source/libr2c2/speedquantizer.cpp

   1 /* $Id$
   2
   3 This file is part of R²C²
   4 Copyright © 2011  Mikkosoft Productions, Mikko Rasa
   5 Distributed under the GPL
   6 */
   7
   8 #include "speedquantizer.h"
   9
  10 using namespace std;
  11 using namespace Msp;
  12
  13 namespace R2C2 {
  14
  15 SpeedQuantizer::SpeedQuantizer(unsigned n):
  16         steps(n+1)
  17 {
  18         if(n<1)
  19                 throw InvalidParameterValue("Must have at leats one speed step");
  20 }
  21
  22 void SpeedQuantizer::learn(unsigned i, float s, float w)
  23 {
  24         if(i>=steps.size())
  25                 throw InvalidParameterValue("Speed step index out of range");
  26         steps[i].add(s, w);
  27 }
  28
  29 float SpeedQuantizer::get_speed(unsigned i) const
  30 {
  31         if(i==0)
  32                 return 0;
  33         if(steps[i].weight)
  34                 return steps[i].speed;
  35
  36         unsigned low;
  37         unsigned high;
  38         for(low=i; low>0; --low)
  39                 if(steps[low].weight)
  40                         break;
  41         for(high=i; high+1<steps.size(); ++high)
  42                 if(steps[high].weight)
  43                         break;
  44
  45         if(steps[high].weight)
  46         {
  47                 if(steps[low].weight)
  48                         return (steps[low].speed*(high-i)+steps[high].speed*(i-low))/(high-low);
  49                 else
  50                         return steps[high].speed*i/high;
  51         }
  52         else if(steps[low].weight)
  53                 return steps[low].speed*i/low;
  54         else
  55                 return 0;
  56 }
  57
  58 float SpeedQuantizer::quantize_speed(float speed) const
  59 {
  60         return get_speed(find_speed_step(speed));
  61 }
  62
  63 unsigned SpeedQuantizer::find_speed_step(float speed) const
  64 {
  65         if(speed<=steps[1].speed*0.5)
  66                 return 0;
  67
  68         unsigned low = 0;
  69         unsigned high = 0;
  70         unsigned last = 0;
  71         for(unsigned i=0; (!high && i<steps.size()); ++i)
  72                 if(steps[i].weight)
  73                 {
  74                         last = i;
  75                         if(steps[i].speed>=speed)
  76                                 high = i;
  77                         else if(steps[i].speed>steps[low].speed)
  78                                 low = i;
  79                 }
  80
  81         if(!high)
  82         {
  83                 unsigned limit = steps.size()/5;
  84                 if(!low)
  85                 {
  86                         if(speed)
  87                                 return limit;
  88                         else
  89                                 return 0;
  90                 }
  91                 return min(min(static_cast<unsigned>(low*speed/steps[low].speed), steps.size()-1), last+limit);
  92         }
  93
  94         float f = (speed-steps[low].speed)/(steps[high].speed-steps[low].speed);
  95         return static_cast<unsigned>(low*(1-f)+high*f+0.5);
  96 }
  97
  98 void SpeedQuantizer::save(list<DataFile::Statement> &st) const
  99 {
 100         for(unsigned i=0; i<steps.size(); ++i)
 101                 if(steps[i].weight)
 102                         st.push_back((DataFile::Statement("step"), i, steps[i].speed, steps[i].weight));
 103 }
 104
 105
 106 SpeedQuantizer::SpeedStep::SpeedStep():
 107         speed(0),
 108         weight(0)
 109 { }
 110
 111 void SpeedQuantizer::SpeedStep::add(float s, float w)
 112 {
 113         speed = (speed*weight+s*w)/(weight+w);
 114         weight = min(weight+w, 300.0f);
 115 }
 116
 117
 118 SpeedQuantizer::Loader::Loader(SpeedQuantizer &q):
 119         DataFile::ObjectLoader<SpeedQuantizer>(q)
 120 {
 121         add("step", &Loader::step);
 122 }
 123
 124 void SpeedQuantizer::Loader::step(unsigned i, float s, float w)
 125 {
 126         if(i>=obj.steps.size())
 127                 return;
 128
 129         obj.steps[i].speed = s;
 130         obj.steps[i].weight = w;
 131 }
 132
 133 } // namespace R2C2