pipeline-private.h
	cogl/cogl-pipeline-state-private.h
	cogl/cogl-pipeline-state.c
	cogl/cogl-pipeline.c
2013-06-21 14:18:37 +01:00
build Update Visual Studio Project Files 2013-03-07 11:37:32 +08:00
cogl Don't generate GLSL for the point size for default pipelines 2013-06-21 14:18:37 +01:00
cogl-gles2 build: update to build with automake 1.13 2013-01-22 18:00:05 +00:00
cogl-pango Add compiler deprecation warnings 2013-04-24 22:23:50 +01:00
deps build: fix make dist 2013-01-22 17:48:03 +00:00
doc Use the Wayland embedded linked list implementation instead of BSD's 2013-06-13 13:45:47 +01:00
examples Add support for per-vertex point sizes 2013-06-07 16:53:29 +01:00
po [l10n] Updated Italian translation. 2013-04-28 19:24:20 +02:00
test-fixtures Add support for per-vertex point sizes 2013-06-07 16:53:29 +01:00
tests Fix freeing an atlas texture that hasn't been allocated 2013-06-13 13:45:46 +01:00
.gitignore gitignore: Ignore the examples/cogl-gles2-gears executable 2013-04-23 18:30:54 +01:00
.vimrc misc: Add a .vimrc file 2011-05-17 15:24:54 +01:00
autogen.sh build: update to build with automake 1.13 2013-01-22 18:00:05 +00:00
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 Update config.h.win32.in 2013-03-15 00:26:35 +08:00
configure.ac tests: Adds our first white-box unit test 2013-06-06 21:27:16 +01:00
COPYING Update the COPYING file 2011-09-05 19:02:05 +01:00
Makefile.am tests: Adds our first white-box unit test 2013-06-06 21:27:16 +01:00
NEWS Updates NEWS for the 1.14.0 release 2013-03-25 13:26:05 +00:00
README.in configure: Add a minimum required version for the wayland package 2013-03-22 00:13:36 +00:00

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@

For the Wayland backend, Cogl requires:
  • Wayland ≥ @WAYLAND_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.