An eye-pattern waveform. More...

#include <EyeWaveform.h>

Inheritance diagram for EyeWaveform:

Collaboration diagram for EyeWaveform:

[legend]

Public Types
enum	EyeType { EYE_NORMAL , EYE_BER }

Public Types inherited from WaveformBase
enum	WaveformFlags_t { WAVEFORM_CLIPPING = 1 }
	Flags which may apply to m_flags. More...

Public Member Functions
	EyeWaveform (size_t width, size_t height, float center, EyeWaveform::EyeType etype)
	Create a new blank eye waveform. More...

	EyeWaveform (const EyeWaveform &)=delete

EyeWaveform &	operator= (const EyeWaveform &)=delete

int64_t *	GetAccumData ()
	Returns a pointer to the raw (not normalized) accumulator data.

void	Normalize ()
	Normalize the integrated integer buffer into float32 output buffer.

size_t	GetTotalUIs ()
	Get the total number of UIs integrated in this eye.

size_t	GetTotalSamples ()
	Get the total number of samples integrated in this eye.

float	GetCenterVoltage ()
	Get the center voltage of the eye plot (not the center of the opening) More...

void	IntegrateUIs (size_t uis, size_t samples)
	Marks a given number of UIs as integrated. More...

float	GetUIWidth ()
	Return the UI width, in X axis units.

float	GetMaskHitRate ()
	Return the mask hit rate, or zero if there is no mask defined.

void	SetMaskHitRate (float rate)
	Set the mask hit rate (normally called by the filter or instrument owning the waveform) More...

double	GetBERAtPoint (ssize_t pointx, ssize_t pointy, ssize_t xmid, ssize_t ymid)
	Gets the BER at a single point, relative to the center of the eye opening. More...

EyeType	GetType ()
	Return the eye type (normal or BER)

virtual void	FreeGpuMemory () override
	Free GPU-side memory if we are short on VRAM or do not anticipate using this waveform for a while. More...

virtual bool	HasGpuBuffer () override
	Returns true if we have at least one buffer resident on the GPU. More...

Public Member Functions inherited from DensityFunctionWaveform
	DensityFunctionWaveform (size_t width, size_t height)
	Initialize a new density function waveform of a given size. More...

	DensityFunctionWaveform (const DensityFunctionWaveform &)=delete

DensityFunctionWaveform &	operator= (const DensityFunctionWaveform &)=delete

virtual void	Rename (const std::string &name="") override
	Assings a human readable name to the waveform for debug purposes. More...

float *	GetData ()
	Returns a pointer to the CPU-side sample data buffer.

AcceleratorBuffer< float > &	GetOutData ()
	Returns a reference to the output data buffer object.

size_t	GetHeight ()
	Returns the height of the bitmap in pixels.

size_t	GetWidth ()
	Returns the width of the bitmap in pixels.

virtual void	clear () override
	Remove all samples from this waveform. More...

virtual void	Resize (size_t unused) override
	Reallocates buffers so the waveform contains the specified number of samples. More...

virtual void	PrepareForCpuAccess () override
	Indicates that this waveform is going to be used by the CPU in the near future. More...

virtual void	PrepareForGpuAccess () override
	Indicates that this waveform is going to be used by the CPU in the near future. More...

virtual void	MarkSamplesModifiedFromCpu () override
	Indicates that this waveform's sample data has been modified on the CPU and the GPU-side copy is no longer coherent. More...

virtual void	MarkSamplesModifiedFromGpu () override
	Indicates that this waveform's sample data has been modified on the GPU and the CPU-side copy is no longer coherent. More...

virtual void	MarkModifiedFromCpu () override
	Indicates that this waveform's sample data and timestamps have been modified on the CPU and the GPU-side copy is no longer coherent. More...

virtual void	MarkModifiedFromGpu () override
	Indicates that this waveform's sample data and timestamps have been modified on the GPU and the CPU-side copy is no longer coherent. More...

virtual size_t	size () const override
	Returns the number of samples in this waveform. More...

Public Member Functions inherited from WaveformBase
	WaveformBase ()
	Creates an empty waveform.

	WaveformBase (const WaveformBase &rhs)
	Creates a waveform, copying metadata from another.

virtual void	Rename (const std::string &name="")=0
	Assings a human readable name to the waveform for debug purposes. More...

virtual void	clear ()=0
	Remove all samples from this waveform. More...

virtual void	Resize (size_t size)=0
	Reallocates buffers so the waveform contains the specified number of samples. More...

virtual size_t	size () const =0
	Returns the number of samples in this waveform. More...

virtual bool	empty ()
	Returns true if this waveform contains no samples, false otherwise.

virtual std::string	GetText (size_t i)
	Returns the text representation of a given protocol sample. More...

virtual std::string	GetColor (size_t)
	Returns the displayed color (in HTML #rrggbb or #rrggbbaa notation) of a given protocol sample. More...

virtual uint32_t	GetColorCached (size_t i)
	Returns the packed RGBA32 color of a given protocol sample calculated by CacheColors() More...

virtual void	PrepareForCpuAccess ()=0
	Indicates that this waveform is going to be used by the CPU in the near future. More...

virtual void	PrepareForGpuAccess ()=0
	Indicates that this waveform is going to be used by the CPU in the near future. More...

virtual void	MarkSamplesModifiedFromCpu ()=0
	Indicates that this waveform's sample data has been modified on the CPU and the GPU-side copy is no longer coherent. More...

virtual void	MarkSamplesModifiedFromGpu ()=0
	Indicates that this waveform's sample data has been modified on the GPU and the CPU-side copy is no longer coherent. More...

virtual void	MarkModifiedFromCpu ()=0
	Indicates that this waveform's sample data and timestamps have been modified on the CPU and the GPU-side copy is no longer coherent. More...

virtual void	MarkModifiedFromGpu ()=0
	Indicates that this waveform's sample data and timestamps have been modified on the GPU and the CPU-side copy is no longer coherent. More...

virtual void	CacheColors ()
	Updates the cache of packed colors to avoid string parsing every frame.

virtual void	FreeGpuMemory ()=0
	Free GPU-side memory if we are short on VRAM or do not anticipate using this waveform for a while. More...

virtual bool	HasGpuBuffer ()=0
	Returns true if we have at least one buffer resident on the GPU. More...

Public Attributes
float	m_uiWidth
	Nominal unit interval width of the eye. More...

float	m_saturationLevel
	Saturation level for normalization. More...

Public Attributes inherited from WaveformBase
int64_t	m_timescale
	The time scale, in X axis units (usually femtoseconds) per timestep, used by this channel. More...

time_t	m_startTimestamp
	Start time of the acquisition, integer part.

int64_t	m_startFemtoseconds
	Start time of the acquisition, fractional part (femtoseconds since since the UTC second)

int64_t	m_triggerPhase
	Offset, in X axis units (usually femtoseconds), from the trigger to the sampling clock. More...

uint8_t	m_flags
	Flags that apply to this waveform. Bitfield containing zero or more WaveformFlags_t values.

uint64_t	m_revision
	Revision number. More...

Protected Attributes
int64_t *	m_accumdata
	Accumulator buffer.

size_t	m_totalUIs
	Total UIs integrated.

size_t	m_totalSamples
	Total samples integrated.

float	m_centerVoltage
	Voltage of the vertical midpoint of the plot.

float	m_maskHitRate
	Mask hit rate.

EyeType	m_type
	Type of the eye pattern.

Protected Attributes inherited from DensityFunctionWaveform
size_t	m_width
	Buffer width, in pixels.

size_t	m_height
	Buffer height, in pixels.

AcceleratorBuffer< float >	m_outdata
	Pixel buffer.

Protected Attributes inherited from WaveformBase
AcceleratorBuffer< uint32_t >	m_protocolColors
	Cache of packed RGBA32 data with colors for each protocol decode event. Empty for non-protocol waveforms.

uint64_t	m_cachedColorRevision
	Revision we last cached colors of.

Detailed Description

An eye-pattern waveform.

May be generated by a filter or directly measured by a BERT, sampling oscilloscope, etc.

The internal data is integrated as int64 to avoid loss of precision, then normalized to float32 by Normalize() after being updated.

The raw accumulator buffer is scaled by EYE_ACCUM_SCALE to enable antialiasing where a sample fits between two rows of samples. In other words, a single sample will produce a total of EYE_ACCUM_SCALE counts in the buffer, often split between several pixel locations.

Constructor & Destructor Documentation

◆ EyeWaveform()

EyeWaveform::EyeWaveform	(	size_t	width,
		size_t	height,
		float	center,
		EyeWaveform::EyeType	etype
	)

Create a new blank eye waveform.

The eye is initialized to all zeroes.

Parameters

width	Width of the buffer, in pixels
height	Height of the buffer, in pixels
center	Center voltage
etype	Type of the eye (BER or normal integrated samples)

Member Function Documentation

◆ FreeGpuMemory()

virtual void EyeWaveform::FreeGpuMemory ( )

inlineoverridevirtual

Free GPU-side memory if we are short on VRAM or do not anticipate using this waveform for a while.

Implements WaveformBase.

◆ GetBERAtPoint()

double EyeWaveform::GetBERAtPoint	(	ssize_t	pointx,
		ssize_t	pointy,
		ssize_t	xmid,
		ssize_t	ymid
	)

Gets the BER at a single point, relative to the center of the eye opening.

Parameters

pointx	X coordinate of the point
pointy	Y coordinate of the point
xmid	X coordinate of the center of the eye
ymid	Y coordinate of the center of the eye

BER is calculated by drawing a vector from the eye center to the point, then continuing to the edge of the eye and calculating what fraction of the points are before vs after the given point.

TODO: if we have multiple eye openings (MLT/PAM) we should stop at the adjacent levels, not the edge of the eye

◆ GetCenterVoltage()

float EyeWaveform::GetCenterVoltage ( )

inline

Get the center voltage of the eye plot (not the center of the opening)

This is normally 0 for AC coupled links but can be nonzero if there is a DC bias.

◆ HasGpuBuffer()

virtual bool EyeWaveform::HasGpuBuffer ( )

inlineoverridevirtual

Returns true if we have at least one buffer resident on the GPU.

Implements WaveformBase.

◆ IntegrateUIs()

void EyeWaveform::IntegrateUIs	(	size_t	uis,
		size_t	samples
	)

inline

Marks a given number of UIs as integrated.

This does not actually do anything to waveform data, it just increments the symbol count.

Typically called by filters at the end of a refresh cycle.

Parameters

uis	Number of UIs integrated
samples	Number of samples integrated

◆ SetMaskHitRate()

void EyeWaveform::SetMaskHitRate ( float rate )

inline

Set the mask hit rate (normally called by the filter or instrument owning the waveform)

Parameters

rate Hit rate

Member Data Documentation

◆ m_saturationLevel

float EyeWaveform::m_saturationLevel

Saturation level for normalization.

Saturation level of 1.0 means mapping all values to [0, 1]. 2.0 means mapping values to [0, 2] and saturating anything above 1.

◆ m_uiWidth

float EyeWaveform::m_uiWidth

Nominal unit interval width of the eye.

The entire displayed eye is two UIs wide.

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

lib/scopehal/EyeWaveform.h
lib/scopehal/EyeWaveform.cpp

Public Types

Public Member Functions

Public Attributes

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ EyeWaveform()

Member Function Documentation

◆ FreeGpuMemory()

◆ GetBERAtPoint()

◆ GetCenterVoltage()

◆ HasGpuBuffer()

◆ IntegrateUIs()

◆ SetMaskHitRate()

Member Data Documentation

◆ m_saturationLevel

◆ m_uiWidth