This greatly speeds up running all the conformance tests by no longer
delaying many of the tests for a number of dummy frames to be painted.
We used to skip frames because we thought there was a problem with the
driver's glReadPixels implementation. Although we have seen driver
issues at times the real reason the delay was needed was because
resizing the stage usually happens asynchronously (because a non
synchronous X request is used by clutter_stage_set_size()). We now force
all X requests to be synchronized for the conformance tests so this is
no longer a problem and we can avoid these hacks.
The required .so file was named using @CLUTTER_WINSYS@ but since
bf9d5f3949 the .so should be named with @CLUTTER_SONAME_INFIX@. This
was breaking the build on eglx.
* cally-merge:
cally: Add introspection generation
cally: Improving cally doc
cally: Cleaning CallyText
cally: Refactoring "window:create" and "window:destroy" emission code
cally: Use proper backend information on CallyActor
cally: Check HAVE_CONFIG_H on cally-util.c
docs: Fix Cally documentation
cally: Clean up the headers
Add binaries of the Cally examples to the ignore file
docs: Add Cally API reference
Avoid to load cally module on a11y examples
Add accessibility tests
Initialize accessibility support on clutter_init
Rename some methods and includes to avoid -Wshadow warnings
Cally initialization code
Add Cally
This makes test-timeline get the default stage so there is at least one
stage instantiated. Without any stages the master clock will never run
which was causing this test to fail.
The report generation was broken by the split of the various test units;
also, we were using GTest in a way that's not really sanctioned by
upstream.
This commit tries to re-use the targets from GLib's Makefile rules while
compensating for our own set up.
Normally the asynchronous nature of X means that setting the clutter
stage size may really happen an indefinite amount of time later but
since the tests are so short lived and may only render a single frame
this is not an acceptable semantic.
This way we should be able to remove all the hacky sleeps and frame
count delays from our tests.
Since we now run every test in a separate process there is no need to
try and avoid state leakage between tests. This removes the code to
cleanup all children of the stage and disconnect handlers from the
stage paint signal. We now explicitly print a warning if the users tries
to run multiple tests in one process.
In the .json file used for the test, there is no null -> "base"
transition defined only a "clicked" -> "base", when the "clicked" state
is removed the "base" state will also disappear.
I was fed up to cd into the tests/conform or tests/interactive directories
to launch a specific test. Now, with the power the abs_ variants of
builddir and srcdir we can run specific test from any directory.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2159
This allows you to tell Cogl that you are planning to replace all the
buffer's data once it is mapped with cogl_buffer_map. This means if the
buffer is currently being accessed by the GPU then the driver doesn't
have to stall and wait for it to finish before it can access it from the
CPU and can instead potentially allocate a new buffer with undefined
data and map that.
There was a missing '* 4' and '* i' in the for() loops that initialized
the first test buffer, so it was containing uninitialized data causing
the test to fail.
Since CoglPixelBuffer was renamed to CoglPixelArray the test entry point
was also renamed to test_cogl_pixel_array, but mistakenly the
corresponding test-conform-main.c change wasn't pushed at the same time.
This removes cogl_pixel_array_new which just took a size in bytes.
Without the image size and pixel format then the driver often doesn't
have enough information to allocate optimal GPU memory that can be
textured from directly. This is because GPUs often have ways to
spatially alter the layout of a texture to improve cache access patterns
which may require special alignment and padding dependant in the images
width, height and bpp.
Although currently we are limited by OpenGL because it doesn't let us
pass on the width and height when allocating a PBO, the hope is that we
can define a better extension at some point.
The usage hint should be implied by the CoglBuffer subclass type so the
public getter and setter APIs for manually changing the usage hint of a
CoglBuffer have now been removed.
This creates a path with an outer clockwise and two internal sub
paths, one clockwise and one counter-clockwise. The path is then
painted twice, once with each fill rule.
Allow using the BindConstraint to bind width and height of a source
actor.
Also, add a test for the BindConstraint showing all types of usages
for this constraint class.
The -rdynamic linker option is specific to ELF so it was breaking
builds on systems with other object formats such as Windows and
Solaris. This patch replaces that option with -export-dynamic which is
a portable libtool option which should do the right thing on each
platform.
http://bugzilla.clutter-project.org/show_bug.cgi?id=1930
When the 'm' key is pressed it will now recursively look for all
ClutterTexture subclasses on the stage and toggle the texture quality
between high and low. This is useful to test the mipmap fallback.
When the mouse button is pressed it would previously draw a small
1-pixel wide fully transparent line to the pixmap. This is a useful
feature to help test the automatic updates but the line is quite hard
to see so it's to easy miss. This patch changes it to draw a thick
black circle. The circle is drawn at a different position every time
the button is clicked.
The hand actor has a feature that if you click on the stage it will
draw a line to the actor. However it's not possible to see the results
of this because automatic updates were disabled so the texture would
never be updated.
test-pixmap has long had a --disable-x11 option that didn't do
anything. This patch adds the neccessary if (disable_x11) to disable
adding the ClutterX11TexturePixmap actor when the option is given.
Previously we were using an internal only HAVE_COGL_GLES2 define to
guard GLES 2 specific changes so for instance the precision modifiers
weren't being emitted in the shader source.
http://bugzilla.o-hand.com/show_bug.cgi?id=2178
This adds a separate variable name "CLUTTER_SONAME_INFIX" to define the
infix for the clutter library that gets linked. Currently the WINSYS
corresponds to the directory we enter when building to compile the
window system and input support, but it is desirable to be able to
define multiple flavours that use the same WINSYS but should result in
different library names.
For example we are planning to combine the eglx and eglnative window
systems into one "egl" winsys but we will need to preserve the current
library names for the eglx and eglnative flavours.
ClutterActor should allow attaching actions, constraints and effects
just like it allows behaviours, e.g.:
{
...
"constraints" : [
{
"type" : "ClutterAlignConstraint",
"source" : "stage",
"align-axis" : "x-axis",
"factor" : 0.5
},
{
"type" : "ClutterAlignConstraint",
"source" : "stage",
"align-axis" : "y-axis",
"factor" : 0.5
}
],
...
}
or:
{
...
"actions" : [
{
"type" : "ClutterDragAction",
"signals" : [
{ "name" : "drag-end", "handler" : "on_drag_end" }
]
}
],
...
}
In order to do so, we use the Scriptable interface implementation and
add three new custom properties accepting an array; then we parse each
member of the array as a new object.
The :sync-size property of ClutterTexture should be set to FALSE by
default by ClutterCairoTexture. The preferred size of the
ClutterCairoTexture is already the size of the internal Cairo surface,
and we override the preferred width/height getters to that effect.
The :sync-size property is also responsible of changing the size of
the Texture actor when changing the texture handle - but since we
encourage that to happen during the CairoTexture allocation, we get a
queue_relayout() invocation (and a warning) when we change the size
of the Cairo image surface.
Since GObject doesn't make it easy to override the default value of the
:sync-size property in sub-classes, we should simply call the setter
function during the ClutterCairoTexture instance initialization.
We should also change one of the interactive tests using a CairoTexture
to rebuild the contents of the actor in response to an allocation.
This redirects the legacy depth testing APIs through CoglMaterial and
adds a new experimental cogl_material_ API for handling the depth
testing state.
This adds the following new functions:
cogl_material_set_depth_test_enabled
cogl_material_get_depth_test_enabled
cogl_material_set_depth_writing_enabled
cogl_material_get_depth_writing_enabled
cogl_material_set_depth_test_function
cogl_material_get_depth_test_function
cogl_material_set_depth_range
cogl_material_get_depth_range
As with other experimental Cogl API you need to define
COGL_ENABLE_EXPERIMENTAL_API to access them and their stability isn't
yet guaranteed.
Both ::drag-begin and ::drag-end have a "button" argument - even though
we assume internally, and externally, that dragging can only be the
result of a primary button operation.
This test breaks out into raw OpenGL to create a foreign texture so it
needs to be careful not to trample on any state that may be cached by
Cogl internally.
This test breaks out into raw OpenGL to create a RECTANGLE texture so it
needs to be careful not to trample on any state that may be cached by
Cogl internally.
Layout properties work similarly to child properties, with the added
headache that they require the 3-tuple:
( layout manager, container, actor )
to be valid in order to be inspected, parsed and applied. This means
using the newly added back-pointer from the container to the layout
manager and then rejigging a bit how the ScriptParser handles the
unresolved properties.
Similarly to the child properties, which use the "child::" prefix, the
layout manager properties use the "layout::" prefix and are defined with
the child of a container holding a layout manager.
Stacking multiple effects sub-classing ClutterOffscreenEffect requires
a small fix in the code that computes the screen coordinates of the
actor to position the FBO correctly with regards to the stage.
Since ClutterEffect is an ActorMeta it should be possible to animate the
properties of named effects using the @effects syntax, just like it
happens for actions and constraints.
ClutterEffect is an abstract class that should be used to apply effects
on generic actors.
The ClutterEffect class just defines what an effect should implement; it
could be defined as an interface, but we might want to add some default
behavior dependent on the internal state at a later point.
The effect API applies to any actor, so we need to provide a way to
assign an effect to an actor, and let ClutterActor call the Effect
methods during the paint sequence.
Once an effect is attached to an actor we will perform the paint in this
order:
• Effect::pre_paint()
• Actor::paint signal emission
• Effect::post_paint()
Since an effect might collide with the Shader class, we either allow a
shader or an effect for the time being.
It's valid C to declare a function omitting it prototype, but it seems
to be a good practise to always declare a function with its
corresponding prototype.
While this is totally fine (None is 0L and, in the pointer context, will
be converted in the right internal NULL representation, which could be a
value with some bits to 1), I believe it's clearer to use NULL instead
of None when we talk about pointers.
This adds a boolean "pick-with-alpha" property to ClutterTexture and when
true, it will use the textures alpha channel to define the actors shape when
picking.
Users should be aware that it's a bit more expensive to pick textures like
this (so probably best not to blindly enable it on *all* your textures)
since it implies rasterizing the texture during picking whereas we would
otherwise just send a solid filled quad to the GPU. It will also interrupt
the internal batching of geometry for pick renders which can otherwise often
be done in a single draw call.
The DragAction should, by default, drag the actor to which it has been
applied, instead of delegating what to do to the developer. If custom
code need to override it, g_signal_stop_emission_by_name() can be called
to stop the default handler to ever running.
The drawing code from test_invalid_texture_layers which draws a
rectangle, a polygon and a vertex buffer has been split out to
separate function. test_using_all_layers now also uses this so that it
will also test the other two primitives. This causes the test to fail
when all of the layers are drawn using a vertex buffer.
http://bugzilla.openedhand.com/show_bug.cgi?id=2132
* wip/state-machine:
Do not use wildcards in test-state
script: Implement State deserialization
state: added a "target-state" property
state: documented data structures
Add State interactive tests to the ignore file
state: Documentation and introspection annotation fixes
state: Minor coding style fixes
state: Clean up the header's documentation
state: Constify StateKey accessors
Do not include clutter.h from a Clutter header file
state-machine: made clutter_state_change take a boolean animate argument
state-machine: use clutter_timeline_get_progress
state-machine: add completed signal
state machine: added state machine
Conflicts:
.gitignore
* wip/constraints: (24 commits)
Add the Cogl API reference to the fixxref extra directories
Document the internal MetaGroup class
Remove the construct-only flag from ActorMeta:name
doc: Remove gtk-doc annotations from the json-glib copy
doc: Fix parameter documentation
Add named modifiers for Action and Constraint
Remove a redundant animation
Set the stage resizable in test-constraints
Use a 9 grid for the constraints test
Miscellaneous documentation fixes
docs: Document animating action and constraint properties
docs: Document BindConstraint and AlignConstraint
constraint: Rename BindConstraint:bind-axis
constraints: Add AlignConstraint
tests: Add a constraints interactive test
constraint: Add BindConstraint
actor: Implement Animatable
animation: Use the new Animatable API for custom properties
animatable: Add custom properties to Animatable
constraint: Add ClutterConstraint base class
...
Conflicts:
configure.ac
The ClutterActor API should have modifier methods for adding, removing
and retrieving Actions and Constraints using the ClutterActorMeta:name
property - mostly, for convenience.
To demonstrate that constraints can be used to reposition actors in a
resizable stage, set the :user-resizable property to TRUE, and spend the
next 15 minutes playing with the stage size.
AlignConstraint is a simple constraint that keeps an actor's position
aligned to the width or height of another actor, multiplied by an
alignment factor.
GLES 2 doesn't have GL_MAX_TEXTURE_UNITS. Instead the cogl backend
uses GL_MAX_TEXTURE_IMAGE_UNITS with a maximum limit of 16. The same
restriction is now used in the test.
DragAction is an Action sub-class that provides dragging capabilities to
any actor. DragAction has:
• drag-begin, drag-motion and drag-end signals, relaying the event
information like coordinates, button and modifiers to user code;
• drag-threshold property, for delaying the drag start by a given
amount of pixels;
• drag-handle property, to allow using other actors as the drag
handle.
• drag-axis property, to allow constraining the dragging to a specific
axis.
An interactive test demonstrating the various features is also provided.
This adds a simple test for ClutterCairoTexture that draws two
rectangles to the cairo surface in an idle callback and then verifies
that they appeared at the right colours in the paint callback. If that
succeeds then the second time the idle callback is invoked it will
replace one of the rectangles with a sub region update and the
following paint callback will again verify the rectangles.
Instead of asking gtester to run ./test-conformance directly we now tell
it to run a list of wrapper scripts. This results in each test being
spawned in a separate process avoiding leakage of state between tests
which has been a big problem with the conformance tests for quite a
while now.
Otherwise it seems that rounding errors will cause the fragments at
the edge of the quad to blend with neighbouring quarters of the
texture which cause the test to fail.
A few of the tests connected to the paint signal but never
disconnected it. Most of these handlers had a call to g_main_quit in
them which meant that it could sometimes cause subsequent tests to
exit after the first frame is painted. Most of the tests don't
validate any of the results until after a couple of frames have been
rendered so this ended up skipping out the test entirely.
To workaround this the test setup function now disconnects all
handlers for the paint signal on the default stage before the test is
run.
The on_paint function for test-cogl-readpixels tries to temporarily
set the projection, modelview and viewport to its own values. However
it was never restoring the saved values so it could affect the results
of subsequent tests.
This adds a test which creates a material using the maximum number of
layers. All of the layers are assigned a white texture except the last
which is set to red. The default combine mode is used for all of the
layers so the final fragment should end up red.
Currently Cogl doesn't provide a way to query the maximum number of
layers so it just uses glGetIntegerv instead. This might cause
problems on GLES 2 because that adds additional restrictions on the
number of layers.
http://bugzilla.openedhand.com/show_bug.cgi?id=2064
This changes the original tests so that it splits the original path
into two sub paths. When adding a new block to the copied path it also
adds another sub path. This further stresses the path copying
mechanism and exposes a bug.
It also tests intersections by drawing a self-intersecting path and a
path with two sub-paths that overlap. Where the path overlaps it
should be inverted.
This renders a texture using different combinations of wrap modes for
the s and t coordinates and then verifies that the expected wrapping
is acheived. The texture is drawn using rectangles, polygons and
vbos. There is also code to test a rectangle using an atlased texture
(which should test the manual repeating) however the validation for
this is currently disabled because it doesn't work.
http://bugzilla.openedhand.com/show_bug.cgi?id=2063
This tests various paths drawing rectangles and verifies that the
expected pixels are filled in. Some of the paths are drawn by copying
an existing path and modifying it which should test the copy-on-write
code.
This updates test-cogl-offscreen to give an example of setting up a
CoglFramebuffer with a Clutter style 2D coordinate system with (0,0) top
left and (framebuffer_width, framebuffer_height) bottom right.
test-cogl-tex-polygon creates a separate material so that it can set
the texture filters. However in the paint functions that use
cogl_polygon it was calling cogl_set_source_texture which replaces the
material and ends up always using GL_LINEAR. This patch makes the
paint functions assume the correct source is set up instead of trying
to select a new source.
Added new "homogeneous" mode to ClutterBoxLayout, that makes layout children
get all the same size.
This is heavily inspired in the "homogeneous" attribute available in GtkBox,
but simplified as we don't have padding nor borders in box layout, only
spacing.
Also added to test-box-layout a key to set/unset homogeneous mode.
* Coding style fixes.
* Added proper test for homogeneous mode in box layout.
* Fix in homogeneous mode.
http://bugzilla.openedhand.com/show_bug.cgi?id=2034
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The test creates a GL_TEXTURE_RECTANGLE_ARB texture using
cogl_texture_new_from_foreign and confirms that rendering it works
correctly. If the rectangle texture extension isn't available then
this test always succeeds.
http://bugzilla.openedhand.com/show_bug.cgi?id=2015
The FlowLayout fails to provide a preferred size in case no sizing is
specified on one axis. It should, instead, have the preferred size of
the sum of its children, depending on the orientation property.
http://bugzilla.openedhand.com/show_bug.cgi?id=2013
cogl_read_pixels() no longer asserts that the format passed in is
RGBA_8888 but instead accepts any format. The appropriate GL enums for
the format are passed to glReadPixels so OpenGL should be perform a
conversion if neccessary.
It currently assumes glReadPixels will always give us premultiplied
data. This will usually be correct because the result of the default
blending operations for Cogl ends up with premultiplied data in the
framebuffer. However it is possible for the framebuffer to be in
whatever format depending on what CoglMaterial is used to render to
it. Eventually we may want to add a way for an application to inform
Cogl that the framebuffer is not premultiplied in case it is being
used for some special purpose.
If the requested format is not premultiplied then Cogl will convert
it. The tests have been changed to read the data as premultiplied so
that they won't be affected by the conversion. Picking in Clutter has
been changed to use COGL_PIXEL_FORMAT_RGB_888 because it doesn't need
the alpha component. clutter_stage_read_pixels is left unchanged
because the application can't specify a format for that so it seems to
make most sense to store unpremultiplied values.
http://bugzilla.openedhand.com/show_bug.cgi?id=1959
Allow a ClutterModel to be constructed through the ClutterScript API.
Currently this allows a model to be generated like like this:
{
"id" : "test-model",
"type" : "ClutterListModel",
"columns" : [
[ "text-column", "gchararray" ],
[ "int-column", "gint" ],
[ "actor-column", "ClutterRectangle" ]
]
}
where 'columns' is an array containing arrays of column-name,
column-type pairs.
http://bugzilla.openedhand.com/show_bug.cgi?id=2007
The adds tests for the remaining layer combine functions, the 1 minus
value operator and the TEXTURE_N source. Note however that Cogl
currently fails when parsing a TEXTURE_N source so the test is
commented out.
We need to make the Stage set the MAPPED flag on itself if we want to
verify the MAPPED state. That was always the case - it just worked
before because the Stage was shown at least once.
It was passing the number of vertices to
cogl_vertex_buffer_draw_elements but instead it should take the
maximum index which would be the number of vertices minus one. This
was causing errors to be reported with the checks filterset of Bugle.
If an actor is lying on the border of the Stage it might miss the LEAVE
event when the pointer of a device leaves the Stage window. Since the
backend is unsetting the Stage back pointer on the InputDevice we can
queue the emission of a LEAVE event on the pointer actor as well.
http://bugzilla.moblin.org/show_bug.cgi?id=9677
Since all conformance tests share the same state we should not touch
stuff like the stage size; sharing is already fairly complex and adds a
lot of caveats on the implementation of a conformance test unit, and if
we make tests influence later ones then we might slip in bugs or false
negatives - thus defeating the whole point of a conformance test suite.
The g_assert_cmpint() macro prints out not just the assertion condition
but also the assertion contents; this is useful to catch wrong values
without incrementing the verbosity of the test itself.
Since the "internal" state is global, it will leak onto actors that you
didn't intend for it to, because it applies not just to the actors you
create, but also to any actors *they* create. Eg, if you have a dialog
box class, you might push/pop_internal around creating its buttons, so
that those buttons get marked as internal to the dialog box. But
ctx->internal_child will still be set during the *button*'s constructor
as well, and so, eg, the label and icon inside the button actor will
*also* be marked as internal children, even if that isn't what the
button class wanted.
The least intrusive change at this point is to make push_internal() and
pop_internal() two methods of the Actor class, and take a ClutterActor
pointer as the argument - thus moving the locality of the internal_child
counter to the Actor itself.
http://bugzilla.openedhand.com/show_bug.cgi?id=1990
When creating a Cogl sub-texture, if the full texture is also a sub
texture it will now just offset the x and y and reference the full
texture instead. This avoids one level of indirection when rendering
the texture which reduces the chances of getting rounding errors in
the calculations.
The test was calling g_object_get to fetch the "opacity-start" property
(unsigned int) into a guint8 local variable. It's a bit of a mean trap
given that the getter function returns guint8 values so this also adds a
comment explaining what's going on.
* animator-parser:
docs: Describe the Animation definition syntax
animator: Provide a ClutterScript parser
animator: Allow retrieving type property type from a key
script: Use a node when resolving an animation mode
The whole point of having the Animator class is that the developer can
describe a complex animation using ClutterScript. Hence, ClutterAnimator
should hook into the Script machinery and parse a specific description
format for its keys.
ClutterAnimator is a class for managing the animation of multiple
properties of multiple actors over time with keyframing of values.
The Animator class is meant to be used to effectively describe
animations using the ClutterScript definition format, and to construct
complex implicit animations from the ground up.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
This adds three new texture backends.
- CoglTexture2D: This is a trimmed down version of CoglTexture2DSliced
which only supports a single texture and only works with the
GL_TEXTURE_2D target. The code is a lot simpler so it has a less
overheads than dealing with slices. Cogl will use this wherever
possible.
- CoglSubTexture: This is used to get a CoglHandle to represent a
subregion of another texture. The texture can be used as if it was a
standalone texture but it does not need to copy the resources.
- CoglAtlasTexture: This collects RGB and RGBA textures into a single
GL texture with the aim of reducing texture state changes and
increasing batching. The backend will try to manage the atlas and
may move the textures around to close gaps in the texture. By
default all textures will be placed in the atlas.
When running tests under Valgrind it would be useful to pass a
suppression file for the known one-off allocations done by Clutter
and by its dependencies. This trims the output of Valgrind and
improves the ability to actually spot leaks.
The coverage of the Behaviour sub-classes is currently abysmal. An
initial test suite for Behaviours should at least verify that the
accessors and the constructors are doing the right thing.
This initial test suite just verifies the BehaviourOpacity sub-class,
but it already bumps up the overall coverage by 2%.
* device-manager: (37 commits)
x11: Re-enable XI1 extension keyboards
x11: Always handle core device events before XI events
docs: Documentation fixes for DeviceManager
device-manager: Fix the signals definition
docs: Add sections for InputDevice and DeviceManager
docs: Add clutter_input_device_get_device_name()
tests: Print out the device details on motion
Always register core devices
device: Remove unused is_default member
win32: Experimental implementation of device support
tests: Print the device name, as well as its Id
x11: Fill out the :name property of the InputDevices
device: Add the :name property to InputDevice
x11: Store core devices on the X11 Backend singleton
device: Unset the cursor actor when leaving the stage
device: Add pointer actor getter
x11: Discard the LeaveNotify for off-stage ButtonRelease
device: Do not overwrite the stage for an InputDevice
event: Off-stage button releases have a click count of 1
event: Scroll events do not have click count
...
It's very useful to see the actual number the reference value is
compared too when the test fails. GTest has g_assert_cmp$type()
functions for that, so make good use of them.
A small doubt has risen about the use of CoglTextureUnit in materials:
will texture matrices still work if we have several materials, each of
them having at texture on the same texture unit? The answer is yes!
test-cogl-multitexture has been extended to use 2 materials with about
the same setup except a little difference: the texture matrices for the
lightmaps rotate in opposite directions.
While at it, changed the rotation behaviour by an implicit animation
with a small additional bonus bling.
The extension keyboard support in XInput 1.x is hopelessly broken.
Nevertheless, it's possible to use some bits of it, as we prefer the
core keyboard events to the XInput events, thus at least having proper
handling for X11 key events on the Stage window.
• The enter/leave event line should take into account the case where
the related field is set to NULL (meaning entering from off-stage
and leaving the stage).
• The ButtonRelease line shows the click count but uses the button; the
button *and* the click count should be displayed for both ButtonPress
and ButtonRelease, to verify they match.
The output of test-events is a bit of a mess; this patch should clean
it up a little bit - at least enough for it to be useful again during
visual inspection.
Otherwise the paint handler will still be run for the subsequent
tests. This ends up writing to the ‘state’ variable which used to be
on the stack so it will end up corrupting some stack variable. This
was causing test-cogl-premult to fail.
The sub texture backend doesn't work well as a completely general
texture backend because for example when rendering with cogl_polygon
it needs to be able to tranform arbitrary texture coordinates without
reference to the other coordintes. This can't be done when the texture
coordinates are a multiple of one because sometimes the coordinate
should represent the left or top edge and sometimes it should
represent the bottom or top edge. For example if the s coordinates are
0 and 1 then 1 represents the right edge but if they are 1 and 2 then
1 represents the left edge.
Instead the sub-textures are now documented not to support coordinates
outside the range [0,1]. The coordinates for the sub-region are now
represented as integers as this helps avoid rounding issues. The
region can no longer be a super-region of the texture as this
simplifies the code quite a lot.
There are two new texture virtual functions:
transform_quad_coords_to_gl - This transforms two pairs of coordinates
representing a quad. It will return FALSE if the coordinates can
not be transformed. The sub texture backend uses this to detect
coordinates that require repeating which causes cogl-primitives
to use manual repeating.
ensure_non_quad_rendering - This is used in cogl_polygon and
cogl_vertex_buffer to inform the texture backend that
transform_quad_to_gl is going to be used. The atlas backend
migrates the texture out of the atlas when it hits this.
This adds a test which renders a texture into a 1x1 pixel quad with
and without filters that use mipmaps. The pixel without mipmaps will
be one of the colors from the texture and the one with will be the
average of all the pixels in the texture.
If a user supplied multiple groups of texture coordinates with
cogl_rectangle_with_multitexture_coords() then we would repeatedly log only
the first group in the journal. This fixes that bug and adds a conformance
test to verify the fix.
Thanks to Gord Allott for reporting this bug.
The test-text "fake scrolling" code stopped working somewhere between
0.8 and 0.9, with the new layout code. Instead of the ::cursor-event
signal it should use an approach similar to the Scrollable interface in
the Moblin User Experience toolkit.
Right now, it makes sense to ignore this code entirely.
* animate-layout-manager:
layout-manager: Document the animation support
layout-manager: Rewind the timeline in begin_animation()
box-layout: Remove the allocations hash table
docs: Clean up the README file
layout: Let begin_animation() return the Alpha
box-layout: Add knobs for controlling animations
box-layout: Animate layout properties
layout: Add animation support to LayoutManager
Add ActorBox animation methods
* stage-use-alpha:
tests: Use accessor methods for :use-alpha
stage: Add accessors for :use-alpha
tests: Allow setting the stage opacity in test-paint-wrapper
stage: Premultiply the stage color
stage: Composite the opacity with the alpha channel
glx: Always request an ARGB visual
stage: Add :use-alpha property
materials: Get the right blend function for alpha
ClutterLayoutManager does not have any state associated with it, and
defers all the state to its sub-classes.
The BoxLayout is thus in charge of controlling:
• whether or not animations should be used
• the duration of the animation
• the easing mode of the animation
By adding three new properties:
• ClutterBoxLayout:use-animations
• ClutterBoxLayout:easing-duration
• ClutterBoxLayout:easing-mode
And their relative accessors pairs we can make BoxLayout decide whether
or not, and with which parameters, call the begin_animation() method of
ClutterLayoutManager.
The test-box-layout has been modified to reflect this new functionality,
by checking the key-press event for the 'a' key symbol to toggle the use
of animations.
This tests creating a sub texture from a larger texture using various
different texture coordinates. It also tries to read back the texture
data using cogl_texture_get_data.
* text-direction:
docs: Add text-direction accessors
Set the default language on the Pango context
actor: Set text direction on parenting
tests: Display the index inside text-box-layout
box-layout: Honour :text-direction
text: Dirty layout cache on text direction changes
actor: Add :text-direction property
Use the newly added ClutterTextDirection enumeration
Add ClutterTextDirection enumeration
This test did not open redhand.png as argc/argv should be handled
normally (argv[0] being the name of the exectutable).
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Some tests can be given extra arguments. The test-interactive dispatch
mechanism handles that but the small shell scripts around the wrapper
do not forward the arguments to the wrapper.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
cogl_push_draw_buffer, cogl_set_draw_buffer and cogl_pop_draw_buffer are now
deprecated and new code should use the new cogl_framebuffer_* API instead.
Code that previously did:
cogl_push_draw_buffer ();
cogl_set_draw_buffer (COGL_OFFSCREEN_BUFFER, buffer);
/* draw */
cogl_pop_draw_buffer ();
should now be re-written as:
cogl_push_framebuffer (buffer);
/* draw */
cogl_pop_framebuffer ();
As can be seen from the example above the rename has been used as an
opportunity to remove the redundant target argument from
cogl_set_draw_buffer; it now only takes one call to redirect to an offscreen
buffer, and finally the term framebuffer may be a bit more familiar to
anyone coming from an OpenGL background.
Since the rectangles packed inside the BoxLayout interactive test
have random colors it's not easy to verify the ordering. By using
the CoglPango API to print out the index in the middle of each
rectangle.
These changes caused the test to try to load redhand.png but this no
longer works since the TESTS_DATADIR changes in 0b4899ef23. The only
use of the hand is commented out anyway so it looks like the changes
were intended for temporary debugging.
cogl_clip_push, and cogl_clip_push_window_rect which are now deprecated were
used in various places internally so this just switches to using the
replacement functions.
cogl_clip_push() which accepts a rectangle in model space shouldn't have
been defined to take x,y,width,height arguments because this isn't consistant
with other Cogl API dealing with model space rectangles. If you are using a
coordinate system with the origin at the center and the y+ extending up,
then x,y,width,height isn't as natural as (x0,y0)(x1,y1). This API has
now been replace with cogl_clip_push_rectangle()
(As a general note: the Cogl API should only use the x,y,width,height style
when the appropriate coordinate space is defined by Cogl to have a top left
origin. E.g. window coordinates, or potentially texture coordinates)
cogl_clip_push_window_rect() shouldn't have been defined to take float
arguments since we only clip with integral pixel precision. We also
shouldn't have abbreviated "rectangle". This API has been replaced with
cogl_clip_push_window_rectangle()
cogl_clip_ensure() wasn't documented at all in Clutter 1.0 and probably
no one even knew it existed. This API isn't useful, and so it's now
deprecated. If no one complains we may remove the API altogether for
Clutter 1.2.
cogl_clip_stack_save() and cogl_clip_stack_restore() were originally added
to allow us to save/restore the clip when switching to/from offscreen
rendering. Now that offscreen draw buffers are defined to own their clip
state and the state will be automatically saved and restored this API is now
redundant and so deprecated.
The build for interactive tests creates symbolic links for the data
under tests/data; it also uses symbolic links for creating "binaries"
for each interactive test. This is less than ideal, though.
Instead, the tests should build a path to the data files by using
a pre-processor define like TESTS_DATADIR; both g_build_filename() and
pre-processor string concatenation can be used to generate a valid
file name with the full path to the files.
The build system should also create wrapper scripts, just like we
do inside the conformance test suite, to be able to launch single
tests.
The ClutterScript parser needs to be extended to parse child properties
and apply them after an actor has been added to a container. In order to
distinguish child properties from regular GObject properties we can use
the "child::" prefix, e.g.:
{
"type" : "ClutterRectangle",
"id" : "child-01",
"child::has-focus" : true,
...
}
Parsing child properties can be deferred to the ClutterScriptable
interface, just like regular properties.
All the ClutterColor parsing rules should be coalesced inside
clutter_script_parse_color(): object, array and string notations
are the canonical ways of defining a ClutterColor inside a
ClutterScript definition. Having a single function in charge of
the parsing cleans up the code.
ClutterScript is a very complicated piece of machinery, with a
parser that has custom variations on top of the basic JSON
format; it could also be extended in the future, so if we don't
want to introduce regressions or break existing ClutterScript
definitions, we'd better have a conformance test suite.
The units under the conformance test suite should be able to use
external files. Linking the files in tests/conform like the
interactive tests do seems like a hack piled on top of a hack, so
instead we should provide a programmatic way for a conformance
test unit to get the full path of a file, regardless of where the
tests/data directory is.
We can use a define to get the full path of tests/data and then
a function using g_build_filename() to construct the path to the
file we want.
This test tried to do too much, and I can't remember the last time I saw this
test work.
It no longer tries to create a texture from an offscreen actor and it no
longer tries to use shaders.
It does though show that chaining of clutter_texture_new_from_actor now
works, and that animating the source actor is reflected in textures created
from it.
When run you should see three actors:
- on the left is the pristine source actor rotating around the y-axis
- in the middle is the first texture created from the source actor
- and on the right a texture created from the middle actor
Note: the somewhat strange bobbing of the middle and right textures is
actually correct given how it was decided long ago to map the transformed
(to screen space) allocation of the source actor to the texture. When the
hand spins around the perspective projection of the top of the hand results
in the origin of the texture bobbing up to a higher stage position, but the
position of the textures is fixed. This design also means we end up
reallocating our offscreen draw buffer every frame that the actors
transformed size changes, which isn't ideal.
Since offscreen rendering is internally forced to be upside down Cogl
needs to reverse the glFrontFace winding order so as not to interfere
with the use of cogl_set_backface_culling_enabled()
This ensures we test that mechanism.
Mostly this was written to verify that we don't flip the data read back from
an offscreen draw buffer. (since all offscreen rendering is done upside
down)
This adds a basic test to check that rendering a few colored rectangles
offscreen works and that the modelview gets restored when switching back to
the previous buffer.
Unlike OpenGL Cogl puts the origin of windows/viewports at the top left
instead of bottom left. This test verifies that we correctly translate Cogl
viewports to OpenGL viewports for the awkward cases where the given viewport
has an offset and/or the viewport has a different size to the current draw
buffer.
It helps to be able to quickly glance at the definition to see which
quadrant of the test actor should be which color, so when debugging a
problem and looking at the visual output you can easily verify if it's being
flipped upside down/left to right.
This contains four tests :-
- A regular onscreen source with a clone next to it
- An offscreen source with a clone. This is currently commented out
because it no longer works.
- An onscreen source with a rectangular clip and a clone.
- An onscreen source with a clip from a path and a clone.
The sources are all a 2x2 grid of colors. Each clone is tested that it
either contains the color that should be at that grid position or that
the stage color is showing through if the source is clipped.
* layout-manager: (50 commits)
docs: Reword a link
layout, docs: Add more documentation to LayoutManager
layout, docs: Fix description of Bin properties
layout, bin: Use ceilf() instead of casting to int
layout, docs: Add long description for FlowLayout
layout, box: Clean up
layout, box: Write long description for Box
layout, docs: Remove unused functions
layout: Document BoxLayout
layout: Add BoxLayout, a single line layout manager
layout: Report the correct size of FlowLayout
layout: Resizing the stage resizes the FlowLayout box
layout: Use the get_request_mode() getter in BinLayout
layout: Change the request-mode along with the orientation
actor: Add set_request_mode() method
[layout] Remove FlowLayout:wrap
[layout] Rename BinLayout and FlowLayout interactive tests
[layout] Skip invisible children in FlowLayout
[layout] Clean up and document FlowLayout
[layout] Snap children of FlowLayout to column/row
...
The additional check draws another front facing rectangle but this time with
the texture coords flipped on the x axis. The code that handles sliced
textures in cogl-primitives.c makes some suspicious changes to the geometry
when the texture coords are inverted.
As part of an incremental process to have Cogl be a standalone project we
want to re-consider how we organise the Cogl source code.
Currently this is the structure I'm aiming for:
cogl/
cogl/
<put common source here>
winsys/
cogl-glx.c
cogl-wgl.c
driver/
gl/
gles/
os/ ?
utils/
cogl-fixed
cogl-matrix-stack?
cogl-journal?
cogl-primitives?
pango/
The new winsys component is a starting point for migrating window system
code (i.e. x11,glx,wgl,osx,egl etc) from Clutter to Cogl.
The utils/ and pango/ directories aren't added by this commit, but they are
noted because I plan to add them soon.
Overview of the planned structure:
* The winsys/ API is the API that binds OpenGL to a specific window system,
be that X11 or win32 etc. Example are glx, wgl and egl. Much of the logic
under clutter/{glx,osx,win32 etc} should migrate here.
* Note there is also the idea of a winsys-base that may represent a window
system for which there are multiple winsys APIs. An example of this is
x11, since glx and egl may both be used with x11. (currently only Clutter
has the idea of a winsys-base)
* The driver/ represents a specific varient of OpenGL. Currently we have "gl"
representing OpenGL 1.4-2.1 (mostly fixed function) and "gles" representing
GLES 1.1 (fixed funciton) and 2.0 (fully shader based)
* Everything under cogl/ should fundamentally be supporting access to the
GPU. Essentially Cogl's most basic requirement is to provide a nice GPU
Graphics API and drawing a line between this and the utility functionality
we add to support Clutter should help keep this lean and maintainable.
* Code under utils/ as suggested builds on cogl/ adding more convenient
APIs or mechanism to optimize special cases. Broadly speaking you can
compare cogl/ to OpenGL and utils/ to GLU.
* clutter/pango will be moved to clutter/cogl/pango
How some of the internal configure.ac/pkg-config terminology has changed:
backendextra -> CLUTTER_WINSYS_BASE # e.g. "x11"
backendextralib -> CLUTTER_WINSYS_BASE_LIB # e.g. "x11/libclutter-x11.la"
clutterbackend -> {CLUTTER,COGL}_WINSYS # e.g. "glx"
CLUTTER_FLAVOUR -> {CLUTTER,COGL}_WINSYS
clutterbackendlib -> CLUTTER_WINSYS_LIB
CLUTTER_COGL -> COGL_DRIVER # e.g. "gl"
Note: The CLUTTER_FLAVOUR and CLUTTER_COGL defines are kept for apps
As the first thing to take advantage of the new winsys component in Cogl;
cogl_get_proc_address() has been moved from cogl/{gl,gles}/cogl.c into
cogl/common/cogl.c and this common implementation first trys
_cogl_winsys_get_proc_address() but if that fails then it falls back to
gmodule.
When computing the pixels value of a ClutterUnits value we should
be caching the value to avoid recomputing for every call of
clutter_units_to_pixels(). We already have a flag telling us to
return the cached value, but we miss the mechanism to evict the
cache whenever the Backend settings affecting the conversion, that
is default font and resolution, change.
In order to implement the eviction we can use a "serial"; the
Backend will have an internal serial field which we retrieve and
put inside the ClutterUnits structure (we split one of the two
64 bit padding fields into two 32 bit fields to maintain ABI); every
time we call clutter_units_to_pixels() we compare the units serial
with that of the Backend; if they match and pixels_set is set to
TRUE then we just return the stored pixels value. If the serials
do not match then we unset the pixels_set flag and recompute the
pixels value.
We can verify this by adding a simple test unit checking that
by changing the resolution of ClutterBackend we get different
pixel values for 1 em.
http://bugzilla.openedhand.com/show_bug.cgi?id=1843
Input Methods require to be able to set a "pre-edit string", that is
a string that it's just displayed into the Text actor without being
committed to the actor's buffer. The string might require custom Pango
attributes, and an update of the cursor position.
FlowLayout should compute the correct height for the assigned width when
in horizontal flow, and the correct width for the assigned height when
in vertical flow. This means pre-computing the number of lines inside
the get_preferred_width() and get_preferred_height(). We can then cache
the computed column width and row height, cache them inside the layout
and then use them when allocating the children.
FlowLayout is a layout manager that arranges its children in a
reflowing line; the orientation controls the major axis for the
layout: horizontal, for reflow on the Y axis, and vertical, for
reflow on the X axis.
There are three potential variants to add a child inside a Box
with a BinLayout:
- clutter_box_pack(), a variadic argument function which
allows passing arbitrary LayoutMeta properties and values;
- clutter_bin_layout_add(), which uses the backpointer to
the container from the LayoutManager and sets the layout
properties directly without GValue (de)marshalling
- clutter_container_add_actor() and
clutter_bin_layout_set_alignment(), similar to the
clutter_bin_layout_add() function above, but split in two
The test-box interactive test should exercise all three variants.
The ClutterBox::add method is a simple wrapper around the Container
add_actor() method and the LayoutManager layout properties API. It
allows adding an actor to a Box and setting the layout properties in
one call.
If the LayoutManager used by the Box does not support layout properties
then the add() method short-circuits out.
Along with the varargs version of the method there's also a vector-based
variant, for language bindings to use.
Each actor managed by a BinLayout policy should reside inside its
own "layer", with horizontal and vertical alignment. The :x-align
and :y-align properties of the BinLayout are the default alignment
policies, which are copied to each new "layer" when it is created.
The set_alignment() and get_alignment() methods of BinLayout can
be changed to operate on a specific "layer".
The whole machinery uses the new ChildMeta support inside the
LayoutManager base abstract class.
Current parsing of units has a number of shortcomings:
* a number followed by trailing space (without any unit specified) was
not recognized,
* "5 emeralds" was parsed as 5em,
* the way we parse the digits after the separator makes us lose
precision for no good reason (5.0 is parsed as 5.00010014...f which
makes g_assert_cmpfloat() fail)
Let's define a stricter grammar we can recognize and try to do so. The
description is in EBNF form, removing the optional <> which is a pain
when having to write DocBook, and using '' for the terminal symbols.
Last step, add more ClutterUnits unit test to get a better coverage of
the grammar we want to parse.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Parse #rgb and #rrggbb in addition to forms with the alpha channel
specified. This allows conversion of colour strings from documents such as
CSS where the alpha channel is not specified when using '#' notation.
This patch also adds the relevant conformance test.
The user-initiated resize is conflicting with the allocated size. This
happens because we change the size of the stage's X Window behind the
back of the size allocation machinery.
Instead, we should change the size of the actor whenever we receive a
ConfigureNotify event to reflect the new size of the actor.
I just wasted a silly amount time trying to bisect an apparently broken
cogl-test-multitexture until I realized it was just silently failing to load
any textures.
This unit verifies that an Actor class will invoke the get_preferred_*
virtual functions unless the caching is in effect; it also verifies
that the cached values are correctly evicted.
The size requisition and allocation mechanisms should be thoroughly
tested to avoid unwanted regressions.
For starters, we can test the explicit size setting and the side
effects of calling clutter_actor_set_size().
The test-script.json UI definition still used old types, like
ClutterLabel and ClutterCloneTexture. It should move to the classes
that have replaced them.
We need to test that the depth sorting of ClutterGroup works correctly
in case we wish to change the data structure that stores the children,
and do so without changing the default behaviour.
in tests/interactive/Makefile.am add wrapper.sh to EXTRA_DIST otherwise
interactive unit tests wont be runnable when building from distributed
tarballs.
We should follow the convention for boxed types initializers of:
<type_name>_from_<another_type> (boxed, value)
For ClutterUnits as well; so:
clutter_units_pixels -> clutter_units_from_pixels
clutter_units_em -> clutter_units_from_em
...
We should still keep the short-hand version as a macro, though.
The ClutterColor conformance test should have a unit for verifying
the RGB<->HLS conversion code, especially the ability to roundtrip
between the two colorspaces.
AM_LDFLAGS is ignored by the LDFLAGS target, and it's also not the right
place to put the libraries used by the linker.
Thanks to Vincent Untz for spotting this.
The perspective test was used essentially to determine whether the
perspective set up in COGL worked correctly. The perspective code
has been changed a lot since Clutter 0.3: we rely on client-side
matrices and we use floating point; so, all the conditions the test
was supposed to verify do not exist anymore.
Fixes and adds a unit test for creating and drawing using materials with
COGL_INVALID_HANDLE texture layers.
This may be valid if for example the user has set a texture combine string
that only references a constant color.
_cogl_material_flush_layers_gl_state will bind the fallback texture for any
COGL_INVALID_HANDLE layer, later though we could explicitly check when the
current blend mode does't actually reference a texture source in which case
binding the fallback texture is redundant.
This tests drawing using cogl_rectangle, cogl_polygon and
cogl_vertex_buffer_draw.
To allow for flushing of batched geometry within Cogl we can't support users
directly calling glReadPixels. glReadPixels is also awkward, not least
because it returns upside down image data.
All the unit tests have been swithed over and clutter_stage_read_pixels now
sits on top of this too.
test-cogl-tex-getset was assuming it was dealing with
COGL_PIXEL_FORMAT_RGBA_8888 but since merging the premultiplcation branch
the pixel format is actually COGL_PIXEL_FORMAT_RGBA_8888_PRE
Texture data is now in premultiplied format and the shader should
output a premultiplied color if the default blend mode is being
used. Shaders that directly manipulate the rgb values now
unpremultiply and premultiply again afterwards.
Now that we can safely check for an uninitialized Clutter we
don't have side effects in calling one of the functions like
clutter_x11_enable_xinput(), which require to be called before
any other Clutter function.
The input device API is split halfway thorugh the backends in a very
weird way. The data structures are private, as they should, but most
of the information should be available in the main API since it's
generic enough.
The device type enumeration, for instance, should be common across
every backend; the accessors for device type and id should live in the
core API. The internal API should always use ClutterInputDevice and
not the private X11 implementation when dealing with public structures
like ClutterEvent.
By adding accessors for the device type and id, and by moving the
device type enumeration into the core API we can cut down the amount
of symbols private and/or visible only to the X11 backends; this way
when other backends start implementing multi-pointer support we can
share the same API across the code.
The test-easing interactive demo for the high-level animation API
is a bit "flat". Instead of using a Rectangle actor we should
probably be using something more "interesting" -- like a CairoTexture
with a gradient.
In order to chain up animations using clutter_actor_animate() and
friends you have to use an idle handler that guarantees that the
main loop spins at least once after the animation pointer has been
detached from the actor.
This has several drawbacks, first and foremost the fact that the
slice of the main loop for the idle handler might be starved by
other operations, like redrawing. This inevitably leads to tricks
with priorities and the like, contributing to the overall complexity.
Instead, we should guarantee that the animation instance created by
clutter_actor_animate() is valid for the ::completed signal until
it reaches its default handler; after that, the animation is detached
from the actor and destroyed. This means that it's possible to
create a new animation after the first is complete by simply using
g_signal_connect_after().
This unfortunately makes it impossible to keep a reference to the
animation pointer attached to the actor by using g_object_ref(); a
way to "fix" this would be to have a clutter_animation_attach()
and a clutter_animation_detach() pair of methods that allow attaching
any animation to an actor. This might overcomplicate what it is
the simple animation API, though, so it's currently not implemented
and left for future versions.
The test-easing interactive demo has been modified to show how
the animation queuing works by adding a command line switch that
recenters the animated actor once the first animation has ended.
In order to be ready for the next major version of GLib we need to
disable single header inclusion by using the G_DISABLE_SINGLE_INCLUDES
define in the build process.
The test has been broken since the change to use floats instead of
fixed point because it was passing degrees to sin and cos but they
expect radians.
It was further broken since the timeline changes because it was
directly using the parameter of the new-frame signal as a frame number
but it now represents the elapsed time.
We need to fix the VBO premultiplication; we also do not need to
forcibly queue a redraw in an idle handler: the timeline and the
master clock will do that for us.
The test-actors test (and its clones, test-actor-clone and
test-paint-wrapper) was written a long time ago for a different API
and has been tweaked to bits. We should probably have something a
little bit more complicated, but at least we should not use semantics
and coding patterns from Clutter 0.2, otherwise we won't be testing
anything except that Clutter 0.2 worked.
Merge branch 'premultiplication'
[cogl-texture docs] Improves the documentation of the internal_format args
[test-premult] Adds a unit test for texture upload premultiplication semantics
[fog] Document that fogging only works with opaque or unmultipled colors
[test-blend-strings] Explicitly request RGBA_888 tex format for test textures
[premultiplication] Be more conservative with what data gets premultiplied
[bitmap] Fixes _cogl_bitmap_fallback_unpremult
[cogl-bitmap] Fix minor copy and paste error in _cogl_bitmap_fallback_premult
Avoid unnecesary unpremultiplication when saving to local data
Don't unpremultiply Cairo data
Default to a blend function that expects premultiplied colors
Implement premultiplication for CoglBitmap
Use correct texture format for pixmap textures and FBO's
Add cogl_color_premultiply()
cogl_texture_new_from_data lets you specify a source format for the users given
data, and an internal format which the user wants the GPU to see. This unit
test verifies that the users data is premultiplied, un-premultiplied or
left alone for a number of (source format, internal format) pairs.
cogl_texture_set_region allows specifying a source format, and the internal
format is determined from the texture being updated. As above we test
a number of format pairs and check Cogl is converting data correctly.
The test verifies that if the user allows COGL_FORMAT_ANY for the
internal_format then by default Cogl will choose a premultipled format for
RGBA textures.
Note: Currently this only tests cogl_texture_new_from_data and
cogl_texture_set_region, we should also test cogl_texture_new_from_file,
cogl_texture_new_from_bitmap and cogl_texture_new_from_foreign.
The fixed function fogging provided by OpenGL only works with unmultiplied
colors (or if the color has an alpha of 1.0) so since we now premultiply
textures and colors by default a note to this affect has been added to
clutter_stage_set_fog and cogl_set_fog.
test-depth.c no longer uses clutter_stage_set_fog for this reason.
In the future when we can depend on fragment shaders we should also be
able to support fogging of premultiplied primitives.
This test assumes that the textures will be stored internally with exactly
the color given so that specific texture combining arithmetic can be
tested. Using COGL_PIXEL_FORMAT_ANY allows Cogl to internally premultiply
the textures, so we have to explicitly request an unmultiplied format.
Many operations, like mixing two textures together or alpha-blending
onto a destination with alpha, are done most logically if texture data
is in premultiplied form. We also have many sources of premultiplied
texture data, like X pixmaps, FBOs, cairo surfaces. Rather than trying
to work with two different types of texture data, simplify things by
always premultiplying texture data before uploading to GL.
Because the default blend function is changed to accommodate this,
uses of pure-color CoglMaterial need to be adapted to add
premultiplication.
gl/cogl-texture.c gles/cogl-texture.c: Always premultiply
non-premultiplied texture data before uploading to GL.
cogl-material.c cogl-material.h: Switch the default blend functions
to ONE, ONE_MINUS_SRC_ALPHA so they work correctly with premultiplied
data.
cogl.c: Make cogl_set_source_color() premultiply the color.
cogl.h.in color-material.h: Add some documentation about
premultiplication and its interaction with color values.
cogl-pango-render.c clutter-texture.c tests/interactive/test-cogl-offscreen.c:
Use premultiplied colors.
http://bugzilla.openedhand.com/show_bug.cgi?id=1406
Signed-off-by: Robert Bragg <robert@linux.intel.com>
Merge branch 'master-clock-updates'
* master-clock-updates: (22 commits)
Change the paint forcing on the Text cache text
[timelines] Improve marker hit check and don't fudge the delta
Revert "[timeline] Don't clamp the elapsed time when a looping tl reaches the end"
[tests] Don't add a newline to the end of g_test_message calls
[test-timeline] Add a marker at the beginning of the timeline
[timeline] Don't clamp the elapsed time when a looping tl reaches the end
[master-clock] Throttle if no redraw was performed
[docs] Update Clutter's API reference
Force a paint instead of calling clutter_redraw()
Fix clutter_redraw() to match the redraw cycle
Run the repaint functions inside the redraw cycle
Remove useless manual timeline ticking
Move elapsed-time calculations into ClutterTimeline
Limit the frame rate when not syncing to VBLANK
Decrease the main-loop priority of the frame cycle
Avoid motion-compression in test-picking test
Compress events as part of the frame cycle
Remove stage update idle and do updates from the master clock
Call g_main_context_wakeup() when we start running timelines
Remove unused msecs_delta member
...
The changes in the master clock and the repaint cycle have been
changed, and broke the way the test for the Text actor cache of
PangoLayouts forces a redraw.
We have to call clutter_actor_paint() on the Stage embedding the
Text actor we want to test; this is kinda fugly because if the
Layout has changed it will end up causing a reallocation cycle
in the middle of the Text actor paint. Since it's a test case,
and since forcing redraws is a bit of a hack as well, we can
close both our eyes on that.
This reverts commit 9c5663d671.
The patch was causing problems for applications that expect the
elapsed_time to be at either end of the timeline when the completed
signal is fired. For example test-behave swaps the direction of the
timeline in the completed handler but if the time has overflowed the
end then the timeline would only take a short time to get back the
beginning. This caused the animation to just vibrate around the
beginning.
The new-frame signal of a timeline was previously guaranteed to be
emitted with the elapsed_time set to the end before it emits the
completed signal. This doesn't necessarily make sense for looping
timelines because it would cause the elapsed time to be clamped to a
slightly off value whenever the timeline restarts. This patch makes it
perform the wrap around before emitting the new-frame signal so that
the elapsed time always corresponds to the time elapsed since the
timeline was started.
Additionally it no longer fudges the msecs_delta property to make the
marker check work so clutter_timeline_get_delta will always return the
wall clock time since the last frame.
The master clock now works fine whether or not there are any stages,
so in the timeline conformance tests don't need to set up their
own times.
Set CLUTTER_VBLANK=none for the conformance tests, which in addition
to removing an test-environment dependency, will result in the ticking
for timeline tests being throttled to the default frame rate.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Instead of calculating a delta in the master clock, and passing that
into each timeline, make each timeline individually responsible for
remembering the last time and computing the delta.
This:
- Fixes a problem where we could spin infinitely processing
timeline-only frames with < 1msec differences.
- Makes timelines consistently start timing on the first frame;
instead of doing different things for the first started timeline
and other timelines.
- Improves accuracy of elapsed time computations by avoiding
accumulating microsecond => millisecond truncation errors.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
clutter-master-clock.c clutter-master-clock.h: When the
SYNC_TO_VBLANK feature is not available, wait for 1/frame_rate
seconds since the start of the last frame before drawing the next
frame. Add _clutter_master_clock_start_running() to abstract
the usage of g_main_context_wakeup()
clutter-stage.c: Add _clutter_master_clock_start_running()
clutter-main.c: Update docs for clutter_set_default_frame_rate()
clutter_get_default_frame_rate() to no longer talk about timeline
frame rates.
test-text-perf.c test-text.c: Set a frame rate of 1000fps so that
frame-rate limiting doesn't affect the result.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Using clutter_stage_get_actor_at_pos() rather than synthesizing
events; the synthesized events were being compressed, so we were
only tesitng one pick per frame.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The clutter_stage_fullscreen() and clutter_stage_unfullscreen() are
a GDK-ism. The underlying implementation is already using an accessor
with a boolean parameter.
This should take the amount of collisions between properties, methods
and signals to zero.
The :fullscreen property is very much confusing as it is implemented.
It can be written to a value, but the whole process might fail. If we
set:
g_object_set (stage, "fullscreen", TRUE, NULL);
and the fullscreen process fails or it is not implemented, the value
will be reset to FALSE (if we're lucky) or left TRUE (most of the
times).
The writability is just a shorthand for invoking clutter_stage_fullscreen()
or clutter_stage_unfullscreen() depending on a boolean value without
using an if.
The :fullscreen property also greatly confuses high level languages,
since the same symbol is used:
- for a method name (Clutter.Stage.fullscreen())
- for a property name (Clutter.Stage.fullscreen)
- for a signal (Clutter.Stage::fullscreen)
For these reasons, the :fullscreen should be renamed to :fullscreen-set
and be read-only. Implementations of the Stage should only emit the
StageState event to change from normal to fullscreen, and the Stage
will automatically update the value of the property and emit a notify
signal for it.
ClutterEvent is not really gobject-introspection friendly because
of the whole discriminated union thing. In particular, if you get
a ClutterEvent in a signal handler, you probably can't access the
event-type-specific fields, and you probably can't call methods
like clutter_key_event_symbol() either, because you can't cast the
ClutterEvent to a ClutterKeyEvent.
The cleanest solution is to turn every accessor into ClutterEvent
methods, accepting a ClutterEvent* and internally checking the event
type.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1585
The test was quiting after the 2nd frame but it should be the third frame because
the test doesn't actually check results until the third frame due to the workaround
for drivers with broken glReadPixels.
(When first written the test would have been verified with the
clutter_main_quit() commented out which gives visual feedback of what the
test does, so the off by one would have snuck in just before uncommenting
and pushing.)
The load-finished signal has a GError* argument which is meant to
signify whether the loading was successful. However many of the
places in ClutterTexture that emit this signal directly pass their
'error' variable which is a GError** and will be NULL or not
completely independently of whether there was an error. If the
argument was dereferenced it would probably crash.
The test-texture-async interactive test case should also verify
that the ::load-finished signal is correctly emitted.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1622
The texture filters are now a property of the material layer rather
than the texture object. Whenever a texture is painted with a material
it sets the filters on all of the GL textures in the Cogl texture. The
filter is cached so that it won't be changed unnecessarily.
The automatic mipmap generation has changed so that the mipmaps are
only generated when the texture is painted instead of every time the
data changes. Changing the texture sets a flag to mark that the
mipmaps are dirty. This works better if the FBO extension is available
because we can use glGenerateMipmap. If the extension is not available
it will temporarily enable automatic mipmap generation and reupload
the first pixel of each slice. This requires tracking the data for the
first pixel.
The COGL_TEXTURE_AUTO_MIPMAP flag has been replaced with
COGL_TEXTURE_NO_AUTO_MIPMAP so that it will default to
auto-mipmapping. The mipmap generation is now effectively free if you
are not using a mipmap filter mode so you would only want to disable
it if you had some special reason to generate your own mipmaps.
ClutterTexture no longer has to store its own copy of the filter
mode. Instead it stores it in the material and the property is
directly set and read from that. This fixes problems with the filters
getting out of sync when a cogl handle is set on the texture
directly. It also avoids the mess of having to rerealize the texture
if the filter quality changes to HIGH because Cogl will take of
generating the mipmaps if needed.
Instead of passing a boolean value, the ::allocate virtual function
should use a bitmask and flags. This gives us room for expansion
without breaking API/ABI, and allows to encode more information to
the allocation process instead of just changes of absolute origin.
Units as they have been implemented since Clutter 0.4 have always been
misdefined as "logical distance unit", while they were just pixels with
fractionary bits.
Units should be reworked to be opaque structures to hold a value and
its unit type, that can be then converted into pixels when Clutter needs
to paint or compute size requisitions and perform allocations.
The previous API should be completely removed to avoid collisions, and
a new type:
ClutterUnits
should be added; the ability to install GObject properties using
ClutterUnits should be maintained.
Timelines no longer work in terms of a frame rate and a number of
frames but instead just have a duration in milliseconds. This better
matches the working of the master clock where if any timelines are
running it will redraw as fast as possible rather than limiting to the
lowest rated timeline.
Most applications will just create animations and expect them to
finish in a certain amount of time without caring about how many
frames are drawn. If a frame is going to be drawn it might as well
update all of the animations to some fraction of the total animation
rather than rounding to the nearest whole frame.
The 'frame_num' parameter of the new-frame signal is now 'msecs' which
is a number of milliseconds progressed along the
timeline. Applications should use clutter_timeline_get_progress
instead of the frame number.
Markers can now only be attached at a time value. The position is
stored in milliseconds rather than at a frame number.
test-timeline-smoothness and test-timeline-dup-frames have been
removed because they no longer make sense.
All the underlying implementation and the public entry points have
been switched to floats; the only missing bits are the Actor properties
that deal with positioning and sizing.
This usually means a major pain when dealing with GValues and varargs
functions. While GValue will warn you when dealing with the wrong
conversions, varags will simply die an horrible (and hard to debug)
death via segfault. Nothing much to do here, except warn people in the
release notes and hope for the best.
If it doesn't queue a redraw and allow the backend to clear and swap
the buffers then the results will be skewed because it is not
predictable when the driver will actually render the scene.
Previously indices were tightly bound to a particular Cogl vertex buffer
but we would like to be able to share indices so now we have
cogl_vertex_buffer_indices_new () which returns a CoglHandle.
In particular we could like to have a shared set of indices for drawing
lists of quads that can be shared between the pango renderer and the
Cogl journal.
cogl_enable_depth_test and cogl_enable_backface_culling have been renamed
and now have corresponding getters, the new functions are:
cogl_set_depth_test_enabled
cogl_get_depth_test_enabled
cogl_set_backface_culling_enabled
cogl_get_backface_culling_enabled
Originally cogl_vertex_buffer_add_indices let the user pass in their own unique
ID for the indices; now the Id is generated internally and returned to the
caller.
It's now possible to add arrays of indices to a Cogl vertex buffer and
they will be put into an OpenGL vertex buffer object. Since it's quite
common for index arrays to be static it saves the OpenGL driver from
having to validate them repeatedly.
This changes the cogl_vertex_buffer_draw_elements API: It's no longer
possible to provide a pointer to an index array at draw time. So
cogl_vertex_buffer_draw_elements now takes an indices identifier that
should correspond to an idendifier returned when calling
cogl_vertex_buffer_add_indices ()
Setting up layer combine functions and blend modes is very awkward to do
programatically. This adds a parser for string based descriptions which are
more consise and readable.
E.g. a material layer combine function could now be given as:
"RGBA = ADD (TEXTURE[A], PREVIOUS[RGB])"
or
"RGB = REPLACE (PREVIOUS)"
"A = MODULATE (PREVIOUS, TEXTURE)"
The simple syntax and grammar are only designed to expose standard fixed
function hardware, more advanced combining must be done with shaders.
This includes standalone documentation of blend strings covering the aspects
that are common to blending and texture combining, and adds documentation
with examples specific to the new cogl_material_set_blend() and
cogl_material_layer_set_combine() functions.
Note: The hope is to remove the now redundant bits of the material API
before 1.0
The CoglTexture constructors expose the "max-waste" argument for
controlling the maximum amount of wasted areas for slicing or,
if set to -1, disables slicing.
Slicing is really relevant only for large images that are never
repeated, so it's a useful feature only in controlled use cases.
Specifying the amount of wasted area is, on the other hand, just
a way to mess up this feature; 99% the times, you either pull this
number out of thin air, hoping it's right, or you try to do the
right thing and you choose the wrong number anyway.
Instead, we can use the CoglTextureFlags to control whether the
texture should not be sliced (useful for Clutter-GST and for the
texture-from-pixmap actors) and provide a reasonable value for
enabling the slicing ourself. At some point, we might even
provide a way to change the default at compile time or at run time,
for particular platforms.
Since max_waste is gone, the :tile-waste property of ClutterTexture
becomes read-only, and it proxies the cogl_texture_get_max_waste()
function.
Inside Clutter, the only cases where the max_waste argument was
not set to -1 are in the Pango glyph cache (which is a POT texture
anyway) and inside the test cases where we want to force slicing;
for the latter we can create larger textures that will be bigger than
the threshold we set.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Signed-off-by: Robert Bragg <robert@linux.intel.com>
Signed-off-by: Neil Roberts <neil@linux.intel.com>
* master:
[cogl-vertex-buffer] Ensure the clip state before rendering
[test-text-perf] Small fix-ups
Add a test for text performance
[build] Ensure that cogl-debug is disabled by default
[build] The cogl GE macro wasn't passing an int according to the format string
Use the right internal format for GL_ARB_texture_rectangle
[actor_paint] Ensure painting is a NOP for actors with opacity = 0
Make backface culling work with vertex buffers
- Fix a typo in a for loop in create_label which left 'i'
uninitialised and caused a crash if you're unlucky.
- Set the CLUTTER_VBLANK=none environment variable.
- Don't quit on a keypress.
- Trailing whitespace tidy up.
Print out the cursor and selection positions in order to verify
the behaviour of the Text actor.
This is a likely candidate for a conformance test unit as well.
The picking test has two configurables: the number of actors and
the number of events per frame. It makes sense to have them as
command line options to test with multiple configurations without
having to change defines and recompile.
COGLenum, COGLint and COGLuint which were simply typedefs for GL{enum,int,uint}
have been removed from the API and replaced with specialised enum typedefs, int
and unsigned int. These were causing problems for generating bindings and also
considered poor style.
The cogl texture filter defines CGL_NEAREST and CGL_LINEAR etc are now replaced
by a namespaced typedef 'CoglTextureFilter' so they should be replaced with
COGL_TEXTURE_FILTER_NEAREST and COGL_TEXTURE_FILTER_LINEAR etc.
The shader type defines CGL_VERTEX_SHADER and CGL_FRAGMENT_SHADER are handled by
a CoglShaderType typedef and should be replaced with COGL_SHADER_TYPE_VERTEX and
COGL_SHADER_TYPE_FRAGMENT.
cogl_shader_get_parameteriv has been replaced by cogl_shader_get_type and
cogl_shader_is_compiled. More getters can be added later if desired.
With the recent change to internal floating point values, ClutterUnit
has become a redundant type, defined to be a float. All integer entry
points are being internally converted to floating point values to be
passed to the GL pipeline with the least amount of conversion.
ClutterUnit is thus exposed as just a "pixel with fractionary bits",
and not -- as users might think -- as generic, resolution and device
independent units. not that it was the case, but a definitive amount
of people was convinced it did provide this "feature", and was flummoxed
about the mere existence of this type.
So, having ClutterUnit exposed in the public API doubles the entry
points and has the following disadvantages:
- we have to maintain twice the amount of entry points in ClutterActor
- we still do an integer-to-float implicit conversion
- we introduce a weird impedance between pixels and "pixels with
fractionary bits"
- language bindings will have to choose what to bind, and resort
to manually overriding the API
+ *except* for language bindings based on GObject-Introspection, as
they cannot do manual overrides, thus will replicate the entire
set of entry points
For these reason, we should coalesces every Actor entry point for
pixels and for ClutterUnit into a single entry point taking a float,
like:
void clutter_actor_set_x (ClutterActor *self,
gfloat x);
void clutter_actor_get_size (ClutterActor *self,
gfloat *width,
gfloat *height);
gfloat clutter_actor_get_height (ClutterActor *self);
etc.
The issues I have identified are:
- we'll have a two cases of compiler warnings:
- printf() format of the return values from %d to %f
- clutter_actor_get_size() taking floats instead of unsigned ints
- we'll have a problem with varargs when passing an integer instead
of a floating point value, except on 64bit platforms where the
size of a float is the same as the size of an int
To be clear: the *intent* of the API should not change -- we still use
pixels everywhere -- but:
- we remove ambiguity in the API with regard to pixels and units
- we remove entry points we get to maintain for the whole 1.0
version of the API
- we make things simpler to bind for both manual language bindings
and automatic (gobject-introspection based) ones
- we have the simplest API possible while still exposing the
capabilities of the underlying GL implementation
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.
The units in the Timeline test suite just rely on the timeline
being a timeout automatically advanced by the main loop. This
is not the case anymore, since the merge of the master-clock.
To make the test units work again we need to "emulate" the master
clock without effectively having a stage to redraw; we do this
by creating a frame source and manually advancing the timelines
we create for test purposes, using the advance_msecs() "protected"
method.
With the change in commit 87e4e2 painting of hidden source actors
in ClutterClone was fixed. This commit changes the test-actor-clone
to visually verify this.
Setting the wrap mode on the PangoLayout seems to have disappeared
during the text-actor-layout-height branch merge so this brings it
back. The test for this in test-text-cache no longer needs to be
disabled.
We also shouldn't set the width on the layout if there is no wrapping
or ellipsizing because otherwise it implicitly enables wrapping. This
only matters if the actor gets allocated smaller than its natural
size.
Bug 1138 - No trackable "mapped" state
* Add a VISIBLE flag tracking application programmer's
expected showing-state for the actor, allowing us to
always ensure we keep what the app wants while tracking
internal implementation state separately.
* Make MAPPED reflect whether the actor will be painted;
add notification on a ClutterActor::mapped property.
Keep MAPPED state updated as the actor is shown,
ancestors are shown, actor is reparented, etc.
* Require a stage and realized parents to realize; this means
at realization time the correct window system and GL resources
are known. But unparented actors can no longer be realized.
* Allow children to be unrealized even if parent is realized.
Otherwise in effect either all actors or no actors are realized,
i.e. it becomes a stage-global flag.
* Allow clutter_actor_realize() to "fail" if not inside a toplevel
* Rework clutter_actor_unrealize() so internally we have
a flavor that does not mess with visibility flag
* Add _clutter_actor_rerealize() to encapsulate a somewhat
tricky operation we were doing in a couple of places
* Do not realize/unrealize children in ClutterGroup,
ClutterActor already does it
* Do not realize impl by hand in clutter_stage_show(),
since showing impl already does that
* Do not unrealize in various dispose() methods, since
ClutterActor dispose implementation already does it
and chaining up is mandatory
* ClutterTexture uses COGL while unrealizable (before it's
added to a stage). Previously this breakage was affecting
ClutterActor because we had to allow realize outside
a stage. Move the breakage to ClutterTexture, by making
ClutterTexture just use COGL while not realized.
* Unrealize before we set parent to NULL in clutter_actor_unparent().
This means unrealize() implementations can get to the stage.
Because actors need the stage in order to detach from stage.
* Update clutter-actor-invariants.txt to reflect latest changes
* Remove explicit hide/unrealize from ClutterActor::dispose since
unparent already forces those
Instead just assert that unparent() occurred and did the right thing.
* Check whether parent implements unrealize before chaining up
Needed because ClutterGroup no longer has to implement unrealize.
* Perform unrealize in the default handler for the signal.
This allows non-containers that have children to work properly,
and allows containers to override how it's done.
* Add map/unmap virtual methods and set MAPPED flag on self and
children in there. This allows subclasses to hook map/unmap.
These are not signals, because notify::mapped is better for
anything it's legitimate for a non-subclass to do.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Bug 1513 - Allow passing in ClutterPickMode to
clutter_stage_get_actor_at_pos()
At the moment, clutter_stage_get_actor_at_pos() uses CLUTTER_PICK_ALL
internally to find an actor. It would be useful to allow passing in
ClutterPickMode to clutter_stage_get_actor_at_pos(), so that the caller
can specify CLUTTER_PICK_REACTIVE as a criteria.
Three tests are now performed on the picked squares. First there is no
covering actor which is the same as the original test. Then there is a
hidden covering actor which should not affect the results. Finally
there is a covering actor with a clip set on it so that only actors
at the borders of the stage should be pickable.
The wrap mode sub-test inside the ClutterText layout cache test
unit has been broken by the recent changes inside the Text actor.
The sub-test itself might require tweaking.
The cogl_is_* functions were showing up quite high on profiles due to
iterating through arrays of cogl handles.
This does away with all the handle arrays and implements a simple struct
inheritance scheme. All cogl objects now add a CoglHandleObject _parent;
member to their main structures. The base object includes 2 members a.t.m; a
ref_count, and a klass pointer. The klass in turn gives you a type and
virtual function for freeing objects of that type.
Each handle type has a _cogl_##handle_type##_get_type () function
automatically defined which returns a GQuark of the handle type, so now
implementing the cogl_is_* funcs is just a case of comparing with
obj->klass->type.
Another outcome of the re-work is that cogl_handle_{ref,unref} are also much
more efficient, and no longer need extending for each handle type added to
cogl. The cogl_##handle_type##_{ref,unref} functions are now deprecated and
are no longer used internally to Clutter or Cogl. Potentially we can remove
them completely before 1.0.
There is no need for a custom hsl to rgb converter since Clutter implements
this logic; originally it wasn't quite as optimal, but that has now been
fixed.
Using test-cogl-vertex-buffer as a test case which is CPU bound due to
hls -> rgb conversions this alternative algorithm looked to be ~10%
faster when tested on an X61s Lenovo.
The test is a sanity check that dynamic updating of vertex data via the cogl
vertex buffer api works and has reasonable performance. (though it can't be
considered a well designed benchmark since it wastes casual amounts of CPU
time simply choosing pretty colors.)
The code also aims to demonstrate one way of creating, updating and efficiently
drawing a quad mesh structure via the vertex buffer api which could be applied
to lots of different use cases.
Only have load-data-async and load-async properties, both are construct
only and the latter adds the former load-size-async behavior on top of
load-data-async.
The fog and perspective API is currently split in two parts:
- the floating point version, using values
- the fixed point version, using structures
The relative properties are using the structure types, since they
are meant to set multiple values at the same time. Instead of
using bare values, the whole API should be coalesced into two
simple calls using structures to match the GObject properties.
Thus:
clutter_stage_set_fog (ClutterStage*, const ClutterFog*)
clutter_stage_get_fog (ClutterStage*, ClutterFog*)
clutter_stage_set_perspective (ClutterStage*, const ClutterPerspective*)
clutter_stage_get_perspective (ClutterStage*, ClutterPerspective*)
Which supercedes the fixed point and floating point variants.
More importantly, both ClutterFog and ClutterPerspective should
using floating point values, since that's what get passed to
COGL anyway.
ClutterFog should also drop the "density" member, since ClutterStage
only allows linear fog; non-linear fog distribution can be achieved
using a signal handler and calling cogl_set_fog() directly; this keeps
the API compact yet extensible.
Finally, there is no ClutterStage:fog so it should be added.
The ClutterColor API has some inconsistencies:
- the string deserialization function does not match the rest of
the conversion function naming policy; the naming should be:
clutter_color_parse() -> clutter_color_from_string()
and the first parameter should be the ClutterColor that will
be set from the string, not the string itself (a GDK-ism).
- the fixed point API should not be exposed, especially in the
form of ClutterFixed values
- the non-fixed point HLS conversion functions do not make any
sense. The values returned should be:
hue := range [ 0, 360 ]
luminance := range [ 0, 1 ]
saturation := range [ 0, 1 ]
like the current fixed point API does. Returning a value in
the [ 0, 255 ] range is completely useless
- the clutter_color_equal() should be converted for its use inside
a GHashTable; a clutter_color_hash() should be added as well
- the second parameter of the clutter_color_shade() function should
be the shading factor, not the result (another GDK-ism). this way
the function call can be translated from this:
color.shade(out result, factor)
to the more natural:
color.shade(factor, out result)
This somewhat large commit fixes all these issues and updates the
internal users of the API.
The libdisable-npots library is just used as a helper as part of
make test so it should not be installed.
If noinst_* is used then automake will generate a static library but
this won't work with LD_PRELOAD so we then need an extra custom rule
to link that into a shared library. The custom rule uses the $(LINK)
Makefile var which gets put in the Makefile because of the static
library. We pass libtool a stub -rpath option which causes it to
generate a shared library.
The test now explicitly reads back from the framebuffer to sanity check that
texturing is happening as expected, and it now uses a fixed 2x2 texture instead
of redhand.png since redhand.png doesn't have a power of two size which can
cause the vertex buffer code to complain on hardware not supporting npot
textures.
The TEST_CONFORM_TODO macro is a simple placeholder macro that
adds the test function to the "/todo" namespace and skips the
test.
It can be used for tests that are known to fail because of bugs
that haven't been fixed yet, or because of features not yet
implemented.
test-vertex-buffer-configuous now needs redhand.png so it should be
copied in to the build directory. This is copied from similar code in
the tests/interactive Makefile.
ClutterModel has an interactive test but lacks a conformance
unit for automatic testing.
This is the beginning of that unit, which covers the population
and iteration over a ListModel.
Sometimes a test unit should not be executed depending on a
condition. It would be good to have a macro doing this, along
with TEST_CONFORM_SIMPLE().
Additionally, the skipped unit should be added to a specific
namespace, so that any coverage report will be able to catch it.
For this reason, here's TEST_CONFORM_SKIP() which follows the
syntax:
TEST_CONFORM_SKIP (condition, namespace, function);
If condition evaluates to FALSE the test is skipped and the
unit added to the "/skipped" namespace.
The test no longer requires an XID argument to run; instead it creates its
own X Window. The test now also aims to demonstrate whether mipmapping is
working, and clearly informs you if fallbacks are being used for GLX tfp.
Fixes some blending issues when using color arrays since we were
conflicting with the cogl_enable state + fixes a texture layer
validation bug.
Adds a basic textured triangle to test-vertex-buffer-contiguous.
The test simply creates an odd sized texture with different colors at
each of the four corners. It then renders the texture and verifies
that the colors are the expected values. This should help ensure that
the sliced texture rendering code is working properly.
The :alignment property is prone to generate confusion: developers
will set it thinking that the contents of a ClutterText will
automagically align themselves.
Instead of using the generic term :alignment, and following the
GTK+ convention, we should use a more specific term, conveying the
actual effect of the property: alignment of the lines with respect
to each other, and not to the overall allocated area.
See bug 1428:
http://bugzilla.openedhand.com/show_bug.cgi?id=1428
This makes it consistent with cogl_rectangle_with_{multi,}texture_coords.
Notably the reason cogl_rectangle_with_{multi,}texture_coords wasn't changed
instead is that the former approach lets you describe back facing rectangles.
(though technically you could pass negative width/height values to achieve
this; it doesn't seem as neat.)
Bug 1349 - Using the anchor point to set the scale center is messy
The branch adds an extra center point for scaling which can be used
for example to set a scale about the center without affecting the
position of the actor.
The scale center can be specified as a unit offset from the origin or
as a gravity. If specified as a gravity it will be stored as a
fraction of the actor's size so that the position will track when the
actor changes size.
The anchor point and rotation centers have been modified so they can
be set with a gravity in the same way. However, only the Z rotation
exposes a property to set using a gravity because the other two
require a Z coordinate which doesn't make sense to interpret as a
fraction of the actor's width or height.
Conflicts:
clutter/clutter-actor.c
During the upgrade to cogl material, test-backface-culling was
switched to use cogl_rectangle instead of cogl_texture_rectangle to
draw the textures. However, cogl_rectangle takes a width and height
instead of the the top-left and bottom-right vertices so the
rectangles were being drawn in the wrong place.
* generic-actor-clone:
Remove CloneTexture from the API
[tests] Clean up the Clone interactive test
Rename ActorClone to Clone/2
Rename ActorClone to Clone/1
Improves the unit test to verify more awkward scaling and some corresponding fixes
Implements a generic ClutterActorClone that doesn't need fbos.
Conflicts:
clutter/cogl/gl/cogl-texture.c
clutter/cogl/gles/cogl-primitives.c
* cogl-material:
clutter-{clone-,}texture weren't updating their material opacity.
Updates GLES1 support for CoglMaterial
Normalizes gl vs gles code in preperation for synching material changes
Removes cogl_blend_func and cogl_alpha_func
Fully integrates CoglMaterial throughout the rest of Cogl
[cogl-material] Restore the GL_TEXTURE_ENV_MODE after material_rectangle
[cogl-material] Make the user_tex_coords parameter of _rectangle const
[test-cogl-material] Remove return value from material_rectangle_paint
Add cogl-material.h and cogl-matrix.h to libclutterinclude_HEADERS
[cogl-material] improvements for cogl_material_rectangle
[cogl-material] Adds a cogl_material_set_color function
[cogl-material] Some improvements for how we sync CoglMaterial state with OpenGL
[cogl-material] Converts clutter-texture/clutter-clone-texture to the material API
[doc] Hooks up cogl-material reference documentation
Updates previous GLES multi-texturing code to use CoglMaterial
Adds a CoglMaterial abstraction, which includes support for multi-texturing
[doc] Hooks up cogl-matrix reference documentation
Adds CoglMatrix utility code
[tests] Adds an interactive unit test for multi-texturing
[multi-texturing] This adds a new cogl_multi_texture API for GL,GLES1 + GLES2
ClutterClone supercedes ClutterCloneTexture, since it can clone
every kind of actor -- including composite ones.
This is another "brain surgery with a shotgun" kind of commit: it
removes CloneTexture and updates every test case using CloneTexture
to ClutterClone. The API fallout is minimal, luckily for us.
This glues CoglMaterial in as the fundamental way that Cogl describes how to
fill in geometry.
It adds cogl_set_source (), which is used to set the material which will be
used by all subsequent drawing functions
It adds cogl_set_source_texture as a convenience for setting up a default
material with a single texture layer, and cogl_set_source_color is now also
a convenience for setting up a material with a solid fill.
"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 respectivly.
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:
mat = cogl_material_new ();
cogl_material_set_color4ub (r,g,b,a);
cogl_material_set_layer (mat, 0, tex_handle));
cogl_set_source_material (mat);
Code that uses the texture coordinates, 0, 0, 1, 1 don't need to use
cog_rectangle_with_texure_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);
All of the unit tests have been updated to now use the material API and
test-cogl-material has been renamed to test-cogl-multitexture since any
textured quad is now technically a test of CoglMaterial but this test
specifically creates a material with multiple texture layers.
Note: The GLES backend has not been updated yet; that will be done in a
following commit.
Step two: rename the object and its methods.
While we're at it, adhere more strictly to the coding style
practises; rename :clone-source to :source; add a setter method
for the :source property; take a reference on the source actor
to avoid it disappearing while we're still accessing it.
This removes a lot of code from test-cogl-primitives to make it easier
to follow. The TestCoglBox custom actor has gone and instead a blank
ClutterGroup is created with a paint signal handler.
Instead of rendering constantly and updating when a GTimer elapses a
second, a ClutterTimeline is used with 1 fps and a new redraw is
queued every frame.
The custom main loop is replaced with a regular call to clutter_main.
This fixes the close button of the stage window so you can quit
without having to press Ctrl+C.
The rotation centers are now tested in a similar way to the anchor
point and scale centers.
The notification handling code has been simplified a bit to handle the
increased amount of properties.
Since we override the clean-generic target in order to remove
the shell scripts we create for each conformance test unit, we
cannot use CLEANFILES to remove the test reports.
The maintainer compiler flags we use trigger warnings and errors
in the autogenerated code that gtk-doc creates to scan the header
and source files. Since we cannot control that, and we must run
a distcheck with both --enable-gtk-doc and --enable-maintainer-flags
turned on, we need to use less-strict compiler flags when inside
the doc/reference subdirectories.
The way to do this is to split the maintainer compiler flags into
their own Makefile variable, called MAINTAINER_CFLAGS. The we
can use $(MAINTAINER_CFLAGS) in the INCLUDES or _CFLAGS sections
of each part of the source directories we wish to check with the
anal retentiveness suited for maintainers.
* float-alpha-value:
[script] Parse easing modes by name
[docs] Update the easing modes documentation
[animation] Implement new easing functions
[animation] Move the alpha value to floating point
This better reflects the fact that the api manages sets of vertex attributes,
and the attributes really have no implied form. It is only when you use the
attributes to draw that they become mesh like; when you specify how they should
be interpreted, e.g. as triangle lists or fans etc. This rename frees up the
term "mesh", which can later be applied to a concept slightly more fitting.
E.g. at some point it would be nice to have a higher level abstraction that
sits on top of cogl vertex buffers that adds the concept of faces. (Somthing
like Blender's mesh objects.) There have also been some discussions over
particle engines, and these can be defined in terms of emitter faces; so some
other kind of mesh abstraction might be usefull here.
Okey; to summarise the changes...
We have converted Clutter and Cogl over to using floating point internally
instead of 16.16 fixed, but we have maintained the cogl-fixed API as a
utility to applications in case they want to implement their own optimizations.
The Clutter API has not changed (though ClutterFixed and ClutterUnit are now
internally floats) but all Cogl entry points have been changed to accept floats
now instead of CoglFixed.
To summarise the rationale...
There have been a number of issues with using fixed point though out Clutter
and Cogl including: lack of precision, lack of range, excessive format
conversion (GPUs tend to work nativly with IEEE floats) and maintainability.
One of the main arguments for fixed point - performance - hasn't shown
itself to be serious in practice so far since we seem to be more limited
by GPU performance and making improvements regarding how we submit data to
OpenGL[ES]/the GPU has had a more significant impact.
Ref: The recent multiple rectangle queuing changes + the
cogl-texture-agressive-batching branch which show significant performance
gains, and that recent tests on the ipodtouch (ARM + MBX) also showed no
loss of performance running with floats.
So finally; please forgive the inevitable fallout, this is a far reaching
change. There are still a few known issues with the fixed to float
conversion but enough works for all our conformance tests to pass, and the
remaining issues hopefully wont be too tricky to solve. For reference two
tags will be available either side of this change: "cogl-fixed-end" and
"cogl-float-start"
The easing modes for a ClutterAlpha can either be parsed by using
the enumeration "nickname" (the shorthand form of the enumeration
value) or by using the common naming policy used in other
animation frameworks, like:
easeInCubic
easeOutElastic
easeInOutBounce
Instead of using our own homegrown alpha functions, we should
use the easing functions also shared by other animation frameworks,
like jQuery and Tween, in the interests of code portability.
The easing functions have been defined by Robert Penner and
are divided into three categories:
In Out InOut
Each category has a particular curve:
Quadratic
Cubic
Quartic
Quintic
Sinusoidal
Exponential
Circular
In addition, there are "physical" curves:
Elastic
Back (overshooting cubic)
Bounce (exponentially decaying parabolic)
Finally, the Linear curve is also provided as a reference.
The functions are private, and are meant to be used only
through their logical id as provided by the AnimationMode
enumeration.
The tests should be updated as well to match the new
easing functions.
The current Alpha value is an unsigned integer that can be used
implicitly as a fixed point value. This makes writing an alpha
function overshooting below and above the current range basically
impossible without complicating an already complex code, and
creating weird corner cases.
For this reason, the Alpha value should be defined as a floating
point normalized value, spanning a range between 0.0 and 1.0; in
order to allow overshooting, the valid range is extended one unit
below and one unit above, thus making it -1.0 .. 2.0.
This commit updates the various users of the ClutterAlpha API
and the tests cases.
This commit also removes all the current alpha functions exposed
in the public API.
To deal with all the corner cases that couldn't be scripted a number of patches
were written for the remaining 10% of the effort.
Note: again no API changes were made in Clutter, only in Cogl.
This is the result of running a number of sed and perl scripts over the code to
do 90% of the work in converting from 16.16 fixed to single precision floating
point.
Note: A pristine cogl-fixed.c has been maintained as a standalone utility API
so that applications may still take advantage of fixed point if they
desire for certain optimisations where lower precision may be acceptable.
Note: no API changes were made in Clutter, only in Cogl.
Overview of changes:
- Within clutter/* all usage of the COGL_FIXED_ macros have been changed to use
the CLUTTER_FIXED_ macros.
- Within cogl/* all usage of the COGL_FIXED_ macros have been completly stripped
and expanded into code that works with single precision floats instead.
- Uses of cogl_fixed_* have been replaced with single precision math.h
alternatives.
- Uses of COGL_ANGLE_* and cogl_angle_* have been replaced so we use a float for
angles and math.h replacements.
This simplifies the mucking about with the model-view matrix that was previously
done which improves its efficiency when scaling is necessary.
Notably: There should now be no performance advantage to using
ClutterCloneTexture as a special case clone actor since this method is just as
efficient.
The unit test was renamed to test-actor-clone.
Many use cases for clonning an actor don't require running a shader on the
resulting clone image and so requiring FBOs in these cases is overkill and
in-efficient as it requires kicking and synchronizing a render for each clone.
This approach basically just uses the paint function of another actor to
implement the painting for the clone actor with some fiddling of the model-
view matrix to scale according to the different allocation box sizes of
each of the actors.
A simple unit test called test-actors2 was added for testing.
In order to unify alpha functions and animation modes in ClutterAlpha
we should be able to register alpha functions and get a logical id
for them; the logical id will then be available to be used by
clutter_alpha_set_mode().
The registration requires API changes in ClutterAlpha constructors
and methods. It also provides the chance to shift ClutterAlpha
towards the use of animations modes only, and to alpha functions
as a convenience API for language bindings alone.
Directly calling clutter_actor_paint skips out quite a bit code such as the
backend swap buffer call.
Since we are interested in the highest fps possible, and it now goes through
to the backend swap buffer call we now do a setenv (CLUTTER_VBLANK, none, 0)
before calling clutter_init.
The Effects API and all related symbols have been superceded by
the newly added Animation API and clutter_actor_animate().
This commit removes the Effects implementation, the documentation
and the interactive test/example code.
* animation-improvements:
[docs] Add ClutterAnimatable to the API reference
Add license notice to ClutterAnimation files
[docs] Update the ClutterAnimation section
[animation] Extend ClutterAnimation support to all objects
[animation] Use ClutterAnimatable inside Animation
[animation] Add ClutterAnimatable
[animation] Allow registering custom progress function
[animation] Interval::compute_value should return a boolean
Animate ClutterColor properties
ClutterUnits should not be used interchangeably as, or with
ClutterFixed values. ClutterUnits should also not be assumed
to be integers.
This commit fixes the last few improper usages of ClutterUnit
values, and adds a CLUTTER_UNITS_FORMAT macro for safely printing
ClutterUnit values with printf().
Merge branch 'text-actor'
* text-actor: (108 commits)
Re-align ClutterText header file
[text] Fix cursor sizing
Comments and whitespace fixes to ClutterText
[docs] Add newly added :single-line-mode accessors
Update the ignore file
[tests] Add text field interactive test
[text] Add single-line-mode to ClutterText
[text] Fix the deletion actions
[text] Use cached length when possible
[tests] Add unit for the ClutterText:password-char property
[docs] Update the Text section
[text] Coalesce text visibility and password character
Allow localizations to change the text direction
Clean up the update_pango_context() function
Pass the PangoContext, not the MainContext
Revert the logic of the PangoContext check
Remove the binding pool entry from the list
Remove BindingPool::list_actions()
Add ClutterActor::create_pango_context()
Rename the PangoContext creation functions
...
Check that the contents of the Text actor are unaffected by the
:password-char property; that the accessors are correct; and finally
that the initial value for a newly constructed Text actor is valid.
Instead of including GL/gl.h directly it now includes cogl/cogl.h
instead which should include the right GL header.
Instead of using dlopen to specifically open libGL it now tries to use
dlsym with RTLD_NEXT. This requires defining _GNU_SOURCE on GNU
systems. If RTLD_NEXT is not available it will try passing NULL which
is unlikely to work but it will at least catch the case where it
returns the wrapper version of glGetString to prevent infinite
recursion.
This should hopefully make it work on OS X where the name of the
header and library are different (although this is currently
untested).
* units-rework:
[texture] Do not mix fixed point and units values
[tests] Fix the actor detection
[units] Do not use fixed point and units interchangeably
The API has been changed to take an explicit length for the number of
texture coordinates passed, and it's now documented that if there are
more layers to the current material than the number of texture coords
passed, then default coordinates will be generated for the other
layers.
cogl_material_rectangle should now handle the case where a single
sliced texture is supplied as a material layer by falling back to
cogl_texture_rectangle. We are nearly at the point that
cogl_texture_rectangle could be deprecated. A few issues remain
though, such as not considering waste in cogl_material_rectangle.
My previous work to provide muti-texturing support has been extended into
a CoglMaterial abstraction that adds control over the texture combine
functions (controlling how multiple texture layers are blended together),
the gl blend function (used for blending the final primitive with the
framebuffer), the alpha function (used to discard fragments based on
their alpha channel), describing attributes such as a diffuse, ambient and
specular color (for use with the standard OpenGL lighting model), and
per layer rotations. (utilizing the new CoglMatrix utility API)
For now the only way this abstraction is exposed is via a new
cogl_material_rectangle function, that is similar to cogl_texture_rectangle
but doesn't take a texture handle (the source material is pulled from
the context), and the array of texture coordinates is extended to be able
to supply coordinates for each layer.
Note: this function doesn't support sliced textures; supporting sliced
textures is a non trivial problem, considering the ability to rotate layers.
Note: cogl_material_rectangle, has quite a few workarounds, for a number of
other limitations within Cogl a.t.m.
Note: The GLES1/2 multi-texturing support has yet to be updated to use
the material abstraction.
This follows the convention of GtkLabel/GtkEntry in GTK+ and the old
ClutterEntry.
It makes it easier to use strlen/strcmp etc on the output, since we can
assume that it is always a string.
This commit also updates the test unit for ClutterText to verify that
the clutter_text_get_text() function also returns an empty string when
a ClutterText actor has been created.
When building out of tree the generated scripts for the unit tests
need to explicitly reference the original src dir to be able to find
test-launcher.sh, like this:
$(top_srcdir)/tests/conform/test-launcher.sh
Also test-launcher.sh now passes -m slow --verbose to gtester. Without
-m slow then the wrappers dont work for some of the timeline tests.
* cairo-texture:
[cairo-texture] Remove the construct only restriction on surface size
[cairo-texture] Silently discard 0x0 surfaces
Re-indent ClutterPath header
Add a test case for the new cairo path functions
Add clutter_path_to_cairo_path and clutter_path_add_cairo_path
Warn instead of returning in the IN_PAINT check
Small documentation fixes
Print a warning when creating a cairo_t while painting
Do not set the IN_PAINT flag inside the Stage paint
Set the IN_PAINT private flag
[docs] Add ClutterCairoTexture to the API reference
Add ClutterCairoTexture
Require Cairo as a Clutter dependency
Conflicts:
Fix merge conflict in clutter/clutter-path.h
A label is now displayed under the rectangle showing the current
gravity. The text for the gravity is taken from the GEnumClass. This
makes it easier to verify that the test is working correctly.
Currently, the conformance test suite creates symbolic links pointing
to a wrapper script that just parses the name used to invoke it and
calls the gtester with the correct path.
Unfortunately, this presents two issues:
- it does not really work on file systems that do not
support symbolic links
- it leaves behind the symbolic links, which cannot
be automatically cleaning by 'make clean'
Both can be solved by creating a small script that invokes the wrapper
one with the test unit path.
The Makefile will use test-conform to extract the unit test paths
and generate a list that will be iterated over to create the
executable name (using the "test-name" convention also used by the
interactive tests, instead of "test_name"); the executable is then
just a simple shell script that invokes the wrapper script passing
the unit test path on the command line. The wrapper script will
use the first argument to work correctly, so it could be simply
executed like:
./test-wrapper.sh /path/to/unit_test
Which is another improvement over the current implementation, where
the wrapper script does not work when invoked directly.
The gdouble value represents an interval along the path from 0.0 to
1.0. This makes more sense than using an alpha value because paths are
not directly related to ClutterAlphas and the rest of the Clutter API
tends to expose gdouble arguments.
The GTest report output allows the developer to know where exactly
a test unit failure happened. The test-text-cache unit makes it
very hard to pinpoint the exact failure location because it relies
on the output to be printed out - which is not the case when the
tests are run as part of a make check.
This commit makes each sub-test inside the unit fail exactly where
the check function fails, which makes it easier to know which sub-test
did actually fail.
Since commit c7c5cf9b ClutterCloneTexture causes an extra paint of the
source actor during the paint run of the cloned texture if the source
is not yet visible. When the stage is first shown it is redrawn
immediatly before it is mapped which means get_paint_visibility will
fail on the source actor so the inner paint will be run. The paint
guards were a global variable so they didn't cope with a second actor
being painted.
The breakage didn't occur until commit d510a4b0 because
get_paint_visibility was also broken.
The nodes of the test path have been reordered because Cairo coalesces
multiple move operations into a single move so the comparison would
fail if the two move nodes are consecutive.
The test-opacity interactive test is superceded by the equivalent
units inside the conformance test suite.
The test-entry interactive test is superceded by the test-text one.
ClutterText behaviour with regards to the paint opacity has been
changed by commit 07e19fff5ffa9617413fa6c3715914513fec3793.
We need to update the test suite for the paint opacity to reflect
that change as well.
The clutter_text_get_chars() function returns a section of the
contents of the Text actor, delimited by a start and an end position.
This commit adds the implementation for that function and a test
unit that guarantees the offset-to-bytes computations are correct.
