Interface for generating images and path data from string data, using multiple backends. More...

#include <vtkTextRenderer.h>

Inheritance diagram for vtkTextRenderer:

Collaboration diagram for vtkTextRenderer:

Classes
struct	Metrics

Public Types
enum	Backend { Default = -1 , Detect = 0 , FreeType , MathText , UserBackend = 16 }
	Available backends. More...

typedef vtkObject	Superclass

Public Member Functions
virtual vtkTypeBool	IsA (const char *type)
	Return 1 if this class is the same type of (or a subclass of) the named class. More...

vtkTextRenderer *	NewInstance () const

void	PrintSelf (ostream &os, vtkIndent indent) override
	Methods invoked by print to print information about the object including superclasses. More...

virtual bool	FreeTypeIsSupported ()
	Test for availability of various backends. More...

virtual bool	MathTextIsSupported ()

void	SetScaleToPowerOfTwo (bool scale)
	Set to true if the graphics implementation requires texture image dimensions to be a power of two. More...


virtual void	SetDefaultBackend (int)
	The backend to use when none is specified. More...

virtual int	GetDefaultBackend ()
	The backend to use when none is specified. More...


virtual int	DetectBackend (const vtkStdString &str)
	Determine the appropriate back end needed to render the given string. More...

virtual int	DetectBackend (const vtkUnicodeString &str)
	Determine the appropriate back end needed to render the given string. More...


bool	GetBoundingBox (vtkTextProperty *tprop, const vtkStdString &str, int bbox[4], int dpi, int backend=Default)
	Given a text property and a string, get the bounding box {xmin, xmax, ymin, ymax} of the rendered string in pixels. More...

bool	GetBoundingBox (vtkTextProperty *tprop, const vtkUnicodeString &str, int bbox[4], int dpi, int backend=Default)
	Given a text property and a string, get the bounding box {xmin, xmax, ymin, ymax} of the rendered string in pixels. More...


bool	GetMetrics (vtkTextProperty *tprop, const vtkStdString &str, Metrics &metrics, int dpi, int backend=Default)
	Given a text property and a string, get some metrics for the rendered string. More...

bool	GetMetrics (vtkTextProperty *tprop, const vtkUnicodeString &str, Metrics &metrics, int dpi, int backend=Default)
	Given a text property and a string, get some metrics for the rendered string. More...


bool	RenderString (vtkTextProperty tprop, const vtkStdString &str, vtkImageData data, int textDims[2], int dpi, int backend=Default)
	Given a text property and a string, this function initializes the vtkImageData *data and renders it in a vtkImageData. More...

bool	RenderString (vtkTextProperty tprop, const vtkUnicodeString &str, vtkImageData data, int textDims[2], int dpi, int backend=Default)
	Given a text property and a string, this function initializes the vtkImageData *data and renders it in a vtkImageData. More...


int	GetConstrainedFontSize (const vtkStdString &str, vtkTextProperty *tprop, int targetWidth, int targetHeight, int dpi, int backend=Default)
	This function returns the font size (in points) and sets the size in tprop that is required to fit the string in the target rectangle. More...

int	GetConstrainedFontSize (const vtkUnicodeString &str, vtkTextProperty *tprop, int targetWidth, int targetHeight, int dpi, int backend=Default)
	This function returns the font size (in points) and sets the size in tprop that is required to fit the string in the target rectangle. More...


bool	StringToPath (vtkTextProperty tprop, const vtkStdString &str, vtkPath path, int dpi, int backend=Default)
	Given a text property and a string, this function populates the vtkPath path with the outline of the rendered string. More...

bool	StringToPath (vtkTextProperty tprop, const vtkUnicodeString &str, vtkPath path, int dpi, int backend=Default)
	Given a text property and a string, this function populates the vtkPath path with the outline of the rendered string. More...

Public Member Functions inherited from vtkObject
	vtkBaseTypeMacro (vtkObject, vtkObjectBase)

virtual void	DebugOn ()
	Turn debugging output on. More...

virtual void	DebugOff ()
	Turn debugging output off. More...

bool	GetDebug ()
	Get the value of the debug flag. More...

void	SetDebug (bool debugFlag)
	Set the value of the debug flag. More...

virtual void	Modified ()
	Update the modification time for this object. More...

virtual vtkMTimeType	GetMTime ()
	Return this object's modified time. More...

void	PrintSelf (ostream &os, vtkIndent indent) override
	Methods invoked by print to print information about the object including superclasses. More...

void	RemoveObserver (unsigned long tag)

void	RemoveObservers (unsigned long event)

void	RemoveObservers (const char *event)

void	RemoveAllObservers ()

vtkTypeBool	HasObserver (unsigned long event)

vtkTypeBool	HasObserver (const char *event)

int	InvokeEvent (unsigned long event)

int	InvokeEvent (const char *event)

unsigned long	AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...

unsigned long	AddObserver (const char event, vtkCommand , float priority=0.0f)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...

vtkCommand *	GetCommand (unsigned long tag)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...

void	RemoveObserver (vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...

void	RemoveObservers (unsigned long event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...

void	RemoveObservers (const char event, vtkCommand )
	Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...

vtkTypeBool	HasObserver (unsigned long event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...

vtkTypeBool	HasObserver (const char event, vtkCommand )
	Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)
	Overloads to AddObserver that allow developers to add class member functions as callbacks for events. More...

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)
	Overloads to AddObserver that allow developers to add class member functions as callbacks for events. More...

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, bool(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)
	Allow user to set the AbortFlagOn() with the return value of the callback method. More...

int	InvokeEvent (unsigned long event, void *callData)
	This method invokes an event and return whether the event was aborted or not. More...

int	InvokeEvent (const char event, void callData)
	This method invokes an event and return whether the event was aborted or not. More...

Public Member Functions inherited from vtkObjectBase
const char *	GetClassName () const
	Return the class name as a string. More...

virtual vtkTypeBool	IsA (const char *name)
	Return 1 if this class is the same type of (or a subclass of) the named class. More...

virtual vtkIdType	GetNumberOfGenerationsFromBase (const char *name)
	Given the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class). More...

virtual void	Delete ()
	Delete a VTK object. More...

virtual void	FastDelete ()
	Delete a reference to this object. More...

void	InitializeObjectBase ()

void	Print (ostream &os)
	Print an object to an ostream. More...

virtual void	Register (vtkObjectBase *o)
	Increase the reference count (mark as used by another object). More...

virtual void	UnRegister (vtkObjectBase *o)
	Decrease the reference count (release by another object). More...

int	GetReferenceCount ()
	Return the current reference count of this object. More...

void	SetReferenceCount (int)
	Sets the reference count. More...

bool	GetIsInMemkind () const
	A local state flag that remembers whether this object lives in the normal or extended memory space. More...

virtual void	PrintHeader (ostream &os, vtkIndent indent)
	Methods invoked by print to print information about the object including superclasses. More...

virtual void	PrintTrailer (ostream &os, vtkIndent indent)
	Methods invoked by print to print information about the object including superclasses. More...

Static Public Member Functions
static vtkTypeBool	IsTypeOf (const char *type)

static vtkTextRenderer *	SafeDownCast (vtkObjectBase *o)

static vtkTextRenderer *	New ()
	This is a singleton pattern New. More...

static vtkTextRenderer *	GetInstance ()
	Return the singleton instance with no reference counting. More...

Static Public Member Functions inherited from vtkObject
static vtkObject *	New ()
	Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...

static void	BreakOnError ()
	This method is called when vtkErrorMacro executes. More...

static void	SetGlobalWarningDisplay (int val)
	This is a global flag that controls whether any debug, warning or error messages are displayed. More...

static void	GlobalWarningDisplayOn ()
	This is a global flag that controls whether any debug, warning or error messages are displayed. More...

static void	GlobalWarningDisplayOff ()
	This is a global flag that controls whether any debug, warning or error messages are displayed. More...

static int	GetGlobalWarningDisplay ()
	This is a global flag that controls whether any debug, warning or error messages are displayed. More...

Static Public Member Functions inherited from vtkObjectBase
static vtkTypeBool	IsTypeOf (const char *name)
	Return 1 if this class type is the same type of (or a subclass of) the named class. More...

static vtkIdType	GetNumberOfGenerationsFromBaseType (const char *name)
	Given a the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class). More...

static vtkObjectBase *	New ()
	Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...

static void	SetMemkindDirectory (const char *directoryname)
	The name of a directory, ideally mounted -o dax, to memory map an extended memory space within. More...

static bool	GetUsingMemkind ()
	A global state flag that controls whether vtkObjects are constructed in the usual way (the default) or within the extended memory space. More...

Protected Member Functions
virtual vtkObjectBase *	NewInstanceInternal () const

	vtkTextRenderer ()

	~vtkTextRenderer () override


virtual bool	GetBoundingBoxInternal (vtkTextProperty *tprop, const vtkStdString &str, int bbox[4], int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual bool	GetBoundingBoxInternal (vtkTextProperty *tprop, const vtkUnicodeString &str, int bbox[4], int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual bool	GetMetricsInternal (vtkTextProperty *tprop, const vtkStdString &str, Metrics &metrics, int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual bool	GetMetricsInternal (vtkTextProperty *tprop, const vtkUnicodeString &str, Metrics &metrics, int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual bool	RenderStringInternal (vtkTextProperty tprop, const vtkStdString &str, vtkImageData data, int textDims[2], int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual bool	RenderStringInternal (vtkTextProperty tprop, const vtkUnicodeString &str, vtkImageData data, int textDims[2], int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual int	GetConstrainedFontSizeInternal (const vtkStdString &str, vtkTextProperty *tprop, int targetWidth, int targetHeight, int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual int	GetConstrainedFontSizeInternal (const vtkUnicodeString &str, vtkTextProperty *tprop, int targetWidth, int targetHeight, int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual bool	StringToPathInternal (vtkTextProperty tprop, const vtkStdString &str, vtkPath path, int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual bool	StringToPathInternal (vtkTextProperty tprop, const vtkUnicodeString &str, vtkPath path, int dpi, int backend)=0
	Virtual methods for concrete implementations of the public methods. More...

virtual void	SetScaleToPowerOfTwoInternal (bool scale)=0
	Virtual methods for concrete implementations of the public methods. More...


virtual void	CleanUpFreeTypeEscapes (vtkStdString &str)
	Replace all instances of "\$" with "$". More...

virtual void	CleanUpFreeTypeEscapes (vtkUnicodeString &str)
	Replace all instances of "\$" with "$". More...

Protected Member Functions inherited from vtkObject
	vtkObject ()

	~vtkObject () override

void	RegisterInternal (vtkObjectBase *, vtkTypeBool check) override

void	UnRegisterInternal (vtkObjectBase *, vtkTypeBool check) override

void	InternalGrabFocus (vtkCommand mouseEvents, vtkCommand keypressEvents=nullptr)
	These methods allow a command to exclusively grab all events. More...

void	InternalReleaseFocus ()
	These methods allow a command to exclusively grab all events. More...

Protected Member Functions inherited from vtkObjectBase
	vtkObjectBase ()

virtual	~vtkObjectBase ()

virtual void	RegisterInternal (vtkObjectBase *, vtkTypeBool check)

virtual void	UnRegisterInternal (vtkObjectBase *, vtkTypeBool check)

virtual void	ReportReferences (vtkGarbageCollector *)

	vtkObjectBase (const vtkObjectBase &)

void	operator= (const vtkObjectBase &)

Static Protected Member Functions
static void	SetInstance (vtkTextRenderer *instance)
	Set the singleton instance. More...

Static Protected Member Functions inherited from vtkObjectBase
static vtkMallocingFunction	GetCurrentMallocFunction ()

static vtkReallocingFunction	GetCurrentReallocFunction ()

static vtkFreeingFunction	GetCurrentFreeFunction ()

static vtkFreeingFunction	GetAlternateFreeFunction ()

Protected Attributes
vtksys::RegularExpression *	MathTextRegExp

vtksys::RegularExpression *	MathTextRegExp2

vtksys::RegularExpression *	MathTextRegExpColumn

int	DefaultBackend
	The backend to use when none is specified. More...

Protected Attributes inherited from vtkObject
bool	Debug

vtkTimeStamp	MTime

vtkSubjectHelper *	SubjectHelper

Protected Attributes inherited from vtkObjectBase
std::atomic< int32_t >	ReferenceCount

vtkWeakPointerBase **	WeakPointers

Static Protected Attributes

static vtkTextRenderer *	Instance
	The singleton instance and the singleton cleanup instance. More...

static vtkTextRendererCleanup	Cleanup
	The singleton instance and the singleton cleanup instance. More...

Friends
class	vtkTextRendererCleanup

Detailed Description

Interface for generating images and path data from string data, using multiple backends.

vtkTextRenderer produces images, bounding boxes, and vtkPath objects that represent text. The advantage of using this class is to easily integrate mathematical expressions into renderings by automatically switching between FreeType and MathText backends. If the input string contains at least two "$" symbols separated by text, the MathText backend will be used. If the string does not meet this criteria, or if no MathText implementation is available, the faster FreeType rendering facilities are used. Literal $ symbols can be used by escaping them with backslashes, "\$" (or "\\$" if the string is set programmatically).

For example, "Acceleration ($\\frac{m}{s^2}$)" will use MathText, but "\\$500, \\$100" will use FreeType.

By default, the backend is set to Detect, which determines the backend based on the contents of the string. This can be changed by setting the DefaultBackend ivar.

Note that this class is abstract – link to the vtkRenderingFreetype module to get the default implementation.

Definition at line 74 of file vtkTextRenderer.h.

Member Typedef Documentation

◆ Superclass

typedef vtkObject vtkTextRenderer::Superclass

Definition at line 122 of file vtkTextRenderer.h.

Member Enumeration Documentation

◆ Backend

enum vtkTextRenderer::Backend

Available backends.

FreeType and MathText are provided in the default implementation of this interface. Enum values less than 16 are reserved. Custom overrides should define other backends starting at 16.

Enumerator
Default
Detect
FreeType
MathText
UserBackend

Definition at line 147 of file vtkTextRenderer.h.

Constructor & Destructor Documentation

◆ vtkTextRenderer()

vtkTextRenderer::vtkTextRenderer ( )

protected

◆ ~vtkTextRenderer()

vtkTextRenderer::~vtkTextRenderer ( )

overrideprotected

Member Function Documentation

◆ IsTypeOf()

static vtkTypeBool vtkTextRenderer::IsTypeOf ( const char * type )

static

◆ IsA()

virtual vtkTypeBool vtkTextRenderer::IsA ( const char * name )

virtual

Return 1 if this class is the same type of (or a subclass of) the named class.

Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.

Reimplemented from vtkObjectBase.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

◆ SafeDownCast()

static vtkTextRenderer * vtkTextRenderer::SafeDownCast ( vtkObjectBase * o )

static

◆ NewInstanceInternal()

virtual vtkObjectBase * vtkTextRenderer::NewInstanceInternal ( ) const

protectedvirtual

Reimplemented in vtkMathTextFreeTypeTextRenderer.

◆ NewInstance()

vtkTextRenderer * vtkTextRenderer::NewInstance ( ) const

◆ PrintSelf()

void vtkTextRenderer::PrintSelf	(	ostream &	os,
		vtkIndent	indent
	)

overridevirtual

Methods invoked by print to print information about the object including superclasses.

Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from vtkObject.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

◆ New()

static vtkTextRenderer * vtkTextRenderer::New ( )

static

This is a singleton pattern New.

There will be only ONE reference to a vtkTextRenderer subclass object per process. Clients that call this method must use Delete() on the object so that reference counting will work. The single instance will be unreferenced when the program exits. You should just use the static GetInstance() method anyway to get the singleton. This method may return NULL if the object factory cannot find an override.

◆ GetInstance()

static vtkTextRenderer * vtkTextRenderer::GetInstance ( )

static

Return the singleton instance with no reference counting.

May return NULL if the object factory cannot find an override.

◆ SetDefaultBackend()

virtual void vtkTextRenderer::SetDefaultBackend ( int )

virtual

The backend to use when none is specified.

Default: Detect

◆ GetDefaultBackend()

virtual int vtkTextRenderer::GetDefaultBackend ( )

virtual

The backend to use when none is specified.

Default: Detect

◆ DetectBackend() [1/2]

virtual int vtkTextRenderer::DetectBackend ( const vtkStdString & str )

virtual

Determine the appropriate back end needed to render the given string.

◆ DetectBackend() [2/2]

virtual int vtkTextRenderer::DetectBackend ( const vtkUnicodeString & str )

virtual

Determine the appropriate back end needed to render the given string.

◆ FreeTypeIsSupported()

virtual bool vtkTextRenderer::FreeTypeIsSupported ( )

inlinevirtual

Test for availability of various backends.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

Definition at line 176 of file vtkTextRenderer.h.

◆ MathTextIsSupported()

virtual bool vtkTextRenderer::MathTextIsSupported ( )

inlinevirtual

Reimplemented in vtkMathTextFreeTypeTextRenderer.

Definition at line 177 of file vtkTextRenderer.h.

◆ GetBoundingBox() [1/2]

bool vtkTextRenderer::GetBoundingBox	(	vtkTextProperty *	tprop,
		const vtkStdString &	str,
		int	bbox[4],
		int	dpi,
		int	backend = `Default`
	)

inline

Given a text property and a string, get the bounding box {xmin, xmax, ymin, ymax} of the rendered string in pixels.

The origin of the bounding box is the anchor point described by the horizontal and vertical justification text property variables. Return true on success, false otherwise.

Definition at line 187 of file vtkTextRenderer.h.

◆ GetBoundingBox() [2/2]

bool vtkTextRenderer::GetBoundingBox	(	vtkTextProperty *	tprop,
		const vtkUnicodeString &	str,
		int	bbox[4],
		int	dpi,
		int	backend = `Default`
	)

Given a text property and a string, get the bounding box {xmin, xmax, ymin, ymax} of the rendered string in pixels.

The origin of the bounding box is the anchor point described by the horizontal and vertical justification text property variables. Return true on success, false otherwise.

◆ GetMetrics() [1/2]

bool vtkTextRenderer::GetMetrics	(	vtkTextProperty *	tprop,
		const vtkStdString &	str,
		Metrics &	metrics,
		int	dpi,
		int	backend = `Default`
	)

inline

Given a text property and a string, get some metrics for the rendered string.

Return true on success, false otherwise.

Definition at line 204 of file vtkTextRenderer.h.

◆ GetMetrics() [2/2]

bool vtkTextRenderer::GetMetrics	(	vtkTextProperty *	tprop,
		const vtkUnicodeString &	str,
		Metrics &	metrics,
		int	dpi,
		int	backend = `Default`
	)

Given a text property and a string, get some metrics for the rendered string.

Return true on success, false otherwise.

◆ RenderString() [1/2]

bool vtkTextRenderer::RenderString	(	vtkTextProperty *	tprop,
		const vtkStdString &	str,
		vtkImageData *	data,
		int	textDims[2],
		int	dpi,
		int	backend = `Default`
	)

inline

Given a text property and a string, this function initializes the vtkImageData *data and renders it in a vtkImageData.

Return true on success, false otherwise. If using the overload that specifies "textDims", the array will be overwritten with the pixel width and height defining a tight bounding box around the text in the image, starting from the upper-right corner. This is used when rendering for a texture on graphics hardware that requires texture image dimensions to be a power of two; textDims can be used to determine the texture coordinates needed to cleanly fit the text on the target. The origin of the image's extents is aligned with the anchor point described by the text property's vertical and horizontal justification options.

Definition at line 230 of file vtkTextRenderer.h.

◆ RenderString() [2/2]

bool vtkTextRenderer::RenderString	(	vtkTextProperty *	tprop,
		const vtkUnicodeString &	str,
		vtkImageData *	data,
		int	textDims[2],
		int	dpi,
		int	backend = `Default`
	)

Given a text property and a string, this function initializes the vtkImageData *data and renders it in a vtkImageData.

Return true on success, false otherwise. If using the overload that specifies "textDims", the array will be overwritten with the pixel width and height defining a tight bounding box around the text in the image, starting from the upper-right corner. This is used when rendering for a texture on graphics hardware that requires texture image dimensions to be a power of two; textDims can be used to determine the texture coordinates needed to cleanly fit the text on the target. The origin of the image's extents is aligned with the anchor point described by the text property's vertical and horizontal justification options.

◆ GetConstrainedFontSize() [1/2]

int vtkTextRenderer::GetConstrainedFontSize	(	const vtkStdString &	str,
		vtkTextProperty *	tprop,
		int	targetWidth,
		int	targetHeight,
		int	dpi,
		int	backend = `Default`
	)

inline

This function returns the font size (in points) and sets the size in tprop that is required to fit the string in the target rectangle.

The computed font size will be set in tprop as well. If an error occurs, this function will return -1.

Definition at line 248 of file vtkTextRenderer.h.

◆ GetConstrainedFontSize() [2/2]

int vtkTextRenderer::GetConstrainedFontSize	(	const vtkUnicodeString &	str,
		vtkTextProperty *	tprop,
		int	targetWidth,
		int	targetHeight,
		int	dpi,
		int	backend = `Default`
	)

This function returns the font size (in points) and sets the size in tprop that is required to fit the string in the target rectangle.

The computed font size will be set in tprop as well. If an error occurs, this function will return -1.

◆ StringToPath() [1/2]

bool vtkTextRenderer::StringToPath	(	vtkTextProperty *	tprop,
		const vtkStdString &	str,
		vtkPath *	path,
		int	dpi,
		int	backend = `Default`
	)

inline

Given a text property and a string, this function populates the vtkPath path with the outline of the rendered string.

The origin of the path coordinates is aligned with the anchor point described by the text property's horizontal and vertical justification options. Return true on success, false otherwise.

Definition at line 269 of file vtkTextRenderer.h.

◆ StringToPath() [2/2]

bool vtkTextRenderer::StringToPath	(	vtkTextProperty *	tprop,
		const vtkUnicodeString &	str,
		vtkPath *	path,
		int	dpi,
		int	backend = `Default`
	)

Given a text property and a string, this function populates the vtkPath path with the outline of the rendered string.

The origin of the path coordinates is aligned with the anchor point described by the text property's horizontal and vertical justification options. Return true on success, false otherwise.

◆ SetScaleToPowerOfTwo()

void vtkTextRenderer::SetScaleToPowerOfTwo ( bool scale )

inline

Set to true if the graphics implementation requires texture image dimensions to be a power of two.

Default is true, but this member will be set appropriately by vtkOpenGLRenderWindow::OpenGLInitContext when GL is inited.

Definition at line 286 of file vtkTextRenderer.h.