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2022-06-10til: introduce til_frame_plan_t and .cpu_affinityVito Caputo
modules/checkers w/fill_module=$module requires a consistent mapping of cpu to fragnum since it creates a per-cpu til_module_context_t for the fill_module. The existing implementation for threaded rendering maximizes performance by letting *any* scheduled to run thread advance fragnum atomically and render the acquired fragnum indiscriminately. A side effect of this is any given frame, even rendered by the same module, will have a random mapping of cpus/threads to fragnums. With this change, the simple til_module_t.prepare_frame() API of returning a bare fragmenter function is changed to instead return a "frame plan" in til_frame_plan_t. Right now til_frame_plan_t just contains the same fragmenter as before, but also has a .cpu_affinity member for setting if the frame requires a stable relationship of cpu/thread to fragnum. Setting .cpu_affinity should be avoided if unnecessary, and that is the default if you don't mention .cpu_affinity at all when initializing the plan in the ergonomic manner w/designated initializers. This is because the way .cpu_affinity is implemented will leave threads spinning while they poll for *their* next fragnum using atomic intrinsics. There's probably some room for improvement here, but this is good enough for now to get things working and correct.
2022-06-10til: add ticks to til_module_context_tVito Caputo
Also wire this up to the til_module_context_new() helper and all its callers. This is in preparation for modules doing more correct delta-T derived animation.
2022-05-29*: pivot to til_module_context_tVito Caputo
- modules now allocate their contexts using til_module_context_new() instead of [cm]alloc(). - modules simply embed til_module_context_t at the start of their respective private context structs, if they do anything with contexts - modules that do nothing with contexts (lack a create_context() method), will now *always* get a til_module_context_t supplied to their other methods regardless of their create_context() presence. So even if you don't have a create_context(), your prepare_frame() and/or render_fragment() methods can still access seed and n_cpus from within the til_module_context_t passed in as context, *always*. - modules that *do* have a create_context() method, implying they have their own private context type, will have to cast the til_module_context_t supplied to the other methods to their private context type. By embedding the til_module_context_t at the *start* of their private context struct, a simple cast is all that's needed. If it's placed somewhere else, more annoying container_of() style macros are needed - this is strongly discouraged, just put it at the start of struct. - til_module_create_context() now takes n_cpus, which may be set to 0 for automatically assigning the number of threads in its place. Any non-zero value is treated as an explicit n_cpus, primarily intended for setting it to 1 for single-threaded contexts necessary when embedded within an already-threaded composite module. - modules like montage which open-coded a single-threaded render are now using the same til_module_render_fragment() as everything else, since til_module_create_context() is accepting n_cpus. - til_module_create_context() now produces a real type, not void *, that is til_module_context_t *. All the other module context functions now operate on this type, and since til_module_context_t.module tracks the module this context relates to, those functions no longer require both the module and context be passed in. This is especially helpful for compositing modules which do a lot of module context creation and destruction; the module handle is now only needed to create the contexts. Everything else operating on that context only needs the single context pointer, not module+context pairs, which was unnecessarily annoying. - if your module's context can be destroyed with a simple free(), without any deeper knowledge or freeing of nested pointers, you can now simply omit destroy_context() altogether. When destroy_context() is missing, til_module_context_free() will automatically use libc's free() on the pointer returned from your create_context() (or on the pointer that was automatically created if you omitted create_context() too, for the bare til_module_context_t that got created on your behalf anyways). For the most part, these changes don't affect module creation. In some ways this eases module creation by making it more convenient access seed and n_cpus if you had no further requirement for a context struct. In other ways it's slightly annoying to have to do type-casts when you're working with your own context type, since before it was all void* and didn't require casts when assigning to your typed context variables. The elimination for requiring a destroy_context() method in simple free() of private context scenarios removes some boilerplate in simple cases. I think it's a wash for module writers, or maybe a slight win for the simple cases.
2022-05-21modules/*: first stab at utilizing supplied seedsVito Caputo
This is a mostly mechanical change of using rand_r() in place of rand(), using the provided seed as the seed state. There's some outstanding rand()s outside of create_context() which should probably get switched over, with the seed being stowed in the context struct. I didn't bother going deeper on this at the moment in the interests of getting to sleep soon.
2022-05-21til: supply a seed to til_module_t.create_context()Vito Caputo
In the recent surge of ADD-style rtv+compose focused development, a bunch of modules were changed to randomize initial states at context_create() so they wouldn't be so repetitive. But the way this was done in a way that made it impossible to suppress the randomized initial state, which sometimes may be desirable in compositions. Imagine for instance something like the checkers module, rendering one module in the odd cells, and another module into the even cells. Imagine if these modules are actually the same, but if checkers used one seed for all the odd cells and another seed for all the even cells. If the modules used actually utilized the seed provided, checkers would be able to differentiate the odd from even by seeding them differently even when the modules are the same. This commit is a step in that direction, but rototiller and all the composite modules (rtv,compose,montage) are simply passing rand() as the seeds. Also none of the modules have yet been modified to actually make use of these seeds. Subsequent commits will update modules to seed their pseudo-randomized initial state from the seed value rather than always calling things like rand() themselves.
2022-05-01til_fb: add draw flags for controlling texturabilityVito Caputo
Just adds TIL_FB_DRAW_FLAG_TEXTURABLE so callers can granularly inhibit texturing if desired.
2022-05-01modules/*: make use of generic fragmentersVito Caputo
Just one case, modules/submit, was using 32x32 tiles and is now using 64x64. I don't expect it to make any difference. While here I fixed up the num_cpus/n_cpus naming inconsistencies, normalizing on n_cpus.
2022-05-01til: wire n_cpus up to the fragmenter functionVito Caputo
Fragmenting is often dimensioned according to the number of cpus, and by not supplying this to the fragmenter it was made rather common for module contexts to plumb this themselves - in some cases incorporating a context type/create/destroy rigamarole for the n_cpus circuit alone. So just plumb it in libtil, and the prepare_frame functions can choose to ignore it if they have something more desirable onhand. Future commits will remove a bunch of n_cpus from module contexts in favor of this.
2022-04-24*: s/void */til_setup_t */Vito Caputo
This brings something resembling an actual type to the private objects returrned in *res_setup. Internally libtil/rototiller wants this to be a til_setup_t, and it's up to the private users of what's returned in *res_setup to embed this appropriately and either use container_of() or casting when simply embedded at the start to go between til_setup_t and their private containing struct. Everywhere *res_setup was previously allocated using calloc() is now using til_setup_new() with a free_func, which til_setup_new() will initialize appropriately. There's still some remaining work to do with the supplied free_func in some modules, where free() isn't quite appropriate. Setup freeing isn't actually being performed yet, but this sets the foundation for that to happen in a subsequent commit that cleans up the setup leaks. Many modules use a static default setup for when no setup has been provided. In those cases, the free_func would be NULL, which til_setup_new() refuses to do. When setup freeing actually starts happening, it'll simply skip freeing when til_setup_t.free_func is NULL.
2022-03-30*: wire up context-specific setup instancesVito Caputo
This is a preparatory commit for cleaning up the existing sloppy global-ish application of settings during the iterative _setup() call sequences. Due to how this has evolved from a very rudimentary thing enjoying many assumptions about there ever only being a single module instance being configured by the settings, there's a lot of weirdness and inconsistency surrounding module setup WRT changes being applied instantaneously to /all/ existing and future context's renderings of a given module vs. requiring a new context be created to realize changes. This commit doesn't actually change any of that, but puts the plumbing in place for the setup methods to allocate and initialize a private struct encapsulating the parsed and validated setup once the settings are complete. This opaque setup pointer will then be provided to the associated create_context() method as the setup pointer. Then the created context can configure itself using the provided setup when non-NULL, or simply use defaults when NULL. A future commit will update the setup methods to allocate and populate their respective setup structs, adding the structs as needed, as well as updating their create_context() methods to utilize those setups. One consequence of these changes when fully realized will be that every setting change will require a new context be created from the changed settings for the change to be realized. For settings appropriately manipulated at runtime the concept of knobs was introduced but never finished. That will have to be finished in the future to enable more immediate/interactive changing of settings-like values appropriate for interactive manipulation
2022-03-19*: drop til_module_t.licenseVito Caputo
Originally the thinking was that rototiller modules would become dlopen()ed shared objects, and that it would make sense to let them be licensed differently. At this time only some modules I have written were gplv3, Phil's modules are all gplv2, and I'm not inclined to pivot towards a dlopen model. So this commit drops the license field from til_module_t, relicenses my v3 code to v2, and adds a gplv2 LICENSE file to the source root dir. As of now rototiller+libtil and all its modules are simply gplv2, and anything linking in libtil must use a gplv2 compatible license - the expectation is that you just use gplv2.
2021-10-01*: librototiller->libtilVito Caputo
Largely mechanical rename of librototiller -> libtil, but introducing a til_ prefix to all librototiller (now libtil) functions and types where a rototiller prefix was absent. This is just a step towards a more libized librototiller, and til is just a nicer to type/read prefix than rototiller_.
2021-02-14*: split rototiller.[ch] into lib and mainVito Caputo
This is a first approximation of separating the core modules and threaded rendering from the cli-centric rototiller program and its sdl+drm video backends. Unfortunately this seemed to require switching over to libtool archives (.la) to permit consolidating the per-lib and per-module .a files into the librototiller.a and linking just with librototiller.a to depend on the aggregate of libs+modules+librototiller-glue in a simple fashion. If an alternative to .la comes up I will switch over to it, using libtool really slows down the build process. Those are implementation/build system details though. What's important in these changes is establishing something resembling a librototiller API boundary, enabling creating alternative frontends which vendor this tree as a submodule and link just to librototiller.{la,a} for all the modules+threaded rendering of them, while providing their own fb_ops_t for outputting into, and their own settings applicators for driving the modules setup.
2020-02-21modules/snow: use rand() on WIN32Vito Caputo
My current version of mingw in debian 9.11 doesn't seem to have rand_r(), so let's just use plain rand() and lose the improved parallelization on win builds.
2020-01-25rototiller: introduce ticks and wire up to modulesVito Caputo
Most modules find themselves wanting some kind of "t" value increasing with time or frames rendered. It's common for them to create and maintain this variable locally, incrementing it with every frame rendered. It may be interesting to introduce a global notion of ticks since rototiller started, and have all modules derive their "t" value from this instead of having their own private versions of it. In future modules and general innovations it seems likely that playing with time, like jumping it forwards and backwards to achieve some visual effects, will be desirable. This isn't applicable to all modules, but for many their entire visible state is derived from their "t" value, making them entirely reversible. This commit doesn't change any modules functionally, it only adds the plumbing to pull a ticks value down to the modules from the core. A ticks offset has also been introduced in preparation for supporting dynamic shifting of the ticks value, though no API is added for doing so yet. It also seems likely an API will be needed for disabling the time-based ticks advancement, with functions for explicitly setting its value. If modules are created for incorporating external sequencers and music coordination, they will almost certainly need to manage the ticks value explicitly. When a sequencer jumps forwards/backwards in the creative process, the module glue responsible will need to keep ticks synchronized with the sequencer/editor tool. Before any of this can happen, we need ticks as a first-class core thing shared by all modules. Future commits will have to modify existing modules to use the ticks appropriately, replacing their bespoke variants.
2019-11-24snow: only create n_cpus fragmentsVito Caputo
Since snow_context_t needs another member anyways, stick n_cpus in there to inform the fragmenter of precisely how many fragments to make. This renderer doesn't benefit from tiling or any such locality, so it uses the slice fragmenter and really only benefits from as many fragments as there are CPUs. Any additional fragments is just wasted fragmenting overhead.
2019-11-24snow: per-cpu rand_r() seed stateVito Caputo
Snow was already threaded, but used a global seed with rand_r() meaning the CPUs were hammering on the same address. There wasn't any locking or atomics, as it isn't terribly critical when generating white noise if the seed access is racy. But the writes still caused cache lines to ping-pong. This commit gives a ~15.5% speedup in my measurements on an i7-2640M. Note without the padded union, using just an array of ints, zero gain is realized. I used a padding of 256 just to have some headroom, x86 is 64 but other CPUs vary, POWER9 is 128 for example.
2019-11-24rototiller: rototiller_fragmenter_t s/num/number/Vito Caputo
Mechanical change removing abbreviation for consistency
2019-11-23rototiller: pass cpu to .render_fragment()Vito Caputo
Mostly mechanical change, though threads.c needed some jiggering to make the logical cpu id available to the worker threads. Now render_fragment() can easily addresss per-cpu data created by create_context().
2019-11-14snow: add a simple tv snow / white noise moduleVito Caputo
I wanted to add some noise to the rtv module and figured why not just add a snow module and make rtv pass through it briefly when switching modules. It's not interesting by itself, but as more composite/meta modules like rtv get made it might be handy beyond rtv.
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