glx_usefont.c revision 10eb2ca9540dc4d96933fa1d7c1a92d3e040a5bd
1/* 2 * Mesa 3-D graphics library 3 * Version: 7.6 4 * 5 * Copyright (C) 1995 Thorsten.Ohl @ Physik.TH-Darmstadt.de 6 * Copyright (C) 1999-2008 Brian Paul All Rights Reserved. 7 * Copyright (C) 2009 VMware, Inc. All Rights Reserved. 8 * 9 * Permission is hereby granted, free of charge, to any person obtaining a 10 * copy of this software and associated documentation files (the "Software"), 11 * to deal in the Software without restriction, including without limitation 12 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 13 * and/or sell copies of the Software, and to permit persons to whom the 14 * Software is furnished to do so, subject to the following conditions: 15 * 16 * The above copyright notice and this permission notice shall be included 17 * in all copies or substantial portions of the Software. 18 * 19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 22 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN 23 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 24 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 25 */ 26 27 28/** 29 * Fake implementation of glXUseXFont(). 30 */ 31 32 33#include "context.h" 34#include "imports.h" 35#include <GL/glx.h> 36 37 38/* Some debugging info. */ 39 40#ifdef DEBUG 41#undef _R 42#undef _G 43#undef _B 44#include <ctype.h> 45 46int debug_xfonts = 0; 47 48static void 49dump_char_struct(XCharStruct * ch, char *prefix) 50{ 51 printf("%slbearing = %d, rbearing = %d, width = %d\n", 52 prefix, ch->lbearing, ch->rbearing, ch->width); 53 printf("%sascent = %d, descent = %d, attributes = %u\n", 54 prefix, ch->ascent, ch->descent, (unsigned int) ch->attributes); 55} 56 57static void 58dump_font_struct(XFontStruct * font) 59{ 60 printf("ascent = %d, descent = %d\n", font->ascent, font->descent); 61 printf("char_or_byte2 = (%u,%u)\n", 62 font->min_char_or_byte2, font->max_char_or_byte2); 63 printf("byte1 = (%u,%u)\n", font->min_byte1, font->max_byte1); 64 printf("all_chars_exist = %s\n", font->all_chars_exist ? "True" : "False"); 65 printf("default_char = %c (\\%03o)\n", 66 (char) (isprint(font->default_char) ? font->default_char : ' '), 67 font->default_char); 68 dump_char_struct(&font->min_bounds, "min> "); 69 dump_char_struct(&font->max_bounds, "max> "); 70#if 0 71 for (c = font->min_char_or_byte2; c <= font->max_char_or_byte2; c++) { 72 char prefix[8]; 73 sprintf(prefix, "%d> ", c); 74 dump_char_struct(&font->per_char[c], prefix); 75 } 76#endif 77} 78 79static void 80dump_bitmap(unsigned int width, unsigned int height, GLubyte * bitmap) 81{ 82 unsigned int x, y; 83 84 printf(" "); 85 for (x = 0; x < 8 * width; x++) 86 printf("%o", 7 - (x % 8)); 87 putchar('\n'); 88 for (y = 0; y < height; y++) { 89 printf("%3o:", y); 90 for (x = 0; x < 8 * width; x++) 91 putchar((bitmap[width * (height - y - 1) + x / 8] & (1 << (7 - (x % 92 8)))) 93 ? '*' : '.'); 94 printf(" "); 95 for (x = 0; x < width; x++) 96 printf("0x%02x, ", bitmap[width * (height - y - 1) + x]); 97 putchar('\n'); 98 } 99} 100#endif /* DEBUG */ 101 102 103/* Implementation. */ 104 105/* Fill a BITMAP with a character C from thew current font 106 in the graphics context GC. WIDTH is the width in bytes 107 and HEIGHT is the height in bits. 108 109 Note that the generated bitmaps must be used with 110 111 glPixelStorei (GL_UNPACK_SWAP_BYTES, GL_FALSE); 112 glPixelStorei (GL_UNPACK_LSB_FIRST, GL_FALSE); 113 glPixelStorei (GL_UNPACK_ROW_LENGTH, 0); 114 glPixelStorei (GL_UNPACK_SKIP_ROWS, 0); 115 glPixelStorei (GL_UNPACK_SKIP_PIXELS, 0); 116 glPixelStorei (GL_UNPACK_ALIGNMENT, 1); 117 118 Possible optimizations: 119 120 * use only one reusable pixmap with the maximum dimensions. 121 * draw the entire font into a single pixmap (careful with 122 proportional fonts!). 123*/ 124 125 126/* 127 * Generate OpenGL-compatible bitmap. 128 */ 129static void 130fill_bitmap(Display * dpy, Window win, GC gc, 131 unsigned int width, unsigned int height, 132 int x0, int y0, unsigned int c, GLubyte * bitmap) 133{ 134 XImage *image; 135 unsigned int x, y; 136 Pixmap pixmap; 137 XChar2b char2b; 138 139 pixmap = XCreatePixmap(dpy, win, 8 * width, height, 1); 140 XSetForeground(dpy, gc, 0); 141 XFillRectangle(dpy, pixmap, gc, 0, 0, 8 * width, height); 142 XSetForeground(dpy, gc, 1); 143 144 char2b.byte1 = (c >> 8) & 0xff; 145 char2b.byte2 = (c & 0xff); 146 147 XDrawString16(dpy, pixmap, gc, x0, y0, &char2b, 1); 148 149 image = XGetImage(dpy, pixmap, 0, 0, 8 * width, height, 1, XYPixmap); 150 if (image) { 151 /* Fill the bitmap (X11 and OpenGL are upside down wrt each other). */ 152 for (y = 0; y < height; y++) 153 for (x = 0; x < 8 * width; x++) 154 if (XGetPixel(image, x, y)) 155 bitmap[width * (height - y - 1) + x / 8] |= 156 (1 << (7 - (x % 8))); 157 XDestroyImage(image); 158 } 159 160 XFreePixmap(dpy, pixmap); 161} 162 163/* 164 * determine if a given glyph is valid and return the 165 * corresponding XCharStruct. 166 */ 167static XCharStruct * 168isvalid(XFontStruct * fs, unsigned int which) 169{ 170 unsigned int rows, pages; 171 unsigned int byte1 = 0, byte2 = 0; 172 int i, valid = 1; 173 174 rows = fs->max_byte1 - fs->min_byte1 + 1; 175 pages = fs->max_char_or_byte2 - fs->min_char_or_byte2 + 1; 176 177 if (rows == 1) { 178 /* "linear" fonts */ 179 if ((fs->min_char_or_byte2 > which) || (fs->max_char_or_byte2 < which)) 180 valid = 0; 181 } 182 else { 183 /* "matrix" fonts */ 184 byte2 = which & 0xff; 185 byte1 = which >> 8; 186 if ((fs->min_char_or_byte2 > byte2) || 187 (fs->max_char_or_byte2 < byte2) || 188 (fs->min_byte1 > byte1) || (fs->max_byte1 < byte1)) 189 valid = 0; 190 } 191 192 if (valid) { 193 if (fs->per_char) { 194 if (rows == 1) { 195 /* "linear" fonts */ 196 return (fs->per_char + (which - fs->min_char_or_byte2)); 197 } 198 else { 199 /* "matrix" fonts */ 200 i = ((byte1 - fs->min_byte1) * pages) + 201 (byte2 - fs->min_char_or_byte2); 202 return (fs->per_char + i); 203 } 204 } 205 else { 206 return (&fs->min_bounds); 207 } 208 } 209 return (NULL); 210} 211 212 213void 214glXUseXFont(Font font, int first, int count, int listbase) 215{ 216 Display *dpy; 217 Window win; 218 Pixmap pixmap; 219 GC gc; 220 XGCValues values; 221 unsigned long valuemask; 222 XFontStruct *fs; 223 GLint swapbytes, lsbfirst, rowlength; 224 GLint skiprows, skippixels, alignment; 225 unsigned int max_width, max_height, max_bm_width, max_bm_height; 226 GLubyte *bm; 227 int i; 228 229 dpy = glXGetCurrentDisplay(); 230 if (!dpy) 231 return; /* I guess glXMakeCurrent wasn't called */ 232 i = DefaultScreen(dpy); 233 win = RootWindow(dpy, i); 234 235 fs = XQueryFont(dpy, font); 236 if (!fs) { 237 _mesa_error(NULL, GL_INVALID_VALUE, 238 "Couldn't get font structure information"); 239 return; 240 } 241 242 /* Allocate a bitmap that can fit all characters. */ 243 max_width = fs->max_bounds.rbearing - fs->min_bounds.lbearing; 244 max_height = fs->max_bounds.ascent + fs->max_bounds.descent; 245 max_bm_width = (max_width + 7) / 8; 246 max_bm_height = max_height; 247 248 bm = (GLubyte *) MALLOC((max_bm_width * max_bm_height) * sizeof(GLubyte)); 249 if (!bm) { 250 XFreeFontInfo(NULL, fs, 1); 251 _mesa_error(NULL, GL_OUT_OF_MEMORY, 252 "Couldn't allocate bitmap in glXUseXFont()"); 253 return; 254 } 255 256#if 0 257 /* get the page info */ 258 pages = fs->max_char_or_byte2 - fs->min_char_or_byte2 + 1; 259 firstchar = (fs->min_byte1 << 8) + fs->min_char_or_byte2; 260 lastchar = (fs->max_byte1 << 8) + fs->max_char_or_byte2; 261 rows = fs->max_byte1 - fs->min_byte1 + 1; 262 unsigned int first_char, last_char, pages, rows; 263#endif 264 265 /* Save the current packing mode for bitmaps. */ 266 glGetIntegerv(GL_UNPACK_SWAP_BYTES, &swapbytes); 267 glGetIntegerv(GL_UNPACK_LSB_FIRST, &lsbfirst); 268 glGetIntegerv(GL_UNPACK_ROW_LENGTH, &rowlength); 269 glGetIntegerv(GL_UNPACK_SKIP_ROWS, &skiprows); 270 glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &skippixels); 271 glGetIntegerv(GL_UNPACK_ALIGNMENT, &alignment); 272 273 /* Enforce a standard packing mode which is compatible with 274 fill_bitmap() from above. This is actually the default mode, 275 except for the (non)alignment. */ 276 glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE); 277 glPixelStorei(GL_UNPACK_LSB_FIRST, GL_FALSE); 278 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0); 279 glPixelStorei(GL_UNPACK_SKIP_ROWS, 0); 280 glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0); 281 glPixelStorei(GL_UNPACK_ALIGNMENT, 1); 282 283 pixmap = XCreatePixmap(dpy, win, 10, 10, 1); 284 values.foreground = BlackPixel(dpy, DefaultScreen(dpy)); 285 values.background = WhitePixel(dpy, DefaultScreen(dpy)); 286 values.font = fs->fid; 287 valuemask = GCForeground | GCBackground | GCFont; 288 gc = XCreateGC(dpy, pixmap, valuemask, &values); 289 XFreePixmap(dpy, pixmap); 290 291#ifdef DEBUG 292 if (debug_xfonts) 293 dump_font_struct(fs); 294#endif 295 296 for (i = 0; i < count; i++) { 297 unsigned int width, height, bm_width, bm_height; 298 GLfloat x0, y0, dx, dy; 299 XCharStruct *ch; 300 int x, y; 301 unsigned int c = first + i; 302 int list = listbase + i; 303 int valid; 304 305 /* check on index validity and get the bounds */ 306 ch = isvalid(fs, c); 307 if (!ch) { 308 ch = &fs->max_bounds; 309 valid = 0; 310 } 311 else { 312 valid = 1; 313 } 314 315#ifdef DEBUG 316 if (debug_xfonts) { 317 char s[7]; 318 sprintf(s, isprint(c) ? "%c> " : "\\%03o> ", c); 319 dump_char_struct(ch, s); 320 } 321#endif 322 323 /* glBitmap()' parameters: 324 straight from the glXUseXFont(3) manpage. */ 325 width = ch->rbearing - ch->lbearing; 326 height = ch->ascent + ch->descent; 327 x0 = -ch->lbearing; 328 y0 = ch->descent - 0; /* XXX used to subtract 1 here */ 329 /* but that caused a conformace failure */ 330 dx = ch->width; 331 dy = 0; 332 333 /* X11's starting point. */ 334 x = -ch->lbearing; 335 y = ch->ascent; 336 337 /* Round the width to a multiple of eight. We will use this also 338 for the pixmap for capturing the X11 font. This is slightly 339 inefficient, but it makes the OpenGL part real easy. */ 340 bm_width = (width + 7) / 8; 341 bm_height = height; 342 343 glNewList(list, GL_COMPILE); 344 if (valid && (bm_width > 0) && (bm_height > 0)) { 345 346 MEMSET(bm, '\0', bm_width * bm_height); 347 fill_bitmap(dpy, win, gc, bm_width, bm_height, x, y, c, bm); 348 349 glBitmap(width, height, x0, y0, dx, dy, bm); 350#ifdef DEBUG 351 if (debug_xfonts) { 352 printf("width/height = %u/%u\n", width, height); 353 printf("bm_width/bm_height = %u/%u\n", bm_width, bm_height); 354 dump_bitmap(bm_width, bm_height, bm); 355 } 356#endif 357 } 358 else { 359 glBitmap(0, 0, 0.0, 0.0, dx, dy, NULL); 360 } 361 glEndList(); 362 } 363 364 FREE(bm); 365 XFreeFontInfo(NULL, fs, 1); 366 XFreeGC(dpy, gc); 367 368 /* Restore saved packing modes. */ 369 glPixelStorei(GL_UNPACK_SWAP_BYTES, swapbytes); 370 glPixelStorei(GL_UNPACK_LSB_FIRST, lsbfirst); 371 glPixelStorei(GL_UNPACK_ROW_LENGTH, rowlength); 372 glPixelStorei(GL_UNPACK_SKIP_ROWS, skiprows); 373 glPixelStorei(GL_UNPACK_SKIP_PIXELS, skippixels); 374 glPixelStorei(GL_UNPACK_ALIGNMENT, alignment); 375} 376