src/glbitmapfont.cc

   1 //
   2 //  glbitmapfont.cc
   3 //
   4 //  Draw text using glBitmap.
   5 //
   6 //  Copyright (C) 2011,2012,2013,2014,2015,2018 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 "gllogerror.h"
  31 #include "useful.h"
  32 #include "wx.h"
  33
  34 #include <cerrno>
  35 #ifdef HAVE_MMAP
  36 #include <sys/mman.h>
  37 #else
  38 #include <unistd.h>
  39 #endif
  40
  41 using namespace std;
  42
  43 #include "../lib/preload_font.h"
  44
  45 BitmapFont::~BitmapFont() {
  46     if (!gllist_base) return;
  47     glDeleteLists(gllist_base, BITMAPFONT_MAX_CHAR);
  48     CHECK_GL_ERROR("BitmapFont::~BitmapFont", "glDeleteLists");
  49 }
  50
  51 bool
  52 BitmapFont::load(const wxString & font_file_)
  53 {
  54     font_file = font_file_;
  55
  56     if (!gllist_base) {
  57         gllist_base = glGenLists(BITMAPFONT_MAX_CHAR);
  58         CHECK_GL_ERROR("BitmapFont::load", "glGenLists");
  59     }
  60
  61     const unsigned char * p = fontdata_preloaded;
  62     const unsigned char * end = p + sizeof(fontdata_preloaded);
  63     for (int ch = 0; ch < BITMAPFONT_MAX_CHAR; ++ch) {
  64         glNewList(gllist_base + ch, GL_COMPILE);
  65         CHECK_GL_ERROR("BitmapFont::load", "glNewList");
  66         if (p == end) {
  67             return false;
  68         }
  69         unsigned int byte_width = *p++;
  70
  71         char_width[ch] = (byte_width & 0x0f) + 2;
  72         byte_width >>= 6;
  73
  74         int start = 0;
  75         unsigned int n = 0;
  76         if (byte_width) {
  77             if (p == end) {
  78                 return false;
  79             }
  80             unsigned int start_and_n = *p++;
  81             start = start_and_n >> 4;
  82             n = (start_and_n & 15) + 1;
  83
  84             if (unsigned(end - p) < n * byte_width) {
  85                 return false;
  86             }
  87         }
  88
  89         // Even if there's nothing to display, we want to advance the
  90         // raster position.
  91         glBitmap(8 * byte_width, n, 0, -start, char_width[ch], 0, p);
  92         CHECK_GL_ERROR("BitmapFont::load", "glBitmap");
  93         glEndList();
  94         CHECK_GL_ERROR("BitmapFont::load", "glEndList");
  95
  96         p += n * byte_width;
  97     }
  98
  99     return true;
 100 }
 101
 102 inline void call_lists(GLsizei n, const GLvoid * lists)
 103 {
 104 #if SIZEOF_WXCHAR == 1
 105     glCallLists(n, GL_UNSIGNED_BYTE, lists);
 106 #elif SIZEOF_WXCHAR == 2
 107     glCallLists(n, GL_UNSIGNED_SHORT, lists);
 108 #elif SIZEOF_WXCHAR == 4
 109     glCallLists(n, GL_UNSIGNED_INT, lists);
 110 #else
 111 # error "sizeof(wxChar) not 1, 2 or 4"
 112 #endif
 113 }
 114
 115 void
 116 BitmapFont::init_extra_chars() const
 117 {
 118     int fd = wxOpen(font_file,
 119 #ifdef __WXMSW__
 120             _O_RDONLY|_O_SEQUENTIAL|_O_BINARY,
 121 #else
 122             O_RDONLY,
 123 #endif
 124             0);
 125
 126     int data_len = 0;
 127     unsigned char * data = NULL;
 128     if (fd >= 0) {
 129         struct stat sb;
 130         if (fstat(fd, &sb) >= 0) {
 131             data_len = sb.st_size;
 132         }
 133     }
 134
 135 #if HAVE_MMAP
 136     if (data_len) {
 137         void * p = mmap(NULL, data_len, PROT_READ, MAP_SHARED, fd, 0);
 138         if (p == MAP_FAILED) {
 139             data_len = 0;
 140         } else {
 141             extra_data = data = static_cast<unsigned char*>(p);
 142         }
 143     }
 144 #else
 145     data = new unsigned char[data_len];
 146     extra_data = data;
 147     if (data_len) {
 148         size_t c = data_len;
 149         unsigned char * p = data;
 150         while (c) {
 151             ssize_t n = read(fd, p, c);
 152             if (n <= 0) {
 153                 if (errno == EINTR) continue;
 154                 data_len = 0;
 155                 // FIXME: do something better.  wxGetApp().ReportError(m);
 156                 // We have this message available: Error in format of font file “%s”
 157                 // fprintf(stderr, "Couldn't load extended font.\n");
 158                 break;
 159             }
 160             p += n;
 161             c -= n;
 162         }
 163     }
 164 #endif
 165
 166     if (fd >= 0)
 167         close(fd);
 168
 169     extra_chars = new int[0x10000 - BITMAPFONT_MAX_CHAR];
 170     int data_ch = 0;
 171     for (int i = 0; i < 0x10000 - BITMAPFONT_MAX_CHAR; ++i) {
 172         if (data_ch >= data_len) {
 173             extra_chars[i] = -1;
 174             continue;
 175         }
 176         extra_chars[i] = data_ch;
 177         unsigned int byte_width = data[data_ch++];
 178         byte_width >>= 6;
 179
 180         if (byte_width) {
 181             unsigned int start_and_n = data[data_ch];
 182             int n = (start_and_n & 15) + 1;
 183             data_ch += n * byte_width + 1;
 184         }
 185     }
 186 }
 187
 188 int
 189 BitmapFont::glyph_width(wxChar ch) const
 190 {
 191 #if SIZEOF_WXCHAR > 2
 192     if (ch >= 0x10000) return 0;
 193 #endif
 194     if (!extra_chars)
 195         init_extra_chars();
 196
 197     int width = 8;
 198
 199     int char_idx = extra_chars[ch - BITMAPFONT_MAX_CHAR];
 200     if (char_idx >= 0) {
 201         unsigned int byte_width = extra_data[char_idx];
 202         width = (byte_width & 0x0f) + 2;
 203     }
 204
 205     return width;
 206 }
 207
 208 void
 209 BitmapFont::write_glyph(wxChar ch) const
 210 {
 211 #if SIZEOF_WXCHAR > 2
 212     if (ch >= 0x10000) return;
 213 #endif
 214     if (!extra_chars)
 215         init_extra_chars();
 216
 217     unsigned int byte_width = 0;
 218     int start = 0;
 219     int n = 0;
 220     int width = 8;
 221
 222     int char_idx = extra_chars[ch - BITMAPFONT_MAX_CHAR];
 223     const unsigned char * p = extra_data;
 224     if (char_idx >= 0) {
 225         p += char_idx;
 226         byte_width = *p++;
 227         width = (byte_width & 0x0f) + 2;
 228         byte_width >>= 6;
 229
 230         if (byte_width) {
 231             unsigned int start_and_n = *p++;
 232             start = start_and_n >> 4;
 233             n = (start_and_n & 15) + 1;
 234         }
 235     }
 236
 237     // Even if there's nothing to display, we want to advance the
 238     // raster position.
 239     glBitmap(8 * byte_width, n, 0, -start, width, 0, p);
 240     CHECK_GL_ERROR("BitmapFont::write_glyph", "glBitmap");
 241 }
 242
 243 void
 244 BitmapFont::write_string(const wxChar *s, size_t len) const
 245 {
 246     if (!gllist_base) return;
 247     glListBase(gllist_base);
 248 #if SIZEOF_WXCHAR == 1
 249     call_lists(len, s);
 250 #elif SIZEOF_WXCHAR == 2 || SIZEOF_WXCHAR == 4
 251     while (len) {
 252         size_t n;
 253         for (n = 0; n < len; ++n)
 254             if (int(s[n]) >= BITMAPFONT_MAX_CHAR)
 255                 break;
 256         call_lists(n, s);
 257         s += n;
 258         len -= n;
 259         while (len && int(*s) >= BITMAPFONT_MAX_CHAR) {
 260             write_glyph(*s);
 261             ++s;
 262             --len;
 263         }
 264     }
 265 #else
 266 # error "sizeof(wxChar) not 1, 2 or 4"
 267 #endif
 268 }