1 /* Copyright (c) 1987, 1989, 2012 University of Maryland Department of 2 Computer Science. 3 4 Permission is hereby granted, free of charge, to any person obtaining 5 a copy of this software and associated documentation files (the 6 "Software"), to deal in the Software without restriction, including 7 without limitation, the rights to use, copy, modify, merge, publish, 8 distribute, sublicense, and/or sell copies of the Software, and to 9 permit persons to whom the Software is furnished to do so, subject to 10 the following conditions: The above copyright notice, this permission 11 notice and the disclaimer statement shall be included in all copies 12 or substantial portions of the Software. 13 14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 15 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 16 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 17 IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 18 CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 19 TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 20 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 21 */ 22 23 #ifndef _MCTEX_FONT_ 24 #define _MCTEX_FONT_ 25 26 /* 27 * Font file information, readers, etc. 28 */ 29 30 #ifndef _MCTEX_TYPES_ 31 #include "types.h" 32 #endif 33 34 /* 35 * First, font independent information: per glyph info, and per font 36 * info. 37 */ 38 struct glyph { 39 short g_flags; /* see below */ 40 /* 41 * The following cannot be used with GetRasterlessFont 42 */ 43 short g_rotation; /* see below */ 44 char *g_raster; /* raster, if known */ 45 /* 46 * These, however, do come with rasterless fonts, 47 * even though they relate only to the raster. 48 */ 49 i32 g_height; /* height of bounding box */ 50 i32 g_width; /* width of bounding box */ 51 i32 g_yorigin; /* y origin (>= 0 -> within box) */ 52 i32 g_xorigin; /* x origin (>= 0 -> within box) */ 53 /* 54 * These of course come with every font. 55 */ 56 i32 g_rawtfmwidth; /* raw TFM width (in FIXes) */ 57 i32 g_tfmwidth; /* TFM width in scaled points */ 58 /* 59 * The X and Y escapements come from PK and GF fonts. 60 * They are in scaled pixels (65536 scaled pixels = 1 pixel). 61 * If they are not defined by the font, these are set to 62 * NO_ESCAPEMENT. 63 */ 64 i32 g_xescapement; /* x escapement (`chardx') */ 65 i32 g_yescapement; /* y escapement (`chardy') */ 66 #define NO_ESCAPEMENT ((i32)0x89abcdef) 67 /* 68 * This is provided purely for DVI to device conversion programs. 69 */ 70 int g_pixwidth; /* width in pixels */ 71 /* 72 * Mainly for internal use, index is the glyph index within the 73 * font. That is, f->f_gly[i]->g_index == i. 74 */ 75 int g_index; /* character index */ 76 /* 77 * g_details and g_integer are purely for the font reading 78 * subroutines to use however they will. g_next makes lists 79 * of glyphs while the glyphs are free. 80 */ 81 union { /* various options */ 82 char *g_details; /* details: arbitrary */ 83 i32 g_integer; /* 32 bit integer */ 84 struct glyph *g_next; /* linked list */ 85 } g_un; 86 }; 87 88 /* 89 * Glyph flags. 90 */ 91 #define GF_VALID 0x0001 /* glyph is `real' */ 92 #define GF_SEEN 0x0002 /* glyph has been encountered/loaded */ 93 94 #define GF_USR0 0x0100 /* reserved to user code */ 95 #define GF_USR1 0x0200 /* reserved to user code */ 96 #define GF_USR2 0x0400 /* reserved to user code */ 97 #define GF_USR3 0x0800 /* reserved to user code */ 98 99 /* 100 * Rotations are in quarter-pi steps, counterclockwise of course. 101 * This order must be maintained; see rotate.c. 102 */ 103 #define ROT_NORM 0 /* no rotation: `normal' position */ 104 #define ROT_LEFT 1 /* 1/4 turn counterclockwise */ 105 #define ROT_DOWN 2 /* 1/2 turn, i.e., upside-down */ 106 #define ROT_RIGHT 3 /* 3/4 turn ccw, or 1/4 turn cw */ 107 108 struct font { 109 int f_flags; /* see below */ 110 struct fontops *f_ops; /* operations */ 111 /* 112 * f_un is provided for DVI drivers, which typically need 113 * some way to translate DVI font numbers into local values. 114 * Most seem to need integers. 115 */ 116 union { 117 int f_int; /* value if int */ 118 i32 f_i32; /* value if i32 */ 119 char *f_ptr; /* value if pointer */ 120 } f_un; 121 #ifdef notdef 122 /* for LRU cacheing; not yet implemented */ 123 i32 f_lastuse; 124 #endif 125 /* 126 * f_details is provided for font reading subroutines. 127 * It is intended to be cast to a pointer to a structure 128 * that is allocated by those routines, and used to keep 129 * track of whatever information those routines need to 130 * determine glyph boxes and (if asked for) rasters. 131 */ 132 char *f_details; /* type dependent stuff */ 133 /* 134 * f_path is the full pathname to the font file, filled in 135 * by GetFont and GetRasterlessFont. Note that since we 136 * hold on to the path until the font is freed, it should be 137 * possible to cache glyph accesses on memory-poor machines. 138 */ 139 char *f_path; /* font file pathname */ 140 /* 141 * f_dvimag and f_dvidsz are the magnification and design size 142 * values from the DVI file. f_font and f_scaled correspond to 143 * TeX's idea of the proper name for the font (e.g., `cmr10', 144 * `cmbx10 scaled 1440'). (Note that f_scaled is just the 145 * ratio of f_dvimag and f_dvidsz; you could save a bit of memory 146 * by eliminating it and altering the routine Font_TeXName()). 147 * f_design_size is the font's design size, or 0 for fake (TFM) 148 * fonts. f_checksum should be set by the font reading routines 149 * to the font checksum. If the value is nonzero, it will be 150 * compared to the checksum in the DVI file. 151 */ 152 i32 f_dvimag; /* magnification from DVI file */ 153 i32 f_dvidsz; /* design size from DVI file */ 154 char *f_font; /* TeX's name for the font */ 155 int f_scaled; /* the ratio of dvimag to dvidsz, x1000 */ 156 i32 f_design_size; /* font design size */ 157 i32 f_checksum; /* font checksum, or 0 */ 158 /* 159 * The three values f_pspace, f_nspace, and f_vspace correspond 160 * to the amount of positive, negative, and vertical space that 161 * limits `kerning' (if horizontal) or `in-line motion' (vertical). 162 * f_pspace is equal to 1/6 of f_dvimag, and f_nspace and f_vspace 163 * are -4 and 5 times this value respectively. DVItype puts it 164 * this way (slightly edited): 165 * 166 * Rounding to the nearest pixel is best done in [this] 167 * manner ... so as to be inoffensive to the eye: When [a] 168 * horizontal motion is small, like a kern, [the device 169 * position] changes by rounding the kern; but when the 170 * motion is large, [the device position] changes by rounding 171 * the [DVI position] so that accumulated rounding errors 172 * disappear. We allow a larger space in the negative 173 * direction than in the positive one, because TeX makes 174 * comparatively large backspaces when it positions accents. 175 * 176 * Vertical motion is done similarly, but with the threshold 177 * between ``small'' and ``large'' increased by a factor of 178 * five. The idea is to make fractions like ``$1\over2$'' 179 * round consistently, but to absorb accumulated rounding 180 * errors in the baseline-skip moves. 181 * 182 * There is, however, an exception: 183 * 184 * A sequence of consecutive rules, or consecutive characters 185 * in a fixed-width font whose width is not an integer number 186 * of pixels, can cause [the device position] to drift far 187 * away from a correctly rounded value. 188 * 189 * The drift correction is applied after every horizontal or 190 * vertical motion, including any resulting from printing a 191 * character. 192 */ 193 i32 f_pspace; /* limit on positive kerns */ 194 i32 f_nspace; /* limit on negative kerns */ 195 i32 f_vspace; /* limit on vertical `kerns' */ 196 197 /* 198 * If set, f_hppp and f_vppp tell how many pixels there are 199 * per scaled point in the font. For instance, a 300 dpi font 200 * has 300pixels/1inch * 1inch/72.27pt * 65536pt/1sp ~= 201 * 272046 pixels/sp. 202 * 203 * If they are zero, the font does not tell us. 204 */ 205 i32 f_hppp; /* horizontal pixels per point */ 206 i32 f_vppp; /* vertical pixels per point */ 207 /* 208 * f_lowch and f_highch bound the region in which f_gly 209 * indicies are valid. Specificially, f_gly[i] may be 210 * read or written if and only if i is in the half-open 211 * interval [f_lowch..f_highch). f_gly is an array of 212 * pointers to glyph structures. The structures themselves 213 * are not allocated until requested. 214 * 215 * f_glybase is the actual return from malloc(), since it 216 * is theoretically possible for f_gly-f_lowch to become 217 * NULL. 218 */ 219 int f_lowch; /* first character */ 220 int f_highch; /* last character, plus 1 */ 221 struct glyph **f_gly; /* glyphs */ 222 struct glyph **f_glybase; 223 }; 224 225 /* 226 * Macros for rounding DVI and device motions per DVItype rules. 227 */ 228 #define F_SMALLH(f, m) ((m) < (f)->f_pspace && (m) > (f)->f_nspace) 229 #define F_SMALLV(f, m) ((m) < (f)->f_vspace && -(m) < (f)->f_vspace) 230 231 /* 232 * Font flags. 233 */ 234 #define FF_RASTERS 0x0001 /* font has rasters */ 235 #define FF_USR0 0x0100 /* reserved to user code */ 236 #define FF_USR1 0x0200 /* reserved to user code */ 237 #define FF_USR2 0x0400 /* reserved to user code */ 238 #define FF_USR3 0x0800 /* reserved to user code */ 239 240 /* 241 * Operations on fonts. 242 * 243 * The `fo_dpitomag' field is used as a multiplier for a desired 244 * resolution in dots per inch. The result of the multiplication 245 * is converted to a font name by multipying by 1000.0 and rounding. 246 * The idea is that PXL files will have a multiplier of 5.0, and 247 * others will have a multiplier of 1.0. This suffices for the 248 * present, at any rate; in the future, this field may be replaced 249 * with something more general. 250 * 251 * N.B.: more operations may be added as they are discovered to be 252 * useful. 253 */ 254 struct fontops { 255 char *fo_name; /* name, e.g., "gf" */ 256 int fo_fakefont; /* 1="box", 2="blank"; else 0 */ 257 double fo_dpitomag; /* multiplier */ 258 int (*fo_read)(); /* open and read the font itself */ 259 int (*fo_getgly)(); /* obtain specified glyphs (range) */ 260 #ifdef notdef 261 void (*fo_freegly)(); /* release specified glyphs */ 262 #endif 263 int (*fo_rasterise)(); /* rasterise specified glyphs */ 264 void (*fo_freefont)(); /* discard font (free details) */ 265 struct fontops *fo_next; /* purely for font.c */ 266 }; 267 268 /* 269 * Return a pointer to the glyph information for character `c' in 270 * font `f'. 271 */ 272 #define GLYPH(f, c) \ 273 ((c) < (f)->f_lowch || (c) >= (f)->f_highch ? (struct glyph *)0 : \ 274 ((f)->f_gly[c] ? (f)->f_gly[c] : GetGlyph(f, (int)(c)))) 275 276 /* 277 * True iff glyph `g' is valid. Useful for checking return values 278 * from GLYPH(). 279 */ 280 #define GVALID(g) ((g) && ((g)->g_flags & GF_VALID)) 281 282 /* 283 * True iff glyph g has a raster. 284 */ 285 #define HASRASTER(g) ((g)->g_height && (g)->g_width) 286 287 /* 288 * Return a pointer to the raster information for glyph `g' in font 289 * `f' at rotation `r'. 290 */ 291 #define RASTER(g, f, r) ((g)->g_rotation == (r) && (g)->g_raster ? \ 292 (g)->g_raster : GetRaster(g, f, r)) 293 294 /* 295 * Function types. 296 */ 297 struct font *GetFont(char *nm, i32 dvimag, i32 dvidsz, char *dev, char **fname); 298 struct font *GetRasterlessFont(char *nm, i32 dvimag, i32 dvidsz, char *dev, char **fname); 299 struct glyph *GetGlyph(); 300 char *GetRaster(); 301 void FreeFont(); 302 void FreeGlyph(); 303 void FreeRaster(); 304 char *Font_TeXName(); 305 void fontinit(char *file); 306 307 /* 308 * Normally from stdio.h 309 */ 310 #ifndef NULL 311 #define NULL 0 312 #endif 313 314 /* 315 * The following environment variable overrides the default font 316 * configuration file. That default is used when fontinit() is not 317 * called, or is passed a null pointer. 318 */ 319 #define CONFENV "TEXFONTDESC" 320 321 #endif /* _MCTEX_FONT_ */ 322