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:

Public Types
typedef vtkObject	Superclass
Public Member Functions
virtual int	IsA (const char *type)
vtkTextRenderer *	NewInstance () const
virtual void	PrintSelf (ostream &os, vtkIndent indent)

virtual int	DetectBackend (const vtkStdString &str)
virtual int	DetectBackend (const vtkUnicodeString &str)

bool	FreeTypeIsSupported ()
bool	MathTextIsSupported ()

bool	GetBoundingBox (vtkTextProperty *tprop, const vtkStdString &str, int bbox[4], int dpi=120, int backend=Default)
bool	GetBoundingBox (vtkTextProperty *tprop, const vtkUnicodeString &str, int bbox[4], int dpi=120, int backend=Default)

bool	RenderString (vtkTextProperty tprop, const vtkStdString &str, vtkImageData data, int textDims[2]=NULL, int dpi=120, int backend=Default)
bool	RenderString (vtkTextProperty tprop, const vtkUnicodeString &str, vtkImageData data, int textDims[2]=NULL, int dpi=120, int backend=Default)

int	GetConstrainedFontSize (const vtkStdString &str, vtkTextProperty *tprop, int targetWidth, int targetHeight, int dpi=120, int backend=Default)
int	GetConstrainedFontSize (const vtkUnicodeString &str, vtkTextProperty *tprop, int targetWidth, int targetHeight, int dpi=120, int backend=Default)

bool	StringToPath (vtkTextProperty tprop, const vtkStdString &str, vtkPath path, int backend=Default)
bool	StringToPath (vtkTextProperty tprop, const vtkUnicodeString &str, vtkPath path, int backend=Default)

void	SetScaleToPowerOfTwo (bool scale)
Static Public Member Functions
static int	IsTypeOf (const char *type)
static vtkTextRenderer *	SafeDownCast (vtkObjectBase *o)
static vtkTextRenderer *	New ()
static vtkTextRenderer *	GetInstance ()
Protected Member Functions
virtual vtkObjectBase *	NewInstanceInternal () const
	vtkTextRenderer ()
	~vtkTextRenderer ()

virtual bool	GetBoundingBoxInternal (vtkTextProperty *tprop, const vtkStdString &str, int bbox[4], int dpi, int backend)=0
virtual bool	GetBoundingBoxInternal (vtkTextProperty *tprop, const vtkUnicodeString &str, int bbox[4], int dpi, int backend)=0
virtual bool	RenderStringInternal (vtkTextProperty tprop, const vtkStdString &str, vtkImageData data, int textDims[2], int dpi, int backend)=0
virtual bool	RenderStringInternal (vtkTextProperty tprop, const vtkUnicodeString &str, vtkImageData data, int textDims[2], int dpi, int backend)=0
virtual int	GetConstrainedFontSizeInternal (const vtkStdString &str, vtkTextProperty *tprop, int targetWidth, int targetHeight, int dpi, int backend)=0
virtual int	GetConstrainedFontSizeInternal (const vtkUnicodeString &str, vtkTextProperty *tprop, int targetWidth, int targetHeight, int dpi, int backend)=0
virtual bool	StringToPathInternal (vtkTextProperty tprop, const vtkStdString &str, vtkPath path, int backend)=0
virtual bool	StringToPathInternal (vtkTextProperty tprop, const vtkUnicodeString &str, vtkPath path, int backend)=0
virtual void	SetScaleToPowerOfTwoInternal (bool scale)=0

virtual void	CleanUpFreeTypeEscapes (vtkStdString &str)
virtual void	CleanUpFreeTypeEscapes (vtkUnicodeString &str)
Static Protected Member Functions
static void	SetInstance (vtkTextRenderer *instance)
Protected Attributes
vtksys::RegularExpression *	MathTextRegExp
vtksys::RegularExpression *	MathTextRegExp2
int	DefaultBackend

bool	HasFreeType
bool	HasMathText
Static Protected Attributes

static vtkTextRenderer *	Instance
static vtkTextRendererCleanup	Cleanup
Friends
class	vtkTextRendererCleanup
enum	Backend { Default = -1, Detect = 0, FreeType, MathText, UserBackend = 16 }
virtual void	SetDefaultBackend (int)
virtual int	GetDefaultBackend ()

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 programatically).

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.

Tests:: vtkTextRenderer (Tests)

Definition at line 68 of file vtkTextRenderer.h.

Member Typedef Documentation

typedef vtkObject vtkTextRenderer::Superclass

Reimplemented from vtkObject.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

Definition at line 71 of file vtkTextRenderer.h.

Member Enumeration Documentation

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

Enumerator:

Default
Detect
FreeType
MathText
UserBackend

Definition at line 92 of file vtkTextRenderer.h.

Constructor & Destructor Documentation

vtkTextRenderer::vtkTextRenderer ( ) [protected]

vtkTextRenderer::~vtkTextRenderer ( ) [protected]

Member Function Documentation

static int vtkTextRenderer::IsTypeOf ( const char * name ) [static]

Return 1 if this class type 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 vtkObject.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

virtual int 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 vtkObject.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

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

Reimplemented from vtkObject.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

virtual vtkObjectBase* vtkTextRenderer::NewInstanceInternal ( ) const [protected, virtual]

Reimplemented from vtkObject.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

vtkTextRenderer* vtkTextRenderer::NewInstance ( ) const

Reimplemented from vtkObject.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

virtual void vtkTextRenderer::PrintSelf	(	ostream &	os,
		vtkIndent	indent
	)		`[virtual]`

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.

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.

Reimplemented from vtkObject.

Reimplemented in vtkMathTextFreeTypeTextRenderer.

static vtkTextRenderer* vtkTextRenderer::GetInstance ( ) [static]

Return the singleton instance with no reference counting. May return NULL if the object factory cannot find an override.

virtual void vtkTextRenderer::SetDefaultBackend ( int ) [virtual]

The backend to use when none is specified. Default: Detect

virtual int vtkTextRenderer::GetDefaultBackend ( ) [virtual]

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

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

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

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

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

bool vtkTextRenderer::FreeTypeIsSupported ( ) [inline]

Test for availability of various backends

Definition at line 117 of file vtkTextRenderer.h.

bool vtkTextRenderer::MathTextIsSupported ( ) [inline]

Test for availability of various backends

Definition at line 118 of file vtkTextRenderer.h.

bool vtkTextRenderer::GetBoundingBox	(	vtkTextProperty *	tprop,
		const vtkStdString &	str,
		int	bbox[4],
		int	dpi = `120`,
		int	backend = `Default`
	)		`[inline]`

Given a text property and a string, get the bounding box [xmin, xmax] x [ymin, ymax]. Note that this is the bounding box of the area where actual pixels will be written, given a text/pen/baseline location of (0,0). For example, if the string starts with a 'space', or depending on the orientation, you can end up with a [-20, -10] x [5, 10] bbox (the math to get the real bbox is straightforward). Some rendering backends need the DPI of the target. If it is not provided, a DPI of 120 is assumed. Return true on success, false otherwise.

Definition at line 130 of file vtkTextRenderer.h.

bool vtkTextRenderer::GetBoundingBox	(	vtkTextProperty *	tprop,
		const vtkUnicodeString &	str,
		int	bbox[4],
		int	dpi = `120`,
		int	backend = `Default`
	)		`[inline]`

Given a text property and a string, get the bounding box [xmin, xmax] x [ymin, ymax]. Note that this is the bounding box of the area where actual pixels will be written, given a text/pen/baseline location of (0,0). For example, if the string starts with a 'space', or depending on the orientation, you can end up with a [-20, -10] x [5, 10] bbox (the math to get the real bbox is straightforward). Some rendering backends need the DPI of the target. If it is not provided, a DPI of 120 is assumed. Return true on success, false otherwise.

Definition at line 135 of file vtkTextRenderer.h.

bool vtkTextRenderer::RenderString	(	vtkTextProperty *	tprop,
		const vtkStdString &	str,
		vtkImageData *	data,
		int	textDims[2] = `NULL`,
		int	dpi = `120`,
		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. Some rendering backends need the DPI of the target. If it is not provided, a DPI of 120 is assumed.

Definition at line 154 of file vtkTextRenderer.h.

bool vtkTextRenderer::RenderString	(	vtkTextProperty *	tprop,
		const vtkUnicodeString &	str,
		vtkImageData *	data,
		int	textDims[2] = `NULL`,
		int	dpi = `120`,
		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. Some rendering backends need the DPI of the target. If it is not provided, a DPI of 120 is assumed.

Definition at line 160 of file vtkTextRenderer.h.

int vtkTextRenderer::GetConstrainedFontSize	(	const vtkStdString &	str,
		vtkTextProperty *	tprop,
		int	targetWidth,
		int	targetHeight,
		int	dpi = `120`,
		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. Some rendering backends need the DPI of the target. If it is not provided, a DPI of 120 is assumed.

Definition at line 175 of file vtkTextRenderer.h.

int vtkTextRenderer::GetConstrainedFontSize	(	const vtkUnicodeString &	str,
		vtkTextProperty *	tprop,
		int	targetWidth,
		int	targetHeight,
		int	dpi = `120`,
		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. Some rendering backends need the DPI of the target. If it is not provided, a DPI of 120 is assumed.

Definition at line 182 of file vtkTextRenderer.h.

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

Given a text property and a string, this function populates the vtkPath path with the outline of the rendered string. Return true on success, false otherwise.

Definition at line 195 of file vtkTextRenderer.h.

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

Given a text property and a string, this function populates the vtkPath path with the outline of the rendered string. Return true on success, false otherwise.

Definition at line 200 of file vtkTextRenderer.h.

void vtkTextRenderer::SetScaleToPowerOfTwo ( bool scale ) [inline]

Set to true if the graphics implmentation 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 212 of file vtkTextRenderer.h.

virtual bool vtkTextRenderer::GetBoundingBoxInternal	(	vtkTextProperty *	tprop,
		const vtkStdString &	str,
		int	bbox[4],
		int	dpi,
		int	backend
	)		`[protected, pure virtual]`