OGLFT::TranslucentTexture Class Reference

Render text as texture mapped translucent quads. More...

#include <moOGLFT.h>

Inheritance diagram for OGLFT::TranslucentTexture:

Public Member Functions
	TranslucentTexture (const char *filename, float point_size=12, FT_UInt resolution=100)
	TranslucentTexture (FT_Face face, float point_size=12, FT_UInt resolution=100)
	~TranslucentTexture (void)
Public Member Functions inherited from OGLFT::Texture
	Texture (const char *filename, float point_size=12, FT_UInt resolution=100)
	Texture (FT_Face face, float point_size=12, FT_UInt resolution=100)
virtual	~Texture (void)
void	setCharacterRotationX (GLfloat character_rotation_x)
void	setCharacterRotationY (GLfloat character_rotation_y)
void	setCharacterRotationZ (GLfloat character_rotation_z)
GLfloat	characterRotationX (void) const
GLfloat	characterRotationY (void) const
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::Texture
typedef std::map< FT_UInt, TextureInfo >	GlyphTexObjs
	Type of the cache of defined glyph to texture objects mapping. More...
typedef GlyphTexObjs::const_iterator	GTOCI
typedef GlyphTexObjs::iterator	GTOI
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 Member Functions inherited from OGLFT::Texture
unsigned int	nearestPowerCeil (unsigned int a)
Protected Attributes inherited from OGLFT::Texture
struct {
bool   active_
	the other values.) More...
GLfloat   x_
	Angle of rotation in the X direction. More...
GLfloat   y_
	Angle of rotation in the Y direction. More...
GLfloat   z_
	Angle of rotation in the Z direction. More...
}	character_rotation_
	Angle of rotation of characters relative to text orientation. More...
GlyphTexObjs	glyph_texobjs_
	Cache of defined glyph texture objects. More...
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 texture mapped translucent quads.

This style is similar to the Translucent raster style, except instead of using glDrawPixels to draw the raster image, the image is used as a texture map on a quad. If drawing is confined to the Z plane, then you will see no difference between this style and Translucent. However, because the quad is a 3D object, it can be transformed by the usual modeling operations; so, texture mapped glyphs can be rotated in the X and Y directions as well as Z direction. Also, if the viewing (or modeling) transformation has a non-unity scale or shear, the glyphs will also be scaled or sheared (unlike the raster styles). Also, there is no problem with clipping glyphs which lie off the screen; texture mapped quads are properly clipped to the screen boundary.

If this is not convincing enough, the performance of texture mapped glyphs is generally as good as or better than the equivalent raster style (especially with hardware texture acceleration). However, they do consume more memory space.

Note: you must call

glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );

before drawing in order for textured 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 );

Definition at line 2286 of file moOGLFT.h.

Constructor & Destructor Documentation

OGLFT::TranslucentTexture::TranslucentTexture	(	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 3743 of file moOGLFT.cpp.

OGLFT::TranslucentTexture::TranslucentTexture	(	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 3748 of file moOGLFT.cpp.

OGLFT::TranslucentTexture::~TranslucentTexture

(

void

)

The translucent texture destructor doesn't really do anything.

Definition at line 3753 of file moOGLFT.cpp.

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

• libmoldeo/moOGLFT.h
• libmoldeo/moOGLFT.cpp