If we have the GLX_SGI_video_sync extension then it's possible to always
keep track for the video sync counter each time we call glXSwapBuffers
or do a sub stage blit. This then allows us to avoid waiting before
issuing a blit if we can see that the counter has already progressed.
Also since we expect that glXCopySubBuffer is synchronized to the vblank
we don't need to use glFinish () in conjunction with the vblank wait
since the vblank wait's only purpose is to add a delay.
The GLX_SGI_video_sync spec explicitly says that it's only supported for
direct contexts so we don't setup up the function pointers if
glXIsDirect () returns GL_FALSE.
Neither glXCopySubBuffer or glBlitFramebuffer are integrated with the
swap interval of a framebuffer so that means when we do partial stage
updates (as Mutter does in response to window damage) then the blits
aren't throttled which means applications that throw lots of damage
events at the compositor can effectively cause Clutter to run flat out
taking up all the system resources issuing more blits than can even be
seen.
This patch now makes sure we use the GLX_SGI_video_sync or a
DRM_VBLANK_RELATIVE ioctl to throttle blits to the vblank frequency as
we do when using glXSwapBuffers.
Currently glXCopySubBufferMESA is used for sub stage redraws, but in case
a driver does not support GLX_MESA_copy_sub_buffer we fall back to redrawing
the complete stage which isn't really optimal.
So instead to directly fallback to complete redraws try using GL_EXT_framebuffer_blit
to do the BACK to FRONT buffer copies.
http://bugzilla.openedhand.com/show_bug.cgi?id=2128
At two places in cogl_wrap_prepare_for_draw it was trying to loop over
the texture units to flush some state. However it was retrieving the
texture unit pointer using w->active_texture_unit instead of the loop
index so it would end up with the wrong state.
Also in glEnableClientState it was using the active unit instead of
the client active unit.
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.
Store a back pointer of the layout manager inside the container using
the GObject instance data. This introduces a change in the implementation
of ClutterLayoutManager, though it's still binary compatible.
• 3 general fixes (typos, copy/paste),
• ignore cogl-object-private.h,
• cogl_fixed_atani() was in reality cogl_fixed_atan(), fixed in commit
43564f05.
• Fix the cogl-vector section: sections must have a </SECTION> tag at
the end. Also the cogl-vector section was added in the middle of the
cogl-buffer one. Let's shiffle it out and add that </SECTION> tag.
GCC can catch errors when it knows that a variadic function must be
ended with NULL. Let's use the glib macro encapsulating the GCC
attribute to clutter_animator_set() and clutter_state_set().
As with a351ff2af earlier, distributing headers generated at configure
time conflicts with out of tree builds as the distributed headers will
be included first instead of including the generated ones.
This provides a mechanism for associating private data with any
CoglObject. We expect Clutter will use this to associate weak materials
with normal materials.
Various headers are build in builddirs (clutter-marshal.h, mkenums
headers and cogl-define.h) so we need to add the corresponding include
paths for gtk-doc to build its scanner.
clutter-jon.h is generated at configure time, we should not distribute it.
This caused a build issue when compiling from a tarballs and out of tree
builds as we ended up with two clutter-json.h one in $(top_srcdir)/json
and the other in $(top_builddir)/json and picked up the wrong one
($(top_srcdir)/json is included first in the include search path).
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.
Sub-classes of ShaderEffect currently have to get the handle for the
Cogl shader and call cogl_shader_source(); this makes it awkward to
implement a ShaderEffect, and it exposes handles and Cogl API that we
might want to change in the future.
We should provide a ClutterShaderEffect method that allows to (safely)
set the shader source at the right time for sub-classes to use.
The OffscreenEffect should set up the off screen draw buffer so that it
has the same projection and modelview as if it where on screen; we
achieve that by setting up the viewport to be the same size of the stage
but with an initial offset given by the left-most vertex of the actor.
When we paint the texture attached to the FBO we then set up the
modelview matrix of the on screen draw buffer so that it's the same as
the stage one: this way, the texture will be painted in screen
coordinates and it will occupy the same area as the actor would have
had.
A simple, GLSL shader-based blur effect.
The blur shader is taken straight from the test-shader.c interactive
test case. It's a fairly clunky, inefficient and visually incorrect
implementation of a box blur, but it's all we have right now until I
figure out a way to do multi-pass shading with the current API.
The ShaderEffect class is an abstract base type for shader-based
effects. GLSL-based effects should be implemented by sub-classing
ShaderEffect and overriding ActorMeta::set_actor() to set the source
code of the shader, and Effect::pre_paint() to update the uniform
values, if any.
The ShaderEffect has a generic API for sub-classes to set the values
of the uniforms defined by their shaders, and it uses the shader
types we defined for ClutterShader, to avoid re-inventing the wheel
every time.
The OffscreenEffect class is meant to be used to implement Effect
sub-classes that create an offscreen framebuffer and redirect the
actor's paint sequence there. The OffscreenEffect is useful for
effects using fragment shaders.
Any shader-based effect being applied to an actor through an offscreen
buffer should be used before painting the resulting target material and
not for every actor. This means that doing:
pre_paint: cogl_program_use(program)
set up offscreen buffer
paint: [ actors ] → offscreen buffer → target material
post_paint: paint target material
cogl_program_use(null)
Is not correct. Unfortunately, we cannot really do:
post_paint: cogl_program_use(program)
paint target material
cogl_program_use(null)
Because the OffscreenEffect::post_paint() implementation also pops the
offscreen buffer and re-instates the previous framebuffer:
post_paint: cogl_program_use(program)
change frame buffer ← ouch!
paint target material
cogl_program_use(null)
One way to fix it is to allow using the shader right before painting
the target material - which means adding a new virtual inside the
OffscreenEffect class vtable in additions to the ones defined by the
parent Effect class.
The newly-added paint_target() virtual allows the correct sequence of
actions by adding an entry point for sub-classes to wrap the "paint
target material" operation with custom code, in order to implement the
case above correctly as:
post_paint: change frame buffer
cogl_program_use(program)
paint target material
cogl_program_use(null)
The added upside is that sub-classes of OffscreenEffect involving
shaders really just need to override the prepare() and paint_target()
virtuals, since the pre_paint() and post_paint() do all that's needed.
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.
When getting the relative modelview matrix we need to reset it to the
stage's initial state or, at least, initialize it to the identity
matrix, instead of assuming we have an empty stack.
This replaces the use of CoglHandle with strongly type CoglClipStack *
pointers instead. The only function not converted for now is
cogl_is_clip_stack which will be done in a later commit.
This replaces the use of CoglHandle with strongly type CoglBitmap *
pointers instead. The only function not converted for now is
cogl_is_bitmap which will be done in a later commit.
This replaces the use of CoglHandle with strongly type CoglPath *
pointers instead. The only function not converted for now is
cogl_is_path which will be done in a later commit.
This patch makes it so that only the backwards compatibility
COGL_HANDLE_DEFINE macro defines a _cogl_xyz_handle_new function. The
new COGL_OBJECT_DEFINE macro only defines a _cogl_xyz_object_new
function.
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.
While this is totally fine (0 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 in the pointer
context.
It seems that, in most case, it's more an overlook than a deliberate
choice to use FALSE/0 as NULL, eg. copying a _COGL_GET_CONTEXT (ctx, 0)
or a g_return_val_if_fail (cond, 0) from a function returning a
gboolean.
