mutter/README
Robert Bragg a5cdfdfd87 [cogl-offscreen] Cleans up the cogl offscreen API and adds documentation
There were several functions I believe no one is currently using that were
only implemented in the GL backend (cogl_offscreen_blit_region and
cogl_offscreen_blit) that have simply been removed so we have a chance to
think about design later with a real use case.

There was one nonsense function (cogl_offscreen_new_multisample) that
sounded exciting but in all cases it just returned COGL_INVALID_HANDLE
(though at least for GL it checked for multisampling support first!?)
it has also been removed.

The MASK draw buffer type has been removed. If we want to expose color
masking later then I think it at least would be nicer to have the mask be a
property that can be set on any draw buffer.

The cogl_draw_buffer and cogl_{push,pop}_draw_buffer function prototypes
have been moved up into cogl.h since they are for managing global Cogl state
and not for modifying or creating the actual offscreen buffers.

This also documents the API so for example desiphering the semantics of
cogl_offscreen_new_to_texture() should be a bit easier now.
2009-05-02 04:12:26 +01:00

667 lines
27 KiB
Plaintext

Clutter 1.0 README
==================
Clutter is an open source software library for creating fast, visually
rich and animated graphical user interfaces.
Clutter currently requires:
* GLib >= 2.14.0
* PangoCairo >= 1.18
* OpenGL >= 1.4, OpenGL ES 1.1 or OpenGL ES 2.0
* GLX, SDL, WGL or an EGL Implementation
The official website is:
http://www.clutter-project.org
The Clutter blog is at
http://www.clutter-project.org/blog
To subscribe to the Clutter mailing list, send mail to:
clutter+subscribe@o-hand.com
The official mailing list archive is:
http://lists.o-hand.com/clutter/
New bug page on Bugzilla:
http://bugzilla.o-hand.com/enter_bug.cgi?product=Clutter
Clutter is licensed under the terms of the GNU Lesser General Public
License, version 2.1 or (at your option) later.
INSTALLATION
============
See the INSTALL file. Info on specific Clutter options;
--enable-debug=[no/minimum/yes]
Turn on debugging (default=yes):
yes: All glib asserts, checks and runtime clutter verbose messages.
minimum: Just glib cast checks and runtime clutter verbose messagaes.
no: No glib asserts or checks and no runtime clutter verbose messages
(Only really of use in extreme performance cases)
--enable-maintainer-flags=[no/yes]
Use strict compiler flags (default=no)
--enable-gtk-doc
use gtk-doc to build API documentation (default=no). Requires gtk-doc
present on system
--enable-manual=[no/yes]
Build application developers manual. Requires jw and xmlto binaries.
Presently incomplete.
--without-fpu
Assume target hardware has no floating point unit. Useful only
for embedded targets such as ARM.
--with-flavour=[glx/eglx/eglnative/sdl/osx/win32]
Select the Clutter backend: (default=glx)
glx: Fully featured GLX backend. Using Open GL.
eglx: EGL/Open GL ES backend for EGL on X windows implementations
eglnative:
EGL/Open GL ES backend on 'native windowing system' - i.e
raw framebuffer. Expects the EGL implementation to provide
a createNativeWindow() call. Also it optionally supports
tslib for touchscreen events.
sdl: Basic SDL backend, using Open GL. Should provide portability
to Windows and possibly other OS's.
osx: OS X backend. (experimental)
win32:
Microsoft Windows(tm) WGL backend (experimental)
fruity:
Apple iPod Touch(tm)/iPhone(tm) backend (experimental)
--with-imagebackend=[gdk-pixbuf/quartz/internal]
Select the image loading backend used by COGL
gdk-pixbuf: Depend on gdk-pixbuf-2.0 (default for the glx, eglx,
eglnative, sdl, win32 flavours and recommended)
quartz: Depend on CoreGraphics (default for the osx flavour)
internal: Internal JPEG and PNG loader. Should only be used
for testing on new platforms
--with-gles=[1.1/2.0]
Select the GLES version (for EGL backends) (default=1.1)
--with-json=[internal/check]
Select the JSON-GLib copy to use (default=internal)
internal: Use the internal copy of JSON-GLib for ClutterScript
check: Check for the existence of a system copy of JSON-GLib
and if it is available, make Clutter depend on it
VERSIONING
==========
Clutter uses the common "Linux kernel" versioning system, where
even-numbered minor versions are stable and odd-numbered minor
versions are development snapshots.
Different Minor versions break both API and ABI but are parallel
installable. The same Minor version with differing Micro version is
expected to be ABI compatible with other micro versions. Though this
is not guarenteed, especially for odd numbered minor releases, we'll
try our very hardest (promise).
The micro version indicates the origin of the release: even micro
numbers are only used for released archives; odd micro numbers are
only used on the SVN repository.
HACKING
=======
If you want to hack on and improve Clutter, check the contained TODO
file for pending tasks, and HACKING for general coding guidelines.
BUGS
====
Bugs should be reported to the OpenedHand Bugzilla at:
http://bugzilla.o-hand.com/enter_bug.cgi?product=Clutter
You will need an account.
In the report you should include:
* what system you're running Clutter on;
* which version of Clutter you are using;
* which version of GLib and OpenGL you are using;
* which video card and which drivers you are using, including output of
glxinfo and xdpyinfo;
* how to reproduce the bug.
If you cannot reproduce the bug with one of the tests that come with Clutter
source code, you should 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.
PATCHES
=======
Patches should be submitted using Bugzilla. Patches fixing a bug should be
attached to the bug report; patches for new features or for fixing bugs not
yet reported should be attached to a newly opened bug. Patches should always
be in the unified diff format, using:
diff -Nuarp clutter.source clutter.patched > clutter-patch.diff
If diffing against the SVN repository, you should use:
svn diff --diff-cmd=diff -x -Nuarp > clutter-patch.diff
RELEASE NOTES
=============
Relevant information for developers with existing Clutter applications
wanting to port to newer releases (See NEWS for general new feature info).
Release Notes for Clutter 1.0
-------------------------------
* The clutter_actor_set_shader_param() function now takes a
GValue, which can be set using the clutter_value_set_shader()
family of functions. The floating point wrapper has been
rename clutter_actor_set_shader_param_float() to match the newly
added clutter_actor_set_shader_param_int().
* The Pango renderer API has been exposed as public API, after
a full rename from PangoClutter to CoglPango, to avoid namespace
collisions with upstream Pango. The Pango font map, renderer and
glyph cache can be used by third party code and depend only on
COGL.
* Both Clutter and COGL only allow including <clutter/clutter.h>
and <cogl/cogl.h> directly, respectively. This allows avoiding
breaking API every time a type definition is moved across
headers, and improves the reliability of third party code against
internal refactorings.
* COGL has an internal Color type, used to store a color definition
that can be efficiently used with the least amount of conversions
by both the GL and GLES implementations. The COGL API has been
changed to drop the usage of ClutterColor in favour of CoglColor.
* The fixed point API implementation Clutter uses internally has been
moved from the Clutter namespace to the COGL one.
* ClutterLabel and ClutterEntry have been removed from the API, as
both have been superceded by the ClutterText actor.
* ClutterCloneTexture has been removed from the API; in its place,
there is a generic ClutterClone actor which allows to "clone"
any existing actors -- even composite ones -- without using
frame buffer objects (FBOs).
* The ClutterEffectTemplate and clutter_effect_* functions have been
superceded by ClutterAnimation and thus removed from the public API.
* The ClutterBehaviourBspline has been superceded by the usage of
ClutterPath inside ClutterBehaviourPath, and thus removed from the
public API.
* ClutterColor API has received a much needed review to increase its
consistency. This has led to the following changes:
- clutter_color_parse() has been renamed to clutter_color_from_string()
and the order of the arguments has been changed
- the factor argument of clutter_color_shade() has been swapped with
the return location for the new color
- the fixed point entry points have been removed
- clutter_color_from_hls() and clutter_color_to_hls() do not
normalize the values in the [ 0, 255 ] interval but use the
correct HLS intervals
* The ClutterFixed symbols have been completely removed: fixed-point
public entry points now take a CoglFixed.
Cogl API changes for Clutter 1.0
--------------------------------
* All drawing functions now use a source material to determine how geometry is
filled. The source material is set via cogl_set_source. Or the convenience
functions cogl_set_source_color and cogl_set_source_texture.
"drawing functions" include: cogl_rectangle, cogl_texture_rectangle,
cogl_texture_multiple_rectangles, cogl_texture_polygon (though the
cogl_texture_* funcs have been renamed; see below for details),
cogl_path_fill/stroke and cogl_vertex_buffer_draw*.
cogl_texture_rectangle, cogl_texture_multiple_rectangles and
cogl_texture_polygon no longer take a texture handle; instead the current
source material is referenced. The functions have also been renamed to:
cogl_rectangle_with_texture_coords, cogl_rectangles_with_texture_coords
and cogl_polygon respectively.
Most code that previously did:
cogl_texture_rectangle (tex_handle, x, y,...);
needs to be changed to now do:
cogl_set_source_texture (tex_handle);
cogl_rectangle_with_texture_coords (x, y,....);
In the less likely case where you were blending your source texture with a
color like:
cogl_set_source_color4ub (r,g,b,a); /* (where r,g,b,a isn't just white) */
cogl_texture_rectangle (tex_handle, x, y,...);
you will need your own material to do that:
material = cogl_material_new ();
cogl_material_set_color4ub (r,g,b,a);
cogl_material_set_layer (material, 0, tex_handle));
cogl_set_source_material (material);
Code that uses the texture coordinates, 0, 0, 1, 1 don't need to use
cogl_rectangle_with_texture_coords since these are the coordinates that
cogl_rectangle will use.
For cogl_texture_polygon; as well as dropping the texture handle, the
n_vertices and vertices arguments were transposed for consistency. So
code previously written as:
cogl_texture_polygon (tex_handle, 3, verts, TRUE);
need to be written as:
cogl_set_source_texture (tex_handle);
cogl_polygon (verts, 3, TRUE);
* The arguments to cogl_rectangle, cogl_path_rectangle and
cogl_path_round_rectangle have been changed - for consistency - from
x, y, width, height, to x1, y1, x2, y2.
* A CoglMatrix type and utility API has been added; this is currently used to
support describing texture matrices.
* cogl_alpha_func has been removed, since this is now controlled using the
material API via cogl_material_set_alpha_test_function ()
* A Cogl Vertex Buffer API has been added that allows you to efficiently
manage arrays of vertex attributes in buffers that may be stored on
the GPU. These allow you to avoid the costs of repeatedy validating
vertex data and mapping it into the GPU.
* cogl_scale now supports scaling on the z axis
* cogl_clip_set* and cogl_clip_unset have been renamed to cogl_clip_push and
cogl_clip_pop respectively so they self document their stacking semantics.
* cogl_paint_init was renamed to cogl_clear and no longer disables lighting and
fogging. cogl_clear also now takes a mask of the auxiliary buffers you want
to clear so you can avoid redundant clears of buffers you aren't using.
* cogl_fog_set was renamed to cogl_set_fog and it now takes a mode argument
giving control over the fogging blend factor equation, so that the
density argument isn't just ignored. A cogl_disable_fog function was
also added.
* cogl_get_*_matrix were changed to use the CoglMatrix type instead of
GLfloat m[16] arrays.
* cogl_offscreen_blit_region, cogl_offscreen_blit were removed since they were
only implemnted for GL, not GLES, and it was assumed no one was using them.
* cogl_offscreen_new_multisample was removed since it only ever returned
COGL_INVALID_HANDLE so it wasn't usefull.
* The COGL_MASK_BUFFER type was removed, since there should be nicer ways of
exposing color mask if anyone wants it later. It was assumed that no one was
using this currently.
Release Notes for Clutter 0.8
-------------------------------
* The COGL GL wrapper API has been completely overhauled and now
contains many new features including new greatly improved texture
abstractions (slicing, mipmapping, deformations etc, greatly
simplifying ClutterTexture), image loading and abstraction, path
based primitive drawing, clipping, and improved FBO and shader
support. It is now also fully documented.
* GL Texture Rectangle ext is no longer used, the regular 2D NPOTS
extension is preffered instead but not required.
* Clutter now has basic suppport for multiple input devices assuming
the backend supports it (currently X11 based via XInput and Fruity
backends). New API supporting this includes
clutter_event_get_device_id, clutter_get_input_device_for_id,
clutter_grab_pointer_for_device & clutter_ungrab_pointer_for_device.
XInput support needs to be explicitly enabled at runtime by calling
clutter_x11_enable_xinput () before clutter_init. clutter_x11_has_xinput ()
can then be called after to check if XInput extension present and use-able.
* The functions that return the transformed position of an actor have
been renamed to be more explicit about it:
clutter_actor_get_abs_position - clutter_actor_get_transformed_position
clutter_actor_get_abs_size - clutter_actor_get_transformed_size
Their behaviour has not been changed.
* To increase portability, Clutter does not strictly depend on
GdkPixbuf anymore; this means that you will have to include
<gdk-pixbuf/gdk-pixbuf.h> yourself if you are operating with
GdkPixbuf objects and not including that header. The GdkPixbuf-based
API has been removed from Clutter core:
clutter_texture_new_from_pixbuf
clutter_texture_set_pixbuf
clutter_texture_get_pixbuf
are all deprecated functions. It is still possible to load a GdkPixbuf
into a ClutterTexture with this sample code:
clutter_texture_set_from_rgb_data (texture,
gdk_pixbuf_get_pixels (pixbuf),
gdk_pixbuf_get_has_alpha (pixbuf),
gdk_pixbuf_get_width (pixbuf),
gdk_pixbuf_get_height (pixbuf),
gdk_pixbuf_get_rowstride (pixbuf),
4, 0,
&error);
ClutterTexture also now has a new filename property and
clutter_texture_new_from_file which is intended as an alternate to
common previous GdkPixbuf primary usage (i.e loading images from
disk).
To read texture data back into a pixbuf or system memory use a combination
of clutter_texture_get_cogl_texture & cogl_texture_get_data.
The clutter-gtk integration library has API for using GdkPixbuf with
ClutterTextures (among others).
ClutterTexture now supports a keep-aspect property which is set to FALSE
by default.
* clutter_texture_from_actor will now reparent source actors if they
are not parented. This behaviour may change in future releases.
There are known not yet fixed issues with source actors that set
depth or use clipping.
* The size negotiation API has been completely changed in order to allow
the creation of non-fixed layout managers. These functions have been
removed:
clutter_actor_request_coords()
clutter_actor_query_coords()
from the ClutterActor API, as well as their virtual functions inside
the ClutterActorClass. The size of an actor is now split into two
different concepts: the preferred size (width and height
separatedly) and the size that has been allocated by the container
to which that actor belongs. Clutter still defaults to the fixed
layout management (i.e ClutterGroup) of the actors, but supports
fluid layout managers written using the new API.
Composite actors (actors with 'private' children not implementing the
container interface) now need to implement an allocate method here pass
an allocation to any composite children.
* Clutter now depends on PangoCairo for the font rendering. The PangoClutter
API is still considered semi-private and no guarantees are made on its
stability.
* ClutterShader API has been slightly changed: the ClutterStage:bound
property, clutter_shader_bind() and clutter_shader_is_bound() have
been renamed to :compiled, clutter_shader_compile() and
clutter_shader_is_compiled(), respectively. The previously semi-private
clutter_shader_release_all() function is now not exported anymore.
* ClutterStage is not an abstract type anymore: it can be instantiated
using clutter_stage_new() and it can be properly subclassed. If the
backend supports multiple stages, every stage will be a new window,
whose lifetime will have to be managed by the developer. Clutter will
still create the default stage, and guarantees that every call to
clutter_stage_get_default() will return exactly the same pointer.
* Actors now have a new 'show-on-set-parent' property set to TRUE by
default. With this property set to TRUE, actors will automatically
have clutter_actor_show() called on them when a parent is set (i.e
added to a container).
* Clutter now features support for multiple stages assuming supported
by the backend. See test-multistage.c for example of usage. This
does not change the automatic creation of the default stage.
A single GL context is used across all stages meaning GL resources
are shared.
* There is now an experimental native iPod Touch/iPhone UIKit backend
named 'fruity'.
* There is now an experimental native Win32 WGL backend.
* COGL (and therefor Clutter) now optionally features initial support for
OpenGL ES 2.0. It features support for shaders.
* Some more focused timeline unit tests have been added and some tweaks to
timeline semantics were made; E.g. For a 10 frame timeline here are some
points about the semantics:
- When you create a timeline it starts with current_frame_num == 0
- After starting a timeline, the first timeout is for current_frame_num == 1
(Notably it isn't 0 since there is a delay before the first timeout signals
so re-asserting the starting frame (0) wouldn't make sense.)
- For a non looping timeline the last timeout would be for
current_frame_num == 10
- For a looping timeline the timeout for current_frame_num == 10 would be
followed by a timeout for current_frame_num == 1 and frame 0 is considered
== frame 10.
- Asking for a timeline of N frames might better be described as asking for
a timeline of _length_ N.
* The behaviour of clutter_actor_get_opacity() has been slightly changed;
instead of returning the composited opacity of the entire parents chain
of an actor, clutter_actor_get_opacity() does what you mean, and returns
the opacity set with clutter_actor_set_opacity(). The composited
opacity value is now returned by clutter_actor_get_paint_opacity().
* Until 0.6, clutter_label_get_color() would have returned a ClutterColor
with the alpha component equal to the composited opacity of the label.
Now, clutter_label_get_color() returns a copy of the exact color set
with clutter_label_set_color().
* The ClutterEntry actor will automatically handle key events inside
a key-press-event handler. This deprecates the usage of
clutter_entry_handle_key_event() to update the contents of the
entry using the ClutterKeyEvent.
* The Clutter X11 and GLX backends feature support for wrapping external
X Drawables (such as windows as pixmaps) via the 'texture_from_pixmap' GLX
extension if available and fallback to slower XGetImage copies if not.
* ClutterContainer can have per child custom properties via ClutterChildMeta.
Release Notes for Clutter 0.6
-------------------------------
* Now that every actor has events, the class signal handlers have been
removed from ClutterStageClass and moved into ClutterActorClass.
* The CLUTTER_2BUTTON_PRESS and CLUTTER_3BUTTON_PRESS event types have been
removed in favour of the ClutterButtonEvent:click_count counter
* X11 related called for glx and eglx backends are now shared and moved into
a clutter_x11 prefix.
* Scaling with gravity functionality was replaced by more generic and
powerful anchor point.
* The ClutterLayout interface, the ClutterBox and its implementations have
been moved outside Clutter core.
* The Effects API has been simplified, and it only requires the final value
of the effect instead of both the start and end value.
* The per-axis rotation API has been deprecated in favour of a single
pair of accessors, clutter_actor_set_rotation() and
clutter_actor_get_rotation().
* Every actor sub-class that is overriding the ClutterActor::request_coords()
virtual function *must* chain up to the parent's implementation in order
to store the bounding box inside the ClutterActor private data.
* It is now impossible to call clutter_actor_destroy() on the stage. Backends
will have to unset the CLUTTER_ACTOR_IS_TOPLEVEL private flag to actually
destroy the stage.
* The default value of the ClutterLabel:wrap property has been changed from
TRUE to FALSE.
* All the behaviours properties have been renamed to match the $PROPERTY-start
and $PROPERTY-end convention.
* The clutter_group_add() function has been "undeprecated" and reimplemented
as a commodity macro; a clutter_stage_add() commodity macro has also been
added. Both macros just safely wrap clutter_container_add_actor().
* The ClutterContainer::find_child_by_id() virtual function has been removed;
Clutter keeps track of every actor, so there's no need to recurse into
containers anymore.
* The unused ClutterActor::set_depth() and ClutterActor::get_depth() virtual
functions have been removed.
* It is now possible to roundtrip the string created by
clutter_color_to_string() to clutter_color_parse().
* The amount of motion events is now being throttled using the default frame
rate setting as the base value to compute the default and maximum frequency
of motion events to be delivered to every actor.
* ClutterAngle usage has been removed from the public API: it is an internal
optimization, which can be used for faster angle computations; users of
ClutterAngle now take a fixed point number in form of a ClutterFixed.
* ClutterGravity usage when scaling has been superceded by the anchor point.
* The precision of the clutter_sqrti() algorithm has been improved for small
values.
* ClutterBehaviourScale constructor, scale properties and accessors have
been changed to accomodate the scaling factors on both the X and Y axis,
matching the clutter_actor_set_scale() function. This also changed the
clutter_effect_scale() function, which now accepts the final scale
factor on both the X and Y axis. The gravity property has also been
removed, as it behaved incorrectly with regards to the anchor point. When
scaling an actor using a BehaviourScale, the anchor point should be set
before applying the behaviour (remember to adjust the positioning as
well by factoring in the anchor point).
* The clutter_do_event() is now public; it can be used to feed an event to
Clutter and let it generate the capture-bubble signal emissions; it should
not be used by applications.
* In the X11-based backends, the DestroyNotify event is not propagated to
Clutter core if the stage is using a foreign window.
* To avoid method name collisions between ClutterActor and ClutterEntry
in high-level languages, the clutter_entry_set_position() and
clutter_entry_get_position() functions have been renamed to
clutter_entry_set_cursor_position() and clutter_entry_get_cursor_position()
respectively.
Release Notes for Clutter 0.4.0
-------------------------------
* clutter_actor_show_all does not recurse for groups at least (this is to
match the original group_show_all behaviour). This is like 0.3 but was
never noted.
* ClutterBox API has changed: clutter_box_pack_start() and
clutter_box_pack_end() have been removed in favour of the clutter_box_pack()
API.
* Both clutter_threads_enter() and clutter_threads_leave() have been
removed from the API, as they just created confusion and the wrong
idea that Clutter is either thread-safe or thread-aware. Full
thread-awareness is arriving in the next revision (see bug #429).
* The ClutterBehaviourRotate and ClutterBehaviourEllsipse APIs have been
overhauled.
Release Notes for Clutter 0.3.1
-------------------------------
* clutter_actor_apply_transform_to_point() parameters changed to use
ClutterVertices.
* New 'Native API' backend expects EGL implementation to provide a
CreateNativeWindow() API call.
* Exisiting X11 based egl backend public API calls now prefixed eglx.
Release Notes for Clutter 0.3
-----------------------------
* ClutterTexture changes:
+ clutter_texture_set_pixbuf() now takes a GError paremeter.
+ clutter_texture_upload_data has been split into two new and
more functional versions; clutter_texture_set_from_rgb_data(),
clutter_texture_set_from_yuv_data().
* The GLX specific API has been moved to the GLX backend code and
it's now under the ClutterGlx namespace.
* The priority of the various users of the GLib main loop has been
reviewed and changed were necessary. Every paint is queued with a
priority of G_PRIORITY_DEFAULT + 10; timelines are allocated with
a G_PRIORITY_DEFAULT + 30 priority; events are processed with a
G_PRIORITY_DEFAULT priority. This ensures that events are processed
before the paints take place.
* The ClutterActor::allocate_coords() has been renamed to
ClutterActor::query_coords(), in order to clarify its usage.
* Actors overriding ClutterActor::request_coords() and
ClutterActor::query_coords() must convert sizes obtained from the
public API from pixels to ClutterUnits, using the conversion
macros found in clutter-units.h. The conversion will be necessary
until the public API will switch over to returning the generic
units too.
* Users of Intel video cards should find that disabling sync-to-vblank
is no longer necessary. In case Clutter applications take really
long times for redrawing and appear stuck and unresponsive, the
sync-to-vblank feature might still be the culprit; in that case, use
"export CLUTTER_VBLANK=none" to disable it and file a bug reporting the
video card model, the driver version and the X server version.
* ClutterTimeline objects now share the same timeout pool (see the
ClutterTimeoutPool API). This might cause problems with heavily
threaded libraries without integration with the GLib main loop.
If an application experiences bad behaviours during animations
use "export CLUTTER_TIMELINE=no-pool" to disable the timeout pool.
* clutter_color_parse() now handles color definitions with alpha. Alpha
will default to fully Opaque rather than fully transparent if not specified.
* The Clutter examples/ directory has been removed and replaced with a
tests/ directory.
* The ClutterEvent API has been changed, and specific functions have been
removed in favour of event-agnostic ones.
* The ClutterStage::input-event signal has been removed. All the events now
emit the ClutterStage::event and ClutterStage::event-after signals, for
generic event handling.
* Runtime options now dependant on backend.
* ClutterGroup API to add, remove and list children has been deprecated in
favour of ClutterContainer API. The ClutterGroup::add and
ClutterGroup::remove signals have been deprecated:
ClutterContainer::actor-added and ClutterContainer::actor-removed should
be used instead.
$LastChangedDate$