1 /*
2 * Copyright 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "interpolator.h"
18 #include <math.h>
19 #include "interpolator.h"
20
21 namespace ndk_helper
22 {
23
24 //-------------------------------------------------
25 //Ctor
26 //-------------------------------------------------
Interpolator()27 Interpolator::Interpolator()
28 {
29 list_params_.clear();
30 }
31
32 //-------------------------------------------------
33 //Dtor
34 //-------------------------------------------------
~Interpolator()35 Interpolator::~Interpolator()
36 {
37 list_params_.clear();
38 }
39
Clear()40 void Interpolator::Clear()
41 {
42 list_params_.clear();
43 }
44
Set(const float start,const float dest,const INTERPOLATOR_TYPE type,const double duration)45 Interpolator& Interpolator::Set( const float start,
46 const float dest,
47 const INTERPOLATOR_TYPE type,
48 const double duration )
49 {
50 //init the parameters for the interpolation process
51 start_time_ = PerfMonitor::GetCurrentTime();
52 dest_time_ = start_time_ + duration;
53 type_ = type;
54
55 start_value_ = start;
56 dest_value_ = dest;
57 return *this;
58 }
59
Add(const float dest,const INTERPOLATOR_TYPE type,const double duration)60 Interpolator& Interpolator::Add( const float dest,
61 const INTERPOLATOR_TYPE type,
62 const double duration )
63 {
64 InterpolatorParams param;
65 param.dest_value_ = dest;
66 param.type_ = type;
67 param.duration_ = duration;
68 list_params_.push_back( param );
69 return *this;
70 }
71
Update(const double current_time,float & p)72 bool Interpolator::Update( const double current_time, float& p )
73 {
74 bool bContinue;
75 if( current_time >= dest_time_ )
76 {
77 p = dest_value_;
78 if( list_params_.size() )
79 {
80 InterpolatorParams& item = list_params_.front();
81 Set( dest_value_, item.dest_value_, item.type_, item.duration_ );
82 list_params_.pop_front();
83
84 bContinue = true;
85 }
86 else
87 {
88 bContinue = false;
89 }
90 }
91 else
92 {
93 float t = (float) (current_time - start_time_);
94 float d = (float) (dest_time_ - start_time_);
95 float b = start_value_;
96 float c = dest_value_ - start_value_;
97 p = GetFormula( type_, t, b, d, c );
98
99 bContinue = true;
100 }
101 return bContinue;
102 }
103
GetFormula(const INTERPOLATOR_TYPE type,const float t,const float b,const float d,const float c)104 float Interpolator::GetFormula( const INTERPOLATOR_TYPE type,
105 const float t,
106 const float b,
107 const float d,
108 const float c )
109 {
110 float t1;
111 switch( type )
112 {
113 case INTERPOLATOR_TYPE_LINEAR:
114 // simple linear interpolation - no easing
115 return (c * t / d + b);
116
117 case INTERPOLATOR_TYPE_EASEINQUAD:
118 // quadratic (t^2) easing in - accelerating from zero velocity
119 t1 = t / d;
120 return (c * t1 * t1 + b);
121
122 case INTERPOLATOR_TYPE_EASEOUTQUAD:
123 // quadratic (t^2) easing out - decelerating to zero velocity
124 t1 = t / d;
125 return (-c * t1 * (t1 - 2) + b);
126
127 case INTERPOLATOR_TYPE_EASEINOUTQUAD:
128 // quadratic easing in/out - acceleration until halfway, then deceleration
129 t1 = t / d / 2;
130 if( t1 < 1 )
131 return (c / 2 * t1 * t1 + b);
132 else
133 {
134 t1 = t1 - 1;
135 return (-c / 2 * (t1 * (t1 - 2) - 1) + b);
136 }
137 case INTERPOLATOR_TYPE_EASEINCUBIC:
138 // cubic easing in - accelerating from zero velocity
139 t1 = t / d;
140 return (c * t1 * t1 * t1 + b);
141
142 case INTERPOLATOR_TYPE_EASEOUTCUBIC:
143 // cubic easing in - accelerating from zero velocity
144 t1 = t / d - 1;
145 return (c * (t1 * t1 * t1 + 1) + b);
146
147 case INTERPOLATOR_TYPE_EASEINOUTCUBIC:
148 // cubic easing in - accelerating from zero velocity
149 t1 = t / d / 2;
150
151 if( t1 < 1 )
152 return (c / 2 * t1 * t1 * t1 + b);
153 else
154 {
155 t1 -= 2;
156 return (c / 2 * (t1 * t1 * t1 + 2) + b);
157 }
158 case INTERPOLATOR_TYPE_EASEINQUART:
159 // quartic easing in - accelerating from zero velocity
160 t1 = t / d;
161 return (c * t1 * t1 * t1 * t1 + b);
162
163 case INTERPOLATOR_TYPE_EASEINEXPO:
164 // exponential (2^t) easing in - accelerating from zero velocity
165 if( t == 0 )
166 return b;
167 else
168 return (c * powf( 2, (10 * (t / d - 1)) ) + b);
169
170 case INTERPOLATOR_TYPE_EASEOUTEXPO:
171 // exponential (2^t) easing out - decelerating to zero velocity
172 if( t == d )
173 return (b + c);
174 else
175 return (c * (-powf( 2, -10 * t / d ) + 1) + b);
176 default:
177 return 0;
178 }
179 }
180
181 } //namespace ndkHelper
182