When determining whether to hash the combine constant Cogl checks the
arguments to the combine funcs to determine whether the combine
constant is used. However is was using the GLenums GL_CONSTANT_COLOR
and GL_CONSTANT_ALPHA but these are not valid values for the
CoglPipelineCombineSource enum so presumably the constant would never
get hashed. This patch makes it use Cogl's enum of
COGL_PIPELINE_COMBINE_SOURCE_CONSTANT instead.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2516
There are several places where we need to compare the texture state of a
pipeline and sometimes we need to take into consideration if the
underlying texture has changed but other times we may only care to know
if the texture target has changed.
For example the fragends typically generate programs that they want to
share with all pipelines with equivalent fragment processing state, and
in this case when comparing pipelines we only care about the texture
targets since changes to the underlying texture won't affect the
programs generated.
Prior to this we had tried to handle this by passing around some special
flags to various functions that evaluate pipeline state to say when we
do/don't care about the texture data, but this wasn't working in all
cases and was more awkward to manage than the new approach.
Now we simply have two state bits:
COGL_PIPELINE_LAYER_STATE_TEXTURE_TARGET and
COGL_PIPELINE_LAYER_STATE_TEXTURE_DATA and CoglPipelineLayer has an
additional target member. Since all the appropriate code takes masks of
these state bits to determine what to evaluate we don't need any extra
magic flags.
When notifying that a pipeline property is going to change, then at
times a pipeline will take over being the authority of the corresponding
state group. Some state groups can contain multiple properties and so to
maintain the integrity of all of the properties we have to initialize
all the property values in the new authority. For state groups with only
one property we don't have to initialize anything during the
pre_change_notify() because we can assume the value will be initialized
as part of the change being notified.
This patch optimizes how we handle this initialization of state groups
in a couple of ways; firstly we no longer do anything to initialize
state-groups with only one property, secondly we no longer use
_cogl_pipeline_copy_differences - (we have a new
_cogl_pipeline_init_multi_property_sparse_state() func) so we can avoid
lots calls to handle_automatic_blend_enable() which is sometimes seen
high in sysprof profiles.
Once the GLES2 wrapper is removed then we won't have the GLenums
needed for setting up the layer combine state. This adds Cogl enums
instead which have the same values as the corresponding GLenums. The
enums are:
CoglPipelineCombineFunc
CoglPipelineCombineSource
and
CoglPipelineCombineOp
This returns the layer matrix given a pipeline and a layer index. The
API is kept as internal because it directly returns a pointer into the
layer private data to avoid a copy into an out-param. We might also
want to add a public function which does the copy.
The GLSL vertend is mostly only useful for GLES2. The fixed function
vertend is kept at higher priority than the GLSL vertend so it is
unlikely to be used in any other circumstances.
The vertends are intended to flush state that would be represented in
a vertex program. Code to handle the layer matrix, lighting and
point size has now been moved from the common cogl-pipeline-opengl
backend to the fixed vertend.
'progend' is short for 'program backend'. The progend is intended to
operate on combined state from a fragment backend and a vertex
backend. The progend has an 'end' function which is run whenever the
pipeline is flushed and the two pipeline change notification
functions. All of the progends are run whenever the pipeline is
flushed instead of selecting a single one because it is possible that
multiple progends may be in use for example if the vertends and
fragends are different. The GLSL progend will take the shaders
generated by the fragend and vertend and link them into a single
program. The fragend code has been changed to only generate the shader
and not the program. The idea is that pipelines can share fragment
shader objects even if their vertex state is different. The authority
for the progend needs to be the combined authority on the vertend and
fragend state.
The pipeline function _cogl_pipeline_find_codegen_authority has been
renamed to _cogl_pipeline_find_equivalent_parent and it now takes a
set of flags for the pipeline and layer state that affects the
authority. This is needed so that we can reuse the same code in the
vertend and progends.
The current Cogl pipeline backends are entirely concerned with the
fragment processing state. We also want to eventually have separate
backends to generate shaders for the vertex processing state so we
need to rename the fragment backends. 'Fragend' is a somewhat weird
name but we wanted to avoid ending up with illegible symbols like
CoglPipelineFragmentBackendGlslPrivate.
_cogl_pipeline_needs_blending_enabled tries to determine whether each
layer is using the default combine state. However it was using
argument 0 for both checks so the if-statement would never be true.
There are a set of "EvalFlags" that get passed to _cogl_pipeline_hash
that can tweak the semantics of what state is evaluated for hashing but
these flags weren't getting passed via the HashState state structure
so it would be undefined if you would get the correct semantics.
According to 9cc9033347 the windows headers #define near as nothing,
and presumable the same is true for 'far' too. Apparently this define is
to improve compatibility with code written for Windows 3.1, so it's good
that people will be able to incorporate such code into their Clutter
applications.
The constant 'True' is defined by Xlib which isn't used for all clutter
builds so this replaces occurrences of True with TRUE which is defined
by glib. This should hopefully fix the win32 builds.
This allows us to get a hash for a set of state groups for a given
pipeline. This can be used for example to get a hash of the fragment
processing state of a pipeline so we can implement a cache for compiled
arbfp/glsl programs.
_cogl_pipeline_equal now accepts a mask of pipeline differences and layer
differences to constrain what state will be compared. In addition a set
of flags are passed that can tweak the comparison semantics for some
state groups. For example when comparing layer textures we sometimes
only need to compare the texture target and can ignore the data itself.
In updating the code this patch also changes it so all required pipeline
authorities are resolved in one step up-front instead of resolving the
authority for each state group in turn and repeatedly having to traverse
the pipeline's ancestry. This adds two new functions
_cogl_pipeline_resolve_authorities and
_cogl_pipeline_layer_resolve_authorities to handle resolving a set of
authorities.
This removes the unused array of per-packend priv data pointers
associated with every CoglPipelineLayer. This reduces the size of all
layer allocations and avoids having to zero an array for each
_cogl_pipeline_layer_copy.
In _cogl_pipeline_needs_blending_enabled after first checking whether
the property most recently changed requires blending we would then
resort to checking all other properties too in case some other state
also requires blending. We now avoid checking all other properties in
the case that blending was previously disabled and checking the property
recently changed doesn't require blending.
Note: the plan is to improve this further by explicitly keeping track
of the properties that currently cause blending to be enabled so that we
never have to resort to checking all other properties we can constrain
the checks to those masked properties.
This moves _cogl_pipeline_get_parent and _cogl_pipeline_get_authority
into cogl-pipeline-private.h so they can be inlined since they have been
seen to get quite high in profiles. Given that they both contain such
small amounts of code the function call overhead is significant.
When compiling for GLES2, the codegen is affected by state other than
the layers. That means when we find an authority for the codegen state
we can't directly look at authority->n_layers to determine the number
of layers because it isn't necessarily the layer state authority. This
patch changes it to use cogl_pipeline_get_n_layers instead. Once we
have two authorities that differ in codegen state we then compare all
of the layers to decide if they would affect codegen. However it was
ignoring the fact that the authorities might also differ by the other
codegen state. This path also adds an extra check for whether
_cogl_pipeline_compare_differences contains any codegen bits other
than COGL_PIPELINE_STATE_LAYERS.
When determining if a layer would require a different shader to be
generated it needs to check a certain set of state changes and it
needs to check whether the texture target is different. However it was
checking whether texture texture was different only if the other state
was also different which doesn't make any sense. It also only checked
the texture difference if that was the only state change which meant
that effectively the code was impossible to reach. Now it does the
texture target check indepent of the other state changes.
Before commit 49898d43 CoglPipeline would compare whether a pipeline
layer's texture is equal by fetching the underlying GL handle. I
changed that so that it would only compare the CoglHandles because
that commit removes the GL handle texture overrides and sliced
textures instead log the underlying primitive texture. However I
forgot that the primitives don't always use
_cogl_texture_foreach_sub_texture_in_region when the quad fits within
the single texture so it won't use a texture override. This meant that
atlas textures and sub textures get logged with the atlas handle so
the comparison still needs to be done using the GL handles. It might
be nice to add a CoglTexture virtual to get the underlying primitive
texture instead to avoid having the pipeline poke around with GL
handles.
Previously we used the layers->backend_priv[] members to determine when
to notify backends about layer changes, but it entirely up to the
backends if they want to associate private state with layers, even
though they may still be interested in layer change notifications (they
may associate layer related state with the owner pipeline).
We now make the observation that in
_cogl_pipeline_backend_layer_change_notify we should be able to assume
there can only be one backend currently associated with the layer
because we wouldn't allow changes to a layer with multiple dependants.
This means we can determine the backend to notify by looking at the
owner pipeline instead.
Previously the flag to mark the differences for the alpha test
function and reference value were conflated into one. However this is
awkward when generating shader code to simulate the alpha testing for
GLES 2 because in that case changing the function would need a
different program but changing the reference value just requires
updating a uniform. This patch makes the function and reference have
their own state flags.
need_texture_combine_separate is moved to cogl-pipeline.c and renamed
to _cogl_pipeline_need_texture_combine_separate. The function is
needed by both the ARBfp and GLSL codegen backends so it makes sense to
share it.
The code for finding the arbfp authority for a pipeline should be the
same as finding the GLSL authority. So that the code can be shared the
function has been moved to cogl-pipeline.c and renamed to
_cogl_pipeline_find_codegen_authority.
Switch _cogl_rectangles_with_multitexture_coords to using
_cogl_pipeline_foreach_layer to iterate the layers of a pipeline when
validating instead of iterating the pipelines internal list, which is
risky since any modifications to pipelines (even to an override pipeline
derived from the original), could potentially corrupt the list as it is
being iterated.
This removes the possibility to specify wrap mode overrides within a
CoglPipelineFlushOptions struct since the right way to handle these
overrides is by copying the user's material and making the changes to
that copy before flushing. All primitives code has already switched away
from using these wrap mode overrides so this patch just removes unused
code and types. It also remove the wrap_mode_overrides argument for
_cogl_journal_log_quad.
Since d5634e37 the sliced texture backend now works in terms of
CoglTexture2Ds so there's no need to have special casing for
overriding the texture of a pipeline layer with a GL handle. Instead
we can just use cogl_pipeline_set_layer_texture with the
CoglHandle. The special _cogl_pipeline_set_layer_gl_texture_slice
function has now been removed and parts of the code for comparing
materials have been simplified.
During _cogl_pipeline_needs_blending_enabled we were always checking the
current lighting properties (ambient,diffuse,specular,emission) which
had a notable impact during micro-benchmarks that exercise journal
throughput of simple colored rectangles. This #if 0's the offending code
considering that Cogl doesn't actually support lighting currently and
when it actually does then we will be able to optimize this by avoiding
the checks when lighting is disabled.
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.
