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 //------------------------------------------------- 27 Interpolator::Interpolator() 28 { 29 list_params_.clear(); 30 } 31 32 //------------------------------------------------- 33 //Dtor 34 //------------------------------------------------- 35 Interpolator::~Interpolator() 36 { 37 list_params_.clear(); 38 } 39 40 void Interpolator::Clear() 41 { 42 list_params_.clear(); 43 } 44 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 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 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 } 103 104 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
