Commit Graph

117 Commits

Author SHA1 Message Date
Damien Leone
f3fa86b482 Add 30-bit color depth pixel formats X101010 and 2101010
30-bit color depth formats are defined by using value 13 in the least
significant nibble of the pixel format enumeration. This nibble
encodes bytes-per-pixel and byte alignment.

The _cogl_pixel_format_get_bytes_per_pixl() function is updated
accordingly to support these new formats.

https://bugzilla.gnome.org/show_bug.cgi?id=660188

edit: dropped the X101010 formats but also added 1010102 formats since
Cogl avoids exposing any padded formats and leaves it to applications to
consider the A component to be padding as needed. -- Robert Bragg

Reviewed-by: Robert Bragg <robert@linux.intel.com>
Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-20 23:12:45 +00:00
Robert Bragg
07e972505c Adds _cogl_pixel_format_is_endian_dependant api
This adds an internal utility function
_cogl_pixel_format_is_endian_dependant() that can query whether
accessing the components of a given format depends on the endianness of
the current host CPU or whether a pixel can be loaded as a word and
channels accessed using bit masking and shifting.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-20 23:12:44 +00:00
Robert Bragg
fbec2a5ad7 moves and renames _cogl_get_format_bpp
This moves _cogl_get_format_bpp from cogl-bitmap.c to cogl.c and renames
it to _cogl_pixel_format_get_bytes_per_pixel. This makes it clearer that
it doesn't return bits per pixel and makes the naming consistent with
other cogl api. The prototype has been moved to cogl-private.h since it
seems we should be aiming to get rid of cogl-internal.h at some point.

The patch also adds a simple gtk-doc comment since we might want to make
this api public.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-20 23:12:44 +00:00
Robert Bragg
ee940a3d0d Move all types/prototypes from cogl.h -> cogl[1]-context.h
So we can get to the point where cogl.h is merely an aggregation of
header includes for the 1.x api this moves all the function prototypes
and type definitions into a cogl-context.h and a new cogl1-context.h.

Ideally no code internally should ever need to include cogl.h as it just
represents the public facing header for accessing the 1.x api which
should only be used by Clutter.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-20 23:12:44 +00:00
Robert Bragg
7283e0a49c rework enabling of attributes, removing _cogl_enable()
This removes the limited caching of enabled attributes done by
_cogl_enable() and replaces it with a more generalized set of bitmasks
associated with the context that allow us to efficiently compare the set
of attribute locations that are currently enabled vs the new locations
that need enabling so we only have to inform OpenGL of the changes in
which locations are enabled/disabled.

This also adds a per-context hash table for mapping attribute names to
global name-state structs which includes a unique name-index for any
name as well as pre-validated information about builtin "cogl_"
attribute names including whether the attribute is normalized and what
texture unit a texture attribute corresponds too.

The name-state hash table means that cogl_attribute_new() now only needs
to validate names the first time they are seen.

CoglAttributes now reference a name-state structure instead of just the
attribute name, so now we can efficiently get the name-index for any
attribute and we can use that to index into a per-glsl-program cache
that maps name indices to real GL attribute locations so when we get
asked to draw a set of attributes we can very quickly determine what GL
attributes need to be setup and enabled. If we don't have a cached
location though we can still quickly access the string name so we can
query OpenGL.

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
ccde191191 framebuffer: Add CoglFramebuffer matrix stack methods
This adds cogl_framebuffer_ methods to update the modelview and
projection matrix stacks to replace functions like cogl_translate(),
cogl_rotate() and cogl_scale() etc.

This is part of the on-going effort to get rid of the global CoglContext
pointer since the existing methods don't take an explicit pointer to a
CoglContext. All the methods are now related to a context via the
framebuffer.

We added framebuffer methods instead of direct context methods because
the matrix stacks are per-framebuffer and as well as removing the global
CoglContext we would rather aim for a more direct state access API
design than, say, cairo or OpenGL, so we'd like to avoid needing the
cogl_push/pop_framebuffer(). We anticipate that Cogl will mostly be
consumed by middleware graphics layers such as toolkits or game engines
and feel that a more stateless model will avoid impedance mismatches if
higher levels want to expose a stateless model to their developers and
statefullness can still be added by higher levels if really desired.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-06 18:51:56 +00:00
Robert Bragg
b72f255c0a Start to reduce dependence on glib
Since we've had several developers from admirable projects say they
would like to use Cogl but would really prefer not to pull in
gobject,gmodule and glib as extra dependencies we are investigating if
we can get to the point where glib is only an optional dependency.
Actually we feel like we only make minimal use of glib anyway, so it may
well be quite straightforward to achieve this.

This adds a --disable-glib configure option that can be used to disable
features that depend on glib.

Actually --disable-glib doesn't strictly disable glib at this point
because it's more helpful if cogl continues to build as we make
incremental progress towards this.

The first use of glib that this patch tackles is the use of
g_return_val_if_fail and g_return_if_fail which have been replaced with
equivalent _COGL_RETURN_VAL_IF_FAIL and _COGL_RETURN_IF_FAIL macros.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-11-01 12:03:02 +00:00
Robert Bragg
426c8b8f41 features: Support more than 32 features!
Currently features are represented as bits in a 32bit mask so we
obviously can't have more than 32 features with that approach. The new
approach is to use the COGL_FLAGS_ macros which lets us handle bitmasks
without a size limit and we change the public api to accept individual
feature enums instead of a mask. This way there is no limit on the
number of features we can add to Cogl.

Instead of using cogl_features_available() there is a new
cogl_has_feature() function and for checking multiple features there is
cogl_has_features() which takes a zero terminated vararg list of
features.

In addition to being able to check for individual features this also
adds a way to query all the features currently available via
cogl_foreach_feature() which will call a callback for each feature.

Since the new functions take an explicit context pointer there is also
no longer any ambiguity over when users can first start to query
features.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-11-01 12:03:01 +00:00
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
Neil Roberts
dbff3a357e Make backface culling be part of the legacy state
This adds an internal function to set the backface culling state on a
pipeline. This includes properties to set the culling mode (front,
back or both) and also to set which face is considered the front
(COGL_WINDING_CLOCKWISE or COGL_WINDING_COUNTER_CLOCKWISE). The actual
front face flushed to GL depends on whether we are rendering to an
offscreen buffer or not. This means that when changing between on- and
off- screen framebuffers it now checks whether the last flushed
pipeline has backface culling enabled and forces a reflush of the cull
face state if so.

The backface culling is now set on a pipeline as part of the legacy
state. This is important because some code in Cogl assumes it can
flush a temporary pipeline to revert to a known state, but previously
this wouldn't disable backface culling so things such as flushing the
clip stack could get confused.

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-09-19 16:40:07 +01:00
Neil Roberts
2059ae3ac8 Add internal _cogl_push_source to optionally disable legacy state
Some code in Cogl such as when flushing a stencil clip assumes that it
can push a temporary simple pipeline to reset to a known state for
internal drawing operations. However this breaks down if the
application has set any legacy state because that is set globally so
it will also get applied to the internal pipeline.

_cogl_draw_attributes already had an internal flag to disable applying
the legacy state but I think this is quite awkward to use because not
all places that push a pipeline draw the attribute buffers directly so
it is difficult to pass the flag down through the layers.

Conceptually the legacy state is meant to be like a layer on top of
the purely pipeline-based state API so I think ideally we should have
an internal function to push the source without the applying the
legacy state. The legacy state can't be applied as the pipeline is
pushed because the global state can be modified even after it is
pushed. This patch adds a _cogl_push_source() function which takes an
extra boolean flag to mark whether to enable the legacy state. The
value of this flag is stored alongside the pipeline in the pipeline
stack. Another new internal function called
_cogl_get_enable_legacy_state queries whether the top entry in the
pipeline stack has legacy state enabled. cogl-primitives and the
vertex array drawing code now use this to determine whether to apply
the legacy state when drawing. The COGL_DRAW_SKIP_LEGACY_STATE flag is
now removed.

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-09-19 16:40:06 +01:00
Neil Roberts
c7969a33af cogl: Bind the locale dir for the Cogl domain
dgettext (which Cogl is using) doesn't work unless you first tell
gettext where the locale dir is for the library's domain. This just
adds the necessary calls into _cogl_init.

https://bugzilla.gnome.org/show_bug.cgi?id=658700

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-09-19 12:53:58 +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
2ac4002084 cogl: Add support for reading a cogl.conf config file
When cogl initializes we now check for a cogl/cogl.conf in any of the
system config dirs (determined using $XDG_CONFIG_DIRS on linux) we then
also check the user's config directory (determined using XDG_CONFIG_HOME
on linux) for a cogl/cogl.conf file. Options specified in the user
config file have priority over the system config options.

The config file has an .ini style syntax with a mandatory [global]
section and we currently understand 3 keynames: COGL_DEBUG, COGL_DRIVER
and COGL_RENDERER which have the same semantics as the corresponding
environment variables.

Options set using the environment variables have priority over options
set in the config files. To allow users to undo the enabling of debug
options in config files this patch also adds a check for COGL_NO_DEBUG
environment variable which will disable the specified options which may
have been enabled in config files.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-08-12 15:28:42 +01:00
Robert Bragg
89fd2edeb0 Flush the journal before changing the projection
Since the projection matrix isn't tracked in the journal and since our
software transform of vertices as we log into the journal doesn't
include the projective transform we need to make sure we flush all
primitives in the journal before ever changing the projection.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-08-02 12:05:37 +01:00
Neil Roberts
d259a87602 Don't use the 'NULL' GModule to resolve GL symbols
Previously, _cogl_get_proc_address had a fallback to resolve the
symbol using g_module_open(NULL) to get the symbol from anywhere in
the address space. The EGL backend ends up using this on some drivers
because eglGetProcAddress isn't meant to return a pointer for core
functions. This causes problems if something in the process is linking
against a different GL library, for example Cairo may be linking
against libGL itself. In this case it may end up resolving symbols
from the GL library even if GLES is being used.

This patch removes the fallback. The EGL version now has its own
fallback instead which passes the existing libgl_module from the
renderer to g_module_symbol so that it should only get symbols from
that library or its dependency chain. The GLX and WGL winsys only call
glXGetProcAddress and wglGetProcAddress. The stub winsys does however
continue using the global symbol lookup.

The internal _cogl_get_proc_address function has been renamed to
_cogl_renderer_get_proc_address because it needs a connected renderer
to work so it could be considered to be a renderer method. The pointer
to the renderer is passed down to the winsys backends so that it can
use the data attached to the renderer to get the module pointers.

https://bugzilla.gnome.org/show_bug.cgi?id=655412

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-07-27 16:10:02 +01:00
Robert Bragg
6f79eb8a5a Use MESA_pack_invert to avoid read_pixels flip
cogl_read_pixels returns image data in a top-down memory order, but
because OpenGL normally returns pixel data in a bottom-up order we
have to flip the data before returning it to the user. If the OpenGL
driver supports the GL_MESA_pack_invert extension though we can ask the
driver to return the data in a top-down order in the first place.

Signed-off-by: Neil Roberts <neil@linux.intel.com>
2011-07-13 19:06:19 +01:00
Neil Roberts
b2e735ff7f Dynamically load the GL or GLES library
The GL or GLES library is now dynamically loaded by the CoglRenderer
so that it can choose between GL, GLES1 and GLES2 at runtime. The
library is loaded by the renderer because it needs to be done before
calling eglInitialize. There is a new environment variable called
COGL_DRIVER to choose between gl, gles1 or gles2.

The #ifdefs for HAVE_COGL_GL, HAVE_COGL_GLES and HAVE_COGL_GLES2 have
been changed so that they don't assume the ifdefs are mutually
exclusive. They haven't been removed entirely so that it's possible to
compile the GLES backends without the the enums from the GL headers.

When using GLX the winsys additionally dynamically loads libGL because
that also contains the GLX API. It can't be linked in directly because
that would probably conflict with the GLES API if the EGL is
selected. When compiling with EGL support the library links directly
to libEGL because it doesn't contain any GL API so it shouldn't have
any conflicts.

When building for WGL or OSX Cogl still directly links against the GL
API so there is a #define in config.h so that Cogl won't try to dlopen
the library.

Cogl-pango previously had a #ifdef to detect when the GL backend is
used so that it can sneakily pass GL_QUADS to
cogl_vertex_buffer_draw. This is now changed so that it queries the
CoglContext for the backend. However to get this to work Cogl now
needs to export the _cogl_context_get_default symbol and cogl-pango
needs some extra -I flags to so that it can include
cogl-context-private.h
2011-07-11 12:57:38 +01:00
Neil Roberts
5f181973a6 Move the cogl texture driver functions to a vtable
The texture driver functions are now accessed through a vtable pointed
to by a struct in the CoglContext so that eventually it will be
possible to compile both the GL and GLES texture drivers into a single
binary and then select between them at runtime.
2011-07-08 15:35:51 +01:00
Neil Roberts
2b119b07da Use all core GL functions through indirect pointers
cogl-ext-functions.h now contains definitions for all of the core GL
and GLES functions that we would normally link to directly. All of the
code has changed to access them through the cogl context pointer. The
GE macro now takes an extra parameter to specify the context because
the macro itself needs to make GL calls but various points in the Cogl
source use different names for the context variable.
2011-07-08 15:35:46 +01:00
Robert Bragg
dcb033489e framebuffer: Add _get_XYZ_bits() functions
This exposes the previously internal only
_cogl_framebuffer_get_red/green/blue/alpha_bits() functions as 2.0
experimental API.

Signed-off-by: Neil Roberts <neil@linux.intel.com>
2011-07-04 15:31:50 +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
Robert Bragg
a1234ee8d1 Add internal _cogl_init() function
This adds a _cogl_init function for Cogl that we expect to be the first
thing called before anything else is done with Cogl. It's not a public
API so it's expected that all entry points for Cogl that might be the
first function used should call _cogl_init().

We currently call _cogl_init() in these functions:
  cogl_renderer_new
  cogl_display_new
  cogl_context_new
  cogl_android_set_native_window

_cogl_init() can be called multiple times, and only the first call has
any affect.

For example _cogl_init() gives us a place check and parse the COGL_DEBUG
environment variable.

Since we don't have any need to parse command line arguments (we can
always get user configuration options from the environment) our init
function doesn't require argc/argv pointers.

By saying up front that we aren't interested in command line arguments
that means we can avoid the mess that is GOption based library
initialization which is extremely fragile due to its lack of dependency
tracking between modules.

Signed-off-by: Neil Roberts <neil@linux.intel.com>
2011-06-30 14:33:11 +01:00
Robert Bragg
be15bf75e4 Add internal _cogl_get_proc_address
This adds an internal _cogl_get_proc_address that doesn't need a
CoglContext. This will enable us to check driver features earlier.
2011-06-01 20:44:41 +01:00
Robert Bragg
b380fed23d Make stub winsys into a proper winsys backend
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.
2011-06-01 20:44:41 +01:00
Robert Bragg
ce2da79440 Don't reference GL_STACK_OVERFLOW/UNDERFLOW for GLES
These symbols aren't available when building with GLES so only reference
them when building with OpenGL.
2011-05-05 14:46:02 +01:00
Robert Bragg
dc7383b714 Add a vtable of indirection to the winsys code
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.
2011-05-05 14:46:01 +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
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
Robert Bragg
fdbc741770 cogl: rename cogl-context.h cogl-context-private.h
Since we plan to add public cogl_context_* API we need to rename the
current cogl-context.h which contains private member details.
2011-04-11 15:18:12 +01:00
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
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
9b0fd92527 cogl: rename CoglVertexAttribute CoglAttribute
This is part of a broader cleanup of some of the experimental Cogl API.
One of the reasons for this particular rename is to reduce the verbosity
of using the API. Another reason is that CoglVertexArray is going to be
renamed CoglAttributeBuffer and we want to help emphasize the
relationship between CoglAttributes and CoglAttributeBuffers.
2011-01-21 16:24:14 +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
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
dc1f1949d0 Remove the GLES2 wrapper
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.
2010-12-13 17:29:14 +00:00
Neil Roberts
e38e9e0355 cogl-vertex-attribute: Use glVertexAttribPointer on GLES2
When the GLES2 wrapper is removed we can't use the fixed function API
such as glColorPointer to set the builtin attributes. Instead the GLSL
progend now maintains a cache of attribute locations that are queried
with glGetAttribLocation. The code that previously maintained a cache
of the enabled texture coord arrays has been modified to also cache
the enabled vertex attributes under GLES2. The vertex attribute API is
now the only place that is using this cache so it has been moved into
cogl-vertex-attribute.c
2010-12-13 17:28:29 +00:00
Neil Roberts
f8449582c8 Revert "cogl: Remove the generated array size for cogl_tex_coord_in"
This reverts commit 4cfe90bde2.

GLSL 1.00 on GLES doesn't support unsized arrays so the whole idea
can't work.

Conflicts:

	clutter/cogl/cogl/cogl-pipeline-glsl.c
2010-12-03 15:27:17 +00:00
Neil Roberts
6607306a2d cogl: Remove the generated array size for cogl_tex_coord_in
Under GLES2 we were defining the cogl_tex_coord_in varying as an array
with a size determined by the number of texture coordinate arrays
enabled whenever the program is used. This meant that we may have to
regenerate the shader with a different size if the shader is used with
more texture coord arrays later. However in OpenGL the equivalent
builtin varying gl_TexCoord is simply defined as:

varying vec4 gl_TexCoord[]; /* <-- no size */

GLSL is documented that if you declare an array with no size then you
can only access it with a constant index and the size of the array
will be determined by the highest index used. If you want to access it
with a non-constant expression you need to redeclare the array
yourself with a size.

We can replicate the same behaviour in our Cogl shaders by instead
declaring the cogl_tex_coord_in with no size. That way we don't have
to pass around the number of tex coord attributes enabled when we
flush a material. It also means that CoglShader can go back to
directly uploading the source string to GL when cogl_shader_source is
called so that we don't have to keep a copy of it around.

If the user wants to access cogl_tex_coord_in with a non-constant
index then they can simply redeclare the array themself. Hopefully
developers will expect to have to do this if they are accustomed to
the gl_TexCoord array.
2010-12-02 12:27:29 +00:00
Damien Lespiau
e905087e70 cogl: Revert "build: Remove unused variable"
Having ctx here produces a warning on GLES. However it's needed for Big
GL as we have at the top of the file:

 #ifdef HAVE_COGL_GL
 #define glClientActiveTexture ctx->drv.pf_glClientActiveTexture
 #endif

This reverts commit 27a3a2056a.
2010-11-30 16:39:00 +00:00
Damien Lespiau
5eb800656d build: Remove unused variable
and be 100% warning free again.
2010-11-30 14:40:38 +00:00
Neil Roberts
7474d320f6 cogl-context: Get rid of the features_cached member
The features_cached member of CoglContext is intended to mark when
we've calculated the features so that we know if they are ready in
cogl_get_features. However we always intialize the features while
creating the context so features_cached will never be FALSE so it's
not useful. We also had the odd behaviour that the COGL_DEBUG feature
overrides were only applied in the first call to
cogl_get_features. However there are other functions that use the
feature flags such as cogl_features_available that don't use this
function so in some cases the feature flags will be interpreted before
the overrides are applied. This patch makes it always initialize the
features and apply the overrides immediately while creating the
context. This fixes a problem with COGL_DEBUG=disable-arbfp where the
first material flushed is done before any call to cogl_get_features so
it may still use ARBfp.
2010-11-24 18:39:07 +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
8fd47276b7 cogl_read_pixels: Fix the format used in GLES2
When converting the data in cogl_read_pixels it was using bmp_format
instead of the format passed in to the function. bmp_format is the
same as the passed in format except that it always has the premult bit
set. Therefore the conversion would not handle premultiply correctly.

http://bugzilla.clutter-project.org/show_bug.cgi?id=2414
2010-11-24 15:56:35 +00:00
Neil Roberts
e41e5efac0 Add an internal _cogl_read_pixels_with_rowstride
This is the same as _cogl_read_pixels except that it takes a rowstride
parameter for the destination buffer. Under OpenGL setting the
rowstride this will end up calling GL_ROW_LENGTH so that the buffer
region can be directly written to. Under GLES GL_ROW_LENGTH is not
supported so it will use an intermediate buffer as it does if the
format is not GL_RGBA.

cogl_read_pixels now just calls the full version of the function with
the rowstride set to width*bpp.

http://bugzilla.clutter-project.org/show_bug.cgi?id=2414
2010-11-24 15:56:34 +00:00