MaterialNodes are used for the sparse graph of material state and layer
state. In the case of materials there is the idea of weak materials that
don't take a reference on their parent and in that case we need to be
careful not to unref our parent during
_cogl_material_node_unparent_real. This adds a has_parent_reference
member to the CoglMaterialNode struct so we now know when to skip the
unref.
This is a counter part for _cogl_material_layer_get_texture which takes
a layer index instead of a direct CoglMaterialLayer pointer. The aim is
to phase out code that directly iterates the internal layer pointers of
a material since the layer pointers can change if any property of any
layer is changed making direct layer pointers very fragile.
This adds internal _cogl_material_get_layer_filters and
_cogl_material_get_layer_{min,mag}_filter functions which can be used to
query the filters associated with a layer using a layer_index, as
opposed to a layer pointer. Accessing layer pointers is considered
deprecated so we need to provide layer_index based replacements.
This is a counter part for _cogl_material_layer_pre_paint which takes a
layer index instead of a direct CoglMaterialLayer pointer. The aim is to
phase out code that directly iterates the internal layer pointers of a
material since the layer pointers can change if any property of any
layer is changed making direct layer pointers very fragile.
When using the debug function _cogl_debug_dump_materials_dot_file to
write a dot file representing the sparse graph of material state we now
only show a link between materials and layers when the material directly
owns that layer reference (i.e. just those referenced in
material->layer_differences) This makes it possible to see when
ancestors of a material are being deferred too for layer state.
For example when looking at the graph if you see that a material has an
n_layers of 3 but there is only a link to 2 layers, then you know you
need to look at it's ancestors to find the last layer.
Each time a material property changes we look to see if any of its
ancestry has become redundant and if so we prune that redundant
ancestry.
There was a problem with the logic that handles this though because we
weren't considering that a material which is a layer state authority may
still defer to ancestors to define the state of individual layers.
For example a material that derives from a parent with 5 layers can
become a STATE_LAYERS authority by simply changing it's ->n_layers count
to 4 and in that case it can still defer to its ancestors to define the
state of those 4 layers.
This patch checks first if a material is a layer state authority and if
so only tries to prune its ancestry if it also *owns* all the individual
layers it depends on. (I.e. if g_list_length
(material->layer_differences) != material->n_layers then it's not safe
to try pruning its ancestry!)
http://bugzilla-attachments.gnome.org/attachment.cgi?id=170907
This adds a way to iterate the layer indices of the given material since
cogl_material_get_layers has been deprecated. The user provides a
callback to be called once for each layer.
Because modification of layers in the callback may potentially
invalidate any number of the internal CoglMaterialLayer structures and
invalidate the material's layer cache this should be more robust than
cogl_material_get_layers() which used to return a const GList *
pointing directly to internal state.
This makes it so we only notify backends of either a single material
change or a single layer change. Previously all material STATE_LAYERS
changes would be followed by a more detailed layer change.
For backends that perform code generation for fragment processing they
typically need to understand the details of how layers get changed to
determine if they need to repeat codegen. It doesn't help them to report
a material STATE_LAYERS change for all layer changes since it's so
broad, they really need to wait for the layer change to be notified.
What does help though is to report a STATE_LAYERS change for a change in
material->n_layers because they typically do need to repeat codegen in
that case.
When notifying a backend about a layer being modified we now pass the
layers current owner for reference. NB: Although a layer can indirectly
be referenced by multiple layers, a layer is considered immutable once
it has dependants, so there is only ever one material associated with a
layer being modified. Passing the material pointer to the backends
layer_pre_change callback can be useful for backends that associate
their private state with materials and may need to update that state in
response to layer changes.
We now pass a boolean to _cogl_material_pre_change_notify to know when
a material change is as a result of a layer change. We plan to use this
information to avoid notifying the backends about material changes if
they are as a result of layer changes. This will simplify the handling
of state changes in the backends because they can assume that layer and
material changes are mutually exclusive.
This adds an internal _cogl_material_get_layer_combine_constant function
so we can query the current layer combine constant back. We should
probably make this a public property getter, but for now we just need
this so we can read the constant in the arbfp backend.
When disposing a material layer of type 'texture' we should check that
the texture handle is still valid before calling cogl_handle_unref().
This avoids an assertion failure when disposing a ClutterTexture.
Weak materials are ones that don't take a reference on their parent and
they are associated with a callback that notifies when the material is
destroyed, because its parent was freed or modified.
More details can be found at:
http://wiki.clutter-project.org/wiki/CoglDesign/CoglMaterial
For now the concept is internal only but the plan is to make this public
at some point once we have tested the design internally.
Textures within a layer were compared for equality by comparing their
texture handle. However this means that sub textures and atlas
textures which may be internally using the same GL handle would not be
batched together. Instead it now tries to determine the underlying GL
handle using either the slice override or _cogl_texture_get_gl_texture
and then compares those.
Previously we had an internal only _cogl_material_set_user_program to
redirect legacy usage of cogl_program_use() through CoglMaterial. This
instead makes the API public because until we implement our planned
"snippet" framework we need a stop-gap solution for using shaders in
Cogl.
The plan is to also support ARBfp with the cogl_program/shader API so
this API will also allow clutter-gst to stop using direct OpenGL calls
that conflict with Cogl's state tracking.
A change to a layer is also going to be a change to its owning material
so we have to chain up in _cogl_material_layer_pre_change_notify and
call _cogl_material_pre_change_notify. Previously we were only
considering if the owning material was referenced in the journal but
that ignores that it might also have dependants. We no longer need to
flush the journal directly in layer_pre_change_notify.
In _cogl_material_layer_pre_change_notify when we see that a layer has
dependants and it can't be modified directly then we allocate a new
layer. In this case we also have to link the new layer to its required
owner. If the immutable layer we copied had the same owner though we
weren't unlinking that old layer.
In _cogl_material_pre_change_notify we need to identify if it's a sparse
property being changed and if so initialize the state group if the given
material isn't currently the authority for it.
Previously we were unconditionally calling
_cogl_material_initialize_state which would e.g. NULL the layer
differences list of a material each time a layer change was notified.
It would also call _cogl_material_initialize_state for non-sparse
properties which should always be valid at this point so the function
has been renamed to _cogl_material_initialize_sparse_state to make this
clearer with a corresponding g_return_if_fail check.
This fixes how we copy layer differences in
_cogl_material_copy_layer_differences.
We were making a redundant g_list_copy of the src differences and then
iterating the src list calling _cogl_material_add_layer_difference for
each entry which would double the list length, but the initial copy
directly referenced the original layers which wasn't correct.
Also we were initializing dest->n_layers before copying the layer
differences but the act of copying the differences will re-initialize
n_layers to 0 when adding the first layer_difference since it will
trigger a layer_pre_change_notify and since the dest material isn't yet
a STATE_LAYERS authority the state group is initialized before allowing
the change.
This improve the dot file output available when calling
_cogl_debug_dump_materials_dot_file. The material graph now directly
points into the layer graph and the layers now show the texture unit
index.
When the texture is set on a layer so that it is back to the parent's
texture it would clear the texture change flag but it wouldn't unref
the texture. The free function for a material layer does not unref the
texture if the change flag is cleared so the texture would end up
leaking. This happens for ClutterTexture because it disposes the
texture by setting layer 0 of the material to COGL_INVALID_HANDLE
which ends up the same as the default material.
In _cogl_material_layer_pre_paint we were mistakenly dereferencing the
layer->texture member for the passed layer instead of dereferencing the
texture state authority which was causing crashes in some cases.
In OpenGL the 'shininess' lighting parameter is floating point value
limited to the range 0.0→128.0. This number is used to affect the size
of the specular highlight. Cogl materials used to only accept a number
between 0.0 and 1.0 which then gets multiplied by 128.0 before sending
to GL. I think the assumption was that this is just a weird GL quirk
so we don't expose it. However the value is used as an exponent to
raise the attenuation to a power so there is no conceptual limit to
the value.
This removes the mapping and changes some of the documentation.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2222
This moves the code supporting _cogl_material_flush_gl_state into
cogl-material-opengl.c as part of an effort to reduce the size of
cogl-material.c to keep it manageable.
In general cogl-material.c has become far to large to manage in one
source file. As one of the ways to try and break it down this patch
starts to move some of lower level texture unit state management out
into cogl-material-opengl.c. The naming is such because the plan is to
follow up and migrate the very GL specific state flushing code into the
same file.
When the support for redirecting the legacy fog state through cogl
material was added in 9b9e764dc, the code to handle copying the fog
state in _cogl_material_copy_differences was missed.
Using 'r' to name the third component is problematic because that is
commonly used to represent the red component of a vector representing
a color. Under GLSL this is awkward because the texture swizzling for
a vector uses a single letter for each component and the names for
colors, textures and positions are synonymous. GLSL works around this
by naming the components of the texture s, t, p and q. Cogl already
effectively already exposes this naming because it exposes GLSL so it
makes sense to use that naming consistently. Another alternative could
be u, v and w. This is what Blender and Direct3D use. However the w
component conflicts with the w component of a position vertex.
We can use this error in more unsupported situations than just when we
have a Cogl feature flag for the error. For example if a non-sliced
texture is created with dimensions that are too large then we could
throw this error. Therefore it seems good to rename to something more
general.
This adds a COGL_OBJECT_INTERNAL_DEFINE macro and friends that are the
same as COGL_OBJECT_DEFINE except that they prefix the cogl_is_*
function with an underscore so that it doesn't get exported in the
shared library.
Previously COGL_OBJECT_DEFINE would always define deprecated
cogl_$type_{ref,unref} functions even if the type is new or if the
type is entirely internal. An application would still find it
difficult to use these because they wouldn't be in the headers, but it
still looks bad that they are exported from the shared library. This
patch changes it so that the deprecated ref counting functions are
defined using a separate macro and only the types that have these
functions in the headers call this macro.
Since 365605cf42, materials and layers are represented in a tree
structure that allows traversing up through parents and iterating down
through children. This re-works the related typedefs and reparenting
code so that they can be shared.
There were a few problems flushing texture overrides so that sliced
textures would not work:
* In _cogl_material_set_layer_texture it ignored the 'overriden'
parameter and always set texture_overridden to FALSE.
* cogl_texture_get_gl_texture wasn't being called correctly in
override_layer_texture_cb. It returns a gboolean to indicate the
error status but this boolean was being assigned to gl_target.
* _cogl_material_layer_texture_equal did not take into account the
override.
* _cogl_material_layer_get_texture_info did not return the overridden
texture so it would always use the first texture slice.
This adds a new API call to enable point sprite coordinate generation
for a material layer:
void
cogl_material_set_layer_point_sprite_coords_enabled (CoglHandle material,
int layer_index,
gboolean enable);
There is also a corresponding get function.
Enabling point sprite coords simply sets the GL_COORD_REPLACE of the
GL_POINT_SPRITE glTexEnv when flusing the material. There is no
separate application control for glEnable(GL_POINT_SPRITE). Instead it
is left permanently enabled under the assumption that it has no affect
unless GL_COORD_REPLACE is enabled for a texture unit.
http://bugzilla.openedhand.com/show_bug.cgi?id=2047
Recently I added a _cogl_debug_dump_materials_dot_file function for
debugging the sparse material state. This extends the state dumped to
include the graph of layer state also.
We were mistakenly only initializing layer->layer_index for new layers
associated with texture units > 0. This had gone unnoticed because
normally layers associated with texture unit0 have a layer index of 0
too. Mutter was hitting this issue because it was initializing layer 1
before layer 0 for one of its materials so layer 1 was temporarily
associated with texture unit 0.
Previously cogl_set_fog would cause a flush of the Cogl journal and
would directly bang the GL state machine to setup fogging. As part of
the ongoing effort to track most state in CoglMaterial to support
renderlists this now adds an indirection so that cogl_set_fog now just
updates ctx->legacy_fog_state. The fogging state then gets enabled as a
legacy override similar to how the old depth testing API is handled.
This adds a _cogl_debug_dump_materials_dot_file function that can be
used to dump all the descendants of the default material to a file using
the dot format which can then be converted to an image to visualize.
In _cogl_material_pre_change_notify if a material with descendants is
modified then we create a new material that is a copy of the one being
modified and reparent those descendants to the new material.
This patch ensures we drop the reference we get from cogl_material_copy
since we can rely on the descendants to keep the new material alive.
cogl_material_copy was taking a reference on the original texture when
making a copy. However it then calls _cogl_material_set_parent on the
material which also takes a reference on the parent. The second
reference is cleaned up whenever _cogl_material_unparent is called and
this is also called by _cogl_material_free. However, it seems that
nothing was cleaning up the first reference. I think the reference is
entirely unnecessary so this patch removes it.
As part of the ongoing effort to remove CoglHandle from the API this
switches the cogl_material API to use a strongly typed CoglMaterial
pointer instead of CoglHandle.
This splits the fragment processing backends (glsl, arbfp and fixed) out
from cogl-material.c into their own cogl-material-{glsl,arbfp,fixed}.c
files in an effort to help and keep cogl-material.c maintainable.
Some of the arguments to the material and path functions were taking a
pointer to a CoglColor or an array of floats that was not intended to
be written to but were not marked with const.
in _cogl_material_prune_empty_layer_difference we sometimes unref the
given layer before dereferencing it to get a pointer to its parent. This
defers the unref until after we have fetched the parent pointer.
