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//========= Copyright Valve Corporation, All rights reserved. ============//
#include "movieobjects/timeutils.h"
#include "tier0/dbg.h"
#include "mathlib/mathlib.h"
#include <math.h>
////////////////////////////////////////////////////////////////////////////////////////
//
// DmeFramerate_t
//
// exact (rational) representation of common framerates - any integral or ntsc framerate
//
////////////////////////////////////////////////////////////////////////////////////////
DmeFramerate_t::DmeFramerate_t( float fps )
{
SetFramerate( fps );
}
DmeFramerate_t::DmeFramerate_t( int fps /*= 0*/ ) :
m_num( fps ), m_den( 10000 )
{
}
DmeFramerate_t::DmeFramerate_t( int nNumerator, int nDenominator ) :
m_num( nNumerator ), m_den( nDenominator * 10000 )
{
}
void DmeFramerate_t::SetFramerate( float flFrameRate )
{
if ( IsIntegralValue( flFrameRate ) )
{
SetFramerate( RoundFloatToInt( flFrameRate ) );
}
else if ( IsIntegralValue( flFrameRate * 1001.0f / 1000.0f ) ) // 1001 is the ntsc divisor (30*1000/1001 = 29.97, etc)
{
SetFramerateNTSC( RoundFloatToInt( flFrameRate * 1001.0f / 1000.0f ) );
}
else
{
Assert( 0 );
SetFramerate( RoundFloatToInt( flFrameRate ) );
}
}
void DmeFramerate_t::SetFramerate( int fps )
{
m_num = fps;
m_den = 10000;
}
// other (uncommon) options besides 30(29.97 - ntsc video) are 24 (23.976 - ntsc film) and 60 (59.94 - ntsc progressive)
void DmeFramerate_t::SetFramerateNTSC( int multiplier /*= 30*/ )
{
// ntsc = 30 fps * 1000 / 1001
// = ( 30 / 10000 fptms ) * 1000 / 1001
// = 30 / 10010
m_num = multiplier;
m_den = 10010;
}
float DmeFramerate_t::GetFramesPerSecond() const
{
return 10000.0f * m_num / float( m_den );
}
////////////////////////////////////////////////////////////////////////////////////////
//
// DmeTime_t
//
// representing time as integral tenths of a millisecond (tms)
//
////////////////////////////////////////////////////////////////////////////////////////
DmeTime_t::DmeTime_t( int frame, DmeFramerate_t framerate )
{
int64 num = int64( framerate.m_num );
int64 prod = frame * int64( framerate.m_den );
// add signed offset to force integer truncation (towards 0) to give us truncation towards -inf
if ( frame < 0 )
{
prod -= num - 1;
}
m_tms = int( prod / num ); // round tms towards 0
}
// float operators - comment these out to find potentially incorrect uses of DmeTime_t
DmeTime_t DmeTime_t::operator*=( float f )
{
m_tms = int( floor( m_tms * f + 0.5f ) );
return *this;
}
DmeTime_t DmeTime_t::operator/=( float f )
{
m_tms = int( floor( m_tms / f + 0.5f ) );
return *this;
}
// helper methods
void DmeTime_t::Clamp( DmeTime_t lo, DmeTime_t hi )
{
m_tms = clamp( m_tms, lo.m_tms, hi.m_tms );
}
bool DmeTime_t::IsInRange( DmeTime_t lo, DmeTime_t hi ) const
{
return m_tms >= lo.m_tms && m_tms < hi.m_tms;
}
// helper functions
float GetFractionOfTimeBetween( DmeTime_t t, DmeTime_t start, DmeTime_t end, bool bClamp /*= false*/ )
{
return GetFractionOfTime( t - start, end - start, bClamp );
}
float GetFractionOfTime( DmeTime_t t, DmeTime_t duration, bool bClamp /*= false*/ )
{
if ( duration == DMETIME_ZERO )
return 0.0f;
if ( bClamp )
{
t.Clamp( DMETIME_ZERO, duration );
}
return t.m_tms / float( duration.m_tms );
}
int FrameForTime( DmeTime_t t, DmeFramerate_t framerate )
{
return t.CurrentFrame( framerate );
}
// framerate-dependent conversions to/from frames
int DmeTime_t::CurrentFrame( DmeFramerate_t framerate, bool bRoundDown ) const
{
int64 den = int64( framerate.m_den );
int64 num = int64( framerate.m_num );
int64 prod = int64( m_tms ) * num;
// times within this range are considered on a frame: (frame*den/num - 1, frame*den/num]
// this follows from the truncation towards -inf behavior of the frame,framerate constructor above
// the following logic is there to ensure the above rule,
// while working around the truncation towards 0 behavior of integer divide
if ( m_tms < 0 )
{
if ( bRoundDown )
prod -= den - num;
}
else
{
if ( bRoundDown )
prod += num - 1;
else
prod += den - 1;
}
return int( prod / den );
}
DmeTime_t DmeTime_t::TimeAtCurrentFrame( DmeFramerate_t framerate, bool bRoundDown ) const
{
int frame = CurrentFrame( framerate, bRoundDown );
return DmeTime_t( frame, framerate );
}
DmeTime_t DmeTime_t::TimeAtNextFrame( DmeFramerate_t framerate ) const
{
// since we always round towards -inf, go to next frame whether we're on a frame or not
int frame = CurrentFrame( framerate, true );
return DmeTime_t( frame + 1, framerate );
}
DmeTime_t DmeTime_t::TimeAtPrevFrame( DmeFramerate_t framerate ) const
{
int frame = CurrentFrame( framerate, false );
return DmeTime_t( frame - 1, framerate ); // we're exactly on a frame
}
int DmeTime_t::RoundSecondsToTMS( float sec )
{
return floor( 10000.0f * sec + 0.5f ); // round at half-tms boundary
}
int DmeTime_t::RoundSecondsToTMS( double sec )
{
return floor( 10000.0 * sec + 0.5 ); // round at half-tms boundary
}
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