1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457
|
// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "third_party/blink/renderer/core/animation/timing_calculations.h"
#include "base/metrics/histogram_macros.h"
namespace blink {
namespace {
inline bool EndsOnIterationBoundary(double iteration_count,
double iteration_start) {
DCHECK(std::isfinite(iteration_count));
return !fmod(iteration_count + iteration_start, 1);
}
void RecordBoundaryMisalignment(AnimationTimeDelta misalignment) {
// Animations require 1 microsecond precision. For a scroll-based animation,
// percentages are internally converted to time. The animation duration in
// microseconds is 16 * (range in pixels).
// Refer to cc/animations/scroll_timeline.h for details.
//
// It is not particularly meaningful to report the misalignment as a time
// since there is no dependency on having a high resolution timer. Instead,
// we convert back to 16ths of a pixel by scaling accordingly.
int sample = std::round<int>(misalignment.InMicrosecondsF());
UMA_HISTOGRAM_EXACT_LINEAR("Blink.Animation.SDA.BoundaryMisalignment", sample,
64);
}
} // namespace
double TimingCalculations::TimingCalculationEpsilon() {
// Permit 2-bits of quantization error. Threshold based on experimentation
// with accuracy of fmod.
return 2.0 * std::numeric_limits<double>::epsilon();
}
AnimationTimeDelta TimingCalculations::TimeTolerance() {
return ANIMATION_TIME_DELTA_FROM_SECONDS(0.000001 /*one microsecond*/);
}
bool TimingCalculations::IsWithinAnimationTimeEpsilon(double a, double b) {
return std::abs(a - b) <= TimingCalculationEpsilon();
}
bool TimingCalculations::IsWithinAnimationTimeTolerance(AnimationTimeDelta a,
AnimationTimeDelta b) {
if (a.is_inf() || b.is_inf()) {
return a == b;
}
AnimationTimeDelta difference = a >= b ? a - b : b - a;
return difference <= TimeTolerance();
}
bool TimingCalculations::LessThanOrEqualToWithinEpsilon(double a, double b) {
return a <= b + TimingCalculationEpsilon();
}
bool TimingCalculations::LessThanOrEqualToWithinTimeTolerance(
AnimationTimeDelta a,
AnimationTimeDelta b) {
return a <= b + TimeTolerance();
}
bool TimingCalculations::GreaterThanOrEqualToWithinEpsilon(double a, double b) {
return a >= b - TimingCalculationEpsilon();
}
bool TimingCalculations::GreaterThanOrEqualToWithinTimeTolerance(
AnimationTimeDelta a,
AnimationTimeDelta b) {
return a >= b - TimeTolerance();
}
bool TimingCalculations::GreaterThanWithinTimeTolerance(AnimationTimeDelta a,
AnimationTimeDelta b) {
return a > b - TimeTolerance();
}
double TimingCalculations::MultiplyZeroAlwaysGivesZero(double x, double y) {
DCHECK(!std::isnan(x));
DCHECK(!std::isnan(y));
return x && y ? x * y : 0;
}
AnimationTimeDelta TimingCalculations::MultiplyZeroAlwaysGivesZero(
AnimationTimeDelta x,
double y) {
DCHECK(!std::isnan(y));
return x.is_zero() || y == 0 ? AnimationTimeDelta() : (x * y);
}
// https://w3.org/TR/web-animations-1/#animation-effect-phases-and-states
Timing::Phase TimingCalculations::CalculatePhase(
const Timing::NormalizedTiming& normalized,
std::optional<AnimationTimeDelta>& local_time,
Timing::AnimationDirection direction) {
DCHECK(GreaterThanOrEqualToWithinTimeTolerance(normalized.active_duration,
AnimationTimeDelta()));
if (!local_time) {
return Timing::kPhaseNone;
}
AnimationTimeDelta before_active_boundary_time =
std::max(std::min(normalized.start_delay, normalized.end_time),
AnimationTimeDelta());
if (IsWithinAnimationTimeTolerance(local_time.value(),
before_active_boundary_time)) {
local_time = before_active_boundary_time;
}
if (local_time.value() < before_active_boundary_time) {
if (normalized.is_start_boundary_aligned) {
RecordBoundaryMisalignment(before_active_boundary_time -
local_time.value());
}
return Timing::kPhaseBefore;
}
if ((direction == Timing::AnimationDirection::kBackwards &&
local_time.value() == before_active_boundary_time &&
!normalized.is_start_boundary_aligned)) {
return Timing::kPhaseBefore;
}
AnimationTimeDelta active_after_boundary_time =
std::max(std::min(normalized.start_delay + normalized.active_duration,
normalized.end_time),
AnimationTimeDelta());
if (IsWithinAnimationTimeTolerance(local_time.value(),
active_after_boundary_time)) {
local_time = active_after_boundary_time;
}
if (local_time.value() > active_after_boundary_time) {
if (normalized.is_end_boundary_aligned) {
RecordBoundaryMisalignment(local_time.value() -
active_after_boundary_time);
}
return Timing::kPhaseAfter;
}
if ((direction == Timing::AnimationDirection::kForwards &&
local_time.value() == active_after_boundary_time &&
!normalized.is_end_boundary_aligned)) {
return Timing::kPhaseAfter;
}
return Timing::kPhaseActive;
}
// https://w3.org/TR/web-animations-1/#calculating-the-active-time
std::optional<AnimationTimeDelta> TimingCalculations::CalculateActiveTime(
const Timing::NormalizedTiming& normalized,
Timing::FillMode fill_mode,
std::optional<AnimationTimeDelta> local_time,
Timing::Phase phase) {
DCHECK(GreaterThanOrEqualToWithinTimeTolerance(normalized.active_duration,
AnimationTimeDelta()));
switch (phase) {
case Timing::kPhaseBefore:
if (fill_mode == Timing::FillMode::BACKWARDS ||
fill_mode == Timing::FillMode::BOTH) {
DCHECK(local_time.has_value());
return std::max(local_time.value() - normalized.start_delay,
AnimationTimeDelta());
}
return std::nullopt;
case Timing::kPhaseActive:
DCHECK(local_time.has_value());
return local_time.value() - normalized.start_delay;
case Timing::kPhaseAfter:
if (fill_mode == Timing::FillMode::FORWARDS ||
fill_mode == Timing::FillMode::BOTH) {
DCHECK(local_time.has_value());
return std::max(AnimationTimeDelta(),
std::min(normalized.active_duration,
local_time.value() - normalized.start_delay));
}
return std::nullopt;
case Timing::kPhaseNone:
DCHECK(!local_time.has_value());
return std::nullopt;
default:
NOTREACHED();
}
}
// Calculates the overall progress, which describes the number of iterations
// that have completed (including partial iterations).
// https://w3.org/TR/web-animations-1/#calculating-the-overall-progress
std::optional<double> TimingCalculations::CalculateOverallProgress(
Timing::Phase phase,
std::optional<AnimationTimeDelta> active_time,
AnimationTimeDelta iteration_duration,
double iteration_count,
double iteration_start) {
// 1. If the active time is unresolved, return unresolved.
if (!active_time) {
return std::nullopt;
}
// 2. Calculate an initial value for overall progress.
double overall_progress = 0;
if (IsWithinAnimationTimeTolerance(iteration_duration,
AnimationTimeDelta())) {
if (phase != Timing::kPhaseBefore) {
overall_progress = iteration_count;
}
} else {
overall_progress = (active_time.value() / iteration_duration);
}
return overall_progress + iteration_start;
}
// Calculates the simple iteration progress, which is a fraction of the progress
// through the current iteration that ignores transformations to the time
// introduced by the playback direction or timing functions applied to the
// effect.
// https://w3.org/TR/web-animations-1/#calculating-the-simple-iteration-progress
std::optional<double> TimingCalculations::CalculateSimpleIterationProgress(
Timing::Phase phase,
std::optional<double> overall_progress,
double iteration_start,
std::optional<AnimationTimeDelta> active_time,
AnimationTimeDelta active_duration,
double iteration_count) {
// 1. If the overall progress is unresolved, return unresolved.
if (!overall_progress) {
return std::nullopt;
}
// 2. If overall progress is infinity, let the simple iteration progress be
// iteration start % 1.0, otherwise, let the simple iteration progress be
// overall progress % 1.0.
double simple_iteration_progress = std::isinf(overall_progress.value())
? fmod(iteration_start, 1.0)
: fmod(overall_progress.value(), 1.0);
// active_time is not null is because overall_progress != null and
// CalculateOverallProgress() only returns null when active_time is null.
DCHECK(active_time);
// 3. If all of the following conditions are true,
// * the simple iteration progress calculated above is zero, and
// * the animation effect is in the active phase or the after phase, and
// * the active time is equal to the active duration, and
// * the iteration count is not equal to zero.
// let the simple iteration progress be 1.0.
if (IsWithinAnimationTimeEpsilon(simple_iteration_progress, 0.0) &&
(phase == Timing::kPhaseActive || phase == Timing::kPhaseAfter) &&
IsWithinAnimationTimeTolerance(active_time.value(), active_duration) &&
!IsWithinAnimationTimeEpsilon(iteration_count, 0.0)) {
simple_iteration_progress = 1.0;
}
// 4. Return simple iteration progress.
return simple_iteration_progress;
}
// https://w3.org/TR/web-animations-1/#calculating-the-current-iteration
std::optional<double> TimingCalculations::CalculateCurrentIteration(
Timing::Phase phase,
std::optional<AnimationTimeDelta> active_time,
double iteration_count,
std::optional<double> overall_progress,
std::optional<double> simple_iteration_progress) {
// 1. If the active time is unresolved, return unresolved.
if (!active_time) {
return std::nullopt;
}
// 2. If the animation effect is in the after phase and the iteration count
// is infinity, return infinity.
if (phase == Timing::kPhaseAfter && std::isinf(iteration_count)) {
return std::numeric_limits<double>::infinity();
}
if (!overall_progress) {
return std::nullopt;
}
// simple iteration progress can only be null if overall progress is null.
DCHECK(simple_iteration_progress);
// 3. If the simple iteration progress is 1.0, return floor(overall progress)
// - 1.
if (simple_iteration_progress.value() == 1.0) {
// Safeguard for zero duration animation (crbug.com/954558).
return fmax(0, floor(overall_progress.value()) - 1);
}
// 4. Otherwise, return floor(overall progress).
return floor(overall_progress.value());
}
// https://w3.org/TR/web-animations-1/#calculating-the-directed-progress
bool TimingCalculations::IsCurrentDirectionForwards(
std::optional<double> current_iteration,
Timing::PlaybackDirection direction) {
const bool current_iteration_is_even =
current_iteration &&
(std::isinf(current_iteration.value()) ||
IsWithinAnimationTimeEpsilon(fmod(current_iteration.value(), 2), 0));
switch (direction) {
case Timing::PlaybackDirection::NORMAL:
return true;
case Timing::PlaybackDirection::REVERSE:
return false;
case Timing::PlaybackDirection::ALTERNATE_NORMAL:
return current_iteration_is_even;
case Timing::PlaybackDirection::ALTERNATE_REVERSE:
return !current_iteration_is_even;
}
}
// https://w3.org/TR/web-animations-1/#calculating-the-directed-progress
std::optional<double> TimingCalculations::CalculateDirectedProgress(
std::optional<double> simple_iteration_progress,
std::optional<double> current_iteration,
Timing::PlaybackDirection direction) {
// 1. If the simple progress is unresolved, return unresolved.
if (!simple_iteration_progress) {
return std::nullopt;
}
// 2. Calculate the current direction.
bool current_direction_is_forwards =
IsCurrentDirectionForwards(current_iteration, direction);
// 3. If the current direction is forwards then return the simple iteration
// progress. Otherwise return 1 - simple iteration progress.
return current_direction_is_forwards ? simple_iteration_progress.value()
: 1 - simple_iteration_progress.value();
}
// https://w3.org/TR/web-animations-1/#calculating-the-transformed-progress
std::optional<double> TimingCalculations::CalculateTransformedProgress(
Timing::Phase phase,
std::optional<double> directed_progress,
bool is_current_direction_forward,
scoped_refptr<TimingFunction> timing_function) {
if (!directed_progress) {
return std::nullopt;
}
// Set the before flag to indicate if at the leading edge of an iteration.
// This is used to determine if the left or right limit should be used if at a
// discontinuity in the timing function.
bool before = is_current_direction_forward ? phase == Timing::kPhaseBefore
: phase == Timing::kPhaseAfter;
TimingFunction::LimitDirection limit_direction =
before ? TimingFunction::LimitDirection::LEFT
: TimingFunction::LimitDirection::RIGHT;
// Snap boundaries to correctly render step timing functions at 0 and 1.
// (crbug.com/949373)
if (phase == Timing::kPhaseAfter) {
if (is_current_direction_forward &&
IsWithinAnimationTimeEpsilon(directed_progress.value(), 1)) {
directed_progress = 1;
} else if (!is_current_direction_forward &&
IsWithinAnimationTimeEpsilon(directed_progress.value(), 0)) {
directed_progress = 0;
}
}
// Return the result of evaluating the animation effect’s timing function
// passing directed progress as the input progress value.
return timing_function->Evaluate(directed_progress.value(), limit_direction);
}
// Offsets the active time by how far into the animation we start (i.e. the
// product of the iteration start and iteration duration). This is not part of
// the Web Animations spec; it is used for calculating the time until the next
// iteration to optimize scheduling.
std::optional<AnimationTimeDelta> TimingCalculations::CalculateOffsetActiveTime(
AnimationTimeDelta active_duration,
std::optional<AnimationTimeDelta> active_time,
AnimationTimeDelta start_offset) {
DCHECK(GreaterThanOrEqualToWithinTimeTolerance(active_duration,
AnimationTimeDelta()));
DCHECK(GreaterThanOrEqualToWithinTimeTolerance(start_offset,
AnimationTimeDelta()));
if (!active_time) {
return std::nullopt;
}
DCHECK(GreaterThanOrEqualToWithinTimeTolerance(active_time.value(),
AnimationTimeDelta()) &&
LessThanOrEqualToWithinTimeTolerance(active_time.value(),
active_duration));
if (active_time->is_max()) {
return AnimationTimeDelta::Max();
}
return active_time.value() + start_offset;
}
// Maps the offset active time into 'iteration time space'[0], aka the offset
// into the current iteration. This is not part of the Web Animations spec (note
// that the section linked below is non-normative); it is used for calculating
// the time until the next iteration to optimize scheduling.
//
// [0] https://w3.org/TR/web-animations-1/#iteration-time-space
std::optional<AnimationTimeDelta> TimingCalculations::CalculateIterationTime(
AnimationTimeDelta iteration_duration,
AnimationTimeDelta active_duration,
std::optional<AnimationTimeDelta> offset_active_time,
AnimationTimeDelta start_offset,
Timing::Phase phase,
const Timing& specified) {
DCHECK(
GreaterThanWithinTimeTolerance(iteration_duration, AnimationTimeDelta()));
DCHECK(IsWithinAnimationTimeTolerance(
active_duration, MultiplyZeroAlwaysGivesZero(iteration_duration,
specified.iteration_count)));
if (!offset_active_time) {
return std::nullopt;
}
DCHECK(GreaterThanWithinTimeTolerance(offset_active_time.value(),
AnimationTimeDelta()));
DCHECK(LessThanOrEqualToWithinTimeTolerance(
offset_active_time.value(), (active_duration + start_offset)));
if (offset_active_time->is_max() ||
(IsWithinAnimationTimeTolerance(offset_active_time.value() - start_offset,
active_duration) &&
specified.iteration_count &&
EndsOnIterationBoundary(specified.iteration_count,
specified.iteration_start))) {
return std::make_optional(iteration_duration);
}
DCHECK(!offset_active_time->is_max());
AnimationTimeDelta iteration_time = ANIMATION_TIME_DELTA_FROM_SECONDS(
fmod(offset_active_time->InSecondsF(), iteration_duration.InSecondsF()));
// This implements step 3 of
// https://w3.org/TR/web-animations-1/#calculating-the-simple-iteration-progress
if (iteration_time.is_zero() && phase == Timing::kPhaseAfter &&
!active_duration.is_zero() && !offset_active_time.value().is_zero()) {
return std::make_optional(iteration_duration);
}
return iteration_time;
}
} // namespace blink
|