1 /*
2 * Copyright (c) 2021 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include "core/animation/spring_animation.h"
17
18 namespace OHOS::Ace {
19 namespace {
20
21 constexpr float DEFAULT_VALUE_THRESHOLD = 0.001f;
22 constexpr float VELOCITY_THRESHOLD_RATIO = 25.0f;
23 constexpr float DEFAULT_START_POSITION = 0.0f;
24 constexpr float DEFAULT_END_POSITION = 1.0f;
25 constexpr float DEFAULT_START_VELOCITY = 0.0f;
26 constexpr int32_t DEFAULT_ESTIMATE_STEPS = 100;
27
28 } // namespace
29
SpringAnimation(const RefPtr<SpringProperty> & property)30 SpringAnimation::SpringAnimation(const RefPtr<SpringProperty>& property)
31 {
32 property_ = property;
33 valueThreshold_ = (DEFAULT_END_POSITION - DEFAULT_START_POSITION) * DEFAULT_VALUE_THRESHOLD;
34 SetEndPosition(DEFAULT_END_POSITION, DEFAULT_START_VELOCITY);
35 }
36
SpringAnimation(const RefPtr<SpringProperty> & property,float velocity)37 SpringAnimation::SpringAnimation(const RefPtr<SpringProperty>& property, float velocity)
38 {
39 property_ = property;
40 valueThreshold_ = (DEFAULT_END_POSITION - DEFAULT_START_POSITION) * DEFAULT_VALUE_THRESHOLD;
41 SetEndPosition(DEFAULT_END_POSITION, velocity);
42 }
43
SpringAnimation(const RefPtr<SpringProperty> & property,float velocity,float valueThreshold)44 SpringAnimation::SpringAnimation(const RefPtr<SpringProperty>& property, float velocity, float valueThreshold)
45 {
46 property_ = property;
47 valueThreshold_ = valueThreshold;
48 SetEndPosition(DEFAULT_END_POSITION, velocity);
49 }
50
SetEndPosition(float endPosition,float startVelocity)51 void SpringAnimation::SetEndPosition(float endPosition, float startVelocity)
52 {
53 startPosition_ = 0.0f;
54 endPosition_ = endPosition;
55 currentVelocity_ = startVelocity;
56 currentPosition_ = startPosition_;
57 velocityThreshold_ = valueThreshold_ * VELOCITY_THRESHOLD_RATIO;
58 solution_ = SpringModel::Build(endPosition_, startVelocity, property_);
59 InitEstimateDuration();
60 }
61
UpdatePosition(float normalized)62 void SpringAnimation::UpdatePosition(float normalized)
63 {
64 currentPosition_ = endPosition_ - solution_->Position(normalized * estimateDuration_);
65 currentVelocity_ = solution_->Velocity(normalized * estimateDuration_);
66 if (NearEqual(currentPosition_, endPosition_, valueThreshold_) &&
67 NearZero(currentVelocity_, velocityThreshold_)) {
68 currentPosition_ = endPosition_;
69 currentVelocity_ = 0.0f;
70 }
71 }
72
InitEstimateDuration()73 void SpringAnimation::InitEstimateDuration()
74 {
75 float position = 0.0f;
76 float velocity = 0.0f;
77 float time = 1.0f / DEFAULT_ESTIMATE_STEPS;
78 for (int32_t i = 1; i < DEFAULT_ESTIMATE_STEPS; ++i) {
79 position = endPosition_ - solution_->Position(time * i);
80 velocity = solution_->Velocity(time * i);
81 if (NearEqual(position, endPosition_, valueThreshold_) && NearZero(velocity, velocityThreshold_)) {
82 estimateDuration_ = time * i;
83 break;
84 }
85 }
86 }
87
GetCurve()88 RefPtr<Curve> SpringAnimation::GetCurve()
89 {
90 return MakeRefPtr<CustomCurve>([weak = AceType::WeakClaim(this)](float fraction) -> float {
91 auto animation = weak.Upgrade();
92 if (animation == nullptr) {
93 LOGE("create spring curve failed, animation is null!");
94 return NORMALIZED_DURATION_MAX;
95 }
96
97 animation->UpdatePosition(fraction);
98 return animation->currentPosition_;
99 });
100 }
101
102 } // namespace OHOS::Ace
103