Render text as a translucent raster image. More...

#include <moOGLFT.h>

Inheritance diagram for OGLFT::Translucent:

Public Member Functions
	Translucent (const char *filename, float point_size=12, FT_UInt resolution=100)

	Translucent (FT_Face face, float point_size=12, FT_UInt resolution=100)

	~Translucent (void)

Public Member Functions inherited from OGLFT::Raster
	Raster (const char *filename, float point_size=12, FT_UInt resolution=100)

	Raster (FT_Face face, float point_size=12, FT_UInt resolution=100)

virtual	~Raster (void)

void	setCharacterRotationZ (GLfloat character_rotation_z)

GLfloat	characterRotationZ (void) const

double	height (void) const

BBox	measure (unsigned char c)

BBox	measure (const char *s)

Public Member Functions inherited from OGLFT::Face
	Face (const char *filename, float point_size=12, FT_UInt resolution=100)

	Face (FT_Face face, float point_size=12, FT_UInt resolution=100)

virtual	~Face (void)

bool	isValid (void) const

bool	addAuxiliaryFace (const char *filename)

bool	addAuxiliaryFace (FT_Face face)

void	setCompileMode (enum GlyphCompileMode compile_mode)

enum GlyphCompileMode	compileMode (void) const

void	setPointSize (float point_size)

float	pointSize (void)

void	setResolution (FT_UInt resolution)

FT_UInt	resolution (void)

void	setAdvance (bool advance)

bool	advance (void) const

void	setForegroundColor (GLfloat red=0.0, GLfloat green=0.0, GLfloat blue=0.0, GLfloat alpha=1.0)

void	setForegroundColor (const GLfloat foreground_color[4])

GLfloat	foregroundRed (void) const

GLfloat	foregroundGreen (void) const

GLfloat	foregroundBlue (void) const

GLfloat	foregroundAlpha (void) const

void	setBackgroundColor (GLfloat red=1.0, GLfloat green=1.0, GLfloat blue=1.0, GLfloat alpha=0.0)

void	setBackgroundColor (const GLfloat background_color[4])

GLfloat	backgroundRed (void) const

GLfloat	backgroundGreen (void) const

GLfloat	backgroundBlue (void) const

GLfloat	backgroundAlpha (void) const

void	setCharacterRotationReference (unsigned char c)

void	setStringRotation (GLfloat string_rotation)

GLfloat	stringRotation (void) const

void	setHorizontalJustification (enum HorizontalJustification horizontal_justification)

enum HorizontalJustification	horizontalJustification (void) const

void	setVerticalJustification (enum VerticalJustification vertical_justification)

enum VerticalJustification	verticaljustification (void) const

void	setCharacterDisplayLists (const DisplayLists &character_display_lists)

DisplayLists &	characterDisplayLists (void)

virtual BBox	measureRaw (const char *s)

GLuint	compile (const char *s)

GLuint	compile (unsigned char c)

void	draw (const char *s)

void	draw (unsigned char c)

void	draw (GLfloat x, GLfloat y, unsigned char c)

void	draw (GLfloat x, GLfloat y, GLfloat z, unsigned char c)

void	draw (GLfloat x, GLfloat y, const char *s)

void	draw (GLfloat x, GLfloat y, GLfloat z, const char *s)

int	ascender (void)

int	descender (void)

Additional Inherited Members
Public Types inherited from OGLFT::Face
enum	HorizontalJustification { LEFT, ORIGIN, CENTER, RIGHT }

enum	VerticalJustification { BOTTOM, BASELINE, MIDDLE, TOP }

enum	GlyphCompileMode { COMPILE, IMMEDIATE }

Protected Types inherited from OGLFT::Face
typedef std::map< FT_UInt, GLuint >	GlyphDLists
	Type of the cache of defined glyph to display list mapping. More...

typedef GlyphDLists::const_iterator	GDLCI

typedef GlyphDLists::iterator	GDLI

Protected Attributes inherited from OGLFT::Raster
GLfloat	character_rotation_z_

Protected Attributes inherited from OGLFT::Face
std::vector< FaceData >	faces_

bool	valid_
	Did a font load OK? More...

enum GlyphCompileMode	compile_mode_
	Glyph display list creation mode. More...

float	point_size_
	Nominal point size. More...

FT_UInt	resolution_
	Display resolution in pixels per inch. More...

bool	advance_
	Does rendering text affect the MODELVIEW matrix? More...

GLfloat	foreground_color_ [4]

GLfloat	background_color_ [4]
	Background color (what modes would use this?) More...

enum HorizontalJustification	horizontal_justification_
	PHIGS-like horizontal positioning of text. More...

enum VerticalJustification	vertical_justification_
	PHIGS-like vertical positioning of text. More...

GLfloat	string_rotation_
	Rotate an entire string in the Z plane. More...

FT_UInt	rotation_reference_glyph_

FT_Face	rotation_reference_face_
	The rotation reference character could be in any face. More...

GLfloat	rotation_offset_y_

GlyphDLists	glyph_dlists_
	Cache of defined glyph display lists. More...

DisplayLists	character_display_lists_

Detailed Description

Render text as a translucent raster image.

The Translucent style is similar to the Grayscale style. FreeType is used to rasterize a glyph and this is then drawn on the screen using glDrawPixels. The FreeType rasterization is done in anti-aliased mode. When Translucent draws the glyph image, the grayscale levels provided by FreeType are used as Alpha values in the raster image. This allows the glyphs to be smoothly blended into complicated backgrounds.

Note: you must call

glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );

before drawing in order for translucent glyphs to be rendered properly. Additionally, you need to activate blending in order to achieve the translucent effect:

glEnable( GL_BLEND );

glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );

Another note: It is helpful to have the option GL_RASTER_POSITION_UNCLIPPED_IBM available if you intend to draw text at MODELVIEW based positions, otherwise if the initial text position is off the screen, the entire image is clipped.

Definition at line 1917 of file moOGLFT.h.

Constructor & Destructor Documentation

OGLFT::Translucent::Translucent	(	const char *	filename,
		float	point_size = `12`,
		FT_UInt	resolution = `100`
	)

Parameters

filename	the filename which contains the font face.
point_size	the initial point size of the font to generate. A point is essentially 1/72th of an inch. Defaults to 12.
resolution	the pixel density of the display in dots per inch (DPI). Defaults to 100 DPI.

Definition at line 1817 of file moOGLFT.cpp.

OGLFT::Translucent::Translucent	(	FT_Face	face,
		float	point_size = `12`,
		FT_UInt	resolution = `100`
	)

Parameters

face	open FreeType FT_Face.
point_size	the initial point size of the font to generate. A point is essentially 1/72th of an inch. Defaults to 12.
resolution	the pixel density of the display in dots per inch (DPI). Defaults to 100 DPI.

Definition at line 1822 of file moOGLFT.cpp.

OGLFT::Translucent::~Translucent ( void )

The destructor doesn't do anything in particular.

Definition at line 1826 of file moOGLFT.cpp.

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

libmoldeo/moOGLFT.h
libmoldeo/moOGLFT.cpp

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation