1 | // |
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2 | // fnt.cc |
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3 | // |
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4 | // Draw text using texture mapped fonts. |
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5 | // |
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6 | // Copyright (C) 2003,2004,2006,2010 Olly Betts |
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7 | // |
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8 | // Based on code from PLIB - http://plib.sourceforge.net |
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9 | // Copyright (C) 1998,2002 Steve Baker |
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10 | // Relicensed under the GNU GPL as permitted by the GNU LGPL |
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11 | // |
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12 | // This program is free software; you can redistribute it and/or modify |
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13 | // it under the terms of the GNU General Public License as published by |
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14 | // the Free Software Foundation; either version 2 of the License, or |
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15 | // (at your option) any later version. |
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16 | // |
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17 | // This program is distributed in the hope that it will be useful, |
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18 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
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19 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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20 | // GNU General Public License for more details. |
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21 | // |
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22 | // You should have received a copy of the GNU General Public License |
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23 | // along with this program; if not, write to the Free Software |
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24 | // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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25 | // |
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26 | |
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27 | #include "fnt.h" |
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28 | |
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29 | #include <stdio.h> |
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30 | |
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31 | static bool isSwapped = false; |
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32 | |
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33 | inline unsigned char fnt_readByte(FILE *fd) { |
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34 | return (unsigned char)getc(fd); |
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35 | } |
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36 | |
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37 | inline unsigned short fnt_readShort(FILE *fd) { |
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38 | unsigned short x; |
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39 | if (isSwapped) { |
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40 | x = getc(fd) | (getc(fd) << 8); |
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41 | } else { |
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42 | x = (getc(fd) << 8) | getc(fd); |
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43 | } |
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44 | return x; |
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45 | } |
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46 | |
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47 | inline unsigned int fnt_readInt(FILE *fd) { |
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48 | unsigned int x; |
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49 | if (isSwapped) { |
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50 | x = getc(fd) | (getc(fd) << 8) | (getc(fd) << 16) | (getc(fd) << 24); |
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51 | } else { |
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52 | x = (getc(fd) << 24) | (getc(fd) << 16) | (getc(fd) << 8) | getc(fd); |
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53 | } |
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54 | return x; |
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55 | } |
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56 | |
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57 | #define FNT_BYTE_FORMAT 0 |
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58 | #define FNT_BITMAP_FORMAT 1 |
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59 | |
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60 | bool |
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61 | fntTexFont::load(const char *fname) |
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62 | { |
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63 | FILE *fd; |
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64 | |
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65 | if ((fd = fopen(fname, "rb")) == NULL) { |
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66 | fprintf(stderr, "Failed to open '%s' for reading.\n", fname); |
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67 | return false; |
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68 | } |
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69 | |
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70 | unsigned char magic[4]; |
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71 | |
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72 | if (fread(&magic, 4, 1, fd) != 1) { |
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73 | fprintf(stderr, "'%s' an empty file!\n", fname); |
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74 | return false; |
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75 | } |
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76 | |
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77 | if (memcmp(magic, "\xfftxf", 4) != 0) { |
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78 | fprintf(stderr, "'%s' is not a 'txf' font file.\n", fname); |
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79 | return false; |
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80 | } |
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81 | |
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82 | isSwapped = false; |
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83 | int endianness = fnt_readInt(fd); |
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84 | |
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85 | isSwapped = (endianness != 0x12345678); |
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86 | |
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87 | int format = fnt_readInt(fd); |
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88 | int tex_width = fnt_readInt(fd); |
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89 | int tex_height = fnt_readInt(fd); |
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90 | /* int max_height = */ fnt_readInt(fd); |
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91 | /* int unknown = */ fnt_readInt(fd); |
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92 | int num_glyphs = fnt_readInt(fd); |
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93 | list_base = glGenLists(256 - 32) - 32; |
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94 | |
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95 | int i, j; |
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96 | |
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97 | // Skip the glyph info first so we can set up the texture, then create |
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98 | // display lists from it using the glyph info |
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99 | int fpos = ftell(fd); |
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100 | fseek(fd, num_glyphs * 12, SEEK_CUR); |
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101 | // Load the image part of the file |
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102 | int ntexels = tex_width * tex_height; |
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103 | |
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104 | unsigned char *teximage = new unsigned char[ntexels]; |
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105 | |
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106 | switch (format) { |
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107 | case FNT_BYTE_FORMAT: { |
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108 | if ((int)fread(teximage, 1, ntexels, fd) != ntexels) { |
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109 | delete [] teximage; |
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110 | fprintf(stderr, "Premature EOF in '%s'.\n", fname); |
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111 | return false; |
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112 | } |
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113 | break; |
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114 | } |
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115 | |
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116 | case FNT_BITMAP_FORMAT: { |
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117 | int stride = (tex_width + 7) >> 3; |
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118 | |
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119 | unsigned char *texbitmap = new unsigned char[stride * tex_height]; |
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120 | |
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121 | if ((int)fread(texbitmap, 1, stride * tex_height, fd) |
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122 | != stride * tex_height) { |
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123 | delete [] texbitmap; |
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124 | delete [] teximage; |
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125 | fprintf(stderr, "Premature EOF in '%s'.\n", fname); |
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126 | return false; |
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127 | } |
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128 | |
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129 | memset((void*)teximage, 0, ntexels); |
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130 | |
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131 | for (i = 0; i < tex_height; ++i) { |
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132 | for (j = 0; j < tex_width; ++j) { |
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133 | if (texbitmap[i * stride + (j >> 3)] & (1 << (j & 7))) { |
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134 | teximage[i * tex_width + j] = 0xff; |
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135 | } |
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136 | } |
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137 | } |
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138 | |
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139 | delete [] texbitmap; |
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140 | break; |
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141 | } |
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142 | |
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143 | default: |
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144 | delete [] teximage; |
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145 | fprintf(stderr, "Unrecognised format type in '%s'.\n", fname); |
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146 | return false; |
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147 | } |
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148 | glPixelStorei(GL_UNPACK_ALIGNMENT, 1); |
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149 | |
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150 | glGenTextures(1, & texture); |
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151 | glBindTexture(GL_TEXTURE_2D, texture); |
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152 | |
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153 | glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); |
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154 | |
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155 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP); |
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156 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); |
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157 | glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, tex_width, tex_height, 0 /* Border */, |
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158 | GL_ALPHA, GL_UNSIGNED_BYTE, (GLvoid *)teximage); |
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159 | delete [] teximage; |
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160 | |
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161 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); |
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162 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); |
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163 | |
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164 | fseek(fd, fpos, SEEK_SET); |
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165 | |
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166 | for (i = 0; i < FNT_MAXCHAR; ++i) widths[i] = -1; |
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167 | |
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168 | // Load the glyph array |
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169 | |
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170 | float W = 1.0f / (float)tex_width; |
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171 | float H = 1.0f / (float)tex_height; |
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172 | unsigned char max_w = 0; |
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173 | int u = 0, d = 0; |
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174 | for (i = 0; i < num_glyphs; ++i) { |
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175 | unsigned short ch = fnt_readShort(fd); |
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176 | unsigned char w = fnt_readByte(fd); |
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177 | if (w > max_w) max_w = w; |
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178 | unsigned char h = fnt_readByte(fd); |
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179 | int vtx_left = (signed char)fnt_readByte(fd); |
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180 | int vtx_bot = (signed char)fnt_readByte(fd); |
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181 | signed char step = fnt_readByte(fd); |
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182 | /* signed char unknown =*/ fnt_readByte(fd); |
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183 | short x = fnt_readShort(fd); |
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184 | short y = fnt_readShort(fd); |
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185 | |
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186 | if (ch < 32 || ch >= FNT_MAXCHAR) continue; |
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187 | |
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188 | float tex_left = x * W; |
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189 | float tex_right = (x + w) * W; |
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190 | float tex_bot = y * H; |
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191 | float tex_top = (y + h) * H; |
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192 | int vtx_right = vtx_left + w; |
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193 | int vtx_top = vtx_bot + h; |
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194 | glNewList(list_base + ch, GL_COMPILE); |
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195 | if (w != 0 && h != 0) { |
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196 | glBegin(GL_QUADS); |
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197 | glTexCoord2f(tex_left, tex_bot); |
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198 | glVertex2i(vtx_left, vtx_bot); |
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199 | glTexCoord2f(tex_right, tex_bot); |
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200 | glVertex2i(vtx_right, vtx_bot); |
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201 | glTexCoord2f(tex_right, tex_top); |
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202 | glVertex2i(vtx_right, vtx_top); |
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203 | glTexCoord2f(tex_left, tex_top); |
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204 | glVertex2i(vtx_left, vtx_top); |
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205 | glEnd(); |
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206 | } |
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207 | widths[ch] = step; |
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208 | glTranslated(widths[ch], 0, 0); |
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209 | glEndList(); |
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210 | if (vtx_bot < d) d = vtx_bot; |
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211 | if (vtx_top > u) u = vtx_top; |
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212 | } |
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213 | fnt_size = u - d; |
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214 | |
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215 | if (widths[(int)' '] == -1) { |
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216 | glNewList(list_base + ' ', GL_COMPILE); |
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217 | widths[(int)' '] = widths[(int)'n']; |
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218 | glTranslated(widths[(int)' '], 0, 0); |
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219 | glEndList(); |
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220 | } |
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221 | |
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222 | fclose(fd); |
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223 | return true; |
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224 | } |
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