time.cpp

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/*
  Time  -  Lumiera time handling foundation
 
   Copyright (C)
     2008,            Christian Thaeter <ct@pipapo.org>
     2010,            Stefan Kangas <skangas@skangas.se>
     2011,            Hermann Vosseler <Ichthyostega@web.de>
 
 **Lumiera** is free software; you can redistribute it and/or modify it
 under the terms of the GNU General Public License as published by the
 Free Software Foundation; either version 2 of the License, or (at your
 option) any later version. See the file COPYING for further details.
 
* *****************************************************************/
 
 
#include "lib/error.hpp"
#include "lib/rational.hpp"
#include "lib/time/timevalue.hpp"
#include "lib/format-string.hpp"
#include "lib/util-quant.hpp"
#include "lib/util.hpp"
 
#include <limits>
#include <string>
#include <sstream>
#include <boost/rational.hpp>
#include <boost/lexical_cast.hpp>
 
using std::string;
using util::limited;
using util::floordiv;
using lib::time::FSecs;
using lib::time::FrameRate;
using boost::rational_cast;
using boost::lexical_cast;
 
#undef MAX
#undef MIN
 
 
namespace lib {
namespace meta {
  extern const std::string FAILURE_INDICATOR;
}
namespace time {
  
  namespace error = lumiera::error;
  
  const raw_time_64 TimeValue::SCALE = 1'000'000;
  
  
  const Time Time::MAX ( TimeValue::buildRaw_(+std::numeric_limits<raw_time_64>::max() / 30) );
  const Time Time::MIN ( TimeValue::buildRaw_(-_raw(Time::MAX)                             ) );
  const Time Time::ZERO;
  
  const Time Time::ANYTIME(Time::MIN);
  const Time Time::NEVER  (Time::MAX);
  
  const Offset Offset::ZERO (Time::ZERO);
  
  
  
  namespace { // local definitions for the implementation....
    
  const raw_time_64 TIME_SCALE_MS (lib::time::TimeValue::SCALE / 1000);
  
  
  const FSecs FSEC_MAX{std::numeric_limits<int64_t>::max() / lib::time::TimeValue::SCALE};
  
  Literal DIAGNOSTIC_FORMAT{"%s%01d:%02d:%02d.%03d"};
  
  
    raw_time_64
    build_time_from (FSecs const& fractionalSeconds)
    {
      // avoid numeric wrap from values not representable as 64bit µ-ticks
      if (abs(fractionalSeconds) > lib::time::FSEC_MAX)
        return (fractionalSeconds < 0? -1:+1)
             * std::numeric_limits<int64_t>::max();
      
      return raw_time_64(util::reQuant (fractionalSeconds.numerator()
                                       ,fractionalSeconds.denominator()
                                       ,lib::time::TimeValue::SCALE
                                       ));
    }
    
    
    raw_time_64
    build_time_from (long millis, uint secs, uint mins, uint hours)
    {
      raw_time_64 time = millis
                       + 1000 * secs
                       + 1000 * 60 * mins
                       + 1000 * 60 * 60 * hours;
      time *= TIME_SCALE_MS;
      return time;
    }
  }//(End)local definitions
  
  
  
  Time::Time ( long millis
             , uint secs
             , uint mins
             , uint hours
             )
    : TimeValue(build_time_from (millis,secs,mins,hours))
    { }
  
  
  Time::Time (FSecs const& fractionalSeconds)
    : TimeValue(build_time_from (fractionalSeconds))
    { }
  
  Offset::Offset (FSecs const& delta_in_secs)
    : TimeValue{buildRaw_(symmetricLimit (build_time_from (delta_in_secs)
                                         ,Duration::MAX))}
    { }
  
  
  TimeValue::operator string()  const
  {
    raw_time_64 time = t_;
    int64_t millis, seconds;
    bool negative = (time < 0);
    
    if (negative) time = -time;
    time /= TIME_SCALE_MS;
    millis = time % 1000;
    seconds = time / 1000;
    
    return string (negative ? "-" : "")
         + (seconds>0 or time==0? lexical_cast<string> (seconds)+"s" : "")
         + (millis>0? lexical_cast<string> (millis)+"ms" : "")
         ;
  }
  
  Time::operator string()  const
  {
    raw_time_64 time = t_;
    int millis, seconds, minutes, hours;
    bool negative = (time < 0);
    
    if (negative)
        time = -time;
    
    time /= TIME_SCALE_MS;
    millis = time % 1000;
    time /= 1000;
    seconds = time % 60;
    time /= 60;
    minutes = time % 60;
    time /= 60;
    hours = time;
    
    return util::_Fmt{string(DIAGNOSTIC_FORMAT)}
                     % (negative? "-":"")
                     % hours
                     % minutes
                     % seconds
                     % millis;
  }
  
  
  Offset::operator string()  const
  {
    return (t_< 0? "" : "∆")
         + TimeValue::operator string();
  }
  
  Duration::operator string()  const
  {
    return "≺"+TimeValue::operator string()+"≻";
  }
  
  TimeSpan::operator string()  const
  {
    return string (start())
         + string (duration());
  }
  
  
  namespace {
    template<typename RAT>
    string
    renderFraction (RAT const& frac, Literal postfx) noexcept
    try {
      std::ostringstream buffer;
      if (1 == frac.denominator() or 0 == frac.numerator())
        buffer << frac.numerator() << postfx;
      else
        buffer << frac <<postfx;
      return buffer.str();
    }
    catch(...)
    { return meta::FAILURE_INDICATOR; }
  }
 
  FrameRate::operator string() const
  {
    return renderFraction (*this, "FPS");
  }
  
  
  
  TimeValue
  TimeValue::buildRaw_ (raw_time_64 raw)
  {
    return reinterpret_cast<TimeValue const&> (raw);
  }
  
  
  
  const FrameRate FrameRate::PAL  (25);
  const FrameRate FrameRate::NTSC (30000,1001);
  const FrameRate FrameRate::STEP (1);
  
  const FrameRate FrameRate::HALTED (1,std::numeric_limits<int>::max());
  
  
  Duration
  FrameRate::duration() const
  {
    if (HALTED > *this)
      throw error::Logic ("Impossible to quantise to an zero spaced frame grid"
                         , error::LUMIERA_ERROR_BOTTOM_VALUE);
    
    return Duration (1, *this);
  }
  
  
  const uint RATE_LIMIT{std::numeric_limits<uint>::max() / 1024};
  
  boost::rational<uint>
  __framerate_approximation (double fps)
  {
    const double UPPER_LIMIT = int64_t(RATE_LIMIT*1024) << 31;
    const int64_t HAZARD = util::ilog2(RATE_LIMIT);
    
    double doo = limited (1.0, fabs(fps) * RATE_LIMIT + 0.5, UPPER_LIMIT);
    int64_t boo(doo);
    util::Rat quantised{boo
                       ,int64_t(RATE_LIMIT)
                       };
    
    int64_t num = quantised.numerator();
    int64_t toxic = util::ilog2(abs(num));
    toxic = util::max (0, toxic - HAZARD);
    
    int64_t base = quantised.denominator();
    if (toxic)
      {
        base = util::max (base >> toxic, 1);
        num = util::reQuant (num, quantised.denominator(), base);
      }
    return {limited (1u, num,  RATE_LIMIT)
           ,limited (1u, base, RATE_LIMIT)
           };
  }
  
  boost::rational<uint>
  __framerate_approximation (size_t cnt, Duration timeReference)
  {
    boost::rational<uint64_t> quot{cnt, _raw(timeReference)};
    if (quot.denominator() < RATE_LIMIT
        and quot.numerator() < RATE_LIMIT*1024/1e6)
      return {uint(quot.numerator()) * uint(Time::SCALE)
             ,uint(quot.denominator())
             };
    // precise computation can not be handled numerically...
    return __framerate_approximation (rational_cast<double>(quot) * Time::SCALE);
  }
  
 
  
  
  Offset
  Offset::stretchedByRationalFactor (boost::rational<int64_t> factor)  const
  {
    boost::rational<int64_t> distance (this->t_);
    distance *= factor;
    raw_time_64 microTicks = floordiv (distance.numerator(), distance.denominator());
    return Offset{buildRaw_(microTicks)};
  }
  
  
  Offset
  Offset::stretchedByFloatFactor (double factor)  const
  {
    double distance(this->t_);
    distance *= factor;
    raw_time_64 microTicks = floor (distance);
    return Offset{buildRaw_(microTicks)};
  }
  
  
  namespace {
    raw_time_64
    framecount_to_time (uint64_t frameCount, FrameRate const& fps)
    {
      // convert to 64bit
      boost::rational<uint64_t> framerate (fps.numerator(), fps.denominator());
      
      return rational_cast<raw_time_64> (lib::time::TimeValue::SCALE * frameCount / framerate);
    }
  }
  
  Offset::Offset (FrameCnt count, FrameRate const& fps)
    : TimeValue{buildRaw_(
        count? (count<0? -1:+1) * framecount_to_time (::abs(count), fps)
             :_raw(Duration::NIL))}
    { }
  
  
  
  const Duration Duration::NIL {Time::ZERO};
  
  const Duration Duration::MAX = []{
                                     auto maxDelta {Time::MAX - Time::MIN};
                                     // bypass limit check, which requires Duration::MAX
                                     return reinterpret_cast<Duration const&> (maxDelta);
                                   }();
  
  const TimeSpan TimeSpan::ALL {Time::MIN, Duration::MAX};
  
}} // namespace lib::Time
 
 
 
namespace util {
  string
  StringConv<lib::time::FSecs, void>::invoke (lib::time::FSecs val) noexcept
  {
    return lib::time::renderFraction (val, "sec");
  }
} // namespace util