src/glbitmapfont.cc

   1 //
   2 //  glbitmapfont.cc
   3 //
   4 //  Draw text using glBitmap.
   5 //
   6 //  Copyright (C) 2011,2012,2013,2014,2015 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 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include "glbitmapfont.h"
  28
  29 #include "aventypes.h"
  30 #include "useful.h"
  31 #include "wx.h"
  32
  33 #include <cerrno>
  34 #ifdef HAVE_MMAP
  35 #include <sys/mman.h>
  36 #else
  37 #include <unistd.h>
  38 #endif
  39
  40 using namespace std;
  41
  42 #include "../lib/preload_font.h"
  43
  44 #define CHECK_GL_ERROR(M, F) do { \
  45     GLenum error_code_ = glGetError(); \
  46     if (error_code_ != GL_NO_ERROR) { \
  47         wxLogError(wxT(__FILE__ ":" STRING(__LINE__) ": OpenGL error: %s " \
  48                    "(call " F " in method " M ")"), \
  49                    wxString((const char *)gluErrorString(error_code_), \
  50                             wxConvUTF8).c_str()); \
  51     } \
  52 } while (0)
  53
  54 bool
  55 BitmapFont::load(const wxString & font_file_)
  56 {
  57     font_file = font_file_;
  58
  59     if (!gllist_base) {
  60         gllist_base = glGenLists(BITMAPFONT_MAX_CHAR);
  61     }
  62
  63     const unsigned char * p = fontdata_preloaded;
  64     const unsigned char * end = p + sizeof(fontdata_preloaded);
  65     for (int ch = 0; ch < BITMAPFONT_MAX_CHAR; ++ch) {
  66         glNewList(gllist_base + ch, GL_COMPILE);
  67         CHECK_GL_ERROR("BitmapFont::load", "glNewList");
  68         if (p == end) {
  69             return false;
  70         }
  71         unsigned int byte_width = *p++;
  72
  73         char_width[ch] = (byte_width & 0x0f) + 2;
  74         byte_width >>= 6;
  75
  76         int start = 0;
  77         unsigned int n = 0;
  78         if (byte_width) {
  79             if (p == end) {
  80                 return false;
  81             }
  82             unsigned int start_and_n = *p++;
  83             start = start_and_n >> 4;
  84             n = (start_and_n & 15) + 1;
  85
  86             if (unsigned(end - p) < n * byte_width) {
  87                 return false;
  88             }
  89         }
  90
  91         // Even if there's nothing to display, we want to advance the
  92         // raster position.
  93         glBitmap(8 * byte_width, n, 0, -start, char_width[ch], 0, p);
  94         CHECK_GL_ERROR("BitmapFont::load", "glBitmap");
  95         glEndList();
  96         CHECK_GL_ERROR("BitmapFont::load", "glEndList");
  97
  98         p += n * byte_width;
  99     }
 100
 101     return true;
 102 }
 103
 104 inline void call_lists(GLsizei n, const GLvoid * lists)
 105 {
 106 #if SIZEOF_WXCHAR == 1
 107     glCallLists(n, GL_UNSIGNED_BYTE, lists);
 108 #elif SIZEOF_WXCHAR == 2
 109     glCallLists(n, GL_UNSIGNED_SHORT, lists);
 110 #elif SIZEOF_WXCHAR == 4
 111     glCallLists(n, GL_UNSIGNED_INT, lists);
 112 #else
 113 # error "sizeof(wxChar) not 1, 2 or 4"
 114 #endif
 115 }
 116
 117 void
 118 BitmapFont::init_extra_chars() const
 119 {
 120     int fd = wxOpen(font_file,
 121 #ifdef __WXMSW__
 122             _O_RDONLY|_O_SEQUENTIAL|_O_BINARY,
 123 #else
 124             O_RDONLY,
 125 #endif
 126             0);
 127
 128     int data_len = 0;
 129     unsigned char * data = NULL;
 130     if (fd >= 0) {
 131         struct stat sb;
 132         if (fstat(fd, &sb) >= 0) {
 133             data_len = sb.st_size;
 134         }
 135     }
 136
 137 #if HAVE_MMAP
 138     if (data_len) {
 139         void * p = mmap(NULL, data_len, PROT_READ, MAP_SHARED, fd, 0);
 140         if (p == MAP_FAILED) {
 141             data_len = 0;
 142         } else {
 143             extra_data = data = static_cast<unsigned char*>(p);
 144         }
 145     }
 146 #else
 147     data = new unsigned char[data_len];
 148     extra_data = data;
 149     if (data_len) {
 150         size_t c = data_len;
 151         unsigned char * p = data;
 152         while (c) {
 153             ssize_t n = read(fd, p, c);
 154             if (n <= 0) {
 155                 if (errno == EINTR) continue;
 156                 data_len = 0;
 157                 // FIXME: do something better.  wxGetApp().ReportError(m);
 158                 // We have this message available: Error in format of font file “%s”
 159                 // fprintf(stderr, "Couldn't load extended font.\n");
 160                 break;
 161             }
 162             p += n;
 163             c -= n;
 164         }
 165     }
 166 #endif
 167
 168     if (fd >= 0)
 169         close(fd);
 170
 171     extra_chars = new int[0x10000 - BITMAPFONT_MAX_CHAR];
 172     int data_ch = 0;
 173     for (int i = 0; i < 0x10000 - BITMAPFONT_MAX_CHAR; ++i) {
 174         if (data_ch >= data_len) {
 175             extra_chars[i] = -1;
 176             continue;
 177         }
 178         extra_chars[i] = data_ch;
 179         unsigned int byte_width = data[data_ch++];
 180         byte_width >>= 6;
 181
 182         if (byte_width) {
 183             unsigned int start_and_n = data[data_ch];
 184             int n = (start_and_n & 15) + 1;
 185             data_ch += n * byte_width + 1;
 186         }
 187     }
 188 }
 189
 190 int
 191 BitmapFont::glyph_width(wxChar ch) const
 192 {
 193 #if SIZEOF_WXCHAR > 2
 194     if (ch >= 0x10000) return 0;
 195 #endif
 196     if (!extra_chars)
 197         init_extra_chars();
 198
 199     int width = 8;
 200
 201     int char_idx = extra_chars[ch - BITMAPFONT_MAX_CHAR];
 202     if (char_idx >= 0) {
 203         unsigned int byte_width = extra_data[char_idx];
 204         width = (byte_width & 0x0f) + 2;
 205     }
 206
 207     return width;
 208 }
 209
 210 void
 211 BitmapFont::write_glyph(wxChar ch) const
 212 {
 213 #if SIZEOF_WXCHAR > 2
 214     if (ch >= 0x10000) return;
 215 #endif
 216     if (!extra_chars)
 217         init_extra_chars();
 218
 219     unsigned int byte_width = 0;
 220     int start = 0;
 221     int n = 0;
 222     int width = 8;
 223
 224     int char_idx = extra_chars[ch - BITMAPFONT_MAX_CHAR];
 225     const unsigned char * p = extra_data;
 226     if (char_idx >= 0) {
 227         p += char_idx;
 228         byte_width = *p++;
 229         width = (byte_width & 0x0f) + 2;
 230         byte_width >>= 6;
 231
 232         if (byte_width) {
 233             unsigned int start_and_n = *p++;
 234             start = start_and_n >> 4;
 235             n = (start_and_n & 15) + 1;
 236         }
 237     }
 238
 239     // Even if there's nothing to display, we want to advance the
 240     // raster position.
 241     glBitmap(8 * byte_width, n, 0, -start, width, 0, p);
 242     CHECK_GL_ERROR("BitmapFont::write_glyph", "glBitmap");
 243 }
 244
 245 void
 246 BitmapFont::write_string(const wxChar *s, size_t len) const
 247 {
 248     if (!gllist_base) return;
 249     glListBase(gllist_base);
 250 #if SIZEOF_WXCHAR == 1
 251     call_lists(len, s);
 252 #elif SIZEOF_WXCHAR == 2 || SIZEOF_WXCHAR == 4
 253     while (len) {
 254         size_t n;
 255         for (n = 0; n < len; ++n)
 256             if (int(s[n]) >= BITMAPFONT_MAX_CHAR)
 257                 break;
 258         call_lists(n, s);
 259         s += n;
 260         len -= n;
 261         while (len && int(*s) >= BITMAPFONT_MAX_CHAR) {
 262             write_glyph(*s);
 263             ++s;
 264             --len;
 265         }
 266     }
 267 #else
 268 # error "sizeof(wxChar) not 1, 2 or 4"
 269 #endif
 270 }