src/glbitmapfont.h

   1 //
   2 //  glbitmapfont.h
   3 //
   4 //  Draw text using glBitmap.
   5 //
   6 //  Copyright (C) 2011,2013,2014 Olly Betts
   7 //
   8 //  This program is free software; you can redistribute it and/or modify
   9 //  it under the terms of the GNU General Public License as published by
  10 //  the Free Software Foundation; either version 2 of the License, or
  11 //  (at your option) any later version.
  12 //
  13 //  This program is distributed in the hope that it will be useful,
  14 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 //  GNU General Public License for more details.
  17 //
  18 //  You should have received a copy of the GNU General Public License
  19 //  along with this program; if not, write to the Free Software
  20 //  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21 //
  22
  23 #ifndef GLBITMAPFONT_H_INCLUDED
  24 #define GLBITMAPFONT_H_INCLUDED
  25
  26 #include "wx.h"
  27
  28 #ifdef HAVE_GL_GL_H
  29 # include <GL/gl.h>
  30 #elif defined HAVE_OPENGL_GL_H
  31 # include <OpenGL/gl.h>
  32 #endif
  33
  34 class BitmapFont {
  35     enum {
  36         // The highest character point to generate an OpenGL list for.
  37         //
  38         // We can't generate a GL list for every Unicode character, so we
  39         // generate them for the first BITMAPFONT_MAX_CHAR characters and then
  40         // use glBitmap directly to draw other characters if they are needed.
  41         //
  42         // FIXME: We could perhaps even store strings consisting of only the
  43         // first 256 points as ISO8859-1.
  44         BITMAPFONT_MAX_CHAR = 256
  45     };
  46
  47     int gllist_base;
  48
  49     mutable const unsigned char * extra_data;
  50
  51     mutable int * extra_chars;
  52
  53     unsigned char char_width[BITMAPFONT_MAX_CHAR];
  54
  55     void init_extra_chars() const;
  56
  57     int glyph_width(wxChar ch) const;
  58
  59     void write_glyph(wxChar ch) const;
  60
  61     wxString font_file;
  62
  63   public:
  64
  65     BitmapFont() : gllist_base(0), extra_data(0), extra_chars(0) { }
  66
  67     ~BitmapFont() {
  68         if (gllist_base)
  69             glDeleteLists(gllist_base, BITMAPFONT_MAX_CHAR);
  70     }
  71
  72     bool load(const wxString & font_file);
  73
  74     // Hard-code for now.
  75     int get_font_size() const { return 16; }
  76
  77     void get_text_extent(const wxChar *s, size_t len, int *width, int *height) const {
  78         if (width) {
  79             int total_width = 0;
  80             while (len--) {
  81                 int ch = *s++;
  82                 if (ch < BITMAPFONT_MAX_CHAR)
  83                     total_width += char_width[ch];
  84                 else
  85                     total_width += glyph_width(ch);
  86             }
  87             *width = total_width;
  88         }
  89         if (height) {
  90             *height = get_font_size() + 1;
  91         }
  92     }
  93
  94     void write_string(const wxChar *s, size_t len) const;
  95 };
  96
  97 #endif