1/*
2 * Copyright (C) 2013 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef TimingCalculations_h
32#define TimingCalculations_h
33
34#include "core/animation/AnimationNode.h"
35#include "core/animation/Timing.h"
36#include "platform/animation/AnimationUtilities.h"
37#include "wtf/MathExtras.h"
38
39namespace blink {
40
41static inline double multiplyZeroAlwaysGivesZero(double x, double y)
42{
43    ASSERT(!isNull(x));
44    ASSERT(!isNull(y));
45    return x && y ? x * y : 0;
46}
47
48static inline AnimationNode::Phase calculatePhase(double activeDuration, double localTime, const Timing& specified)
49{
50    ASSERT(activeDuration >= 0);
51    if (isNull(localTime))
52        return AnimationNode::PhaseNone;
53    if (localTime < specified.startDelay)
54        return AnimationNode::PhaseBefore;
55    if (localTime >= specified.startDelay + activeDuration)
56        return AnimationNode::PhaseAfter;
57    return AnimationNode::PhaseActive;
58}
59
60static inline bool isActiveInParentPhase(AnimationNode::Phase parentPhase, Timing::FillMode fillMode)
61{
62    switch (parentPhase) {
63    case AnimationNode::PhaseBefore:
64        return fillMode == Timing::FillModeBackwards || fillMode == Timing::FillModeBoth;
65    case AnimationNode::PhaseActive:
66        return true;
67    case AnimationNode::PhaseAfter:
68        return fillMode == Timing::FillModeForwards || fillMode == Timing::FillModeBoth;
69    default:
70        ASSERT_NOT_REACHED();
71        return false;
72    }
73}
74
75static inline double calculateActiveTime(double activeDuration, Timing::FillMode fillMode, double localTime, AnimationNode::Phase parentPhase, AnimationNode::Phase phase, const Timing& specified)
76{
77    ASSERT(activeDuration >= 0);
78    ASSERT(phase == calculatePhase(activeDuration, localTime, specified));
79
80    switch (phase) {
81    case AnimationNode::PhaseBefore:
82        if (fillMode == Timing::FillModeBackwards || fillMode == Timing::FillModeBoth)
83            return 0;
84        return nullValue();
85    case AnimationNode::PhaseActive:
86        if (isActiveInParentPhase(parentPhase, fillMode))
87            return localTime - specified.startDelay;
88        return nullValue();
89    case AnimationNode::PhaseAfter:
90        if (fillMode == Timing::FillModeForwards || fillMode == Timing::FillModeBoth)
91            return activeDuration;
92        return nullValue();
93    case AnimationNode::PhaseNone:
94        ASSERT(isNull(localTime));
95        return nullValue();
96    default:
97        ASSERT_NOT_REACHED();
98        return nullValue();
99    }
100}
101
102static inline double calculateScaledActiveTime(double activeDuration, double activeTime, double startOffset, const Timing& specified)
103{
104    ASSERT(activeDuration >= 0);
105    ASSERT(startOffset >= 0);
106
107    if (isNull(activeTime))
108        return nullValue();
109
110    ASSERT(activeTime >= 0 && activeTime <= activeDuration);
111    return multiplyZeroAlwaysGivesZero(specified.playbackRate < 0 ? activeTime - activeDuration : activeTime, specified.playbackRate) + startOffset;
112}
113
114static inline bool endsOnIterationBoundary(double iterationCount, double iterationStart)
115{
116    ASSERT(std::isfinite(iterationCount));
117    return !fmod(iterationCount + iterationStart, 1);
118}
119
120static inline double calculateIterationTime(double iterationDuration, double repeatedDuration, double scaledActiveTime, double startOffset, const Timing& specified)
121{
122    ASSERT(iterationDuration > 0);
123    ASSERT(repeatedDuration == multiplyZeroAlwaysGivesZero(iterationDuration, specified.iterationCount));
124
125    if (isNull(scaledActiveTime))
126        return nullValue();
127
128    ASSERT(scaledActiveTime >= 0);
129    ASSERT(scaledActiveTime <= repeatedDuration + startOffset);
130
131    if (!std::isfinite(scaledActiveTime)
132        || (scaledActiveTime - startOffset == repeatedDuration && specified.iterationCount && endsOnIterationBoundary(specified.iterationCount, specified.iterationStart)))
133        return iterationDuration;
134
135    ASSERT(std::isfinite(scaledActiveTime));
136    return fmod(scaledActiveTime, iterationDuration);
137}
138
139static inline double calculateCurrentIteration(double iterationDuration, double iterationTime, double scaledActiveTime, const Timing& specified)
140{
141    ASSERT(iterationDuration > 0);
142    ASSERT(isNull(iterationTime) || iterationTime >= 0);
143
144    if (isNull(scaledActiveTime))
145        return nullValue();
146
147    ASSERT(iterationTime >= 0);
148    ASSERT(iterationTime <= iterationDuration);
149    ASSERT(scaledActiveTime >= 0);
150
151    if (!scaledActiveTime)
152        return 0;
153
154    if (iterationTime == iterationDuration)
155        return specified.iterationStart + specified.iterationCount - 1;
156
157    return floor(scaledActiveTime / iterationDuration);
158}
159
160static inline double calculateDirectedTime(double currentIteration, double iterationDuration, double iterationTime, const Timing& specified)
161{
162    ASSERT(isNull(currentIteration) || currentIteration >= 0);
163    ASSERT(iterationDuration > 0);
164
165    if (isNull(iterationTime))
166        return nullValue();
167
168    ASSERT(currentIteration >= 0);
169    ASSERT(iterationTime >= 0);
170    ASSERT(iterationTime <= iterationDuration);
171
172    const bool currentIterationIsOdd = fmod(currentIteration, 2) >= 1;
173    const bool currentDirectionIsForwards = specified.direction == Timing::PlaybackDirectionNormal
174        || (specified.direction == Timing::PlaybackDirectionAlternate && !currentIterationIsOdd)
175        || (specified.direction == Timing::PlaybackDirectionAlternateReverse && currentIterationIsOdd);
176
177    return currentDirectionIsForwards ? iterationTime : iterationDuration - iterationTime;
178}
179
180static inline double calculateTransformedTime(double currentIteration, double iterationDuration, double iterationTime, const Timing& specified)
181{
182    ASSERT(isNull(currentIteration) || currentIteration >= 0);
183    ASSERT(iterationDuration > 0);
184    ASSERT(isNull(iterationTime) || (iterationTime >= 0 && iterationTime <= iterationDuration));
185
186    double directedTime = calculateDirectedTime(currentIteration, iterationDuration, iterationTime, specified);
187    if (isNull(directedTime))
188        return nullValue();
189    if (!std::isfinite(iterationDuration))
190        return directedTime;
191    double timeFraction = directedTime / iterationDuration;
192    ASSERT(timeFraction >= 0 && timeFraction <= 1);
193    return multiplyZeroAlwaysGivesZero(iterationDuration, specified.timingFunction->evaluate(timeFraction, accuracyForDuration(iterationDuration)));
194}
195
196} // namespace blink
197
198#endif
199