flightgear/3rdparty/fonts/fnt.h

/*
     PLIB - A Suite of Portable Game Libraries
     Copyright (C) 1998,2002  Steve Baker
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 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
     Library General Public License for more details.
 
     You should have received a copy of the GNU Library 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
 
     For further information visit http://plib.sourceforge.net

     $Id: fnt.h 1923 2004-04-06 12:53:17Z sjbaker $
*/


#ifndef _FNT_H_
#define _FNT_H_  1

#include <stdio.h>

#include <plib/sg.h>
#include <osg/GL>

//#define FNTMAX_CHAR  256
//zhongjin
#define FNTMAX_CHAR  65536

#define FNT_TRUE  1
#define FNT_FALSE 0

class SGPath;

class fntFont
{
public:
  fntFont () ;

  virtual ~fntFont () ;

  virtual void getBBox ( const char *s, float pointsize, float italic,
                                  float *left, float *right,
                                  float *bot , float *top  ) = 0 ;
  virtual void putch ( sgVec3 curpos, float pointsize, float italic, char  c ) = 0 ;
  virtual void puts  ( sgVec3 curpos, float pointsize, float italic, const char *s ) = 0 ;
  virtual void begin () = 0 ;
  virtual void end   () = 0 ;

  virtual int load ( const SGPath& fname, GLenum mag = GL_NEAREST,
                                  GLenum min = GL_LINEAR_MIPMAP_LINEAR ) = 0 ;

  virtual void setFixedPitch ( int fix ) = 0 ;
  virtual int   isFixedPitch () const    = 0 ;

  virtual void  setWidth     ( float w ) = 0 ;
  virtual void  setGap       ( float g ) = 0 ;

  virtual float getWidth     () const    = 0 ;
  virtual float getGap       () const    = 0 ;

  virtual int hasGlyph ( char c ) const = 0 ;
} ;


class fntTexFont : public fntFont
{
private:
  GLuint texture  ;
  int bound       ;
  int fixed_pitch ;

  float width     ; /* The width of a character in fixed-width mode */
  float gap       ; /* Set the gap between characters */

  int   exists  [ FNTMAX_CHAR ] ; /* TRUE if character exists in tex-map */

  /*
    The quadrilaterals that describe the characters
    in the font are drawn with the following texture
    and spatial coordinates. The texture coordinates
    are in (S,T) space, with (0,0) at the bottom left
    of the image and (1,1) at the top-right.

    The spatial coordinates are relative to the current
    'cursor' position. They should be scaled such that
    1.0 represent the height of a capital letter. Hence,
    characters like 'y' which have a descender will be
    given a negative v_bot. Most capitals will have
    v_bot==0.0 and v_top==1.0.
  */

  /* Nominal baseline widths */

  float widths  [ FNTMAX_CHAR ] ;

  /* Texture coordinates */

  float t_top   [ FNTMAX_CHAR ] ; /* Top    edge of each character [0..1] */
  float t_bot   [ FNTMAX_CHAR ] ; /* Bottom edge of each character [0..1] */
  float t_left  [ FNTMAX_CHAR ] ; /* Left   edge of each character [0..1] */
  float t_right [ FNTMAX_CHAR ] ; /* Right  edge of each character [0..1] */

  /* Vertex coordinates. */

  float v_top   [ FNTMAX_CHAR ] ;
  float v_bot   [ FNTMAX_CHAR ] ;
  float v_left  [ FNTMAX_CHAR ] ;
  float v_right [ FNTMAX_CHAR ] ;

  void bind_texture ()
  {
    glEnable      ( GL_TEXTURE_2D ) ;
#ifdef GL_VERSION_1_1
    glBindTexture ( GL_TEXTURE_2D, texture ) ;
#else
    /* For ancient SGI machines */
    glBindTextureEXT ( GL_TEXTURE_2D, texture ) ;
#endif
  }

  float low_putch ( sgVec3 curpos, float pointsize, float italic, int c ) ;

  int loadTXF ( const SGPath& path, GLenum mag = GL_NEAREST,
                             GLenum min = GL_LINEAR_MIPMAP_LINEAR ) ;
public:

  fntTexFont ()
  {
    bound       = FNT_FALSE ;
    fixed_pitch = FNT_TRUE  ;
    texture     =   0   ;
    width       =  1.0f ;
    gap         =  0.1f ;

    memset ( exists, FNT_FALSE, FNTMAX_CHAR * sizeof(int) ) ;
  }

  fntTexFont ( const SGPath& path, GLenum mag = GL_NEAREST, 
                            GLenum min = GL_LINEAR_MIPMAP_LINEAR ) : fntFont ()
  {
    bound       = FNT_FALSE ;
    fixed_pitch = FNT_TRUE  ;
    texture     =   0   ;
    width       =  1.0f ;
    gap         =  0.1f ;

    memset ( exists, FNT_FALSE, FNTMAX_CHAR * sizeof(int) ) ;
    load ( path, mag, min ) ;
  }

  ~fntTexFont ()
  {
    if ( texture != 0 )
    {
#ifdef GL_VERSION_1_1
      glDeleteTextures ( 1, &texture ) ;
#else
      /* For ancient SGI machines */
      glDeleteTexturesEXT ( 1, &texture ) ;
#endif
    }
  }

  int load ( const SGPath& path, GLenum mag = GL_NEAREST, 
                          GLenum min = GL_LINEAR_MIPMAP_LINEAR ) override ;

  void setFixedPitch ( int fix ) { fixed_pitch = fix ;  } 
  int   isFixedPitch () const    { return fixed_pitch ; } 

  void  setWidth     ( float w ) { width     = w ; } 
  void  setGap       ( float g ) { gap       = g ; } 

  float getWidth     () const { return width     ; } 
  float getGap       () const { return gap       ; } 


  void setGlyph ( int c, float wid,
                  float tex_left, float tex_right,
                  float tex_bot , float tex_top  ,
                  float vtx_left, float vtx_right,
                  float vtx_bot , float vtx_top  ) ;
  void setGlyph ( int c,
                  float tex_left, float tex_right,
                  float tex_bot , float tex_top  ,
                  float vtx_left, float vtx_right,
                  float vtx_bot , float vtx_top  ) /* deprecated */
  {
    setGlyph ( c, vtx_right,
               tex_left, tex_right, tex_bot, tex_top,
               vtx_left, vtx_right, vtx_bot, vtx_top ) ;
  }
  
  int  getGlyph ( char c, float* wid,
                  float *tex_left = NULL, float *tex_right = NULL,
                  float *tex_bot  = NULL, float *tex_top   = NULL,
                  float *vtx_left = NULL, float *vtx_right = NULL,
                  float *vtx_bot  = NULL, float *vtx_top   = NULL) ;
  int  getGlyph ( char c,
                  float *tex_left = NULL, float *tex_right = NULL,
                  float *tex_bot  = NULL, float *tex_top   = NULL,
                  float *vtx_left = NULL, float *vtx_right = NULL,
                  float *vtx_bot  = NULL, float *vtx_top   = NULL) /* deprecated */
  {
    return getGlyph ( c, NULL,
                      tex_left, tex_right, tex_bot, tex_top,
                      vtx_left, vtx_right, vtx_bot, vtx_top ) ;
  }

  int hasGlyph ( char c ) const { return exists[ (GLubyte) c ] ; }

  void getBBox ( const char *s, float pointsize, float italic,
                 float *left, float *right,
                 float *bot , float *top  ) ;
  
  void begin ()
  {
    bind_texture () ;
    bound = FNT_TRUE ;
  }

  void end ()
  {
    bound = FNT_FALSE ;
  }

  void puts ( sgVec3 curpos, float pointsize, float italic, const char *s ) ;

  void putch ( sgVec3 curpos, float pointsize, float italic, char c )
  {
    if ( ! bound )
      bind_texture () ;

    low_putch ( curpos, pointsize, italic, c ) ;
  }

} ;



class fntBitmapFont : public fntFont
{
 protected:
    
    const GLubyte **data;
    int first;
    int count;
    int height;
    float xorig, yorig;
    int fix;
    float wid, gap;

 public:

    // data is a null-terminated list of glyph images:
    //   data[i][0]    - image width
    //   data[i][1..n] - packed bitmap

    fntBitmapFont ( const GLubyte **data, int first, int height, 
		    float xorig, float yorig ) ;

    virtual ~fntBitmapFont () ;

    virtual void getBBox ( const char *s, float pointsize, float italic,
			   float *left, float *right,
			   float *bot , float *top ) ;

    virtual void putch ( sgVec3 curpos, float pointsize, float italic, char c ) ;
    virtual void puts ( sgVec3 curpos, float pointsize, float italic, const char *s ) ;

    virtual void begin () ;
    virtual void end () ;
    
    virtual int load ( const SGPath& fname, GLenum mag, GLenum min ) override { return -1; }
    
    virtual void setFixedPitch ( int f )    { fix = f;    }
    virtual int   isFixedPitch () const     { return fix; }
    
    virtual void  setWidth     ( float w )  { wid = w;    }
    virtual void  setGap       ( float g )  { gap = g;    }
    
    virtual float getWidth     () const     { return wid; }
    virtual float getGap       () const     { return gap; }
    
    virtual int hasGlyph ( char c ) const ;
};


/* Builtin Bitmap Fonts */

#define FNT_BITMAP_8_BY_13         0
#define FNT_BITMAP_9_BY_15         1
#define FNT_BITMAP_HELVETICA_10    2
#define FNT_BITMAP_HELVETICA_12    3
#define FNT_BITMAP_HELVETICA_18    4
#define FNT_BITMAP_TIMES_ROMAN_10  5
#define FNT_BITMAP_TIMES_ROMAN_24  6

fntBitmapFont *fntGetBitmapFont(int id);



class fntRenderer
{
  fntFont *font ;

  sgVec3 curpos ;

  float pointsize ;
  float italic ;

public:
  fntRenderer ()
  {
    start2f ( 0.0f, 0.0f ) ;
    font = NULL ;
    pointsize = 10 ;
    italic = 0 ;
  }

  void start3fv ( sgVec3 pos ) { sgCopyVec3 ( curpos, pos ) ; }
  void start2fv ( sgVec2 pos ) { sgCopyVec2 ( curpos, pos ) ; curpos[2]=0.0f ; }
  void start2f  ( float x, float y ) { sgSetVec3 ( curpos, x, y, 0.0f ) ; }
  void start3f  ( float x, float y, float z ) { sgSetVec3 ( curpos, x, y, z ) ; }

  void getCursor ( float *x, float *y, float *z ) const
  {
    if ( x != NULL ) *x = curpos [ 0 ] ;
    if ( y != NULL ) *y = curpos [ 1 ] ;
    if ( z != NULL ) *z = curpos [ 2 ] ;
  }

  void     setFont ( fntFont *f ) { font = f ; }
  fntFont *getFont () const { return font ; }

  void  setSlant     ( float i ) { italic    = i ; } 
  void  setPointSize ( float p ) { pointsize = p ; }

  float getSlant     () const { return italic    ; } 
  float getPointSize () const { return pointsize ; } 

  void begin () { font->begin () ; }
  void end   () { font->end   () ; }

  void putch ( char  c ) { font->putch ( curpos, pointsize, italic, c ) ; }
  void puts  ( const char *s ) { font->puts  ( curpos, pointsize, italic, s ) ; }
} ;


void fntInit () ;

#endif