The Intel driver currently has an optimisation when calling
glReadPixels into a PBO so that it will use a blit instead of the Mesa
fallback path. However this only works if the GL_PACK_ALIGNMENT is
exactly 1, even if this would be equivalent to a higher alignment
value because the bpp*width is already aligned. To make it more likely
to hit this fast path, we now detect this situation and explicitly use
an alignment of 1. To make this work the texture driver needs to be
passed down the bpp*width as well as the rowstride when configuring
the alignment.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Instead of having a series of if-statements this adds an inline
function to calculate the alignment directly using ffs which is
probably slightly faster. Admittedly this is a pointless
micro-optimisation but I think it makes the code looks a bit neater
anyway.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Two of the meta texture constructors which take a flags parameter were
ignoring the COGL_TEXTURE_NO_AUTO_MIPMAP flag when creating an
underlying CoglTexture2D. These have now been fixed to call
cogl_primitive_texture_set_auto_mipmap after constructing the texture.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
This adds public constructors which take a CoglBitmap to all primitive
texture types. This constructor should be considered the canonical
constructor for initializing the texture with data because it should
be possible to wrap any type of data in a CoglBitmap. Having at least
this single constructor avoids the need to have an explosion of
constructors such as new_from_data, new_from_pixel_buffer and
new_from_file etc.
The already available internal bitmap constructor for CoglTexture2D
has had its flags parameter removed under the assumption that flags do
not make sense for primitive textures. The meta constructor
cogl_texture_new_from_bitmap now just explicitly calls set_auto_mipmap
after constructing the texture depending on the value of the
COGL_TEXTURE_NO_AUTO_MIPMAP flag.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
get_texture_bits_via_offscreen does not check the return value of
cogl_framebuffer_read_pixels_into_bitmap which results into never
using the fallback path texture_get_cb.
cogl_framebuffer_read_pixels_into_bitmap does not check whether the framebuffer
is properly allocated though; so fix that as well.
https://bugzilla.gnome.org/show_bug.cgi?id=673137
Reviewed-by: Neil Roberts <neil@linux.intel.com>
This extension allows an application to upload data in BGRA format. We
can use this to avoid a conversion in Cogl whenever it is given BGRA
data. This is quite useful when uploading data generated by Cairo
because at least on little-endian architectures that ends up as BGRA.
The patch just makes the pixel_format_to_gl implementation return
GL_BGRA_EXT for the data format and internal format whenever
COGL_PIXEL_FORMAT_BGRA_8888{,_PRE} is used.
A small caveat with this patch is that once a texture is created as
GL_BGRA, when later using glTexSubImage2D to update the texture it
must always be given data as GL_BGRA. Currently this just works out
because we store the internal format of a texture as a CoglPixelFormat
and we already swizzle the data if it does not match exactly on GLES.
However if we later switch to using a different enum for internal
formats then we might lose the ability to store the component ordering
so we'll have to think of another way to do this.
Cogl already had a vtable for the texture driver. This ended up being
used for some things that are not strictly related to texturing such
as converting between pixel formats and GL enums. Some other functions
that are driver dependent such as updating the features were not
indirected through a vtable but instead switched directly by looking
at the ctx->driver enum value. This patch normalises to the two uses
by adding a separate vtable for driver functions not related to
texturing and moves the pixel format conversion functions to it from
the texture driver vtable. It also adds a context parameter to all of
the functions in the new driver vtable so that they won't have to rely
on the global context.
This creates a CoglBitmap which points into an existing buffer in
system memory. That way it can be used to create a texture or to read
pixel data into. The function replaces the existing internal function
_cogl_bitmap_new_from_data but removes the destroy notify call back.
If the application wants notification of destruction it can just use
the cogl_object_set_user_data function as normal. Internally there is
now a convenience function to create a bitmap for system memory and
automatically free the buffer using that mechanism.
The name of the function is inspired by
cairo_image_surface_create_for_data which has similar semantics.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
On GLES, when reading texture data back it may need to allocate a
temporary CoglBitmap if the requested format is not supported by the
driver. Previously it would then copy this temporary buffer back into
the user's buffer by calling _cogl_bitmap_convert which would allocate
a second temporary buffer. It would then copy that data into the
user's buffer. This patch changes it to create a CoglBitmap which
points to the user's data and then convert directly into that buffer
using the new _cogl_bitmap_convert_into_bitmap.
This also fixes a small leak where target_bmp would not get freed if
the target format and the closest supported format do match.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
The idea is that CoglPixelBuffer should just be a buffer that can be
used for pixel data and it has no idea about the details of any images
that are stored in it. This is analogous to CoglAttributeBuffer which
itself does not have any information about the attributes. When you
want to use a pixel buffer you should create a CoglBitmap which points
to a region of the attribute buffer and provides the extra needed
information such as the width, height and format. That way it is also
possible to use a single CoglPixelBuffer with multiple bitmaps.
The changes that are made are:
• cogl_pixel_buffer_new_with_size has been removed and in its place is
cogl_bitmap_new_with_size. This will create a pixel buffer at the
right size and rowstride for the given width/height/format and
immediately create a single CoglBitmap to point into it. The old
function had an out-parameter for the stride of the image but with
the new API this should be queriable from the bitmap (although there
is no function for this yet).
• There is now a public cogl_pixel_buffer_new constructor. This takes
a size in bytes and data pointer similarly to
cogl_attribute_buffer_new.
• cogl_texture_new_from_buffer has been removed. If you want to create
a texture from a pixel buffer you should wrap it up in a bitmap
first. There is already API to create a texture from a bitmap.
This patch also does a bit of header juggling because cogl-context.h
was including cogl-texture.h and cogl-framebuffer.h which were causing
some circular dependencies when cogl-bitmap.h includes cogl-context.h.
These weren't actually needed in cogl-context.h itself but a few other
headers were relying on them being included so this adds the #includes
where necessary.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
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>
If we are going to unpack the data into a known format anyway we might
as well do the premult conversion instead of delaying it to do
in-place. This helps because not all formats with alpha channels are
handled by the in-place premult conversion code. This removes the
_cogl_bitmap_convert_format_and_premult function so that now
_cogl_bitmap_convert is a completely general purpose function that can
convert from anything to anything. _cogl_bitmap_convert now includes a
fast path for when the base formats are the same and the premult
conversion can be handled with the in-place code so that we don't need
to unpack and can just copy the bitmap instead.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
There are a few places in Cogl that try to set the premult bit on a
pixel format depending on whether it has an alpha channel. However
this breaks if the pixel format is alpha-only because premultiplying
data without any RGB components doesn't make any sense. This adds an
internal macro to check for cases where we should add the premult bit
called COGL_PIXEL_FORMAT_CAN_HAVE_PREMULT. This now gets used in all
places that previously just checking for COGL_A_BIT.
https://bugzilla.gnome.org/show_bug.cgi?id=671016
Reviewed-by: Robert Bragg <robert@linux.intel.com>
cogl_texture_get_data uses find_best_gl_get_data_format from the
texture driver which returns the closest format to use for retrieving
pixel data given an intended format. However this function doesn't
know about the texture we are reading data from so it doesn't know
that the data we will actually receive will have the same premult
status as the texture's format. With the GL driver, this function ends
up returning exactly the same format as passed in which means it will
never do a premult conversion. Under GLES it always returns
COGL_PIXEL_FORMAT_RGBA_8888 so it will always make the data unpremult
even if the final requested format is premultiplied.
This patch fixes it so that it copies the premult status of the
closest_format from the format of the underlying texture. That way it
will later convert or not depending on the requested target format.
Note this patch breaks test-sub-texture with the GL driver because
that is incorrectly trying to read the texture data back as RGBA_8888
even though it depends on it not doing a premult conversion. The test
was already broken with GLES2 and remains broken.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
As we move towards Cogl 2.0 we are aiming to remove the need for a
default global CoglContext and so everything should be explicitly
related to a context somehow. CoglPipelines are top level objects and
so this patch adds a context argument to cogl_pipeline_new().
Reviewed-by: Neil Roberts <neil@linux.intel.com>
The cogl.h header is meant to be the public header for including the 1.x
api used by Clutter so we should stop using that as a convenient way to
include all likely prototypes and typedefs. Actually we already do a
good job of listing the specific headers we depend on in each of the .c
files we have so mostly this patch just strip out the redundant
includes for cogl.h with a few fixups where that broke the build.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
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>
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>
This adds an internal function to get the type of the underlying
hardware texture for any CoglTexture. It can return one of three
values to represent 2D textures, 3D textures or rectangle textures.
The idea is that this can be used as a replacement for
cogl_texture_get_gl_texture when only the target is required to make
it a bit less GL-centric. The implementation adds a new virtual
function which all of the texture backends now implement.
The enum is in a public header because a later patch will want to use
it from the CoglPipeline API. We may want to consider making the
function public too later.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Both the cogl_texture_get_data and _cogl_blit_begin implementations
will internally try to create an FBO for a texture and have fallbacks
if the FBO fails. However neither of them were catching errors when
allocating the framebuffer so the fallback wouldn't work properly.
This patch just adds an explicit call to cogl_framebuffer_allocate for
these uses and causes it to use the next fallback if it fails.
Based on a patch by Adel Gadllah.
https://bugzilla.gnome.org/show_bug.cgi?id=669368
Reviewed-by: Robert Bragg <robert@linux.intel.com>
When calling cogl_texture_get_data we need to ensure that any
framebuffers rendering to the texture have flushed their journals.
https://bugzilla.gnome.org/show_bug.cgi?id=668913
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Unlike in GObject the type number for a CoglObject is entirely an
internal implementation detail so there is no need to make a GQuark to
make it safe to export out of the library. Instead we can just
directly use a fixed pointer address as the identifier for the type.
This patch makes it use the address of the class struct of the
identifier. This should make it faster to do type checks because it
does not need to call a function every time it wants to get the type
number.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
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>
This improves the documentation for cogl_texture_set_region() and
cogl_texture_set_region_from_bitmap() to explain that the region can't
be larger than the source data and also adds runtime assertions that
such a request isn't made.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
This exposes cogl_sub_texture_new() and cogl_is_sub_texture() as
experimental public API. Previously sub-textures were only exposed via
cogl_texture_new_from_sub_texture() so there wasn't a corresponding
CoglSubTexture type. A CoglSubTexture is a high-level texture defined as
a sub-region of some other parent texture. CoglSubTextures are high
level textures that implement the CoglMetaTexture interface which can
be used to manually handle texture repeating.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
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>
CoglMetaTexture is an interface for dealing with high level textures
that may be comprised of one or more low-level textures internally. The
interface allows the development of primitive drawing APIs that can draw
with high-level textures (such as atlas textures) even though the
GPU doesn't natively understand these texture types.
There is currently just one function that's part of this interface:
cogl_meta_texture_foreach_in_region() which allows an application to
resolve the internal, low-level textures of a high-level texture.
cogl_rectangle() uses this API for example so that it can easily emulate
the _REPEAT wrap mode for textures that the hardware can't natively
handle repeating of.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
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>
This make the CoglTexture2DSliced type public and adds
cogl_texture_2d_sliced_new_with_size() as an experimental API that can
be used to construct a sliced texture without any initial data.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
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>
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>
Instead of calling _cogl_texutre_prepare_for_upload in
cogl_texture_set_region_from_bitmap the call is now deferred to the
implementation of the virtual for set_region. This is needed if the
texture backend is using a different format for the actual GL texture
than what is reported by cogl_texture_get_format. This happens for
example with atlas textures which report the original internal format
specified when the texture was created but actually always store the
data in an RGBA texture.
Also when creating an atlas texture from a bitmap it was preparing the
bitmap to be uploaded to the original format instead of the format of
the actual texture used for the atlas. Then it was using
cogl_texture_set_region_from_bitmap to upload the 5 pieces to make the
copies of the edge pixels. This would end up converting the image to
the actual format 5 times. The atlas textures have now been changed to
prepare the bitmap for the right format.
https://bugzilla.gnome.org/show_bug.cgi?id=657840
Reviewed-by: Robert Bragg <robert@linux.intel.com>
This exposes 2 experimental functions that make it possible to upload a
subregion of a texture from a CoglBuffer by first wrapping the buffer as
a CoglBitmap and then allowing uploading of a subregion from a
CoglBitmap. The new functions are:
cogl_bitmap_new_from_buffer() and
cogl_texture_set_region_from_bitmap()
Actually for now we are exporting this API for practical reasons since
we already had this API internally and it enables a specific feature
that was requested, but it is worth nothing that it's quite likely we
will replace these with functions that don't involve the CoglBitmap API
at some point.
For reference: The CoglBitmap API was actually removed from the 2.0
experimental API reference manual some time ago because the hope was
that we'd come up with a neater replacement. It doesn't seem entirely
clear what the scope of the CoglBitmap api is so it has became a bit of
a dumping ground. CoglBitmap is used for image loading, as a means to
represent the layout of image data and also internally deals with format
conversions.
Note: Because we are avoiding including CoglBitmap as part of the 2.0
API these functions aren't currently included in the 2.0 reference
manual.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
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
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.
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.
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>
This exposes a CoglTexture2D typedef and adds the following experimental
API:
cogl_is_texture_2d
cogl_texture_2d_new_with_size
cogl_texture_2d_new_from_data
cogl_texture_2d_new_from_foreign
Since this is experimental API you need to define
COGL_ENABLE_EXPERIMENTAL_API before including cogl.h.
Note: With these new entrypoints we now expect a CoglContext pointer to
be passed in, instead of assuming there is a default context. The aim is
that for Cogl 2.0 we won't have a default context so this is a step in
that direction.
This is part of a broader cleanup of some of the experimental Cogl API.
One of the reasons for this particular rename is to switch away from
using the term "Array" which implies a regular, indexable layout which
isn't the case. We also want to strongly imply a relationship between
CoglBuffers and CoglPixelBuffers and be consistent with the
CoglAttributeBuffer and CoglIndexBuffer APIs.
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.
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.
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.
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.
If we have to copy the bitmap to do the premultiplication then we were
previously using the rowstride of the source image as the rowstride
for the new image. This is wasteful if the source image is a subregion
of a larger image which would make it use a large rowstride. If we
have to copy the data anyway we might as well compact it to the
smallest rowstride. This also prevents the copy from reading past the
end of the last row of pixels.
An internal function called _cogl_bitmap_copy has been added to do the
copy. It creates a new bitmap with the smallest possible rowstride
rounded up the nearest multiple of 4 bytes. There may be other places
in Cogl that are currently assuming we can read height*rowstride of
the source buffer so they may want to take advantage of this function
too.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2491
* cogl_texture_get_data() is converted to use
_cogl_texture_foreach_sub_texture_in_region() to iterate
through the underlying textures.
* When we need to read only a portion of the underlying
texture, we set up a FBO and use _cogl_read_pixels()
to read the portion we need. This is enormously more
efficient for reading a small portion of a large atlas
texture.
* The CoglAtlasTexture, CoglSubTexture, and CoglTexture2dSliced
implementation of get_texture() are removed.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2414
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.
This exposes the idea of a stack of source materials instead of just
having a single current material. This allows the writing of orthogonal
code that can change the current source material and restore it to its
previous state. It also allows the implementation of new composite
primitives that may want to validate the current source material and
possibly make override changes in a derived material.
