Chris@755: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@755: 
Chris@755: /*
Chris@755:     Sonic Visualiser
Chris@755:     An audio file viewer and annotation editor.
Chris@755:     Centre for Digital Music, Queen Mary, University of London.
Chris@755:     
Chris@755:     This program is free software; you can redistribute it and/or
Chris@755:     modify it under the terms of the GNU General Public License as
Chris@755:     published by the Free Software Foundation; either version 2 of the
Chris@755:     License, or (at your option) any later version.  See the file
Chris@755:     COPYING included with this distribution for more information.
Chris@755: */
Chris@755: 
Chris@755: #ifndef SV_DTW_H
Chris@755: #define SV_DTW_H
Chris@755: 
Chris@755: #include <vector>
Chris@755: 
Chris@755: class DTW
Chris@755: {
Chris@755: public:
Chris@755:     typedef double cost_t;
Chris@755: 
Chris@755:     struct CostOption {
Chris@755:         bool present;
Chris@755:         cost_t cost;
Chris@755:     };
Chris@755: 
Chris@755:     enum class Direction {
Chris@755:         None,
Chris@755:         Up,
Chris@755:         Down
Chris@755:     };
Chris@755:     
Chris@755:     struct Value {
Chris@755:         Direction direction;
Chris@755:         cost_t cost;
Chris@755:     };
Chris@755: 
Chris@755:     static cost_t choose(CostOption x, CostOption y, CostOption d) {
Chris@755:         if (x.present && y.present) {
Chris@755:             if (!d.present) {
Chris@755:                 throw std::logic_error("if x & y both exist, so must diagonal");
Chris@755:             }
Chris@755:             return std::min(std::min(x.cost, y.cost), d.cost);
Chris@755:         } else if (x.present) {
Chris@755:             return x.cost;
Chris@755:         } else if (y.present) {
Chris@755:             return y.cost;
Chris@755:         } else {
Chris@755:             return 0.0;
Chris@755:         }
Chris@755:     }
Chris@755: 
Chris@755:     static cost_t calculateCost(Value a, Value b) {
Chris@755:         auto together = [](cost_t c1, cost_t c2) {
Chris@755:                             auto diff = std::abs(c1 - c2);
Chris@755:                             return (diff < 1.0 ? -1.0 :
Chris@755:                                     diff > 3.0 ?  1.0 :
Chris@755:                                     0.0);
Chris@755:                         };
Chris@755:         auto opposing = [](cost_t c1, cost_t c2) {
Chris@755:                             auto diff = c1 + c2;
Chris@755:                             return (diff < 2.0 ? 1.0 :
Chris@755:                                     2.0);
Chris@755:                         };
Chris@755:         if (a.direction == Direction::None || b.direction == Direction::None) {
Chris@755:             if (a.direction == b.direction) {
Chris@755:                 return 0.0;
Chris@755:             } else {
Chris@755:                 return 1.0;
Chris@755:             }
Chris@755:         } else {
Chris@755:             if (a.direction == b.direction) {
Chris@755:                 return together (a.cost, b.cost);
Chris@755:             } else {
Chris@755:                 return opposing (a.cost, b.cost);
Chris@755:             }
Chris@755:         }
Chris@755:     }
Chris@755: 
Chris@755:     static std::vector<std::vector<cost_t>> costSeries(std::vector<Value> s1,
Chris@755:                                                        std::vector<Value> s2) {
Chris@755:         
Chris@755:     }
Chris@755:     
Chris@755: };
Chris@755: 
Chris@755: #endif