...the improved const correctness on STL iterators uncovered another
latent problem with out diagnositc format helper, which provide
consistently rounded float and double output, but failed to take
CV-qualifiaction into account
This is a subtle and far reaching fix, which hopefully removes
a roadblock regarding a Dispatcher pipeline: Our type rebinding
template used to pick up nested type definitions, especially
'value_type' and 'reference' from iterators and containers,
took an overly simplistic approach, which was then fixed
at various places driven by individual problems.
Now:
- value_type is conceptually the "thing" exposed by the iterator
- and pointers are treated as simple values, and no longer linked
to their pointee type; rather we handle the twist regarding
STL const_iterator direcly (it defines a non const value_type,
which is sensible from the STL point of view, but breaks our
generic iterator wrapping mechanism)
...in an attempt to resolve the deeply nested problems encountered
while building an iterator pipeline for the Dispatcher. It seems
that I was sloppy some years ago and just "bashed them into submission",
thereby mixing up two different meanings of "value_type"
Moreover I seemingly implemented the same helper trait template twice,
so the first step is to switch all usages to meta::TypeBinding
To complete the mock setup, the next step would be to extend the GenNode-based spec langage
to allow defining prerequisite Mock-JobTickets. Setting this up seems rather straight forward --
however, defining a simple testcase to cover this extension runs into surprisingly tricky problems..
- for one, the singleValIterator from Itertools has serious difficulties handling references
- but even more surprising, it seems impossible to make the "prerequisites iterator"
fit into the Tree-Explorer framework (which I intend to use as replacement
for the monadic approach)
after some extended analysis of generic types and template instances,
it seems that not TreeExplorer as such is the primary problem, but rather
there is a conceptual mismatch somewhere deep down in Itertools or Iter-Adapter
By reasoning and analysis I conclude that the differentiation into
multiple channels is likely misplaced in JobTicket; it belongs ratther
into the Segment and should provide a suitable JobTicket for each ModelPort
Handling of prerequisites also needs to be reshaped entirely after
switching to a pipeline builder for the Job-planning pipeline; as
preliminary access point, just add an iterator over the immediate
prerequisites, thereby shifting the exploration mechanism entirely
out of the JobTicket implementation
Testcase: A simple Sementation with a single and bounded Segment
As aside, figured out how to unpack an iterator such as to
tie a fixed number of references through a structural binding:
auto const& [s1,s2,s3] = seqTuple<3> (mockSegs.eachSeg());
...now able to build a mock segmentation which issues dummy jobs,
and is wired such as to verify the right job is invoked for each segment.
And this allows to build and verify the Dispatcher,
without being able to invoke actual render jobs yet.
...this is something I should have done since YEARS, really...
Whenever working with symbolically represented data, tests
typically involve checking *hundreds* of expected results,
and thus it can be really hard to find out where the
failure actually happens; it is better for readability
to have the expected result string immediately in the
test code; now this expected result can be marked
with a user-defined literal, and then on mismatch
the expected and the real value will be printed.
The algorithm coded thus far turns out to be rather generic,
and thus it can be rewritten into a template, while all specific parts
are supplied as λ-Functors.
- instead of Time we use a generic ordering type
- the Iterator is likewise turned into a template parameter
- all the operations are directly supplied as functor types
- C++17 is able to pick up all those λ-Types from the ctor call
This change looks like "low hanging fruit"; the legibility of the code
is not seriously hampered, yet we get the benefit to test this rather
technical piece of logic by an isolated test (which for now is the
primary motivation), and we can hope to re-use it for similar tasks.
There are 12 distinct cases regarding the orientation of two intervals;
The Segmentation::splitSplice() operation shall insert a new Segment
and adjust / truncate / expand / split / delete existing segments
such as to retain the *Invariant* (seamless segmentation covering
the complete time axis)
- how to pass-in a specification given as GenNode
- now this might be translated into a MockJobTicket allocated in the MockSegmentation
Unimplemented: actually build the Segment with suitable start/end time
right now we're lacking a complete working implementation of render node invocation,
and thus the Dispatcher implementation can only be verified with the help
of mocked jobs. However, at least a preliminary implementation of tagging the
invocation instance is available, and thus we're able to verify that
a given job instance indeed belongs to and is "backed" by a specific JobTicket.
This is prerequisite for building up a (likewise mocked) Fixture datastructure,
and this in turn was meant to form the basis for attacking an actual Scheduler
implementation, followed by a real render node invocation.
- can now create a Job from JobTicket::NIL
- on invocation this Job will to nothing
Only when the first real output backend is implemented,
we can decide if this simplistic implementation is enough,
or if an empty output must be explicitly generated...
* using a simplified preliminary implementation of hash chaining (see #1293)
* simplistic implementation of hashing for time values (half-rotation)
* for now just hashing the time into the upper part of the LUID
Maybe we can even live with that implementation for some time,
depending on how important uniform distribution of hash values is
for proper usage of the frame cache.
Needless to say, various further fine points need more consideration,
especially questions of portability (32bit anyone?). Moreover, since
frame times are typically quantised, the search space for the hashed
time values is drastically reduced; conceivably we should rather
research and implement a good hash function for 128bit and then combine
all information into a single hash key....
...using the MockJobTicket setup as point of reference,
since the actual invocation of render nodes will only be drafted
later in this "Vertical Slice" integration effort...
- introduce a JobTicket::NOP (null-object pattern)
- assuming that the function splitSplice() will retain complete coverage allways
Remark:
`Fixture::getPlaylistForRender()` is a leftover from the very early implementation drafts.
This function was more or less based on the way Cinelerra works; it is clear by now
that Lumiera can not possibly work this way, given that we'll build a low-level model
and dispatch precompiled render jobs....
The idea is to escape a "design deadlock" by using a test-driven prototype
implementation of the data structure to back a further development
of the Dispatcher and Scheduler implementation, which then can be used
to gradually elaborate and switch over to an actual implementation
data structure
...requires a first attempt towards defining a `JobTiket`.
This turns out quite tricky, due to using those `LinkedElements`
(intrusive single linked list), which requires all added records
actually to live elsewhere. Since we want to use a custom allocator
later (the `AllocationCluster`), this boils down to allocating those
records only when about to construct the `JobTicket` itself.
What makes matters even worse: at the moment we use a separate spec
per Media channel (maybe these specs can be collapsed later non).
And thus we need to pass a collection -- or better an iterator
with raw specs, which in turn must reveal yet another nested
sequence for the prerequisite `JobTickets`.
Anyhow, now we're able at least to create an empty `JobTicket`,
backed by a dummy `JobFunctor`....
- build the reworked Job-planning pipeline more or less from scratch
- back that with mocked `Dispatcher` and `JobTicket`
- then transfer this into a `RenderDrive`, which can be tested as well
- could continue then to a `CalcStream` integration test....
- introduce a new entity: RenderDrive
- it supersedes the CalcPlanCalculation, but is managed by CalcStream
- moreover, the RenderDrive will house a IterTreeExplorer-Pipeline
- define the concerns and relationships more clearly (see Drawing)
- prerequisite to disentangle the Job-planning "mechanics"
- decision: the Monad-style iteration framework will be abandoned
- the job-planning will be recast in terms of the iter-tree-explorer
- job-planning and frame dispatch will be disentangled
- the Scheduler will deliberately offer a high-level interface
- on this high-level, Scheduler will support dependency management
- the low-level implementation of the Scheduler will be based on Activity verbs
This finishes a long lasting effort to rework the top-level of the Lumiera GTK UI,
to adapt to GTK-3 and the new asynchronous message based architecture.
Special credits and thanks to
* Joel Holdsworth
* Stefan Kangas
Without their relentless foundational work, the Lumiera UI could
never be where it is now. Even if some code was rewritten and several
parts of the old GTK-2 implementation are now obsolete, numerous ideas
solutions and inspirations were drawn from those early contributions
and live on as part of the reworked GUI.
for sake of developement of the timeline body drawing code,
several tweaks were added to make the impact of the styling stand
out clearly. This changeset removes all those tweaks and restors
the code to intended neutral behaviour
Moreover, the cursom drawing of the timeline now requires some
basic aids to be present in the stylesheet, otherwise the track structure
will not be visible. Thus add some minimalistic styling to the
"light-theme-complement"-stylesheet, mostly based on the usual
predefined theme colours and some box-shadow settings.
This is by no means an adequate graphical solution,
yet it should be enough to get on with coding....
check private notes and mindmap and fix some remaining minor inconsistencies,
notably the calculations in the overlay renderer in the `BodyCanvasWidget`.
The drawing code extracts style information from some "virtual"
widgets, which serve as logical placeholder for the actual nested
structure of tracks.
For sake of demonstration, I used rather obvious colours and
also all kinds of margin and padding; a screenshot was added
with annotations to indicate where some specific style settings
are utilised from the drawing code
Not sure if the initial window width is used properly for calibration
of ZoomWindow "pixel width" base setting.
Follow-up to the layout logic established with this commit:
09714cfe28
An extended round of rebuilding and reworking the global UI structures
can be concluded now. A flexible recursive structure of Tracks has
been implemented for the new Timeline-UI, allowing to contro all
relevant aspects of structure composition by **Diff Messages** sent
up from the Steam-Layer into the UI.
Moreover, the ability to control the custom drawing code through regular
**CSS style rules** has been demonstrated, allowing for seamless integration
of Lumiera UI elements with the existing desktop theme.
This completes the initial implementation round for the TrackHead.
- arrangement and layout for nested sub-Tracks is now settled
- a graphical representation of scope nesting was implemented
Postponed for later...
- still some minor discrepancies on synchronisation of vertical space
between TrackHead and custom drawing in the body (off-by-one?)
- Expanding / Collapsing of Tracks
- Implement actual Controls to influence the Scope, e.g. Volume, Mix-Mode
- Dynamically indicate selection and Muting on the structure display
While by default the Cairo Context is scaled to device units,
we must not assume that the given Context is unscaled; rather
it might have been deliberately scaled...
A notable example is the Gtk Inspector, which offers a "Magnifier" feature
- pick up all relevant values from CSS
- also control the width of the StaveBracket
- observe the given overall height
Moreover, complete documentation drawing in Inkscape
and add a page to the TiddlyWiki, describing the principles
underlying this design and construction.
.timeline__head : The complete header container on the left side
.timeline__navi : navigation control at top
.timeline__pbay : container holding the patchbay on the left side
.fork__head : each individual TrackHeadWidget (possibly nested)
.fork__control : container for the control components for each track scope
.fork__bracket : the StaveBracket drawing to indicate the nesting structure
The tricky part is to derive the anchor point for the upper
and the lower cap of the bracket, taking into account possible padding.
There seems to be a bug hidden somewhere in this logic, since the
line turns out too short at the lower end....?
According to the documentation, we should be able to get a Pango
font description from the CSS style context, and from there we should
be able to retrieve a font-size specification (and a DPI for the display)
Running this experimental code yields a font-size value of 9pt,
leading to a scale factor of about ~6, which seems plausible.
after weighting in the pro, and cons,
I decided to follow the standard path and pick up values
for each StaveBracket instance individually from Gtk::StyleContext,
assuming that the GTK framework will care for caching and performance
Identify the elements of the construction geometry in the "Sketch"
object in the FreeCAD document and paste the corresponding coordinate
values into the SVG drawing prepared for documentation.
The arc segment parameters seemingly are given in radians;
and while FreeCAD uses the common mathematical right-handed orientation,
the orientation in SVG is applied clockwise rather.
...since the construction is determined now (and was worked out in FreeCAD),
the SVG will serve to document the construction; thus the drawing
primitives are rearranged to use the unscaled reference coordinates
to be extracted from the FreeCAD document; all scaling and placement
in the SVG document will be applied through common groups.
