Commit Graph

53 Commits

Author SHA1 Message Date
Robert Bragg
7b5b0bef83 framebuffer: drop _ALLOCATE_FLAG_DEPTH24_STENCIL8
There are two extensions, GL_OES_packed_depth_stencil and
GL_EXT_packed_depth_stencil, that inform us that the hardware supports
packing the depth and stencil values together into one format.

The OES extension is the GLES equivalent of the EXT extension and the
two extensions provide the same enums with basically the same semantics,
except that the EXT extension is a lot more wordy due to a larger number
of features in the full OpenGL api and the OES extension has some
asymmetric limitations on when the GL_DEPTH_STENCIL and
GL_DEPTH24_STENCIL8 enums can be used as internal formats.

GL_OES_packed_depth_stencil doesn't allow the GL_DEPTH_STENCIL enum
to be passed to glRenderbufferStorage (GL_DEPTH24_STENCIL8 should be
used instead) and GL_OES_packed_depth_stencil doesn't allow
GL_DEPTH24_STENCIL8 to be passed as an internal format to glTexImage2D.

We had been handling the two extensions differently in Cogl by calling
try_creating_fbo with different flags depending on whether the OES or
EXT extension was available and passing GL_DEPTH_STENCIL to
glRenderbufferStorage when we have the EXT extension or
GL_DEPTH24_STENCIL8 with the OES extension.

To localize the code that deals with the differences between the
extensions this patch does away with the need for separate flags
so we now just have COGL_OFFSCREEN_ALLOCATE_FLAG_DEPTH_DEPTH_STENCIL and
right before calling glRenderbufferStorage we check which extension we
are using to decide whether to use the GL_DEPTH_STENCIL or
GL_DEPTH24_STENCIL8 enums.

(cherry picked from commit 88a05fac6609f88c0f46d9df2611d9fbaf159939)
2012-09-17 23:06:19 +01:00
Robert Bragg
010d16f647 Adds initial GLES2 integration support
This makes it possible to integrate existing GLES2 code with
applications using Cogl as the rendering api.

Currently all GLES2 usage is handled with separate GLES2 contexts to
ensure that GLES2 api usage doesn't interfere with Cogl's own use of
OpenGL[ES]. The api has been designed though so we can provide tighter
integration later.

The api would allow us to support GLES2 virtualized on top of an
OpenGL/GLX driver as well as GLES2 virtualized on the core rendering api
of Cogl itself. Virtualizing the GLES2 support on Cogl will allow us to
take advantage of Cogl debugging facilities as well as let us optimize
the cost of allocating multiple GLES2 contexts and switching between
them which can both be very expensive with many drivers.

As as a side effect of this patch Cogl can also now be used as a
portable window system binding API for GLES2 as an alternative to EGL.

Parts of this patch are based on work done by Tomeu Vizoso
<tomeu.vizoso@collabora.com> who did the first iteration of adding GLES2
API support to Cogl so that WebGL support could be added to
webkit-clutter.

This patch adds a very minimal cogl-gles2-context example that shows how
to create a gles2 context, clear the screen to a random color and also
draw a triangle with the cogl api.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 4bb6eff3dbd50d8fef7d6bdbed55c5aaa70036a8)
2012-08-06 14:27:42 +01:00
Neil Roberts
1d3d1732bd Fixes for building with --disable-gl
This fixes a few problems that occur when only using a GLES2 header.

• The use of GL_CLAMP_TO_BORDER and GL_MIRRORED_REPEAT were moved from
  cogl-pipelinelayer-state.h to cogl-sampler-cache-private.h but the
  corresponding defines were not.

• cogl-sampler-cache.c was using GL_TEXTURE_WRAP_R but this is only
  defined as GL_TEXTURE_WRAP_R_OES from the GLES2 header so it needs a
  #define.

• cogl-framebuffer-private.h uses GLuint but it does not include
  cogl-gl-header.h. It gets away with this when GLX support is enabled
  because the GL header would be included via glx.h.

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

(cherry picked from commit 9cdb87c864fc262c4b26c13963670d60d7c18058)
2012-08-06 14:27:41 +01:00
Robert Bragg
54735dec84 Switch use of primitive glib types to c99 equivalents
The coding style has for a long time said to avoid using redundant glib
data types such as gint or gchar etc because we feel that they make the
code look unnecessarily foreign to developers coming from outside of the
Gnome developer community.

Note: When we tried to find the historical rationale for the types we
just found that they were apparently only added for consistent syntax
highlighting which didn't seem that compelling.

Up until now we have been continuing to use some of the platform
specific type such as gint{8,16,32,64} and gsize but this patch switches
us over to using the standard c99 equivalents instead so we can further
ensure that our code looks familiar to the widest range of C developers
who might potentially contribute to Cogl.

So instead of using the gint{8,16,32,64} and guint{8,16,32,64} types this
switches all Cogl code to instead use the int{8,16,32,64}_t and
uint{8,16,32,64}_t c99 types instead.

Instead of gsize we now use size_t

For now we are not going to use the c99 _Bool type and instead we have
introduced a new CoglBool type to use instead of gboolean.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit 5967dad2400d32ca6319cef6cb572e81bf2c15f0)
2012-08-06 14:27:39 +01:00
Neil Roberts
cb146dc515 Add a workaround for slow read pixels on Mesa
Mesa before version 8.0.2 has a slow read pixels path that gets used
with the Intel driver where it converts all of the pixels into a
floating point representation and back even if the data is being read
into exactly the same format. There is however a faster path using the
blitter when reading into a PBO with BGRA format. It works out faster
to read into a PBO and then memcpy back out into the application's
buffer even though it adds an extra memcpy. This patch adds a
workaround in cogl_framebuffer_read_pixels_into_bitmap when it detects
this situation. In that case it will create a temporary CoglBitmap
using cogl_bitmap_new_with_size, read into it and then memcpy the data
back out.

The main impetus for this patch is that Gnome Shell has implemented
this workaround directly using GL calls but it seems like the kind of
thing that would sit better at the Cogl layer.

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2012-04-05 13:52:43 +01:00
Neil Roberts
10a38bb14f Add a public cogl_framebuffer_read_pixels_into_bitmap
This adds a public function to read pixels from a framebuffer into a
CoglBitmap. This replaces the internal function
_cogl_read_pixels_with_rowstride because a CoglBitmap contains a
rowstride so it can be used for the same purpose. A CoglBitmap already
has public API to make one that points to a CoglPixelBuffer so this
function can be used to read pixels into a PBO. It also avoids the
need to push the framebuffer on to the context's stack so it provides
a function which can be used in the 2.0 API after the stack is
removed.

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2012-03-05 18:16:10 +00:00
Robert Bragg
13c36fff0d offscreen: Replace use of CoglHandle with CoglOffscreen
This updates cogl_offscreen_new_to_texture to return a CoglOffscreen
pointer instead of a CoglHandle.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-21 12:38:10 +00:00
Robert Bragg
92c3063014 framebuffer: Add cogl_framebuffer draw methods
This adds cogl_framebuffer_ apis for drawing attributes and primitives
that replace corresponding apis that depend on the default CoglContext.
This is part of the on going effort to adapt the Cogl api so it no
longer depends on a global context variable.

All the new drawing functions also take an explicit pipeline argument
since we are also aiming to avoid being a stateful api like Cairo and
OpenGL. Being stateless makes it easier for orthogonal components to
share access to the GPU. Being stateless should also minimize any
impedance miss-match for those wanting to build higher level stateless
apis on top of Cogl.

Note: none of the legacy, global state options such as
cogl_set_depth_test_enabled(), cogl_set_backface_culling_enabled() or
cogl_program_use() are supported by these new drawing apis and if set
will simply be silently ignored.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-09 13:09:15 +00:00
Neil Roberts
d42f1873fc framebuffer: Flush the journal on destruction
Instead of flushing the journal whenever the current framebuffer on a
context is changed it is now flushed whenever the framebuffer is about
to be destroyed instead. To do this it implements a custom unref
function which detects when there is going to be exactly one reference
on the framebuffer and then flushes its journal. The journal now
always has a reference on the framebuffer whenever it is non-empty.
That means the unref will only cause a flush if the only thing keeping
the framebuffer alive is the entries in the journal.

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2012-01-27 17:23:03 +00:00
Robert Bragg
3161f1b0e6 template: Allow configuration of swap throttle
This adds cogl_onscreen_template_set_swap_throttled() api that allows
developers to specify their preference for swap buffer throttling
up-front as part of the onscreen template that is used to create a
CoglDisplay when initializing Cogl. This is desirable because some
platforms may not support configuring swap throttling on a per
framebuffer basis and also since applications often want to apply the
same policy to all onscreen framebuffers anyway.
2012-01-16 18:27:20 +00:00
Robert Bragg
2112af0bc5 framebuffer: deal with winding state like other state
We should not be deciding whether we need to really update the GL face
winding state at the point where a new framebuffer has been pushed, we
should be waiting until we have really been asked to flush some
framebuffer state otherwise we may do redundant work if multiple
framebuffers are pushed/popped before something is really drawn.

This integrates the face winding state tracking with the design we have
for handling most of the other framebuffer state so we benefit from the
optimizations for minimizing the cost of _cogl_framebuffer_flush_state()

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-06 18:51:57 +00:00
Robert Bragg
cf4b228fc0 framebuffer: track fb color mask like other fb state
We should not be deciding whether we need to really update the GL color
mask state at the point where a new framebuffer has been pushed, we
should be waiting until we have really been asked to flush some
framebuffer state otherwise we may do redundant work if multiple
framebuffers are pushed/popped before something is really drawn.

This integrates the color mask state tracking with the design we have
for handling most of the other framebuffer state so we benefit from the
optimizations for minimizing the cost of _cogl_framebuffer_flush_state()

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-06 18:51:57 +00:00
Robert Bragg
042dc7c8cd framebuffer: Optimize _cogl_framebuffer_flush_state()
Previously the cost of _cogl_framebuffer_state_flush() would always
scale by the total amount of state tracked by CoglFramebuffer even in
cases where we knew up-front that we only wanted to flush a subset of
the state or in cases where we requested to flush the same framebuffer
multiple times with no changes being made to the framebuffer.

We now track a set of state changed flags with each framebuffer and
track the current read/draw buffers as part of the CoglContext so that
we can quickly bail out when asked to flush the same framebuffer
multiple times with no changes.

_cogl_framebuffer_flush_state() now takes a mask of the state that we
want to flush and the implementation has been redesigned so that the
cost of checking what needs to be flushed and flushing those changes
now scales by how much state we actually plan to update.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-06 18:51:57 +00:00
Robert Bragg
6bb409e996 framebuffer: Add CoglFramebuffer clip stack methods
This adds CoglFramebuffer methods for accessing the clip stack. We plan
on making some optimizations to how framebuffer state is flushed which
will require us to track when a framebuffer's clip state has changed.

This api also ties in to the longer term goal of removing the need for a
default global CoglContext since these methods are all implicitly
related to a specific context via their framebuffer argument.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-06 18:51:56 +00:00
Robert Bragg
652c8c31cf avoid touching fb matrix stack directly
This ensures we don't touch a framebuffer's matrix stack directly if we
are also relying on _cogl_framebuffer_flush_state(). We want to get to
the point where we can set dirty flags against framebuffer state at the
point it changes but that means we can't allow direct access to the
matrix stack. _cogl_texture_draw_and_read() has now been changed so it
uses cogl_framebuffer_ methods to update the matrix stacks including
adding new internal _cogl_framebuffer_push/pop_projection() functions
that allow us to set transient projections.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-06 18:51:56 +00:00
Robert Bragg
1ee861a82c framebuffer: adds cogl_framebuffer_get_samples_per_pixel
It's useful to be able to query back the number of
point_samples_per_pixel that may have previously be chosen using
cogl_framebuffer_set_samples_per_pixel().

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-11-01 12:03:03 +00:00
Robert Bragg
79719347c8 framebuffer: split out CoglOnscreen code
This factors out the CoglOnscreen code from cogl-framebuffer.c so we now
have cogl-onscreen.c, cogl-onscreen.h and cogl-onscreen-private.h.
Notably some of the functions pulled out are currently namespaced as
cogl_framebuffer but we know we are planning on renaming them to be in
the cogl_onscreen namespace; such as cogl_framebuffer_swap_buffers().

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-11-01 12:03:02 +00:00
Robert Bragg
abbd28f484 make COGL_FEATURE_OFFSCREEN_BLIT a private feature
Cogl doesn't expose public api for blitting between framebuffers so it
doesn't make much sense to have this feature as part of the public api
currently. We can't break the api by removing the enum but at least we
no longer ever set the feature flag.

We now have a replacement private feature flag
COGL_PRIVATE_FEATURE_OFFSCREEN_BLIT which cogl now checks for
internally.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-11-01 12:03:00 +00:00
Robert Bragg
dd7b16faf2 offscreen: Adds support for offscreen multisampling
This adds support for multisample rendering to offscreen framebuffers.
After an offscreen framebuffer is first instantiated using
cogl_offscreen_new_to_texture() it is then possible to use
cogl_framebuffer_set_samples_per_pixel() to request multisampling before
the framebuffer is allocated. This also adds
cogl_framebuffer_resolve_samples() for explicitly resolving point
samples into pixels. Even though we currently only support the
IMG_multisampled_render_to_texture extension which doesn't require an
explicit resolve, the plan is to also support the
EXT_framebuffer_multisample extension which uses the framebuffer_blit
extension to issue an explicit resolve.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-10-28 19:10:16 +01:00
Robert Bragg
a74c81ada3 onscreen: Support multisample based onscreen rendering
This adds support for multisample based rendering of onscreen windows
whereby multiple point samples per pixel can be requested and if the
hardware supports that it results in reduced aliasing (especially
considering the jagged edges of polygons)

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-10-28 19:10:16 +01:00
Robert Bragg
98e5a9c777 Rework how we search for winsys configs
When creating new onscreen framebuffers we need to take the
configuration in cogl terms and translate that into a configuration
applicable to any given winsys, e.g. an EGLConfig or a GLXFBConfig
or a PIXELFORMATDESCRIPTOR.

Also when we first create a context we typically have to do a very
similar thing because most OpenGL winsys APIs also associate a
framebuffer config with the context and all future configs need to be
compatible with that.

This patch introduces an internal CoglFramebufferConfig to wrap up some
of the configuration parameters that are common to CoglOnscreenTemplate
and to CoglFramebuffer so we aim to re-use code when dealing with the
above two problems.

This patch also aims to rework the winsys code so it can be more
naturally extended as we start adding more configureability to how
onscreen framebuffers are created.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-10-28 19:10:16 +01:00
Robert Bragg
4c3dadd35e Add a strong CoglTexture type to replace CoglHandle
As part of the on going, incremental effort to purge the non type safe
CoglHandle type from the Cogl API this patch tackles most of the
CoglHandle uses relating to textures.

We'd postponed making this change for quite a while because we wanted to
have a clearer understanding of how we wanted to evolve the texture APIs
towards Cogl 2.0 before exposing type safety here which would be
difficult to change later since it would imply breaking APIs.

The basic idea that we are steering towards now is that CoglTexture
can be considered to be the most primitive interface we have for any
object representing a texture. The texture interface would provide
roughly these methods:

  cogl_texture_get_width
  cogl_texture_get_height
  cogl_texture_can_repeat
  cogl_texture_can_mipmap
  cogl_texture_generate_mipmap;
  cogl_texture_get_format
  cogl_texture_set_region
  cogl_texture_get_region

Besides the texture interface we will then start to expose types
corresponding to specific texture types: CoglTexture2D,
CoglTexture3D, CoglTexture2DSliced, CoglSubTexture, CoglAtlasTexture and
CoglTexturePixmapX11.

We will then also expose an interface for the high-level texture types
we have (such as CoglTexture2DSlice, CoglSubTexture and
CoglAtlasTexture) called CoglMetaTexture. CoglMetaTexture is an
additional interface that lets you iterate a virtual region of a meta
texture and get mappings of primitive textures to sub-regions of that
virtual region. Internally we already have this kind of abstraction for
dealing with sliced texture, sub-textures and atlas textures in a
consistent way, so this will just make that abstraction public. The aim
here is to clarify that there is a difference between primitive textures
(CoglTexture2D/3D) and some of the other high-level textures, and also
enable developers to implement primitives that can support meta textures
since they can only be used with the cogl_rectangle API currently.

The thing that's not so clean-cut with this are the texture constructors
we have currently; such as cogl_texture_new_from_file which no longer
make sense when CoglTexture is considered to be an interface.  These
will basically just become convenient factory functions and it's just a
bit unusual that they are within the cogl_texture namespace.  It's worth
noting here that all the texture type APIs will also have their own type
specific constructors so these functions will only be used for the
convenience of being able to create a texture without really wanting to
know the details of what type of texture you need.  Longer term for 2.0
we may come up with replacement names for these factory functions or the
other thing we are considering is designing some asynchronous factory
functions instead since it's so often detrimental to application
performance to be blocked waiting for a texture to be uploaded to the
GPU.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-09-21 15:27:03 +01:00
Robert Bragg
a3ad808f57 framebuffer: Make framebuffer_clear APIs public experimental
This makes cogl_framebuffer_clear and cogl_framebuffer_clear4f public as
experimental API. Since these functions take explicit framebuffer
pointers you don't need to push/pop a framebuffer just to clear it. Also
these functions are implicitly tied to a specific CoglContext via the
framebuffer pointer unlike cogl_clear.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-08-12 15:28:43 +01:00
Robert Bragg
f7b1bab1ad framebuffer: don't reference default fb in _clear apis
Some of the functions we were calling in cogl_framebuffer_clear[4f] were
referring to the current framebuffer, which would result in a crash
if nothing had been pushed before trying to explicitly clear a given
framebuffer.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-08-12 15:28:43 +01:00
Robert Bragg
8b34a39319 Adds ColorMask support to Cogl
This adds CoglPipeline and CoglFramebuffer support for setting a color
mask which is a bit mask defining which color channels should be written
to the current framebuffer.

The final color mask is the intersection of the framebuffer color mask
and the pipeline color mask. The framebuffer mask affects all rendering
to the framebuffer while the pipeline masks can be used to affect
individual primitives.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-07-19 19:27:09 +01:00
Robert Bragg
3ed8c8d0ba framebuffer: Add dither_enabled getter/setters
This adds a getter and setter for requesting dithering to be enabled.

Dithering is a hardware dependent technique to increase the visible
color resolution beyond what the underlying hardware supports by playing
tricks with the colors placed into the framebuffer to give the illusion
of other colors. (For example this can be compared to half-toning used
by some news papers to show varying levels of grey even though their may
only be black and white are available).

The results of enabling dithering are platform dependent and may have no
effect.

Signed-off-by: Neil Roberts <neil@linux.intel.com>
2011-07-13 19:06:19 +01:00
Robert Bragg
c4eb869bd7 framebuffer: expose viewport getters/setters
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>
2011-06-30 14:33:11 +01:00
Neil Roberts
6788c80342 Add a WGL winsys
This adds a full winsys to handle WGL and Win32.
2011-05-10 17:58:41 +01:00
Robert Bragg
6c23f27801 Adds a way for Cogl to control event_mask of foreign wins
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.
2011-05-05 15:05:42 +01:00
Robert Bragg
2bbb0d895b Make cogl_framebuffer_get_width/height experimental public API
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.
2011-04-11 17:54:36 +01:00
Robert Bragg
d40cdfa3e1 Moves all GLX code down from Clutter to Cogl
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.
2011-04-11 17:54:36 +01:00
Robert Bragg
9f19244971 Add temporary cogl-clutter.h to aid splitting out Cogl
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.
2011-04-11 17:54:35 +01:00
Robert Bragg
0b45110302 framebuffer: expose experimental cogl_get_draw_framebuffer
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.
2011-04-11 15:28:53 +01:00
Robert Bragg
7fc6613fe9 Remove unused _cogl_swap_buffers_notify
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.
2011-04-11 15:26:25 +01:00
Jasper St. Pierre
30fa4e1a20 cogl-clip-state: Adapt to experimental cogl2 API.
The current clip state implementation couldn't be used in
conjunction with the CoglPath experimental API.

http://bugzilla.clutter-project.org/show_bug.cgi?id=2594

Signed-off-by: Neil Roberts <neil@linux.intel.com>
2011-03-10 13:05:43 +00:00
Robert Bragg
bc372d2734 viewport: consistently use floats for viewports
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.
2011-03-07 13:26:19 +00:00
Neil Roberts
9d242b62a9 cogl-framebuffer: Add _cogl_blit_framebuffer
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).
2011-02-15 12:10:54 +00:00
Neil Roberts
a067e7a16b cogl-framebuffer: Separate the draw and read buffer
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.
2011-02-15 12:10:54 +00:00
Robert Bragg
a8d6c3f686 cogl: Implements a software only read-pixel fast-path
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.
2011-01-21 16:18:11 +00:00
Robert Bragg
60fd6ab708 cogl: Adds _cogl_swap_buffers_notify for clutter backends
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.
2011-01-21 16:18:10 +00:00
Robert Bragg
e1563436b1 clip: rename get_clip_stack + add framebuffer_get_stack
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.
2011-01-21 16:18:10 +00:00
Robert Bragg
1a5a4df326 journal: Support per-framebuffer journals
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.
2011-01-21 16:18:10 +00:00
Robert Bragg
a4e50b5ea5 framebuffer: Move clear code to cogl-framebuffer.c
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.)
2011-01-21 16:18:09 +00:00
Neil Roberts
47ccbf472e cogl-framebuffer: Try to track format of the framebuffer
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
2010-11-24 15:56:35 +00:00
Neil Roberts
05d8cc1223 Add an internal _cogl_offscreen_new_to_texture_full function
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
2010-11-24 15:56:34 +00:00
Neil Roberts
6cf01ff0f4 cogl-framebuffer: Add a flag to skip flushing the clip state
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.
2010-11-04 18:10:09 +00:00
Robert Bragg
0c3354acba framebuffer: Replace CoglHandle with CoglFramebuffer *
One more object converted to stop using CoglHandle re:a8c8cbee513
2010-07-07 14:41:54 +01:00
Emmanuele Bassi
676c8a5fd4 Implement accessors for the color bits in a framebuffer
Instead of using cogl_get_bitmasks() to query the GL machinery for the
size of the color bits, we should store the values inside the
CoglFramebuffer object and query them the first time we set the framebuffer
as the current one.

Currently, cogl_get_bitmasks() is re-implemented in terms of
cogl_framebuffer_get_*_bits(). As soon as we are able to expose the
CoglOnscreen framebuffer object in the public API we'll be able to
deprecate cogl_get_bitmasks() altogether.

http://bugzilla.openedhand.com/show_bug.cgi?id=2094
2010-05-05 12:25:16 +01:00
Neil Roberts
f6f375cb36 Separate out CoglClipStackState from cogl-clip-stack.c
CoglClipStackState has now been renamed to CoglClipState and is moved
to a separate file. CoglClipStack now just maintains a stack and
doesn't worry about the rest of the state. CoglClipStack sill contains
the code to flush the stack to GL.
2010-04-15 14:51:00 +01:00
Emmanuele Bassi
72f4ddf532 Remove mentions of the FSF address
Since using addresses that might change is something that finally
the FSF acknowledge as a plausible scenario (after changing address
twice), the license blurb in the source files should use the URI
for getting the license in case the library did not come with it.

Not that URIs cannot possibly change, but at least it's easier to
set up a redirection at the same place.

As a side note: this commit closes the oldes bug in Clutter's bug
report tool.

http://bugzilla.openedhand.com/show_bug.cgi?id=521
2010-03-01 12:56:10 +00:00