GLES has an extension called GL_OES_mapbuffer to support mapping
buffer objects but only for writing. Cogl now has two new feature
flags to advertise whether mapping for reading and writing is
supported. Under OpenGL, these features are always set if the VBO
extension is advertised and under GLES only the write flag is set if
the GL_OES_mapbuffer extension is advertised.
In the journal code and when generating the stroke path the vertices
are generated on the fly and stored in a CoglBuffer using
cogl_buffer_map. However cogl_buffer_map is allowed to fail but it
wasn't checking for a NULL return value. In particular on GLES it will
always fail because glMapBuffer is only provided by an extension. This
adds a new pair of internal functions called
_cogl_buffer_{un,}map_for_fill_or_fallback which wrap
cogl_buffer_map. If the map fails then it will instead return a
pointer into a GByteArray attached to the context. When the buffer is
unmapped the array is copied into the buffer using
cogl_buffer_set_data.
On GLES2 there's no builtin mechanism to replace texture coordinates
with point sprite coordinates so calling glEnable(GL_POINT_SPRITE)
isn't valid. Instead the point sprite coords are implemented by using
a special builtin varying variable in GLSL.
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.
Previously atlasing would be disabled if the GL driver does not
support reading back texture data. This meant that atlasing would not
happen on GLES. However we also require that the driver support FBOs
and the texture data is only read back as a fallback if the FBO
fails. Therefore the atlas should be ok on GLES 2 which has FBO
support in core.
We try and bail out of flushing pipeline state asap if we can see the
pipeline has already been flushed and hasn't changed but we weren't
checking to see if the skip_gl_color flag is the same as when it was
last flush too and so we'd sometimes bail out without updating the
glColor correctly.
When an item is added to the journal the current pipeline immediately
gets the legacy state applied to it and the modified pipeline is
logged instead of the original. However the actual drawing from the
journal is done using the vertex attribute API which was also applying
the legacy state. This meant that the legacy state used would be a
combination of the state set when the journal entry was added as well
as the state set when the journal is flushed. To fix this there is now
an extra CoglDrawFlag to avoid applying the legacy state when setting
up the GL state for the vertex attributes. The journal uses this flag
when flushing.
The vertex attribute API assumes that if there is a color array
enabled then we can't determine if the colors are opaque so we have to
enable blending. The journal always uses a color array to avoid
switching color state between rectangles. Since the journal switched
to using vertex attributes this means we effectively always enable
blending from the journal. To fix this there is now a new flag for
_cogl_draw_vertex_attributes to specify that the color array is known
to only contain opaque colors which causes the draw function not to
copy the pipeline. If the pipeline has blending disabled then the
journal passes this flag.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2481
There is an internal version of cogl_draw_vertex_attributes_array
which previously just bypassed the framebuffer flushing, journal
flushing and pipeline validation so that it could be used to draw the
journal. This patch generalises the function so that it takes a set of
flags to specify which parts to flush. The public version of the
function now just calls the internal version with the flags set to
0. The '_real' version of the function has now been merged into the
internal version of the function because it was only called in one
place. This simplifies the code somewhat. The common code which
flushed the various state has been moved to a separate function. The
indexed versions of the functions have had a similar treatment.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2481
Cogl no longer has any code that assumes the buffer in a CoglBitmap is
allocated to the full size of height*rowstride. We should comment that
this is the case so that we remember to keep it that way. This is
important for cogl_texture_new_from_data because the application may
have created the data from a sub-region of a larger image and in that
case it's not safe to read the full rowstride of the last row when the
sub region contains the last row of the larger image.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2491
When uploading data for GLES we need to deal with cases where the
rowstride is too large to be described only by GL_UNPACK_ALIGNMENT
because there is no GL_UNPACK_ROW_LENGTH. Previously for the
sub-region uploading code it would always copy the bitmap and for the
code to upload the whole image it would copy the bitmap unless the
rowstride == bpp*width. Neither paths took into account that we don't
need to copy if the rowstride is just an alignment of bpp*width. This
moves the bitmap copying code to a separate function that is used by
both upload methods. It only copies the bitmap if the rowstride is not
just an alignment of bpp*width.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2491
The ffs function is defined in C99 so if we want to use it in Cogl we
need to provide a fallback for MSVC. This adds a configure check for
the function and then a fallback using a while loop if it is not
available.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2491
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
The builtin vertex attribute for the normals was incorrectly checked
for as 'cogl_normal' however it is defined as cogl_normal_in in the
shader boilerplate and for the name generated by CoglVertexBuffer.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2499
The ARBfp fragend was bypassing generating a shader if the pipeline
contains a user program. However it shouldn't do this if the pipeline
only contains a vertex shader. This was breaking
test-cogl-just-vertex-shader.
Previously Cogl would only ever use one atlas for textures and if it
reached the maximum texture size then all other new textures would get
their own GL texture. This patch makes it so that we create as many
atlases as needed. This should avoid breaking up some batches and it
will be particularly good if we switch to always using multi-texturing
with a default shader that selects between multiple atlases using a
vertex attribute.
Whenever a new atlas is created it is stored in a GSList on the
context. A weak weference is taken on the atlas using
cogl_object_set_user_data so that it can be removed from the list when
the atlas is destroyed. The atlas textures themselves take a reference
to the atlas and this is the only thing that keeps the atlas
alive. This means that once the atlas becomes empty it will
automatically be destroyed.
All of the COGL_NOTEs pertaining to atlases are now prefixed with the
atlas pointer to make it clearer which atlas is changing.
All of the drawing needed in _cogl_add_path_to_stencil_buffer is done
with the vertex attribute API so there should be no need to flush the
enable flags to enable the vertex array. This was causing problems on
GLES2 where the vertex array isn't available.
The GLES2 wrapper is no longer needed because the shader generation is
done within the GLSL fragend and vertend and any functions that are
different for GLES2 are now guarded by #ifdefs.
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
Once the GLES2 wrapper is removed we won't be able to upload the
matrices with the fixed function API any more. The fixed function API
gives a global state for setting the matrix but if a custom shader
uniform is used for the matrices then the state is per
program. _cogl_matrix_stack_flush_to_gl is called in a few places and
it is assumed the current pipeline doesn't need to be flushed before
it is called. To allow these semantics to continue to work, on GLES2
the matrix flush now just stores a reference to the matrix stack in
the CoglContext. A pre_paint virtual is added to the progend which is
called whenever a pipeline is flushed, even if the same pipeline was
flushed already. This gives the GLSL progend a chance to upload the
matrices to the uniforms. The combined modelview/projection matrix is
only calculated if it is used. The generated programs end up never
using the modelview or projection matrix so it usually only has to
upload the combined matrix. When a matrix stack is flushed a reference
is taked to it by the pipeline progend and the age is stored so that
if the same state is used with the same program again then we don't
need to reupload the uniform.
Sometimes it would be useful if we could efficiently track when a matrix
stack has been modified. For example on GLES2 we have to upload the
modelview as a uniform to our glsl programs but because the modelview
state is part of the framebuffer state it becomes a bit more tricky to
know when to re-sync the value of the uniform with the framebuffer
state. This adds an "age" counter to CoglMatrixStack which is
incremented for any operation that effectively modifies the top of the
stack so now we can save the age of the stack inside the pipeline
whenever we update modelview uniform and later compare that with the
stack to determine if it has changed.
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.
When the GLES2 wrapper is removed we can't use the fixed function API
such as glColorPointer to set the builtin attributes. Instead the GLSL
progend now maintains a cache of attribute locations that are queried
with glGetAttribLocation. The code that previously maintained a cache
of the enabled texture coord arrays has been modified to also cache
the enabled vertex attributes under GLES2. The vertex attribute API is
now the only place that is using this cache so it has been moved into
cogl-vertex-attribute.c
Previously when stroking a path it was flushing a pipeline and then
directly calling glDrawArrays to draw the line strip from the path
nodes array. This patch changes it to build a CoglVertexArray and a
series of attributes to paint with instead. The vertex array and
attributes are attached to the CoglPath so it can be reused later. The
old vertex array for filling has been renamed to fill_vbo.
The code to display the source when the show-source debug option is
given has been moved to _cogl_shader_set_source_with_boilerplate so
that it will show both user shaders and generated shaders. It also
shows the code with the full boilerplate. To make it the same for
ARBfp, cogl_shader_compile_real now also dumps user ARBfp shaders.
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.
Due to Mesa bug 28585 calling glVertexAttrib with attrib location 0
doesn't appear to work. This patch just reorders the vertex and color
attributes in the shader in the hope that Mesa will assign the color
attribute to a different location.
Some builtin attributes such as the matrix uniforms and some varyings
were missing from the boilerplate for GLES2. This also moves the
texture matrix and texture coord attribute declarations to
cogl-shader.c so that they can be dynamically defined depending on the
number of texture coord arrays enabled.
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.
This adds two internal functions:
gboolean
_cogl_program_has_fragment_shader (CoglHandle handle);
gboolean
_cogl_program_has_vertex_shader (CoglHandle handle);
They just check whether any of the contained shaders are of that type.
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.
Previously enabling and disabling textures was done whatever the
backend in cogl-pipeline-opengl. However enabling and disabling
texture targets only has any meaning if no fragment shaders are being
used so this patch moves the code to cogl-pipeline-fragend-fixed.
The GLES2 wrapper has also been changed to ignore enabledness when
deciding whether to update texture coordinate attribute pointers.
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.
We are currently using a pipeline as a key into our arbfp program cache
but because we weren't making a copy of the pipelines used as keys there
were times when doing a lookup in the cache would end up trying to
compare a lookup key with an entry key that would point to invalid
memory.
Note: the current approach isn't ideal from the pov that that key
pipeline may reference some arbitrarily large user textures will now be
kept alive indefinitely. The plan to improve on this is that we will
have a mechanism to create a special "key pipeline" which will derive
from the default Cogl pipeline (to avoid affecting the lifetime of
other pipelines) and only copy state from the original pipeline that
affects the arbfp program and will reference small dummy textures
instead of potentially large user textures.
