This exposes experimental cogl_framebuffer APIs for getting and setting
a viewport without having to refer to the implicit CoglContext. It adds
the following experimental API:
cogl_framebuffer_set_viewport
cogl_framebuffer_get_viewport4fv
cogl_framebuffer_get_viewport_x
cogl_framebuffer_get_viewport_y
cogl_framebuffer_get_viewport_width
cogl_framebuffer_get_viewport_height
Signed-off-by: Neil Roberts <neil@linux.intel.com>
Instead of the stub winsys being a special case set of #ifdef'd code
used when COGL_HAS_FULL_WINSYS wasn't defined, the stub winsys now
implements a CoglWinsysVtable like all other winsys backends (it's just
that everything is a NOP). This way we can get rid of the
COGL_HAS_FULL_WINSYS define and also the stub winsys can be runtime
selected whereas before it was incompatible with all other winsys
backends.
This validates that the viewport width and height arguments are positive
values in _cogl_framebuffer_set_viewport. In addition, just before
calling glViewport we also assert that something else hasn't gone amiss
and that the internal viewport width/height values we track are still
positive before passing to glViewport which generates an error for
negative values.
With GLES 1, frame buffers are a optional extensions. We need to make
sure the pointer exist before calling the function and do that by just
checkout the corresponding feature.
When freeing a framebuffer stack it's possible to have entries with NULL
draw or read buffers so we should check that before calling
cogl_onscreen/offscreen_free. This fixes a crash with the wayland
backend when running conformance tests such as cogl-test-object which
never push a framebuffer.
Some of the virtual functions in CoglWinsysVtable only need to be
implemented for specific backends or when a specific feature is
advertised. This splits the vtable struct into two commented sections
marking which are optional and which are required. Wherever an
optional function is used there is now a g_return_if_fail to ensure
there is an implementation.
If a foreign xid has been set on a CoglOnscreen then
cogl_onscreen_x11_get_window_xid doesn't need to defer to the winsys to
get the underlying window xid. This also means it's possible to read
back the xid before the framebuffer is allocated which fixes a crash in
the x11-foreign example app.
This extends cogl_onscreen_x11_set_foreign_xid to take a callback to a
function that details the event mask the Cogl requires the application
to select on foreign windows. This is required because Cogl, for
example, needs to track size changes of a window and may also in the
future want other notifications such as map/unmap.
Most applications wont need to use the foreign xwindow apis, but those
that do are required to pass a valid callback and update the event mask
of their window according to Cogl's requirements.
This adds Cogl API to show and hide onscreen framebuffers. We don't want
to go too far down the road of abstracting window system APIs with Cogl
since that would be out of its scope but the previous idea that we would
automatically map framebuffers on allocation except for those made from
foreign windows wasn't good enough. The problem is that we don't want to
make Clutter always create stages from foreign windows but with the
automatic map semantics then Clutter doesn't get an opportunity to
select for all the events it requires before mapping. This meant that we
wouldn't be delivered a mouse enter event for windows mapped underneath
the cursor which would break Clutters handling of button press events.
So that we can dynamically select what winsys backend to use at runtime
we need to have some indirection to how code accesses the winsys instead
of simply calling _cogl_winsys* functions that would collide if we
wanted to compile more than one backend into Cogl.
It's generally useful to be able to query the width and height of a
framebuffer and we expect to need this in Clutter when we move the
eglnative backend code into Cogl since Clutter will need to read back
the fixed size of the framebuffer when realizing the stage.
This migrates all the GLX window system code down from the Clutter
backend code into a Cogl winsys. Moving OpenGL window system binding
code down from Clutter into Cogl is the biggest blocker to having Cogl
become a standalone 3D graphics library, so this is an important step in
that direction.
This gives us a way to clearly track the internal Cogl API that Clutter
depends on. The aim is to split Cogl out from Clutter into a standalone
3D graphics API and eventually we want to get rid of any private
interfaces for Clutter so its useful to have a handle on that task.
Actually it's not as bad as I was expecting though.
This renames the two internal functions _cogl_get_draw/read_buffer
as cogl_get_draw_framebuffer and _cogl_get_read_framebuffer. The
former is now also exposed as experimental API.
The long term goal with the Cogl API is that we will get rid of the
default global context. As a step towards this, this patch tracks a
reference back to the context in each CoglFramebuffer so in a lot of
cases we can avoid using the _COGL_GET_CONTEXT macro.
Recently _cogl_swap_buffers_notify was added (in 142b229c5c) so that
Cogl would be notified when Clutter performs a swap buffers request for
a given onscreen framebuffer. It was expected this would be required for
the recent cogl_read_pixel optimization that was implemented (ref
1bdb0e6e98) but in the end it wasn't used.
Since it wasn't used in the end this patch removes the API.
OpenGL < 4.0 only supports integer based viewports and internally we
have a mixture of code using floats and integers for viewports. This
patch switches all viewports throughout clutter and cogl to be
represented using floats considering that in the future we may want to
take advantage of floating point viewports with modern hardware/drivers.
This adds the _cogl_blit_framebuffer internal function which is a
wrapper around glBlitFramebuffer. The API is changed from the GL
version of the function to reflect the limitations provided by the
GL_ANGLE_framebuffer_blit extension (eg, no scaling or mirroring).
The current framebuffer is now internally separated so that there can
be a different draw and read buffer. This is required to use the
GL_EXT_framebuffer_blit extension. The current draw and read buffers
are stored as a pair in a single stack so that pushing the draw and
read buffer is done simultaneously with the new
_cogl_push_framebuffers internal function. Calling
cogl_pop_framebuffer will restore both the draw and read buffer to the
previous state. The public cogl_push_framebuffer function is layered
on top of the new function so that it just pushes the same buffer for
both drawing and reading.
When flushing the framebuffer state, the cogl_framebuffer_flush_state
function now tackes a pointer to both the draw and the read
buffer. Anywhere that was just flushing the state for the current
framebuffer with _cogl_get_framebuffer now needs to call both
_cogl_get_draw_buffer and _cogl_get_read_buffer.
When pushing a framebuffer it would previously push
COGL_INVALID_HANDLE to the top of the framebuffer stack so that when
it later calls cogl_set_framebuffer it will recognise that the
framebuffer is different and replace the top with the new
pointer. This isn't ideal because it breaks the code to flush the
journal because _cogl_framebuffer_flush_journal is called with the
value of the old pointer which is NULL. That function was checking for
a NULL pointer so it wouldn't actually flush. It also would mean that
if you pushed the same framebuffer twice we would end up dirtying
state unnecessarily. To fix this cogl_push_framebuffer now pushes a
reference to the current framebuffer instead.
After a dependent framebuffer is added to a framebuffer it was never
getting removed. Once the journal for a framebuffer is flushed we no
longer depend on any framebuffers so the list should be cleared. This
was causing leaks of offscreens and textures.
There is currently a problem with per-framebuffer journals in that it's
possible to create a framebuffer from a texture which then gets rendered
too but the framebuffer (and corresponding journal) can be freed before
the texture gets used to draw with.
Conceptually we want to make sure when freeing a framebuffer that - if
it is associated with a texture - we flush the journal as the last thing
before really freeing the framebuffer's meta data. Technically though
this is awkward to implement since the obvious mechanism for us to be
notified about the framebuffer's destruction (by setting some user data
internally with a callback) notifies when the framebuffer has a
ref-count of 0. This means we'd have to be careful what we do with the
framebuffer to consider e.g. recursive destruction; anything that would
set more user data on the framebuffer while it is being destroyed and
ensuring nothing else gets notified of the framebuffer's destruction
before the journal has been flushed.
For simplicity, for now, this patch provides another solution which is
to flush framebuffer journals whenever we switch away from a given
framebuffer via cogl_set_framebuffer or cogl_push/pop_framebuffer. The
disadvantage of this approach is that we can't batch all the geometry of
a scene that involves intermediate renders to offscreen framebufers.
Clutter is doing this more and more with applications that use the
ClutterEffect APIs so this is a shame. Hopefully this will only be a
stop-gap solution while we consider how to reliably support journal
logging across framebuffer changes.
The CoglDebugFlags are now stored in an array of unsigned ints rather
than a single variable. The flags are accessed using macros instead of
directly peeking at the cogl_debug_flags variable. The index values
are stored in the enum rather than the actual mask values so that the
enum doesn't need to be more than 32 bits wide. The hope is that the
code to determine the index into the array can be optimized out by the
compiler so it should have exactly the same performance as the old
code.
COGL_DEBUG=disable-fast-read-pixel can be used to disable the
optimization for reading a single pixel colour back by looking at the
geometry in the journal and not involving the GPU. With this disabled we
will always flush the journal, rendering to the framebuffer and then use
glReadPixels to get the result.
This adds a transparent optimization to cogl_read_pixels for when a
single pixel is being read back and it happens that all the geometry of
the current frame is still available in the framebuffer's associated
journal.
The intention is to indirectly optimize Clutter's render based picking
mechanism in such a way that the 99% of cases where scenes are comprised
of trivial quad primitives that can easily be intersected we can avoid
the latency of kicking a GPU render and blocking for the result when we
know we can calculate the result manually on the CPU probably faster
than we could even kick a render.
A nice property of this solution is that it maintains all the
flexibility of the render based picking provided by Clutter and it can
gracefully fall back to GPU rendering if actors are drawn using anything
more complex than a quad for their geometry.
It seems worth noting that there is a limitation to the extensibility of
this approach in that it can only optimize picking a against geometry
that passes through Cogl's journal which isn't something Clutter
directly controls. For now though this really doesn't matter since
basically all apps should end up hitting this fast-path. The current
idea to address this longer term would be a pick2 vfunc for ClutterActor
that can support geometry and render based input regions of actors and
move this optimization up into Clutter instead.
Note: currently we don't have a primitive count threshold to consider
that there could be scenes with enough geometry for us to compensate for
the cost of kicking a render and determine a result more efficiently by
utilizing the GPU. We don't currently expect this to be common though.
Note: in the future it could still be interesting to revive something
like the wip/async-pbo-picking branch to provide an asynchronous
read-pixels based optimization for Clutter picking in cases where more
complex input regions that necessitate rendering are in use or if we do
add a threshold for rendering as mentioned above.
This adds a stop-gap mechanism for Cogl to know when the window system
is requested to present the current backbuffer to the frontbuffer by
adding a _cogl_swap_buffers_notify function that backends are now
expected to call right after issuing the equivalent request to OpenGL
vie the platforms OpenGL binding layer. This (blindly) updates all the
backends to call this new function.
For now Cogl doesn't do anything with the notification but the intention
is to use it as part of a planned read-pixel optimization which will
need to reset some state at the start of each new frame.
Instead of having _cogl_get/set_clip stack which reference the global
CoglContext this instead makes those into CoglClipState method functions
named _cogl_clip_state_get/set_stack that take an explicit pointer to a
CoglClipState.
This also adds _cogl_framebuffer_get/set_clip_stack convenience
functions that avoid having to first get the ClipState from a
framebuffer then the stack from that - so we can maintain the
convenience of _cogl_get_clip_stack.
Instead of having a single journal per context, we now have a
CoglJournal object for each CoglFramebuffer. This means we now don't
have to flush the journal when switching/pushing/popping between
different framebuffers so for example a Clutter scene that involves some
ClutterEffect actors that transiently redirect to an FBO can still be
batched.
This also allows us to track state in the journal that relates to the
current frame of its associated framebuffer which we'll need for our
optimization for using the CPU to handle reading a single pixel back
from a framebuffer when we know the whole scene is currently comprised
of simple rectangles in a journal.
This moves the implementation of cogl_clear into cogl-framebuffer.c as
two new internal functions _cogl_framebuffer_clear and
_cogl_framebuffer_clear4f. It's not clear if this is what the API will
look like as we make more of the CoglFramebuffer API public due to the
limitations of using flags to identify buffers when framebuffers may
contain any number of ancillary buffers but conceptually it makes some
sense to tie the operation of clearing a color buffer to a framebuffer.
The short term intention is to enable tracking the current clear color
as a property of the framebuffer as part of an optimization for reading
back single pixels when the geometry is simple enough that we can
compute the result quickly on the CPU. (If the point doesn't intersect
any geometry we'll need to return the last clear color.)
The GLES2 wrapper is no longer needed because the shader generation is
done within the GLSL fragend and vertend and any functions that are
different for GLES2 are now guarded by #ifdefs.
Previously in cogl_read_pixels we assume the format of the framebuffer
is always premultiplied because that is the most likely format with
the default Cogl blend mode. However when the framebuffer is bound to
a texture we should be able to make a better guess at the format
because we know the texture keeps track of the premult status. This
patch adds an internal format member to CoglFramebuffer. For onscreen
framebuffers we still assume it is RGBA_8888_PRE but for offscreen to
textures we copy the texture format. cogl_read_pixels uses this to
determine whether the data returned by glReadPixels will be
premultiplied.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2414
This function is the same as cogl_offscreen_new_to_texture but it
takes a level parameter and a set of flags so that FBOs can be used to
render to higher mipmap levels and to disable the depth and stencil
buffers. cogl_offscreen_new_to_texture now just calls the new function
with the level set to zero. This function could be useful in a few
places in Cogl where we want to use FBOs as an implementation detail
such as when copying between textures.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2414
This adds a flag to avoid flushing the clip state when flushing the
framebuffer state. This will be used by the journal to manage its own
clip state flushing.
Previously we tracked whether the clip stack needs flushing as part of
the CoglClipState which is part of the CoglFramebuffer state. This is
a bit odd because most of the clipping state (such as the clip planes
and the scissor) are part of the GL context's state rather than the
framebuffer. We were marking the clip state on the framebuffer dirty
every time we change the framebuffer anyway so it seems to make more
sense to have the dirtiness be part of the global context.
Instead of a just a single boolean to record whether the state needs
flushing, the CoglContext now holds a reference to the clip stack that
was flushed. That way we can flush arbitrary stack states and if it
happens to be the same as the state already flushed then Cogl will do
nothing. This will be useful if we log the clip stack in the journal
because then we will need to flush unrelated clip stack states for
each batch.
This applies an API naming change that's been deliberated over for a
while now which is to rename CoglMaterial to CoglPipeline.
For now the new pipeline API is marked as experimental and public
headers continue to talk about materials not pipelines. The CoglMaterial
API is now maintained in terms of the cogl_pipeline API internally.
Currently this API is targeting Cogl 2.0 so we will have time to
integrate it properly with other upcoming Cogl 2.0 work.
The basic reasons for the rename are:
- That the term "material" implies to many people that they are
constrained to fragment processing; perhaps as some kind of high-level
texture abstraction.
- In Clutter they get exposed by ClutterTexture actors which may be
re-inforcing this misconception.
- When comparing how other frameworks use the term material, a material
sometimes describes a multi-pass fragment processing technique which
isn't the case in Cogl.
- In code, "CoglPipeline" will hopefully be a much more self documenting
summary of what these objects represent; a full GPU pipeline
configuration including, for example, vertex processing, fragment
processing and blending.
- When considering the API documentation story, at some point we need a
document introducing developers to how the "GPU pipeline" works so it
should become intuitive that CoglPipeline maps back to that
description of the GPU pipeline.
- This is consistent in terminology and concept to OpenGL 4's new
pipeline object which is a container for program objects.
Note: The cogl-material.[ch] files have been renamed to
cogl-material-compat.[ch] because otherwise git doesn't seem to treat
the change as a moving the old cogl-material.c->cogl-pipeline.c and so
we loose all our git-blame history.
There is GL_INVALID_ENUM error for GL_DEPTH_STENCIL when call
glRenderbufferStorage() with OpenGL ES backend. So enable this
only for OpenGL backend.
Signed-off-by: Robert Bragg <robert@linux.intel.com>
When try_creating_fbo fails it deletes any intermediate render buffers
that were created. However it doesn't clear the list so I think if it
failed a second time it would try to delete the render buffers
again. This could potentially cause problems if a subsequent fbo is
created because the destructor for the original might delete the
renderbuffers of the new fbo.
This adds a COGL_OBJECT_INTERNAL_DEFINE macro and friends that are the
same as COGL_OBJECT_DEFINE except that they prefix the cogl_is_*
function with an underscore so that it doesn't get exported in the
shared library.
Previously COGL_OBJECT_DEFINE would always define deprecated
cogl_$type_{ref,unref} functions even if the type is new or if the
type is entirely internal. An application would still find it
difficult to use these because they wouldn't be in the headers, but it
still looks bad that they are exported from the shared library. This
patch changes it so that the deprecated ref counting functions are
defined using a separate macro and only the types that have these
functions in the headers call this macro.
The place where we actually change the framebuffer is
_cogl_framebuffer_flush_state(), so if we changed to a new frame buffer
we need to initialize the color bits there.
http://bugzilla.openedhand.com/show_bug.cgi?id=2094
OpenGL 3.0 deprecated querying of the GL_{RED,GREEN,BLUE}_BITS
constants, and the FBO extension provides a mechanism to query for the
color buffer sizes which *should* work even with the default
framebuffer. Unfortunately, this doesn't seem to hold for Mesa - so we
just use this for the offscreen CoglFramebuffer type, and we fall back
to glGetIntegerv() for the onscreen one.
http://bugzilla.openedhand.com/show_bug.cgi?id=2094
