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)
Removing CoglHandle has been an on going goal for quite a long time now
and finally this patch removes the last remaining uses of the CoglHandle
type and the cogl_handle_ apis.
Since the big remaining users of CoglHandle were the cogl_program_ and
cogl_shader_ apis which have replaced with the CoglSnippets api this
patch removes both of these apis.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 6ed3aaf4be21d605a1ed3176b3ea825933f85cf0)
Since the original patch was done after removing deprecated API
this back ported patch doesn't affect deprecated API and so
actually this cherry-pick doesn't remove all remaining use of
CoglHandle as it did for the master branch of Cogl.
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>
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>
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>
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 adds experimental 2.0 api replacements for the cogl_rectangle[_*]
functions that don't depend on having a current pipeline set on the
context via cogl_{set,push}_source() or having a current framebuffer set
on the context via cogl_push_framebuffer(). The aim for 2.0 is to switch
away from having a statefull context that affects drawing to having
framebuffer drawing apis that are explicitly passed a framebuffer and
pipeline.
To test this change several of the conformance tests were updated to use
this api instead of cogl_rectangle and
cogl_rectangle_with_texture_coords. Since it's quite laborious going
through all of the conformance tests the opportunity was taken to make
other clean ups in the conformance tests to replace other uses of
1.x api with experimental 2.0 api so long as that didn't affect what was
being tested.
This adds a public convenience wrapper around
cogl_framebuffer_read_pixels_into_bitmap which allocates a temporary
CoglBitmap to read into the application's own buffer. This can only be
used for the 99% common case where the rowstride is exactly the
bpp*width and the source is the color buffer.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Previously when adding a quad to the journal it would assume the
journal belongs to the framebuffer at the top of the framebuffer stack
and store a reference to that. We eventually want to get rid of the
framebuffer stack so we should avoid using it here. The journal now
takes a pointer back to the framebuffer in its constructor and it
always retains the pointer. As was done previously, the journal still
does not take a reference on the framebuffer unless it is non-empty so
it does not create a permanent circular reference.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
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>
The if-undefined fallback declaration for GL_PACK_INVERT_MESA was
originally added in cogl.c along with code to use it (as part of commit
6f79eb8a5a). Later on, commit
10a38bb14f moved the code that used it to
cogl-framebuffer.c but didn't move the define along with it. Do that
now.
https://bugzilla.gnome.org/show_bug.cgi?id=672038
Reviewed-by: Neil Roberts <neil@linux.intel.com>
This option to GCC makes it give a warning whenever a global function
is defined without a declaration. This should catch cases were we've
defined a function but forgot to put it in a header. In that case it
is either only used within one file so we should make it static or we
should declare it in a header.
The following changes where made to fix problems:
• Some functions were made static
• cogl-path.h (the one containing the 1.0 API) was split into two
files, one defining the functions and one defining the enums so that
cogl-path.c can include the enum and function declarations from the
2.0 API as well as the function declarations from the 1.0 API.
• cogl2-clip-state has been removed. This only had one experimental
function called cogl_clip_push_from_path but as this is unstable we
might as well remove it favour of the equivalent cogl_framebuffer_*
API.
• The GLX, SDL and WGL winsys's now have a private header to define
their get_vtable function instead of directly declaring in the C
file where it is called.
• All places that were calling COGL_OBJECT_DEFINE need to have the
cogl_is_whatever function declared so these have been added either
as a public function or in a private header.
• Some files that were not including the header containing their
function declarations have been fixed to do so.
• Any unused error quark functions have been removed. If we later want
them we should add them back one by one and add a declaration for
them in a header.
• _cogl_is_framebuffer has been renamed to cogl_is_framebuffer and
made a public function with a declaration in cogl-framebuffer.h
• Similarly for CoglOnscreen.
• cogl_vdraw_indexed_attributes is called
cogl_framebuffer_vdraw_indexed_attributes in the header. The
definition has been changed to match the header.
• cogl_index_buffer_allocate has been removed. This had no declaration
and I'm not sure what it's supposed to do.
• CoglJournal has been changed to use the internal CoglObject macro so
that it won't define an exported cogl_is_journal symbol.
• The _cogl_blah_pointer_from_handle functions have been removed.
CoglHandle isn't used much anymore anyway and in the few places
where it is used I think it's safe to just use the implicit cast
from void* to the right type.
• The test-utils.h header for the conformance tests explicitly
disables the -Wmissing-declaration option using a pragma because all
of the tests declare their main function without a header. Any
mistakes relating to missing declarations aren't really important
for the tests.
• cogl_quaternion_init_from_quaternion and init_from_matrix have been
given declarations in cogl-quaternion.h
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 the GL_OES_packed_depth_stencil extension is available then we can
try creating a combined depth-stencil buffer with the
GL_DEPTH24_STENCIL8 format. This adds a private flag for the feature.
https://bugzilla.gnome.org/show_bug.cgi?id=666184
Reviewed-by: Robert Bragg <robert@linux.intel.com>
The GL_DEPTH_STENCIL format for renderbuffers is defined in a separate
extension from GL_EXT_framebuffer_object so we probably shouldn't
being trying to use it unless that extension is advertised. This just
replaces the check for whether the driver is GL for a check for a
private feature flag before trying GL_DEPTH_STENCIL. The private
feature flag is set if the extension is available on GL.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Previously for the wireframe debug mode we identified the users
"cogl_position_in" attribute, mapped that, created a replacement
attribute with a LINE_LIST topology and then drew the attribute with a
simple pipeline with a green colour. This meant we completely discarded
the users original pipeline which may have involved vertex processing
that would be useful to visualize in the wireframe.
The new approach instead keeps the users attributes and instead
generates CoglIndices that can be used to refererence the original
attributes in LINE_LIST topology and instead of scrapping the user's
pipeline we now create a weak copy of the original pipeline and just
replace the fragment processing with a snippet to force the output color
to be green.
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>
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>
All CoglBuffer constructors now take an explicit CoglContext
constructor. This is part of the on going effort to adapt to Cogl API so
it no longer depends on a global, default context.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
When using COGL_DEBUG=wireframe we were overlaying a wireframe of the
users geometry over the top of what was drawn for each primitive. It
seems to be more useful though that if the wireframe debug option has
been enabled then we should draw only the wireframes instead of
overlaying them.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
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>
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>
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>
Previously flushing the matrices was performed as part of the
framebuffer state. When on GLES2 this matrix flushing is actually
diverted so that it only keeps a reference to the intended matrix
stack. This is necessary because on GLES2 there are no builtin
uniforms so it can't actually flush the matrices until the program for
the pipeline is generated. When the matrices are flushed it would
store the age of modifications on the matrix stack so that it could
detect when the matrix hasn't changed and avoid flushing it.
This patch changes it so that the pipeline is responsible for flushing
the matrices even when we are using the GL builtins. The same
mechanism for detecting unmodified matrix stacks is used in all
cases. There is a new CoglMatrixStackCache type which is used to store
a reference to the intended matrix stack along with its last flushed
age. There are now two of these attached to the CoglContext to track
the flushed state for the global matrix builtins and also two for each
glsl progend program state to track the flushed state for a
program. The framebuffer matrix flush now just updates the intended
matrix stacks without actually trying to flush.
When a vertex snippet is attached to the pipeline, the GLSL vertend
will now avoid using the projection matrix to flip the rendering. This
is necessary because any vertex snippet may cause the projection
matrix not to be used. Instead the flip is done as a forced final step
by multiplying cogl_position_out by a vec4 uniform. This uniform is
updated as part of the progend pre_paint depending on whether the
framebuffer is offscreen or not.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
_cogl_framebuffer_flush_state needs to handle the case where
ctx->current_draw_buffer is NULL because this will be set in the
destructor for CoglFramebuffer if the framebuffer being destroyed is
the current framebuffer. This patch just makes it assume all state has
changed in that case.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
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>
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>
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>
There was only one place where we called _cogl_clip_state_flush() in
_cogl_framebuffer_flush_state() and we can just as well use
_cogl_clip_state_get_stack() and _cogl_clip_stack_flush() directly
instead.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
The only place we were calling _cogl_clip_stack_dirty() was when
changing the current draw_buffer which also implies a change in
the current clip stack. _cogl_clip_stack_flush() would already
be able to quickly determine that the clip stack has changed by
checking ctx->current_clip_stack so there isn't really any need
to explicitly mark the clip_stack state as dirty.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
The aim is to make cogl-framebuffer.c responsible for avoiding redundant
flushing of its matrix stacks so this removes the checks done directly
within cogl-matrix-stack.c.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
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>
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 adds a cogl_framebuffer_identity_matrix() method that can be used
to reset the current modelview matrix to the identity matrix.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
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>
Cogl keeps a pointer to the last used onscreen framebuffer from the
context to implement the deprecated cogl_set_draw_buffer function
which can take COGL_WINDOW_BUFFER as the target to use the last
onscreen buffer. Previously this would also take a reference to that
pointer. However that was causing a circular reference between the
framebuffer and the context which makes it impossible to clean up
resources properly when onscreen buffers are used. This patch instead
changes it to just store the pointer and then clear the pointer during
_cogl_onscreen_free as a kind of cheap weak reference.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
This adds two new experimental public functions to replace the old
internal _cogl_pipeline_set_cull_face_state function:
void
cogl_pipeline_set_cull_face_mode (CoglPipeline *pipeline,
CoglPipelineCullFaceMode cull_face_mode);
void
cogl_pipeline_set_front_face_winding (CoglPipeline *pipeline,
CoglWinding front_winding);
There are also the corresponding getters.
https://bugzilla.gnome.org/show_bug.cgi?id=663628
Reviewed-by: Robert Bragg <robert@linux.intel.com>
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>
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>
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>
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>
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>
This adds a new experimental function, cogl_framebuffer_finish(), which
can be used to explicitly synchronize the CPU with the GPU. It's rare
that this level of explicit synchronization is desirable but for example
it can be useful during performance analysys to make sure measurements
reflect the working time of the GPU not just the time to queue commands.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
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>
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>
This adds cogl_framebuffer_discard_buffers API that allows applications
to explicitly discard depth and stencil buffers which really helps when
using a tile based GPU architexture by potentially avoiding the need to
save the results of depth and stencil buffer changes to system memory
between frames since these can usually be handled directly with on-chip
memory instead.
The semantics for cogl_framebuffer_swap_buffers and
cogl_framebuffer_swap_region are now documented to include an implicit
discard of all buffers, including the color buffer.
We now recommend that all rendering to a CoglOffscreen framebuffer
should be followed by a call like:
cogl_framebuffer_discard_buffers (fb,
COGL_BUFFER_BIT_DEPTH|
COGL_BUFFER_BIT_STENCIL);
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>
