Commit Graph

42 Commits

Author SHA1 Message Date
Brian Osman
4d76f63e45 Fix particle bug where uniforms are allocated too late
Also adds an example particle system that uses uniforms, and an instance
of the particles GM that draws it.

Change-Id: I64e2514fd17c8ce615b4e13b9f82424f80b8424e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/356840
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
2021-02-03 22:50:28 +00:00
Brian Osman
c81378624f Update all example particle data to new single-code-chunk format
Change-Id: Ic53dc7ecab1b44761fe06e6b528864d24cc5fa58
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/363940
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-02-02 18:07:53 +00:00
Brian Osman
38d8deae8f Revert "Add particle GM that uses uniforms, fix related bug in particle effect"
This reverts commit 964b4465c4.

Reason for revert: Earlier CL needs revert

Original change's description:
> Add particle GM that uses uniforms, fix related bug in particle effect
>
> We weren't allocating uniform storage until after the first update, far
> too late for users to pump uniform values in. They're now allocated as
> soon as the effect is created, which is tested by the new GM.
>
> Change-Id: Ia0084bcec5986479c350ead27d14344c3ed82520
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/362176
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Brian Osman <brianosman@google.com>

TBR=brianosman@google.com

Change-Id: Ib6f963840af2abba0a4e6b99185f4010b61dde54
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/362418
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-01-29 19:21:49 +00:00
Brian Osman
964b4465c4 Add particle GM that uses uniforms, fix related bug in particle effect
We weren't allocating uniform storage until after the first update, far
too late for users to pump uniform values in. They're now allocated as
soon as the effect is created, which is tested by the new GM.

Change-Id: Ia0084bcec5986479c350ead27d14344c3ed82520
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/362176
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-01-29 18:01:48 +00:00
Brian Osman
ea485e5285 Enforce ES2 limits on indexing expressions (in runtime effects)
This enforces an even stricter version of the rules from GLSL ES 1.0
Appendix A, Section 5. Essentially, indices (to arrays, vectors,
matrices) must be made of literals, loop indices, and expressions made
of those two.

Bug: skia:10837
Bug: skia:11096
Change-Id: I437a5ed64da58e24d5991ddbde68859f5214e98b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/354665
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
2021-01-15 22:49:27 +00:00
Brian Osman
bf061a32ef Fix an (int + float) error in "cube" particle demo
Also fix a crash if you try to play an effect that has never compiled
correctly. (After the first compile, the arrays were always large enough
to set "dt" -- this code is all going to be reworked soon for SkVM, but
I hit this while diagnosing the type coercion error).

Change-Id: I5bfab539c7304bde2da36b0b0604991d5b5b303a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/354660
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-01-15 19:15:16 +00:00
Brian Osman
fb79f9faa4 Remove all particle examples that use SkEffectBinding
I'm going to remove this feature to simplify migration to skvm.
fireworks was updated to work without it. raincloud is fairly complex,
and not that attractive, so it's just being deleted.

Change-Id: Id2d5cd490baa7bae627002f41edf7522c8bdfcd8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/353076
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-01-12 19:09:18 +00:00
Brian Osman
2ae02492a7 Remove use of do-while loops from particle examples
This was unnecessary (closed-form unit-disc picking is simpler), and
these loops don't meet the strict ES2 standards that we'll be applying
to the interpreter soon.

Bug: skia:11095
Change-Id: Ic2617c2807fe49d57ff8e4d57d70b9ed1f015916
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/348895
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2020-12-30 21:30:40 +00:00
Brian Osman
e11c43804b Remove use of uint from particle random system
uint (and bitwise operations) aren't supported by our minimum spec, and
they're going to be removed from public SkSL. For now, convert the
random generator to a good-enough chaotic sequence of high-frequency
sine waves.

If/when the interpreter (and particles) are converted to the newer skvm
backend, it will be straightforward to support custom intrinsics that
emit skvm instructions directly into the builder, and re-introduce a
better integer-based PRNG, without requiring SkSL language support.

Bug: skia:11093
Change-Id: I885b15a51a9e5c12b4274b5938d8deb77219d41b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/347036
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2020-12-23 16:21:17 +00:00
Brian Osman
ba2c246259 Simplify raincloud particle effect
The 'flags' field is going away soon (per public SkSL minimum spec), and
the only use of that feature was for this one example. The alternative
is simpler to understand, too.

Bug: skia:11093
Change-Id: I18a85bd48316301edc44c691fbe20f93da243e2f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/346776
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2020-12-22 20:39:38 +00:00
Brian Osman
e7f68f3644 Tweak ParticlesSlide's resource provider to show how to use PathBinding
Adds an example effect that spawns particles along an SkPath.

Change-Id: I53f3c02fefec814bd9e16f3ac593eac4cf6a297c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/341418
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2020-12-07 17:26:39 +00:00
Brian Osman
95c26efc90 Pure SkSL RNG for particles
Change-Id: I2cb6255a553852a292427d6dc9ef8c5ed7f8286d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/252926
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Mike Reed <reed@google.com>
2020-04-10 17:20:07 +00:00
Brian Osman
db2e7641be Particles: SkImageBinding to allow sampling an image from script
Provides functionality similar to AE property maps

Change-Id: I1705706a6b7e25fbab55465f2e20d0b145330b0b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/255977
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-12-03 15:22:20 +00:00
Brian Osman
d12f2786e2 Use ResourceProvider in particles
Currently just for image drawable, but going to use this for
references to other kinds of data in bindings, too.

Change-Id: Ic6673530013337bbaadd2d3f1c040626ec24ffb8
Bug: skia:9513
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/256776
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
2019-11-27 16:45:23 +00:00
Brian Osman
eddfc3562f Particles: Fake 3D example
Change-Id: I6d29290eb2962262bb080a86dc829c39986cae4f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/249226
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-10-17 20:10:05 +00:00
Brian Osman
e8bcc56951 Fix a couple minor bugs in particle code
- Copy effect state to particle uniforms before each script, so changes
  from spawn or update are visible.
- Guard path binding against out of range access
- New effect that actually stresses both of these conditions

Change-Id: Ice6112793099e515438af8bb863e9e1bf03d08b1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/249125
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-10-17 14:55:34 +00:00
Brian Osman
5b43113e75 Interpreter: Reflect all uniform variables in ByteCode
Gives enough information to locate variables by name (using the same
scheme as glGetUniformLocation), and provide hints about type and size.

Bug: skia:9513
Change-Id: I9444f1042471967a79c9f05167dcdb78eca41bad
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/244502
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-10-16 15:35:48 +00:00
Brian Osman
df18296f98 Add accessors to get/set SkParticleEffect fields
Simplify burst handling. Scripts should just add to burst (if
they want to handle programmatic bursting, as well).

Update most effects to handle dynamic updates to position better,
and add a sample effect meant to be used with mouse tracking.

Change-Id: Ia302e1d04e62e2b07974807c44067786cc10a8ad
Bug: skia:9513
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/248798
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2019-10-15 14:54:50 +00:00
Brian Osman
7edfb69406 Remove SkCurve and SkColorCurve
This was only being used in one effect (and for no good reason). SkSL is
plenty powerful to re-implement something similar if required, at no
real performance cost.

Re-implemented the one effect that used it with simpler math in the
script, updated the copy of that effect in the gallery.

Docs-Preview: https://skia.org/?cl=247040
Change-Id: I68c86d6550dd4f003f6ba5ecd0febab37b86540b
Bug: skia:9513
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/247040
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-10-08 15:38:20 +00:00
Brian Osman
647c7a97d3 Particles: New confetti effect, minor tweaks elsewhere
Confetti mimics the look of a standard skottie asset

Change-Id: Iffeedeb24182c4ac2d3ec390614bc1861b821376
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/246518
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-10-07 14:06:56 +00:00
Brian Osman
559ffe4a23 Particles: Added particle flags for tracking state (one-time triggers, etc)
Also removed some older effects that weren't interesting, improved others,
cleaned up the unused functions in several, and renamed most of them to
reflect which feature they're demonstrating.

Change-Id: Ib44a00ec3d25e852a1d1661918137ba13d30c86b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/244119
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-09-25 15:58:09 +00:00
Brian Osman
9a8b846baf Particles: Sub-effect spawning and some slight refactoring
* Added a new binding type, SkEffectBinding. This stores another
  entire effect params structure (so the JSON is just nested).
  The name is a callable value that spawns a new instance of
  that effect, inheriting the parameters of the spawning effect
  or particle (depending on which kind of script made the call).
* Broke up the monolithic update function into some helpers,
  got some code reuse with the script calling logic.
* Unlike particle capacity, there is no upper limit on child
  effects (yet), so it's easy to trigger runaway memory and
  CPU consumption. Be careful.
* Added death scripts to effects and particles, which are a
  common place to want to spawn sub-effects. Like spawn,
  these run on each loop, but for one-shots they play at the
  end. Even with loops, this is helpful for timing sub-effects
  (see fireworks2.json).
* Finally, added a much more comprehensive example effect,
  raincloud.json. This includes a total of three effects, to
  generate a cloud, raindrops, and splashes when those drops
  hit "the ground".

Change-Id: I3d7b72bcbb684642cd9723518b67ab1c7d7a538a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/242479
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-09-19 15:18:13 +00:00
Brian Osman
d46cb9729b Particle effect scripting update
This change adds another layer of complexity and control to
the particle system. There are now two code chunks: the old
code that's run per-particle, and new code that's run for
the effect itself. This allows for effect lifetime to be set
by the script (eg, randomly), as well as the emission rate.
Rate can vary over time (see pulse.json), and particles can
be emitted in bursts by setting the effect's burst field
(see fireworks.json).

Additionally, the effect has its own frame of reference and
color, which becomes the default state for newly emitted
particles. This allows synchronizing state across particles
in various interesting ways (see color in fireworks.json).

Change-Id: Iec2f7a3427ce1d6411ed7ef5b3023cbef2e8a134
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/240498
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-09-16 17:48:04 +00:00
Brian Osman
8a97782956 Move common particle code to an automatically-injected header
Change-Id: If99e1802c8187ebd98b67717d744c6695bb25900
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/238118
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-08-29 18:49:33 +00:00
Brian Osman
e59acb79b8 Particles: Merge spawn & update into one code string with two functions
Change-Id: If57fb79db8f8c5fd185fefaa202167c8082dd846
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/229921
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-07-25 23:51:07 +00:00
Brian Osman
d6108add51 Particles: Use list of lines for multi-line string serialization
Change-Id: Ic81b3433b485ca9ce0e60bd10ec12706e673ee89
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/229917
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Auto-Submit: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
2019-07-25 20:55:43 +00:00
Brian Osman
fe49163cd1 Major rewrite of the particle system based on the SkSL interpreter
This removes all of the fixed-function particle affector classes.
Instead, each particle effect just has two SkSL snippets, one for
spawn logic, and one for update logic. Each one gets an inout copy
of the particle struct. Ultimately, this makes the effects much
simpler and smaller, while also being far more flexible (you can
do whatever you want with any values you want). Finally, because
the interpreter is vectorized and a particular effect's scripts
are usually tuned to the specific behaviors desired, it's faster
on basically every effect I compared.

I re-created all of the old effects in the new system. Many just
use pure SkSL (no curves or anything). Some of the old curve and
path/text stuff was very handy, though - so those are now exposed
as external values in the interpreter. Basically, an effect can
have any number of named "bindings" that are a callable thing.
This can be a path, text (shortcut for making fancy paths), curve,
or color curve. The path ones return a float4 with position and
normal, the curves return one or four floats.

... and this transposes all of the particle data storage into
SoA form, so that it can use the much faster interpreter entry
point.

Change-Id: Iebe711c45994c4201041b12d171af976bc5e758e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/222057
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Reed <reed@google.com>
2019-07-25 19:59:03 +00:00
Brian Osman
4c63a1eada Particles + Interpreter: Bind particle's SkRandom to "rand"
Update sample effects to use that (and remove the need for the
hacky workaround "random -> frame" affector I was using).

Current perf on my workstation, 6k particles updating:
native: 0.67 ms
interp: 0.97 ms

Change-Id: I3a2168c210d7431ffffe2b87ab6adade69f1dce7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/214190
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-05-17 14:29:22 +00:00
Brian Osman
c04cadbb6e Prototype interpreter particle affector
Change-Id: Ib440570ecbd46b5bc98d346592cbbb72f58ae85a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/212500
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2019-05-09 18:37:46 +00:00
Kevin Lubick
966348413f [particles] Clean up build - remove test deps
Bug: skia:
Change-Id: I499262277ac1c8d92a39a66f6e846e248b102aef
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/197767
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
2019-03-05 20:44:10 +00:00
Brian Osman
bdcdf1a7c3 Add SkParticleValue to allow further customization of curve behavior
All curves (and path affectors) are driven by an SkParticleValue. The
value can derive its value from the current defaults (age of particle
or effect), or explicitly choose the other one, a random value, or any
other particle value. Values can be range adjusted and support repeat,
clamp, and mirror tiling.

Also fixed some more issues related to resource path in the slide GUI.

Bug: skia:
Change-Id: I4755018d5b57ae2d5ec400d541055ca4fb542978
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/196760
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-03-04 22:04:17 +00:00
Brian Osman
3d76d1bf46 Particles: Removed emitters, added more full-featured position affectors
Bug: skia:
Change-Id: Ie6485a11bb57fecef470d727dcf3b4fe5dff0b90
Reviewed-on: https://skia-review.googlesource.com/c/195582
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-02-28 21:16:02 +00:00
Brian Osman
34d1331323 Particles: Improvements to SkCurve
Added explicit Linear segment type, merge math evaluation helpers for
scalar and color curves. Add logic to visitFields that cuts down on the
serialized size of simple curves, and makes the GUI easier to work with.

Remove the curve plot from the GUI. It was incorrect (wrong points at
cubic handle locations), not terribly helpful, and difficult to
maintain.

Bug: skia:
Change-Id: I190cb5d118b1f4b910984e4df50ee3351c8be895
Reviewed-on: https://skia-review.googlesource.com/c/195884
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-02-27 16:46:29 +00:00
Brian Osman
e5d532edae Particles: remove non-stable random, add better enum reflection
The other generator was never used (or useful). String-based serialization
of enums is quite helpful, though.

Bug: skia:
Change-Id: Ic9d58f8d20cfe7aba47722bd74f1e6f8f0f219e5
Reviewed-on: https://skia-review.googlesource.com/c/195368
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2019-02-26 20:29:56 +00:00
Brian Osman
0c48681e58 Few more particle features and some generalization work
Add particle "frame" enum, to allow effects relative to local, world,
or velocity. Remove the "orient along velocity" and replace with a much
more general orientation affector (angle curve + frame). Add an angular
velocity affector to mirror the behavior of the linear velocity affector.

Bug: skia:
Change-Id: Ibbaaeb352c9547d00d81c7916d00148dd65ed2b9
Reviewed-on: https://skia-review.googlesource.com/c/195361
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-02-26 15:56:24 +00:00
Brian Osman
d5c57fe289 Add local vs world flag for particle velocity
Adjust reference frame for affector to be consistent (so angles are
counted clockwise from "up" in both local and world modes).

Bug: skia:
Change-Id: I643e1484bc0a58d1f1c0cfe35ac2ab37dc2ea409
Reviewed-on: https://skia-review.googlesource.com/c/194189
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-02-22 17:45:25 +00:00
Brian Osman
d8e1ee9a66 Refactor particle age logic
Move to a model that only needs floats, and puts the age in the
SkParticleState struct. Add a better test case for spawn affector
animation, to verify that things are still working.

Bug: skia:
Change-Id: I97d99de5f5d4cb302b76116e67ecc93368fb1677
Reviewed-on: https://skia-review.googlesource.com/c/193580
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2019-02-20 19:55:20 +00:00
Brian Osman
125daa4d1a Refactor and further generalization of particle model
- Collapsed the per-particle data into a single struct, and
  use that to communicate with drawables, too. Let the drawables
  manage allocation of xforms, colors, etc. Helpful for non-atlas
  drawables, and just to keep the effect code simpler.
- Having all of the params in a single struct allows us to move
  the remaining animated behaviors into affectors (color/frame).
- Added SkColorCurve, which works like SkCurve for SkColor4f.
  Use that to create a color affector (rather than simple
  start/end colors in the effect params).
- Also put the stable random in SkParticleState. This is going
  to be necessary if/when we change affectors to operate on all
  particles (rather than one at a time). Still need to move t
  value into the particle struct (or eval it from the lifetime
  params on demand).

Change-Id: Icf39116acbfd5d6e8eb91e9affbd8898d106211d
Reviewed-on: https://skia-review.googlesource.com/c/193473
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-02-20 18:01:00 +00:00
Brian Osman
543d2e2f2e Moved image params out to SkParticleDrawable
Added a simpler circle drawable, moved drawing code out so that frame
calculation is handled by the drawable. Fixed all the sample effects,
including some size adjustments to better create the intended effect.

Bug: skia:
Change-Id: I60af9cd6262ff98352ca8ceaf6768aef9c7e164c
Reviewed-on: https://skia-review.googlesource.com/c/193029
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-02-15 20:07:43 +00:00
Brian Osman
8b6283fc98 New SkCurve type with multiple curve segments
- Converted all linear force stuff into a single affector,
  used at either spawn or update time appropriately.
  The new affector can either set or adjust velocity.
- Converted lifetime to a curve.
- Removed SkRangedFloat, initial velocity params, etc.

Looks like a large addition, but that's mostly down to the
JSON getting bigger. There's a net reduction in LoC.

Bug: skia:
Change-Id: Iac7417f15f96d0313efd08c4b26dc3250b80fa77
Reviewed-on: https://skia-review.googlesource.com/c/192102
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-02-15 14:10:39 +00:00
Brian Osman
5c1f8eb094 Various particle system improvements
Effects now have a duration, and can be played looped
or one-shot. Added a second list of affectors that are
applied at spawn vs. update.

Effects grab and store the SkRandom at construction,
so it no longer needs to be passed to update().

Bug: skia:
Change-Id: Ib54d60466e162e4d4b70fa64c1215fc01680d47a
Reviewed-on: https://skia-review.googlesource.com/c/191722
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2019-02-14 20:19:08 +00:00
Brian Osman
7c979f52c3 Experimental Particle System
This adds a new "Particles" slide to viewer, that allows
editing, loading, and saving particle effects. All of the
particle system code is in modules/particles.

There are many rough edges and some not-yet-finished changes
to generalize the model[1]. A rough overview:

- SkReflected.h implements a lightweight reflection system
  for classes derived from SkReflected. Adding a new class
  involves deriving from SkReflected, adding a macro to the
  class declaration, and implementing visitFields(), which
  simply calls a virtual on an SkFieldVisitor for each field.
  Currently, emitters and affectors use this mechanism.

- SkParticleSerialization.h demonstrates two useful field
  visitors - for serializing to and from JSON. The driver
  code that uses those is directly in ParticlesSlide.

- SkParticleData.h and SkCurve.h define a variety of helper
  types for talking about particles, both for parameterizing
  individual values, and communicating about the state of a
  particle among the effect, affectors, and emitters.

- SkParticleEffect.h defines the static data definition of
  an effect (SkParticleEffectParams), as well as a running
  instance of an effect (SkParticleEffect). The effect has
  simple update() and draw() methods.

- ParticlesSlide.cpp adds a third field visitor to generate
  GUIs for interactively editing the running effect.

---

1: The critical change I'd like to make is to remove all
special case behavior over time and at spawn (setting sprite
frames, size over time, color over time, etc...). Integration
is the only fixed function behavior. Everything else is driven
by two lists of affectors. One is applied at spawn time, using
the effect's lifetime to evaluate curves. This allows spawning
particles with different colors as the effect ages out, for
example. The second list is applied every frame to update
existing particles, and is driven by the particle's lifetime.
This allows particles to change color after being spawned, for
example.

With a small set of affectors using a single expressive curve
primitive (keyframed list of cubic curve segments), we can
have affectors that update color, size, velocity, position,
sprite frame, etc., and implement many complex behaviors.

Bug: skia:
Change-Id: Id9402bef22825d55d021c5a2f9e5e41791aabaf4
Reviewed-on: https://skia-review.googlesource.com/c/181404
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Reed <reed@google.com>
2019-02-12 18:53:41 +00:00