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// -*- c++ -*-
/*
* OGLFT: A library for drawing text with OpenGL using the FreeType library
* Copyright (C) 2002 lignum Computing, Inc. <oglft@lignumcomputing.com>
* $Id: OGLFT.h.cmake 107 2008-04-25 09:29:24Z brevilo $
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef OGLFT_H
#define OGLFT_H
// CMake activates these definitions.
#cmakedefine ENABLE_QT
#cmakedefine ENABLE_GLE
#cmakedefine GLU_TESS_CALLBACK_TRIPLEDOT
#cmakedefine HAVE_OPENGL_DIR
// Convert to our old options.
#if !defined(ENABLE_QT)
#define OGLFT_NO_QT
#endif
#if !defined(ENABLE_GLE)
#define OGLFT_NO_SOLID
#endif
#include <cmath>
#include <map>
#include <list>
#include <vector>
#ifdef WIN32
#include <windows.h>
#endif
#ifdef HAVE_OPENGL_DIR
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#else
#include <GL/gl.h>
#include <GL/glu.h>
#endif
#ifndef OGLFT_NO_SOLID
#ifdef HAVE_OPENGL_DIR
#include <OpenGL/gle.h>
#else
#include <GL/gle.h>
#endif
#endif
#ifndef OGLFT_NO_QT
#define OGLFT_QT_VERSION @DESIRED_QT_VERSION@
#if OGLFT_QT_VERSION == 3
#include <qstring.h>
#include <qcolor.h>
#elif OGLFT_QT_VERSION == 4
#include <QString>
#include <QColor>
#endif
#endif
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
#include FT_OUTLINE_H
#include FT_TRIGONOMETRY_H
#ifdef _MSC_VER
#ifdef OGLFT_BUILD
#define OGLFT_API __declspec(dllexport)
#else
#define OGLFT_API __declspec(dllimport)
#endif
#else
#define OGLFT_API
#endif
//! All of OGLFT C++ objects are in this namespace.
namespace OGLFT {
//! Thanks to DesCartes, I'd consider these manifest constants.
enum Coordinates {
X, //!< The X component of space
Y, //!< The Y component of space
Z, //!< The Z component of space
W //!< The projection component of space
};
//! Who to credit? Newton? I'd consider these manifest constants.
enum ColorSpace {
R, //!< The Red component of a color
G, //!< The Green component of a color
B, //!< The Blue component of a color
A, //!< The Alpha (or transparency) of a color
};
//! Callback from GLU tessellation routines.
#ifdef GLU_TESS_CALLBACK_TRIPLEDOT
typedef GLvoid (*GLUTessCallback)(...);
#else
typedef GLvoid (*GLUTessCallback)();
#endif
//! The FreeType library instance.
/*!
* The FreeType library has a single, global instance of a library
* handle. This reference is used to load font faces. This detail
* is generally hidden from the user of OGLFT, however, it
* can be useful to get the FT_Library instance if you want to open
* a font file yourself, either from disk or embedded in the program.
*/
class Library {
public:
/*!
* The FreeType library's library handle is only available through this
* accessor method.
* \return the global OGLFT FreeType library handle.
*/
static OGLFT_API FT_Library& instance ( void );
protected:
/*!
* The constructor for this class is automatically called when
* this library is loaded. Access the instance through the instance()
* method.
*/
OGLFT_API Library ( void );
/*!
* This destructor is automatically called when the program exits.
*/
OGLFT_API ~Library( void );
private:
static Library library;
static FT_Library library_;
};
//! Advance describes the "advance" of a glyph, namely the distance in
//! model space at which the NEXT glyph should be drawn. This class exists
//! to assist the computation of string metrics.
struct OGLFT_API Advance {
float dx_; //!< Advance increment in the X direction.
float dy_; //!< Advance increment in the Y direction.
//! Default constructor. An otherwise uninitialized Advance contains zeros.
Advance ( float dx = 0, float dy = 0 ) : dx_( dx ), dy_( dy )
{}
//! Initialize an advance from a FreeType advance member.
Advance ( FT_Vector v )
{
dx_ = v.x / 64.f;
dy_ = v.y / 64.f;
}
//! Increment Advance with a FreeType advance member.
//! \return a reference to oneself.
Advance& operator+= ( const FT_Vector v )
{
dx_ += v.x / 64.f;
dy_ += v.y / 64.f;
return *this;
}
};
//! Describe the metrics of a glyph or string relative to the origin
//! of the first character
struct OGLFT_API BBox {
float x_min_; //!< The left-most position at which "ink" appears.
float y_min_; //!< the bottom-most position at which "ink" appears.
float x_max_; //!< The right-most position at which "ink" appears.
float y_max_; //!< The top-most position at which "ink" appears.
Advance advance_; //!< The (total) advancement
//! Default constructor is all zeros.
BBox () : x_min_( 0 ), y_min_( 0 ), x_max_( 0 ), y_max_( 0 )
{}
/*!
*(Partially) initialize a BBox from a FreeType bounding box member.
*(The advancement is initialized to zero by its default constructor).
* \param ft_bbox a FreeType bounding box as retrieved from
* \c FT_Glyph_Get_CBox.
*/
BBox ( FT_BBox ft_bbox )
{
x_min_ = ft_bbox.xMin / 64.f;
y_min_ = ft_bbox.yMin / 64.f;
x_max_ = ft_bbox.xMax / 64.f;
y_max_ = ft_bbox.yMax / 64.f;
}
//! Scale the bounding box by a constant.
//! \param k a constant to scale the bounding box by.
//! \return a reference to oneself.
BBox& operator*= ( float k )
{
x_min_ *= k;
y_min_ *= k;
x_max_ *= k;
y_max_ *= k;
advance_.dx_ *= k;
advance_.dy_ *= k;
return *this;
}
/*!
* Merge a bounding box into the current one (not really addition).
* Each time a BBox is "added", the current BBox is expanded to include
* the metrics of the new BBox. May only work for horizontal fonts, though.
* \param b the bounding box to merge.
* \return a reference to oneself.
*/
BBox& operator+= ( const BBox& b )
{
float new_value;
new_value = b.x_min_ + advance_.dx_;
if ( new_value < x_min_ ) x_min_ = new_value;
new_value = b.y_min_ + advance_.dy_;
if ( (b.advance_.dy_ != 0.) && new_value < y_min_ ) y_min_ = new_value;
new_value = b.x_max_ + advance_.dx_;
if ( new_value > x_max_ ) x_max_ = new_value;
new_value = b.y_max_ + advance_.dy_;
if ( (b.advance_.dy_ != 0.) && new_value > y_max_ ) y_max_ = new_value;
advance_.dx_ += b.advance_.dx_;
advance_.dy_ += b.advance_.dy_;
return *this;
}
};
//! During tesselation of a polygonal Face (outline, filled or solid),
//! an object which implements this interface can be used to compute a
//! different color for each vertex.
class OGLFT_API ColorTess {
public:
virtual ~ColorTess ( void ) {}
//! Compute a color for this position. Note that the position is
//! in the glyph's local coordinate system.
//! \param p vertex position in glyph's local coordinate system. Argument is
//! a GLdouble[3].
//! \return GLfloat[4] (RGBA) color specification.
virtual GLfloat* color ( GLdouble* p ) = 0;
};
//! During tesselation of a polygonal Face (outline, filled or solid),
//! an object which implements this interface can be used to compute a
//! different texture coordinate for each vertex.
class OGLFT_API TextureTess {
public:
virtual ~TextureTess ( void ) {}
//! Compute a texture coordinate for this position. Note that the
//! position is in the glyph's local coordinate system.
//! \param p vertex position in glyph's local coordinate system. Argument is
//! a GLdouble[3].
//! \return GLfloat[2] (s,t) texture coordinates.
virtual GLfloat* texCoord ( GLdouble* p ) = 0;
};
//! The argument to setCharacterDisplayLists is an STL vector of
//! OpenGL display list names (GLuints).
typedef std::vector<GLuint> DisplayLists;
//! A convenience definition of an iterator for display list vectors.
typedef DisplayLists::const_iterator DLCI;
//! A convenience definition of an iterator for display list vectors.
typedef DisplayLists::iterator DLI;
//! A face (aka font) used to render text with OpenGL.
/*!
* This is an abstract class, but it does define most the functions that
* you are likely to call to manipulate the rendering of the text.
*/
class Face {
public:
//! Thanks to the standard formerly known as PHIGS. Horizontal text
//! justification constants.
enum OGLFT_API HorizontalJustification {
LEFT, //!< Left justified justification of text
ORIGIN, //!< Natural origin alignment of text (default)
CENTER, //!< Center justified alignment of text
RIGHT //!< Right justified alignment of text
};
//! Thanks to the standard formerly known as PHIGS. Vertical text
//! justification constants.
enum OGLFT_API VerticalJustification {
BOTTOM, //!< Descender alignment of text
BASELINE, //!< Baseline alignment of text (default)
MIDDLE, //!< Centered alignment of text
TOP //!< Ascender justification of text
};
//! Control how OpenGL display lists are created for individual glyphs.
//! The default mode is to create display lists for each glyph as it
//! is requested. Therefore, the Face drawing routines cannot themselves
//! be called from within an open display list. In IMMEDIATE mode,
//! cached glyphs will be drawn if available, otherwise the FreeType
//! data for a glyph is re-rendered each time.
enum OGLFT_API GlyphCompileMode {
COMPILE, //!< Compile new glyphs when seen for the first time.
IMMEDIATE //!< Do not \em create display lists for glyphs.
};
private:
//! We allow a Face to be constructed either from a file name
//! or passed in as an already opened FreeType FT_Face. In the case
//! of the later (already opened), we don't close the FT_Face on
//! destruction. This way you can share FT_Faces between related
//! OGLFT faces. Also, we're experimenting with being able to use
//! multiple FT_Faces in a single OGLFT Face, so this is represented
//! as a data structure.
struct FaceData {
FT_Face face_;
bool free_on_exit_;
FaceData ( FT_Face face, bool free_on_exit = true )
: face_( face ), free_on_exit_( free_on_exit )
{}
};
protected:
//! The FreeType face - experimentally, this is now an array of
//! faces so that we can handle a wider range of UNICODE points
//! in case a face doesn't cover the points of interest.
std::vector< FaceData > faces_;
//! Did a font load OK?
bool valid_;
//! Glyph display list creation mode.
enum GlyphCompileMode compile_mode_;
//! Nominal point size.
float point_size_;
//! Display resolution in pixels per inch.
FT_UInt resolution_;
//! Does rendering text affect the MODELVIEW matrix?
bool advance_;
//! Foreground color (I really wanted to avoid this, but not really
//! possible without state queries, which you can't put into
//! display lists. Anyway, you'll be able to get even more fancy
//! by passing in a function to map the color with, so why balk at
//! this?)
GLfloat foreground_color_[4];
//! Background color (what modes would use this?)
GLfloat background_color_[4];
//! PHIGS-like horizontal positioning of text.
enum HorizontalJustification horizontal_justification_;
//! PHIGS-like vertical positioning of text.
enum VerticalJustification vertical_justification_;
//! Rotate an entire string in the Z plane
GLfloat string_rotation_;
//! Let the user decide which character to use as the rotation reference.
//! Use "o" by default, I suppose.
FT_UInt rotation_reference_glyph_;
//! The rotation reference character could be in any face.
FT_Face rotation_reference_face_;
//! These are the translation offsets provided by the rotation reference
//! character; for whom, we've discovered, only the Y position is relevant.
GLfloat rotation_offset_y_;
//! Type of the cache of defined glyph to display list mapping.
typedef std::map< FT_UInt, GLuint > GlyphDLists;
//! A convenience definition of the iterator over the glyph to display
//! list map.
typedef GlyphDLists::const_iterator GDLCI;
//! A convenience definition of the iterator over the glyph to display
//! list map.
typedef GlyphDLists::iterator GDLI;
//! Cache of defined glyph display lists
GlyphDLists glyph_dlists_;
//! The user can supply an array of display list which are invoked
//! before each glyph is rendered.
DisplayLists character_display_lists_;
public:
/*!
* Construct a Face by loading a font from the given file.
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
Face ( const char* filename, float point_size = 12, FT_UInt resolution = 100 );
/*!
* Construct a Face by loading a font from the given memory location.
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
Face ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* Alternatively, the user may have already opened a face and just
* wants to draw with it. This is useful for Multiple Master fonts or
* combining multiple files to increase UNICODE point coverage.
* \param face open Freetype FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
Face ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* Deleting a Face frees its FreeType face (and anything else it's
* styles have allocated).
*/
virtual ~Face ( void );
/*!
* Let the user test to see if the font was loaded OK.
* \return true if the FT_Face was successfully created.
*/
bool isValid ( void ) const { return valid_; }
/*!
* Add another FT_Face to the OGLFT Face. Generally used to add more
* coverage of UNICODE points (at least that's the plan). This
* routine takes a filename and takes ownership of the FT_Face.
* \param filename name of file containing font face data.
* \return true if face was successfully added.
*/
bool addAuxiliaryFace ( const char* filename );
/*!
* Add another FT_Face to the OGLFT Face. Generally used to add more
* coverage of UNICODE points (at least that's the plan). This
* routine takes a memory location and takes ownership of the FT_Face.
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \return true if face was successfully added.
*/
bool addAuxiliaryFace ( const FT_Byte* data_base, const FT_Long data_size );
/*!
* Add another FT_Face to the OGLFT Face. Generally used to add more
* coverage of UNICODE points (at least that's the plan). This
* routine takes an already open FT_Face. The user is responsible
* for clean up.
* \param face open FreeType FT_Face
* \return true if face was successfully added.
*/
bool addAuxiliaryFace ( FT_Face face );
/*!
* By default, each time a new character is seen, its glyph is rendered
* into a display list. This means that a display list cannot already
* be open (since OpenGL doesn't allow nested display list creation).
* Rendering can be set into immediate mode in which case glyphs are
* rendered from display lists if available, but are otherwise generated
* anew each time.
* \param compile_mode the new compile mode.
*/
void setCompileMode ( enum GlyphCompileMode compile_mode )
{
compile_mode_ = compile_mode;
}
/*!
* \return the current glyph compile mode.
*/
enum GlyphCompileMode compileMode ( void ) const { return compile_mode_; }
/*!
* For the rasterized styles (Monochrome, Grayscale, Translucent, Texture),
* glyphs are rendered at the pixel size given by:
*
* point_size [pts] * / 72 [pts/in] * resolution [dots/in] = [dots].
*
* For the polygon styles (Outline, Filled, Solid), the "nominal" size of
* the glyphs is:
*
* point_size[pts] / 72 [pts/in] * resolution [dots/in]
* / units_per_EM [font unit/EM] = [dots * EM].
*
* If the MODELVIEW and PROJECTION matrices are such that one screen pixel
* corresponds to one modeling unit, then polygonal Faces will
* be the same size as raster Faces.
*
* Note that changing the point size after Face creation will invalidate
* the cache of OpenGL display lists and any other information which
* the individual styles have cached.
* \param point_size the new point size in points (1/72-th inch).
*/
void setPointSize ( float point_size );
/*!
* \return the current point size.
*/
float pointSize ( void ) { return point_size_; }
/*!
* For the rasterized styles (Monochrome, Grayscale,
* Translucent, Texture), the exact rendered size of the glyphs depends on
* the resolution of the display (as opposed to the polygon styles
* whose size is controlled by the viewing matrices). The Texture
* style is slightly different because the glyphs are texture-mapped
* onto an arbitrary rectangle; here, the resolution only controls
* how accurately the glyph is rendered.
* \param resolution the resolution in DPI (dots per inch).
*/
void setResolution ( FT_UInt resolution );
/*!
* \return the current raster resolution.
*/
FT_UInt resolution ( void ) { return resolution_; }
/*!
* If advance is true, then the changes made to the MODELVIEW matrix
* to render a string are allowed to remain. Otherwise, the library
* pushes the current MODELVIEW matrix onto the matrix stack, renders
* the string and then pops it off again. Rendering a character always
* modifies the MODELVIEW matrix.
* \param advance whether or not the MODELVIEW matrix should be left
* translated by the advancement of a rendered string.
*/
void setAdvance ( bool advance ) { advance_ = advance; }
/*!
* \return the advance value.
*/
bool advance ( void ) const { return advance_; }
/*!
* This is the nominal color of the glyphs. A lot of other things
* can alter what you actually see! Note that changing the foreground
* color invalidates the glyph cache.
* \param red the red component of the foreground color.
* \param green the green component of the foreground color.
* \param blue the blue component of the foreground color.
* \param alpha the alpha component of the foreground color.
*/
OGLFT_API void setForegroundColor ( GLfloat red = 0.0,
GLfloat green = 0.0,
GLfloat blue = 0.0,
GLfloat alpha = 1.0 );
/*!
* This is the nominal color of the glyphs. A lot of other things
* can alter what you actually see! Note that changing the foreground
* color invalidates the glyph cache.
* \param foreground_color an array of 4 values corresponding to the
* red, green, blue and alpha components of the foreground color.
*/
OGLFT_API void setForegroundColor ( const GLfloat foreground_color[4] );
#ifndef OGLFT_NO_QT
/*!
* This is the nominal color of the glyphs. A lot of other things
* can alter what you actually see! Note that changing the foreground
* color invalidates the glyph cache.
* \param foreground_color the foreground color as an unsigned int.
*/
OGLFT_API void setForegroundColor ( const QRgb foreground_color );
#endif /* OGLFT_NO_QT */
/*!
* \return the red component of the foreground color
*/
GLfloat foregroundRed ( void ) const { return foreground_color_[R]; }
/*!
* \return the green component of the foreground color
*/
GLfloat foregroundGreen ( void ) const { return foreground_color_[G]; }
/*!
* \return the blue component of the foreground color
*/
GLfloat foregroundBlue ( void ) const { return foreground_color_[B]; }
/*!
* \return the alpha component of the foreground color
*/
GLfloat foregroundAlpha ( void ) const { return foreground_color_[A]; }
/*!
* This is the nominal background color of the glyphs. A lot of other things
* can alter what you actually see! Note that changing the background
* color invalidates the glyph cache.
* \param red the red component of the background color.
* \param green the green component of the background color.
* \param blue the blue component of the background color.
* \param alpha the alpha component of the background color.
*/
OGLFT_API void setBackgroundColor ( GLfloat red = 1.0,
GLfloat green = 1.0,
GLfloat blue = 1.0,
GLfloat alpha = 0.0 );
/*!
* This is the nominal background color of the glyphs. A lot of other things
* can alter what you actually see! Note that changing the background
* color invalidates the glyph cache.
* \param background_color an array of 4 values corresponding to the
* red, green, blue and alpha components of the background color.
*/
OGLFT_API void setBackgroundColor ( const GLfloat background_color[4] );
#ifndef OGLFT_NO_QT
/*!
* This is the nominal background color of the glyphs. A lot of other things
* can alter what you actually see! Note that changing the background
* color invalidates the glyph cache.
* \param background_color the background color as an unsigned int.
*/
void setBackgroundColor ( const QRgb background_color );
#endif /* OGLFT_NO_QT */
/*!
* \return the red component of the background color
*/
GLfloat backgroundRed ( void ) const { return background_color_[R]; }
/*!
* \return the green component of the background color
*/
GLfloat backgroundGreen ( void ) const { return background_color_[G]; }
/*!
* \return the blue component of the background color
*/
GLfloat backgroundBlue ( void ) const { return background_color_[B]; }
/*!
* \return the alpha component of the background color
*/
GLfloat backgroundAlpha ( void ) const { return background_color_[A]; }
/*!
* Set the individual character rotation in the Z direction.
* \param character_rotation_z angle in degrees of z rotation.
*/
virtual void setCharacterRotationZ ( GLfloat character_rotation_z ) = 0;
/*!
* \return the character rotation in the Z direction.
*/
virtual GLfloat characterRotationZ ( void ) const = 0;
/*!
* The z rotation angle needs a center. Nominate a character whose
* center is to be the center of rotation. By default, use "o".
* \param c rotation reference character.
*/
void setCharacterRotationReference ( unsigned char c );
/*!
* Rotate an entire string through the given angle (in the Z plane only).
* (Somewhat pointless for the vector styles since you can do mostly
* the same thing with the MODELVIEW transform, however, for what its
* worth, this routine uses the FreeType rotation function to compute
* the "proper" metrics for glyph advance.)
* \param string_rotation angle in degrees of z rotation.
*/
void setStringRotation ( GLfloat string_rotation );
/*!
* \return the (Z plane) string rotation angle.
*/
GLfloat stringRotation ( void ) const { return string_rotation_; }
/*!
* Set the horizontal justification.
* \param horizontal_justification the new horizontal justification.
*/
void setHorizontalJustification ( enum HorizontalJustification
horizontal_justification )
{
horizontal_justification_ = horizontal_justification;
}
/*!
* \return the horizontal justification.
*/
enum HorizontalJustification horizontalJustification ( void ) const
{ return horizontal_justification_; }
/*!
* Set the vertical justification.
* \param vertical_justification the new vertical justification
*/
void setVerticalJustification ( enum VerticalJustification
vertical_justification )
{
vertical_justification_ = vertical_justification;
}
/*!
* \return the vertical justification.
*/
enum VerticalJustification verticaljustification ( void )
const { return vertical_justification_; }
/*!
* Specify an OpenGL display list to be invoked before
* each character in a string. Face makes a copy of the argument. Pass
* an empty DisplayLists to disable this feature.
* \param character_display_lists STL vector<GLuint> containing a display
* list to invoke before each glyph in a string is drawn.
*/
void setCharacterDisplayLists ( const DisplayLists& character_display_lists )
{
character_display_lists_ = character_display_lists;
}
/*!
* \return a reference to the array of character display lists. This is
* the live list as stored in the Face.
*/
DisplayLists& characterDisplayLists ( void )
{ return character_display_lists_; }
/*!
* \return the height (i.e., line spacing) at the current character size.
*/
virtual double height ( void ) const = 0;
/*!
* Compute the bounding box info for a character.
* \param c the (latin1) character to measure.
* \return the bounding box of c.
*/
virtual BBox measure ( unsigned char c ) = 0;
#ifndef OGLFT_NO_QT
/*!
* Compute the bounding box info for a character.
* \param c the (UNICODE) character to measure.
* \return the bounding box of c.
*/
virtual BBox measure ( const QChar c ) = 0;
#endif /* OGLFT_NO_QT */
/*!
* Compute the bounding box info for a string.
* \param s the (latin1) string to measure.
* \return the bounding box of s.
*/
virtual BBox measure ( const char* s );
/*!
* Compute the bounding box info for a string without conversion
* to modeling coordinates.
* \param s the (latin1) string to measure.
* \return the bounding box of s.
*/
virtual BBox measureRaw ( const char* s );
#ifndef OGLFT_NO_QT
/*!
* Compute the bounding box info for a string.
* \param s the (UNICODE) string to measure.
* \return the bounding box of s.
*/
virtual BBox measure ( const QString& s );
/*!
* Compute the bounding box info for a real number formatted as specified.
* \param format (see draw for valid formats)
* \param number real number.
* \return the bounding box of the formatted number.
*/
virtual BBox measure ( const QString& format, double number );
/*!
* Compute the bounding box info for a string without conversion
* to modeling coordinates.
* \param s the (UNICODE) string to measure.
* \return the bounding box of s.
*/
virtual BBox measureRaw ( const QString& s );
#endif /* OGLFT_NO_QT */
/*!
* Compile a string into an OpenGL display list for later
* rendering. Essentially, the string is rendered at the origin
* of the current MODELVIEW. Note: no other display lists should
* be open when this routine is called. Also, the Face does not
* keep track of these lists, so you must delete them in order
* to recover the memory.
* \param s the (latin1) string to compile.
* \return the display list name for the string.
*/
GLuint compile ( const char* s );
#ifndef OGLFT_NO_QT
/*!
* Compile a string into an OpenGL display list for later
* rendering. Essentially, the string is rendered at the origin
* of the current MODELVIEW. Note: no other display lists should
* be open when this routine is called. Also, the Face does not
* keep track of these lists, so you must delete them in order
* to recover the memory.
* \param s the (UNICODE) string to compile.
* \return the display list name for the string.
*/
GLuint compile ( const QString& s );
#endif /* OGLFT_NO_QT */
/*!
* Compile a single character (glyph) into an OpenGL display list
* for later rendering. The Face \em does keep track of these
* display lists, so do not delete them.
* \param c the (latin1) character to compile.
* \return the display list name for the character.
*/
GLuint compile ( unsigned char c );
#ifndef OGLFT_NO_QT
/*!
* Compile a single character (glyph) into an OpenGL display list
* for later rendering. The Face \em does keep track of these
* display lists, so do not delete them.
* \param c the (UNICODE) character to compile.
* \return the display list name for the character.
*/
GLuint compile ( const QChar c );
#endif /* OGLFT_NO_QT */
/*!
* Draw a (latin1) string using the current MODELVIEW matrix. If
* advance is true, then the final glyph advance changes to the
* MODELVIEW matrix are left in place.
* \param s the (latin1) string to draw.
*/
OGLFT_API void draw ( const char* s );
#ifndef OGLFT_NO_QT
/*!
* Draw a (UNICODE) string using the current MODELVIEW
* matrix. If advance is true, then the final glyph advance
* changes to the MODELVIEW matrix are left in place.
* \param s the (UNICODE) string to draw.
*/
OGLFT_API void draw ( const QString& s );
#endif /* OGLFT_NO_QT */
/*!
* Draw the character using the current MODELVIEW matrix. Note that
* the MODELVIEW matrix is modified by the glyph advance. Draw a
* string if you don't want the MODELVIEW matrix changed.
* \param c the (latin1) character to draw.
*/
OGLFT_API void draw ( unsigned char c );
#ifndef OGLFT_NO_QT
/*!
* Draw the character using the current MODELVIEW matrix. Note that
* the MODELVIEW matrix is modified by the glyph advance. Draw a
* string if you don't want the MODELVIEW matrix changed.
* \param c the (UNICODE) character to draw.
*/
OGLFT_API void draw ( const QChar c );
#endif /* OGLFT_NO_QT */
/*!
* Draw the (latin1) character at the given 2D point. Note that
* the MODELVIEW matrix is modified by the glyph advance. Draw
* a string if you don't want the MODELVIEW matrix changed.
* \param x the X position.
* \param y the Y position.
* \param c the (latin1) character to draw.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, unsigned char c );
/*!
* Draw the (latin1) character at the given 3D point. Note that
* the MODELVIEW matrix is modified by the glyph advance. Draw
* a string if you don't want the MODELVIEW matrix changed.
* \param x the X position.
* \param y the Y position.
* \param z the Z position.
* \param c the (latin1) character to draw.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, GLfloat z, unsigned char c );
#ifndef OGLFT_NO_QT
/*!
* Draw the (UNICODE) character at the given 2D point. Note that
* the MODELVIEW matrix is modified by the glyph advance. Draw
* a string if you don't want the MODELVIEW matrix changed.
* \param x the X position.
* \param y the Y position.
* \param c the (UNICODE) character to draw.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, QChar c );
/*!
* Draw the (UNICODE) character at the given 3D point. Note that
* the MODELVIEW matrix is modified by the glyph advance. Draw
* a string if you don't want the MODELVIEW matrix changed.
* \param x the X position.
* \param y the Y position.
* \param z the Z position.
* \param c the (UNICODE) character to draw.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, GLfloat z, QChar c );
#endif /* OGLFT_NO_QT */
/*!
* Draw a string at the given 2D point.
* \param x the X position.
* \param y the Y position.
* \param s the (latin1) string to draw.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, const char* s );
/*!
* Draw a string at the given 3D point.
* \param x the X position.
* \param y the Y position.
* \param z the Z position.
* \param s the (latin1) string to draw.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, GLfloat z, const char* s );
#ifndef OGLFT_NO_QT
/*!
* Draw a string at the given 2D point.
* \param x the X position.
* \param y the Y position.
* \param s the (UNICODE) string to draw.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, const QString& s );
/*!
* Draw a string at the given 3D point.
* \param x the X position.
* \param y the Y position.
* \param z the Z position.
* \param s the (UNICODE) string to draw.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, GLfloat z, const QString& s );
/*!
* Draw a real number per the given format at the given 2D point.
* \param x the X position.
* \param y the Y position.
* \param format Like a typical printf format. Regular text is printed
* while a '%' introduces the real number's format. Includes the
* following format flags:
* \li %%x.yf - floating point in field width x and precision y
* \li %%x.ye - scientific notation in field width x and precision y
* \li %%x.yg - pick best floating or scientific in field width x and
* precision y
* \li %%p - draw as a proper fraction, e.g. 1 1/2. Note: this currently
* requires a special font which encodes glyphs to be drawn for the
* numerator and demoninator in the UNICODE Private Area (0xE000).
*
* \param number the numeric value.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, const QString& format, double number );
/*!
* Draw a real number per the given format at the given 3D point.
* \param x the X position.
* \param y the Y position.
* \param z the Z position.
* \param format Like a typical printf format. Regular text is printed
* while a '%' introduces the real number's format. Includes the
* following format flags:
* \li %%x.yf - floating point in field width x and precision y
* \li %%x.ye - scientific notation in field width x and precision y
* \li %%x.yg - pick best floating or scientific in field width x and
* precision y
* \li %%p - draw as a proper fraction, e.g. 1 1/2. Note: this currently
* requires a special font which encodes glyphs to be drawn for the
* numerator and demoninator in the UNICODE Private Area (0xE000).
*
* \param number the numeric value.
*/
OGLFT_API void draw ( GLfloat x, GLfloat y, GLfloat z, const QString& format,
double number );
#endif /* OGLFT_NO_QT */
/*!
* \return the face ascender, in point units.
*/
int ascender ( void );
/*!
* \return the face descender, in point units.
*/
int descender ( void );
protected:
// The various styles override these routines
//! Some styles, in particular the Texture, need specialized steps
//! to compile a glyph into an OpenGL display list.
//! \param face the FT_Face containing the glyph.
//! \param glyph_index the index of the glyph in face.
//! \return the display list of the compiled glyph.
virtual GLuint compileGlyph ( FT_Face face, FT_UInt glyph_index ) = 0;
//! Each style implements its own glyph rendering routine.
//! \param face the FT_Face containing the glyph.
//! \param glyph_index the index of the glyph in face.
virtual void renderGlyph ( FT_Face face, FT_UInt glyph_index ) = 0;
//! There is a slight different between the way in which the polygonal
//! and raster styles select the character size for FreeType to generate.
virtual void setCharSize ( void ) = 0;
//! The different styles have different caching needs (well, really only
//! the texture style currently has more than the display list cache).
virtual void clearCaches ( void ) = 0;
//! The polygonal and raster styles compute different values for the
//! Z rotation offset. (It's in integer pixels for the raster styles and
//! in floating point pixels for the polygonal styles.)
virtual void setRotationOffset ( void ) = 0;
private:
void init ( void );
BBox measure_nominal ( const char* s );
#ifndef OGLFT_NO_QT
BBox measure_nominal ( const QString& s );
QString format_number ( const QString& format, double number );
#endif /* OGLFT_NO_QT */
};
//! This is the base class of the polygonal styles: outline, filled and solid.
/*!
* In the polygonal styles, the detailed geometric outlines of the glyphs
* are extracted from the font file and rendered as polygons.
*/
class Polygonal : public Face {
protected:
//! Angle of rotation of characters relative to text orientation.
struct {
bool active_;
GLfloat x_, y_, z_;
} character_rotation_;
//! The tessellation of curves is pretty crude; regardless of length,
//! use the same number of increments (and as near as I can tell, this
//! is more than sufficient unless the glyph takes up the whole screen).
unsigned int tessellation_steps_;
//! When curves are tessellated, we use the forward difference algorithm
//! from Foley and van Dam for parametric curves (pg. 511 of 2nd Ed. in C).
//! So, the step size, delta, is in the parametric variable which is always
//! on the interval [0,1]. Therefore, delta = 1/tessellation_steps
double delta_, delta2_, delta3_;
//! For vector rendition modes, FreeType is allowed to generate the
//! lines and arcs at the original face definition resolution. To
//! get to the proper glyph size, the vertices are scaled before
//! they're passed to the GLU tessellation routines.
float vector_scale_;
//! Callbacks for FreeType glyph decomposition into outlines
FT_Outline_Funcs interface_;
//! Default number of steps to break TrueType and Type1 arcs into.
//! (Note: this looks good to me, anyway)
static const unsigned int DEFAULT_TESSELLATION_STEPS = 4;
/*!
* VertexInfo is a private class which is used by the decomposition and
* tessellation routines to store the vertices and other data of the glyph's
* outline. Because of the "impedance mismatch" between the crazy
* 26.6 fixed point format of the FreeType library (well, don't
* blame them; look at what they have to work with) and OpenGL's preference
* for double precision, this simple vector has two constructors: one
* for 26.6 format and one for direct floating point.
*
* VertexInfo also contains (optional) pointers to objects which
* implement the ColorTess and TextureTess interfaces.
*/
struct VertexInfo {
double v_[3]; //!< Why is this double precision? Because the second
//!< argument to the routine gluTessVertex is a pointer
//!< to an array of doubles. Otherwise, we could use
//!< single precision everywhere.
//! The user can provide a ColorTess object which computes a color
//! for each tesselated vertex.
ColorTess* color_tess_;
//! The user can provide a TextureTess object which computes texture
//! coordinates for each tesselated vertex.
TextureTess* texture_tess_;
//! Default constructor just initializes Vertex to zero.
//! \param color_tess optional color tesselation object.
//! \param texture_tess optional texture tesselation object.
VertexInfo ( ColorTess* color_tess = 0, TextureTess* texture_tess = 0 )
: color_tess_( color_tess ), texture_tess_( texture_tess )
{
v_[X] = v_[Y] = v_[Z] = 0.;
}
/*!
* Construct a Vertex from a point in a FreeType contour.
* \param ft_v a FreeType FT_Vector, normally passed into the
* the decomposition callbacks.
* \param color_tess optional color tesselation object.
* \param texture_tess optional texture tesselation object.
*/
VertexInfo ( FT_Vector* ft_v, ColorTess* color_tess = 0,
TextureTess* texture_tess = 0 )
: color_tess_( color_tess ), texture_tess_( texture_tess )
{
v_[X] = (double)( ft_v->x / 64 ) + (double)( ft_v->x % 64 ) / 64.;
v_[Y] = (double)( ft_v->y / 64 ) + (double)( ft_v->y % 64 ) / 64.;
v_[Z] = 0.;
}
/*!
* Construct a Vertex from a 2D point.
* \param p 2D array of doubles.
* \param color_tess optional color tesselation object.
* \param texture_tess optional texture tesselation object.
*/
VertexInfo ( double p[2], ColorTess* color_tess = 0,
TextureTess* texture_tess = 0 )
: color_tess_( color_tess ), texture_tess_( texture_tess )
{
v_[X] = p[X];
v_[Y] = p[Y];
v_[Z] = 0.;
}
/*!
* Construct a Vertex from a 2D point.
* \param x the X coordinate.
* \param y the Y coordinate.
* \param color_tess optional color tesselation object.
* \param texture_tess optional texture tesselation object.
*/
VertexInfo ( double x, double y, ColorTess* color_tess = 0,
TextureTess* texture_tess = 0 )
: color_tess_( color_tess ), texture_tess_( texture_tess )
{
v_[X] = x;
v_[Y] = y;
v_[Z] = 0.;
}
//! Treat the Vertex like a vector: Normalize its length in the
//! usual way.
void normalize ( void )
{
double length = sqrt( v_[X] * v_[X] + v_[Y] * v_[Y] + v_[Z] * v_[Z] );
v_[X] /= length;
v_[Y] /= length;
v_[Z] /= length;
}
};
/*!
* Buffers the last control point as the outline of a glyph is
* decomposed.
*/
VertexInfo last_vertex_;
//! Normally, we will consider a list of vertices.
typedef std::list< VertexInfo* > VertexInfoList;
//! A convenience definition of the iterator over the list of vertices.
typedef VertexInfoList::const_iterator VILCI;
//! A convenience definition of the iterator over the list of vertices.
typedef VertexInfoList::iterator VILI;
/*!
* As curves are decomposed out of the glyph, their vertices are passed
* along to the GLU tessellation functions. These vertices have to
* hang around until gluTessContourEnd is called.
*/
VertexInfoList vertices_;
//! As GLU tessellation proceeds, new contours open with every call
//! to moveTo.
bool contour_open_;
//! The user can provide a ColorTess object which computes a color
//! for each tesselated vertex.
ColorTess* color_tess_;
//! The user can provide a TextureTess object which computes texture
//! coordinates for each tesselated vertex.
TextureTess* texture_tess_;
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Polygonal ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Polygonal ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100);
/*!
* \param face open Freetype FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Polygonal ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* The Polygonal destructor doesn't do anything in particular.
*/
OGLFT_API virtual ~Polygonal ( void );
/*!
* TrueType and Type1 files describe the boundaries of glyphs with
* quadratic and cubic curves, respectively. Since OpenGL can only really
* draw straight lines, these curves have to be tessellated. The
* number of steps used is fixed for all glyphs in the face,
* but can be changed through this method. Other notes: This value is
* only applicable for Outline, Filled and Solid styles. Changing this value
* invalidates any cached display lists for glyphs in this face.
*
* \param tessellation_steps the number of steps to tessellate each curved
* segment of a glyph outline.
*/
OGLFT_API void setTessellationSteps ( unsigned int tessellation_steps );
/*!
* \return the number of steps used to tessellate curves in the
* polygonal font types.
*/
OGLFT_API unsigned int tessellationSteps ( void ) const { return tessellation_steps_; }
/*!
* Set the individual character rotation in the X direction.
* \param character_rotation_x angle in degrees of the X rotation.
*/
OGLFT_API void setCharacterRotationX ( GLfloat character_rotation_x );
/*!
* Set the individual character rotation in the Y direction.
* \param character_rotation_y angle in degrees of the Y rotation.
*/
OGLFT_API void setCharacterRotationY ( GLfloat character_rotation_y );
/*!
* Set the individual character rotation in the Z direction.
* \param character_rotation_z angle in degrees of the Z rotation.
*/
OGLFT_API void setCharacterRotationZ ( GLfloat character_rotation_z );
/*!
* \return the character rotation in the X direction.
*/
OGLFT_API GLfloat characterRotationX ( void ) const { return character_rotation_.x_; }
/*!
* \return the character rotation in the Y direction.
*/
OGLFT_API GLfloat characterRotationY ( void ) const { return character_rotation_.y_; }
/*!
* \return the character rotation in the Z direction.
*/
OGLFT_API GLfloat characterRotationZ ( void ) const { return character_rotation_.z_; }
/*!
* Set an optional color tesselation object. Each tesselated vertex
* is passed to this object, which returns a color for that position
* in space.
* \param color_tess the color tesselation object.
*/
OGLFT_API void setColorTess ( ColorTess* color_tess );
/*!
* \return the color tesselation object.
*/
OGLFT_API ColorTess* colorTess ( void ) const { return color_tess_; }
/*!
* Set an optional texture coordinate tesselation object. Each
* tessellated vertex is passed to this object, which returns
* texture coordinates for that position in space.
* \param texture_tess the texture coordinate tesselation object.
*/
OGLFT_API void setTextureTess ( TextureTess* texture_tess );
/*!
* \return the texture coordinate tesselation object.
*/
OGLFT_API TextureTess* textureTess ( void ) const { return texture_tess_; }
/*!
* \return the height (i.e., line spacing) at the current character size.
*/
OGLFT_API double height ( void ) const;
/*!
* Implement measuring a character in a polygonal face.
* \param c the (latin1) character to measure
* \return the bounding box of c.
*/
OGLFT_API BBox measure ( unsigned char c );
#ifndef OGLFT_NO_QT
/*!
* Implement measuring a character in a polygonal face.
* \param c the (UNICODE) character to measure
* \return the bounding box of c.
*/
OGLFT_API BBox measure ( const QChar c );
#endif /* OGLFT_NO_QT */
/*!
* Measure a string of characters. Note: currently, this merely
* calls Face's measure routine.
* \param s string of (latin1) characters to measure
* \return the bounding box of s.
*/
OGLFT_API BBox measure ( const char* s ) { return Face::measure( s ); }
#ifndef OGLFT_NO_QT
/*!
* Implement measuring a formatted number
* \param format the format string
* \param number to value to format
* \return the bounding box of the formatted number
*/
OGLFT_API BBox measure ( const QString& format, double number )
{ return Face::measure( format, number ); }
#endif /* OGLFT_NO_QT */
private:
void init ( void );
void setCharSize ( void );
void setRotationOffset ( void );
GLuint compileGlyph ( FT_Face face, FT_UInt glyph_index );
protected:
void clearCaches ( void );
};
//! Render text as a polygon outline.
/*!
* \image html outline_class.png
* Text is drawn as an outline of each glyph. The contours are extracted
* from the font file through FreeType. FreeType is used to scale the
* contours to a given size. Usually the outline is drawn in the foreground
* color, however, you can specify a ColorTess object to provide a color
* for each vertex individually. You can also use
* the per-glyph display list functionality to alter the attributes
* of each glyph.
*
* The only complexity to this style is selecting the point size. Since
* the outlines are drawn as a polygon, they are subject to the MODELVIEW
* transformation. The point size is nominally chosen to be the same as a
* raster image generated at the given resolution. Some experimentation
* with point size and resolution may be necessary to achieve the desired
* results.
*/
class Outline : public Polygonal {
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Outline ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Outline ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Outline ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* The destructor doesn't do anything in particular.
*/
~Outline ( void );
private:
void init ( void );
void renderGlyph ( FT_Face face, FT_UInt glyph_index );
static int moveToCallback ( FT_Vector* to, Outline* outline );
static int lineToCallback ( FT_Vector* to, Outline* outline );
static int conicToCallback ( FT_Vector* control, FT_Vector* to, Outline* outline );
static int cubicToCallback ( FT_Vector* control1, FT_Vector* control2,
FT_Vector* to, Outline* outline );
};
//! Render text as a filled polygons.
/*!
* \image html filled_class.png
* Each glyph is drawn as a filled polygon. The contours are extracted
* from the font file through FreeType. FreeType is used to scale the
* contours to the given size. Then the GLU tessellation routines are used
* to tessellate the contours into polygons (well, triangles). By default,
* these are drawn in GL_FILL polygon mode, but any other polygon mode
* can be specified.
*
* Usually, the polygons are drawn only in the
* foreground color, however, you may supply ColorTess and TextureTess
* objects which can alter the color or texture coordinates of each
* vertex individually. You can also use
* the per-glyph display list functionality to alter the attributes
* of each glyph.
*
* The only complexity to this style is selecting the point size. Since
* the glyphs are drawn as polygons, they are subject to the viewing and
* modeling transformations. The point size is nominally chosen to be the same
* as a raster image generated at the given resolution. Some experimentation
* with point size and resolution may be necessary to achieve the desired
* results.
*/
class Filled : public Polygonal {
//! 3D tessellation of glyphs is accomplished through the standard GLU
//! routines
GLUtesselator* tess_obj_;
//! A place to store any extra vertices generated by the Combine callback
VertexInfoList extra_vertices_;
protected:
//! Offset the glyph in the Z direction. Solely for the Solid subclass.
//! Until I can figure out how to shift the glyph outside the context
//! of this class, I guess this has got to stay (but it is redundant
//! to extrusion_.depth_)
GLfloat depth_offset_;
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Filled ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Filled ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Filled ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* The destructor deletes the GLU tessellation object allocated in
* in the constructor.
*/
OGLFT_API virtual ~Filled ( void );
/*!
* \return the list of extra vertices created by the GLU tessellation
* combine callback.
*/
OGLFT_API VertexInfoList& extraVertices ( void ) { return extra_vertices_; }
protected:
void renderGlyph ( FT_Face face, FT_UInt glyph_index );
private:
void init ( void );
static int moveToCallback ( FT_Vector* to, Filled* filled );
static int lineToCallback ( FT_Vector* to, Filled* filled );
static int conicToCallback ( FT_Vector* control, FT_Vector* to, Filled* filled);
static int cubicToCallback ( FT_Vector* control1, FT_Vector* control2,
FT_Vector* to, Filled* filled );
static void vertexCallback ( VertexInfo* vertex );
static void beginCallback ( GLenum which );
static void endCallback ( void );
static void combineCallback ( GLdouble coords[3], void* vertex_data[4],
GLfloat weight[4], void** out_data,
Filled* filled );
static void errorCallback ( GLenum error_code );
};
#ifndef OGLFT_NO_SOLID
//! Render text as solid letters.
/*!
* \image html solid_class.png
* Each glyph is drawn as a closed solid. The contours are extracted
* from the font file through FreeType. FreeType is used to scale the
* contours to the given size. The contours are passed to the GLE
* tubing and extrusion library to create the sides of the solid.
* Then the GLU tessellation routines are used
* to tessellate the contours into polygons which are used to cap the sides.
*
* Currently, the solids are drawn only in the foreground color. However,
* proper surface normals are computed so that the solids may be lighted.
* Eventually, you'll be able to supply a color/texture
* coordinate function to make glyphs more interesting. Note that you can use
* the per-glyph display list functionality to alter each glyph individually.
*
* Another TODO item is to improve the interaction with GLE. Currently,
* you can only create block solids. Eventually, we'll have the capability
* add bevels and rounds to the edges of the solids and maybe even more
* general extrusions (like, for example, the swooshing letters in the title
* sequence of the Salkind's 1978 "Superman" movie).
*
* The only complexity to this style is selecting the point size. Since
* the glyphs are drawn as a collection of polygons, they are subject to the
* viewing and modeling transformations. The point size is nominally chosen
* to be the same as a raster image generated at the given resolution.
* Some experimentation with point size and resolution may be necessary to
* achieve the desired results.
*/
class Solid : public Filled {
private:
//! Callbacks for FreeType glyph decomposition into outlines (note: this
//! has the same name as the variable in Polygonal, but it is distinct since
//! the routines for the GLE contouring are different from the Filled
//! GLU tessellation routines. This may be too confusing?)
FT_Outline_Funcs interface_;
//! For now, you can only get block extruded solids
static const unsigned int N_POLYLINE_PTS = 4;
//! Data for the gleExtrusion routine
struct glePoint2D {
double p_[2];
glePoint2D ( double p[2] ) { p_[X] = p[X]; p_[Y] = p[Y]; }
glePoint2D ( double x, double y ) { p_[X] = x; p_[Y] = y; }
glePoint2D ( const VertexInfo& v ) { p_[X] = v.v_[X]; p_[Y] = v.v_[Y]; }
};
//! Collect all the output from GLE in one of these structures.
struct {
double depth_;
struct {
int x_, y_;
} normal_sign_;
std::vector< glePoint2D > contour_;
std::vector< glePoint2D > contour_normals_;
gleDouble up_[3];
int n_polyline_pts_;
gleDouble point_array_[N_POLYLINE_PTS][3];
} extrusion_;
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Solid ( const char* filename, float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Solid ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Solid ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* The destructor doesn't do anything in particular.
*/
OGLFT_API ~Solid ( void );
/*!
* Set the thickness of the solid
* \param depth thickness of the solid in model units.
*/
OGLFT_API void setDepth ( double depth );
/*!
* \return the solid extrusion depth.
*/
OGLFT_API double depth ( void ) const { return extrusion_.depth_; }
private:
// It would be nice if C/C++ had real matrix notation (like Perl!)
void assign ( gleDouble a[3], double x, double y, double z )
{
a[X] = x;
a[Y] = y;
a[Z] = z;
}
void init ( void );
void renderGlyph ( FT_Face face, FT_UInt glyph_index );
static int moveToCallback ( FT_Vector* to, Solid* solid );
static int lineToCallback ( FT_Vector* to, Solid* solid );
static int conicToCallback ( FT_Vector* control, FT_Vector* to, Solid* solid );
static int cubicToCallback ( FT_Vector* control1, FT_Vector* control2,
FT_Vector* to, Solid* solid );
};
#endif /* OGLFT_NO_SOLID */
//! This is the base class of the raster styles: bitmap, grayscale and
//! translucent.
/*!
* In the raster styles, FreeType's rasterizer is used to generate raster
* images of each glyph.
*/
class Raster : public Face {
protected:
//! Raster glyph can be rotated in the Z plane (in addition to the string
//! rotation).
GLfloat character_rotation_z_;
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Raster ( const char* filename, float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Raster ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Raster ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* The destructor doesn't do anything in particular.
*/
OGLFT_API virtual ~Raster ( void );
/*!
* Set the individual character rotation in the Z direction.
* \param character_rotation_z angle in degrees of Z rotation.
*/
OGLFT_API void setCharacterRotationZ ( GLfloat character_rotation_z );
/*!
* \return the character rotation in the Z direction.
*/
OGLFT_API GLfloat characterRotationZ ( void ) const { return character_rotation_z_; }
/*!
* \return the height (i.e., line spacing) at the current character size.
*/
OGLFT_API double height ( void ) const;
/*!
* Implement measuring a character in a raster face.
* \param c the (latin1) character to measure
* \return the bounding box of c.
*/
OGLFT_API BBox measure ( unsigned char c );
#ifndef OGLFT_NO_QT
/*!
* Implement measuring a character in a raster face.
* \param c the (UNICODE) character to measure
* \return the bounding box of c.
*/
OGLFT_API BBox measure ( const QChar c );
#endif /* OGLFT_NO_QT */
/*!
* Measure a string of characters. Note: currently, this merely
* calls Face's measure routine.
* \param s string of (latin1) characters to measure
* \return the bounding box of s.
*/
OGLFT_API BBox measure ( const char* s ) { return Face::measure( s ); }
#ifndef OGLFT_NO_QT
/*!
* Implement measuring a formatted number
* \param format the format string
* \param number to value to format
* \return the bounding box of the formatted number
*/
OGLFT_API BBox measure ( const QString& format, double number );
#endif /* OGLFT_NO_QT */
private:
void init ( void );
GLuint compileGlyph ( FT_Face face, FT_UInt glyph_index );
void setCharSize ( void );
void setRotationOffset ( void );
void clearCaches ( void );
};
//! Render text as a monochrome raster image.
/*!
* \image html monochrome_class.png
* This is more or less the standard way in which text is intended to
* be rendered in OpenGL. It uses the \c glBitmap call to draw a sequence
* of monochrome bitmaps. Since FreeType is capable of rotating glyphs
* created from faces based on vector outlines, you can rotate (in the Z plane)
* both the text string as well as the individual characters in the string.
*
* Note: you \em must call
* \code
* glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
* \endcode
* before drawing in order for monochrome glyphs to be rendered properly.
*
* Another note: It is helpful to have the option
* \c 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.
*/
class Monochrome : public Raster {
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Monochrome ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Monochrome ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param font open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Monochrome ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* The destructor doesn't do anything in particular.
*/
OGLFT_API ~Monochrome ( void );
private:
GLubyte* invertBitmap ( const FT_Bitmap& bitmap );
void renderGlyph ( FT_Face face, FT_UInt glyph_index );
};
//! Render text as a grayscale raster image.
/*!
* \image html grayscale_class.png
* The Grayscale style is similar to the Monochrome style. FreeType is used
* to rasterize a glyph and this is then drawn on the screen using
* \c glDrawPixels. The FreeType rasterization is done in anti-aliased mode.
* When Grayscale draws the glyph image, the resulting text is blended
* smoothly from the foreground color to the background color. The background
* of the glyph is opaque, so this style works best over a solid background.
*
* Note: you \em must call
* \code
* glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
* \endcode
* before drawing in order for grayscale glyphs to be rendered properly.
*
* Another note: It is helpful to have the option
* \c 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.
*/
class Grayscale : public Raster {
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Grayscale ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Grayscale ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Grayscale ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* The destructor doesn't do anything in particular.
*/
OGLFT_API ~Grayscale ( void );
private:
GLubyte* invertPixmap ( const FT_Bitmap& bitmap );
void renderGlyph ( FT_Face face, FT_UInt glyph_index );
};
//! Render text as a translucent raster image.
/*!
* \image html translucent_class.png
* 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
* \c 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 \em must call
* \code
* glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
* \endcode
* before drawing in order for translucent glyphs to be rendered properly.
* Additionally, you need to activate blending in order to achieve the
* translucent effect:
* \code
* glEnable( GL_BLEND );
* glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
* \endcode
*
* Another note: It is helpful to have the option
* \c 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.
*/
class Translucent : public Raster {
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Translucent ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Translucent ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Translucent ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* The destructor doesn't do anything in particular.
*/
OGLFT_API ~Translucent ( void );
private:
GLubyte* invertPixmapWithAlpha ( const FT_Bitmap& bitmap );
void renderGlyph ( FT_Face face, FT_UInt glyph_index );
};
//! This is the base class of the texture style.
class Texture : public Face {
protected:
//! Angle of rotation of characters relative to text orientation.
struct {
bool active_; //!< Is character rotation non-zero? (faster than checking all
//!< the other values.)
GLfloat x_, //!< Angle of rotation in the X direction.
y_, //!< Angle of rotation in the Y direction.
z_; //!< Angle of rotation in the Z direction.
} character_rotation_;
/*!
* The textured glyphs need a little bit more infrastructure to draw
* since we have to remember the size of the texture object itself
* (at least implicitly). Also, we don't want to create any more
* texture objects than we have to, so they are always cached.
*/
struct TextureInfo {
GLuint texture_name_; //!< A bound texture name is an integer in OpenGL.
FT_Int left_bearing_, //!< The left bearing of the transformed glyph.
bottom_bearing_; //!< The bottom bearing of the transformed glyph.
int width_, //!< The 2**l width of the texture.
height_; //!< The 2**m height of the texture.
GLfloat texture_s_, //!< The fraction of the texture width occupied
//!< by the glyph.
texture_t_; //!< The fraction of the texture height occupied
//!< by the glyph.
FT_Vector advance_; //!< The advance vector of the transformed glyph.
};
//! Type of the cache of defined glyph to texture objects mapping.
typedef std::map< FT_UInt, TextureInfo > GlyphTexObjs;
//! A convenience definition of the iterator over the glyph to texture
//! object map.
typedef GlyphTexObjs::const_iterator GTOCI;
//! A convenience definition of the iterator over the glyph to texture
//! object map.
typedef GlyphTexObjs::iterator GTOI;
//! Cache of defined glyph texture objects.
GlyphTexObjs glyph_texobjs_;
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Texture ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Texture ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API Texture ( FT_Face face, float point_size = 12, FT_UInt resolution = 100 );
/*!
* The texture destructor doesn't really do anything.
*/
OGLFT_API virtual ~Texture ( void );
/*!
* Set the individual character rotation in the X direction.
* \param character_rotation_x angle in degrees of X rotation.
*/
OGLFT_API void setCharacterRotationX ( GLfloat character_rotation_x );
/*!
* Set the individual character rotation in the Y direction.
* \param character_rotation_y angle in degrees of Y rotation.
*/
OGLFT_API void setCharacterRotationY ( GLfloat character_rotation_y );
/*!
* Set the individual character rotation in the Z direction.
* \param character_rotation_z angle in degrees of Z rotation.
*/
OGLFT_API void setCharacterRotationZ ( GLfloat character_rotation_z );
/*!
* \return the character rotation in the X direction.
*/
OGLFT_API GLfloat characterRotationX ( void ) const { return character_rotation_.x_; }
/*!
* \return the character rotation in the Y direction.
*/
OGLFT_API GLfloat characterRotationY ( void ) const { return character_rotation_.y_; }
/*!
* \return the character rotation in the Z direction.
*/
OGLFT_API GLfloat characterRotationZ ( void ) const { return character_rotation_.z_; }
/*!
* \return the height (i.e., line spacing) at the current character size.
*/
OGLFT_API double height ( void ) const;
/*!
* Implement measuring a character in a texture face.
* \param c the (latin1) character to measure
* \return the bounding box of c.
*/
OGLFT_API BBox measure ( unsigned char c );
#ifndef OGLFT_NO_QT
/*!
* Implement measuring a character in a texture face.
* \param c the (UNICODE) character to measure
* \return the bounding box of c.
*/
OGLFT_API BBox measure ( const QChar c );
#endif /* OGLFT_NO_QT */
/*!
* Measure a string of characters. Note: currently, this merely
* calls Face's measure routine.
* \param s string of (latin1) characters to measure
* \return the bounding box of s.
*/
OGLFT_API BBox measure ( const char* s ) { return Face::measure( s ); }
#ifndef OGLFT_NO_QT
OGLFT_API BBox measure ( const QString& s )
{ return Face::measure( s ); }
/*!
* Implement measuring a formatted number
* \param format the format string
* \param number to value to format
* \return the bounding box of the formatted number
*/
OGLFT_API BBox measure ( const QString& format, double number )
{ return Face::measure( format, number ); }
#endif /* OGLFT_NO_QT */
protected:
/*!
* OpenGL texture maps have to be a power of 2 in width and height (including
* apparently 1 = 2**0 ). This function returns the next higher power of
* 2 of the argument. If the argument is already a power of 2, you just
* get that back.
* \param a width or height of an image.
* \return value of a rounded to nearest, higher power of 2.
*/
unsigned int nearestPowerCeil ( unsigned int a );
/*!
* This is all that distinguishes the various texture styles. Each subclass
* defines this method as appropriate. Once the texture is bound, it
* is rendered the same in all cases.
* \param face FT_Face containing the glyph to render.
* \param glyph_index index of glyph in face.
*/
virtual void bindTexture ( FT_Face face, FT_UInt glyph_index ) = 0;
private:
void init ( void );
void setCharSize ( void );
void setRotationOffset ( void );
GLuint compileGlyph ( FT_Face face, FT_UInt glyph_index );
void renderGlyph ( FT_Face face, FT_UInt glyph_index );
void clearCaches ( void );
};
//! Render text as texture mapped monochrome quads.
/*!
* \image html texture_monochrome_class.png
* This style is similar to the Monochrome raster style, except instead
* of using \c glBitmap 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 Monochrome.
* 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 take up more memory space.
*
* Note: you \em must call
* \code
* glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
* \endcode
* before drawing in order for textured glyphs to be rendered properly.
*/
class MonochromeTexture : public Texture {
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API MonochromeTexture ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API MonochromeTexture ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API MonochromeTexture ( FT_Face face, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* The monochrome texture destructor doesn't really do anything.
*/
OGLFT_API ~MonochromeTexture ( void );
private:
GLubyte* invertBitmap ( const FT_Bitmap& bitmap, int* width, int* height );
void bindTexture ( FT_Face face, FT_UInt glyph_index );
};
//! Render text as texture mapped grayscale quads.
/*!
* \image html texture_grayscale_class.png
* This style is similar to the Grayscale raster style, except instead
* of using \c 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 Grayscale.
* 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 \em must call
* \code
* glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
* \endcode
* before drawing in order for textured glyphs to be rendered properly.
*/
class GrayscaleTexture : public Texture {
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API GrayscaleTexture ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API GrayscaleTexture ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API GrayscaleTexture ( FT_Face face, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* The grayscale texture destructor doesn't really do anything.
*/
OGLFT_API ~GrayscaleTexture ( void );
private:
GLubyte* invertPixmap ( const FT_Bitmap& bitmap, int* width, int* height );
void bindTexture ( FT_Face face, FT_UInt glyph_index );
};
//! Render text as texture mapped translucent quads.
/*!
* \image html texture_translucent_class.png
* This style is similar to the Translucent raster style, except instead
* of using \c 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 \em must call
* \code
* glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
* \endcode
* before drawing in order for textured glyphs to be rendered properly.
* Additionally, you need to activate blending in order to achieve the
* translucent effect:
* \code
* glEnable( GL_BLEND );
* glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
* \endcode
*/
class TranslucentTexture : public Texture {
public:
/*!
* \param filename the filename which contains the font face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API TranslucentTexture ( const char* filename, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* \param data_base the memory location (base pointer) which contains the font face.
* \param data_size the size (in bytes) of the font data found at \ref data_base.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API TranslucentTexture ( const FT_Byte* data_base, const FT_Long data_size,
float point_size = 12, FT_UInt resolution = 100 );
/*!
* \param face open FreeType FT_Face.
* \param point_size the initial point size of the font to generate. A point
* is essentially 1/72th of an inch. Defaults to 12.
* \param resolution the pixel density of the display in dots per inch (DPI).
* Defaults to 100 DPI.
*/
OGLFT_API TranslucentTexture ( FT_Face face, float point_size = 12,
FT_UInt resolution = 100 );
/*!
* The translucent texture destructor doesn't really do anything.
*/
OGLFT_API ~TranslucentTexture ( void );
private:
GLubyte* invertPixmap ( const FT_Bitmap& bitmap, int* width, int* height );
void bindTexture ( FT_Face face, FT_UInt glyph_index );
};
} // Close OGLFT namespace
#endif /* OGLFT_H */
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