Bookkeeping for frame durations and associated errors. More...

#include <kanzi/core.ui/main_loop/frame_time_queue.hpp>

Classes
class	ErrorTermCalculator
	Error term calculator. More...

Public Member Functions
	FrameTimeQueue (chrono::nanoseconds window)
	Constructor.

	FrameTimeQueue (chrono::nanoseconds window, size_t desiredFrameRate)
	Constructor.

	FrameTimeQueue (FrameTimeQueue &&other)=default
	Move constructor.

size_t	getDesiredFrameRate () const
	Gets the desired frame rate.

chrono::nanoseconds	getDesiredFrameTime () const
	Gets the desired frame time.

float	getFPS () const
	Gets the current framerate.

chrono::nanoseconds	getFrameTimeErrorTerm () const
	Gets the cumulative frame time error.

chrono::nanoseconds	getWindow () const
	Gets the frame time window.

FrameTimeQueue &	operator= (FrameTimeQueue &&other)=default
	Move operator.

void	update (chrono::nanoseconds frameTime)
	Add a frame time.

Static Public Member Functions
static constexpr chrono::nanoseconds	fpsToDurationCeiled (size_t desiredFrameRate)
	Converts frame rate to desired frame time duration.

Protected Member Functions
size_t	decrementIterator (size_t iter) const
	Decrement an iterator and wrap around if needed.

void	growFrameTimeArray ()
	Enlarges the frame time array.

size_t	incrementIterator (size_t iter) const
	Increment an iterator and wrap around if needed.

Static Protected Member Functions
static constexpr chrono::nanoseconds	durationDivideRoundUp (chrono::nanoseconds duration, size_t divisor)
	Divide time by a value, round up.

Protected Attributes
ErrorTermCalculator	m_errorTermCalculator
	Calculator for frame time error term.

float	m_fps
	Frame rate cache.

size_t	m_frameTimeCount
	Frame time element count.

vector< chrono::nanoseconds >	m_frameTimes
	Array containing frame times for FPS calculation.

size_t	m_insertionIndex
	Frame time insertion index.

size_t	m_removeIndex
	Frame time removal index.

chrono::nanoseconds	m_totalTime
	Total time spent within the frame time window.

chrono::nanoseconds	m_window
	Time window for frame time error bookkeeping.

Detailed Description

Bookkeeping for frame durations and associated errors.

Constructor & Destructor Documentation

◆ FrameTimeQueue() [1/3]

kanzi::FrameTimeQueue::FrameTimeQueue	(	chrono::nanoseconds	window,
		size_t	desiredFrameRate )

inlineexplicit

Constructor.

Parameters

window	Time window for bookkeeping.
desiredFrameRate	Desired frame rate.

◆ FrameTimeQueue() [2/3]

kanzi::FrameTimeQueue::FrameTimeQueue ( chrono::nanoseconds window )

explicit

Constructor.

Frame rate is unlimited.

Parameters

window Time window for bookkeeping.

◆ FrameTimeQueue() [3/3]

kanzi::FrameTimeQueue::FrameTimeQueue ( FrameTimeQueue && other )

default

Move constructor.

Parameters

other Source object.

Member Function Documentation

◆ operator=()

FrameTimeQueue & kanzi::FrameTimeQueue::operator= ( FrameTimeQueue && other )

default

Move operator.

Parameters

other Source object.

◆ update()

void kanzi::FrameTimeQueue::update ( chrono::nanoseconds frameTime )

Add a frame time.

Parameters

frameTime Time spent last frame.

◆ getFPS()

float kanzi::FrameTimeQueue::getFPS ( ) const

inline

Gets the current framerate.

Returns: Current framerate as calculated from recorded frame times.

◆ getDesiredFrameRate()

size_t kanzi::FrameTimeQueue::getDesiredFrameRate ( ) const

inline

Gets the desired frame rate.

Returns: Targeted frame rate.

Since: Kanzi 4.0.0

◆ getDesiredFrameTime()

chrono::nanoseconds kanzi::FrameTimeQueue::getDesiredFrameTime ( ) const

inline

Gets the desired frame time.

Returns: Frame time from the targeted frame rate.

Since: Kanzi 4.0.0

◆ getFrameTimeErrorTerm()

chrono::nanoseconds kanzi::FrameTimeQueue::getFrameTimeErrorTerm ( ) const

inline

Gets the cumulative frame time error.

Returns: Cumulative frame time error.

Since: Kanzi 4.0.0

◆ getWindow()

chrono::nanoseconds kanzi::FrameTimeQueue::getWindow ( ) const

inline

Gets the frame time window.

Returns: Frame window time.

Since: Kanzi 4.0.0

◆ fpsToDurationCeiled()

static constexpr chrono::nanoseconds kanzi::FrameTimeQueue::fpsToDurationCeiled ( size_t desiredFrameRate )

inlinestaticconstexpr

Converts frame rate to desired frame time duration.

Always rounds nanoseconds up.

Parameters

desiredFrameRate Desired Frame rate.

Returns: Frame duration in nanoseconds.

Since: Kanzi 4.0.0

◆ durationDivideRoundUp()

static constexpr chrono::nanoseconds kanzi::FrameTimeQueue::durationDivideRoundUp	(	chrono::nanoseconds	duration,
		size_t	divisor )

inlinestaticconstexprprotected

Divide time by a value, round up.

Parameters

duration	Duration.
divisor	Divisor.

Since: Kanzi 4.0.0

◆ growFrameTimeArray()

void kanzi::FrameTimeQueue::growFrameTimeArray ( )

protected

Enlarges the frame time array.

After calling this function, insertion of

Since: Kanzi 4.0.0

◆ decrementIterator()

size_t kanzi::FrameTimeQueue::decrementIterator ( size_t iter ) const

inlineprotected

Decrement an iterator and wrap around if needed.

Parameters

iter Iterator.

Returns: New iterator location.

Since: Kanzi 4.0.0

◆ incrementIterator()

size_t kanzi::FrameTimeQueue::incrementIterator ( size_t iter ) const

inlineprotected

Increment an iterator and wrap around if needed.

Parameters

iter Iterator.

Returns: New iterator location.

Since: Kanzi 4.0.0

Member Data Documentation

◆ m_window

chrono::nanoseconds kanzi::FrameTimeQueue::m_window

protected

Time window for frame time error bookkeeping.

Since: Kanzi 4.0.0

◆ m_frameTimes

vector<chrono::nanoseconds> kanzi::FrameTimeQueue::m_frameTimes

protected

Array containing frame times for FPS calculation.

Since

Kanzi 4.0.0

Renamed from m_frames.
Changed the type to vector<chrono::nanoseconds>.

◆ m_frameTimeCount

size_t kanzi::FrameTimeQueue::m_frameTimeCount

protected

Frame time element count.

Since: Kanzi 4.0.0 renamed from m_frameCount.

◆ m_insertionIndex

size_t kanzi::FrameTimeQueue::m_insertionIndex

protected

Frame time insertion index.

Insertion index being identical to removal index indicates the array being empty.

Since: Kanzi 4.0.0

◆ m_removeIndex

size_t kanzi::FrameTimeQueue::m_removeIndex

protected

Frame time removal index.

If insertion would increment the insertion index to the removal index, the array must be grown.

Since: Kanzi 4.0.0 renamed from m_firstFrame.

◆ m_totalTime

chrono::nanoseconds kanzi::FrameTimeQueue::m_totalTime

protected

Total time spent within the frame time window.

◆ m_fps

float kanzi::FrameTimeQueue::m_fps

protected

Frame rate cache.

◆ m_errorTermCalculator

ErrorTermCalculator kanzi::FrameTimeQueue::m_errorTermCalculator

protected

Calculator for frame time error term.

Since: Kanzi 4.0.0

The documentation for this class was generated from the following file:

kanzi/core.ui/main_loop/frame_time_queue.hpp

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ FrameTimeQueue() [1/3]

◆ FrameTimeQueue() [2/3]

◆ FrameTimeQueue() [3/3]

Member Function Documentation

◆ operator=()

◆ update()

◆ getFPS()

◆ getDesiredFrameRate()

◆ getDesiredFrameTime()

◆ getFrameTimeErrorTerm()

◆ getWindow()

◆ fpsToDurationCeiled()

◆ durationDivideRoundUp()

◆ growFrameTimeArray()

◆ decrementIterator()

◆ incrementIterator()

Member Data Documentation

◆ m_window

◆ m_frameTimes

◆ m_frameTimeCount

◆ m_insertionIndex

◆ m_removeIndex

◆ m_totalTime

◆ m_fps

◆ m_errorTermCalculator