src/glx/x11/xfont.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  3.1
   4  *
   5  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /* xfonts.c -- glXUseXFont() for Mesa written by
  27  * Copyright (C) 1995 Thorsten.Ohl @ Physik.TH-Darmstadt.de
  28  */
  29
  30 /*
  31   This was take from Mesa and modified to work in the real GLX structure.
  32   It provides a fully client side implementation of glXUseXFont and is
  33   called by that routine when direct rendering is enabled.
  34 */
  35
  36 #ifdef GLX_DIRECT_RENDERING
  37
  38 #include "glxclient.h"
  39
  40 /* Some debugging info.  */
  41
  42 #ifdef DEBUG
  43 #undef _R
  44 #undef _G
  45 #undef _B
  46 #include <ctype.h>
  47
  48 int debug_xfonts = 0;
  49
  50 static void
  51 dump_char_struct (XCharStruct *ch, char *prefix)
  52 {
  53   printf ("%slbearing = %d, rbearing = %d, width = %d\n",
  54           prefix, ch->lbearing, ch->rbearing, ch->width);
  55   printf ("%sascent = %d, descent = %d, attributes = %u\n",
  56           prefix, ch->ascent, ch->descent, (unsigned int) ch->attributes);
  57 }
  58
  59 static void
  60 dump_font_struct (XFontStruct *font)
  61 {
  62   printf ("ascent = %d, descent = %d\n", font->ascent, font->descent);
  63   printf ("char_or_byte2 = (%u,%u)\n",
  64           font->min_char_or_byte2, font->max_char_or_byte2);
  65   printf ("byte1 = (%u,%u)\n", font->min_byte1, font->max_byte1);
  66   printf ("all_chars_exist = %s\n", font->all_chars_exist ? "True" :
  67 "False");
  68   printf ("default_char = %c (\\%03o)\n",
  69           (char) (isprint (font->default_char) ? font->default_char : ' '),
  70           font->default_char);
  71   dump_char_struct (&font->min_bounds, "min> ");
  72   dump_char_struct (&font->max_bounds, "max> ");
  73 #if 0
  74   for (c = font->min_char_or_byte2; c <= font->max_char_or_byte2; c++)
  75     {
  76       char prefix[8];
  77       sprintf (prefix, "%d> ", c);
  78       dump_char_struct (&font->per_char[c], prefix);
  79     }
  80 #endif
  81 }
  82
  83 static void
  84 dump_bitmap (unsigned int width, unsigned int height, GLubyte *bitmap)
  85 {
  86   unsigned int x, y;
  87
  88   printf ("    ");
  89   for (x = 0; x < 8*width; x++)
  90     printf ("%o", 7 - (x % 8));
  91   putchar ('\n');
  92   for (y = 0; y < height; y++)
  93     {
  94       printf ("%3o:", y);
  95       for (x = 0; x < 8*width; x++)
  96         putchar ((bitmap[width*(height - y - 1) + x/8] & (1 << (7 - (x %
  97 8))))
  98                  ? '*' : '.');
  99       printf ("   ");
 100       for (x = 0; x < width; x++)
 101         printf ("0x%02x, ", bitmap[width*(height - y - 1) + x]);
 102       putchar ('\n');
 103     }
 104 }
 105 #endif /* DEBUG */
 106
 107
 108 /* Implementation.  */
 109
 110 /* Fill a BITMAP with a character C from thew current font
 111    in the graphics context GC.  WIDTH is the width in bytes
 112    and HEIGHT is the height in bits.
 113
 114    Note that the generated bitmaps must be used with
 115
 116         glPixelStorei (GL_UNPACK_SWAP_BYTES, GL_FALSE);
 117         glPixelStorei (GL_UNPACK_LSB_FIRST, GL_FALSE);
 118         glPixelStorei (GL_UNPACK_ROW_LENGTH, 0);
 119         glPixelStorei (GL_UNPACK_SKIP_ROWS, 0);
 120         glPixelStorei (GL_UNPACK_SKIP_PIXELS, 0);
 121         glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
 122
 123    Possible optimizations:
 124
 125      * use only one reusable pixmap with the maximum dimensions.
 126      * draw the entire font into a single pixmap (careful with
 127        proportional fonts!).
 128 */
 129
 130
 131 /*
 132  * Generate OpenGL-compatible bitmap.
 133  */
 134 static void
 135 fill_bitmap (Display *dpy, Window win, GC gc,
 136              unsigned int width, unsigned int height,
 137              int x0, int y0, unsigned int c, GLubyte *bitmap)
 138 {
 139   XImage *image;
 140   unsigned int x, y;
 141   Pixmap pixmap;
 142   XChar2b char2b;
 143
 144   pixmap = XCreatePixmap (dpy, win, 8*width, height, 1);
 145   XSetForeground(dpy, gc, 0);
 146   XFillRectangle (dpy, pixmap, gc, 0, 0, 8*width, height);
 147   XSetForeground(dpy, gc, 1);
 148
 149   char2b.byte1 = (c >> 8) & 0xff;
 150   char2b.byte2 = (c & 0xff);
 151
 152   XDrawString16 (dpy, pixmap, gc, x0, y0, &char2b, 1);
 153
 154   image = XGetImage (dpy, pixmap, 0, 0, 8*width, height, 1, XYPixmap);
 155   if (image) {
 156     /* Fill the bitmap (X11 and OpenGL are upside down wrt each other).  */
 157     for (y = 0; y < height; y++)
 158       for (x = 0; x < 8*width; x++)
 159         if (XGetPixel (image, x, y))
 160           bitmap[width*(height - y - 1) + x/8] |= (1 << (7 - (x % 8)));
 161     XDestroyImage (image);
 162   }
 163
 164   XFreePixmap (dpy, pixmap);
 165 }
 166
 167 /*
 168  * determine if a given glyph is valid and return the
 169  * corresponding XCharStruct.
 170  */
 171 static XCharStruct *isvalid(XFontStruct *fs, int which)
 172 {
 173   unsigned int  rows,pages;
 174   int           byte1 = 0, byte2 = 0;
 175   int           i,valid = 1;
 176
 177   rows = fs->max_byte1 - fs->min_byte1 + 1;
 178   pages = fs->max_char_or_byte2 - fs->min_char_or_byte2 + 1;
 179
 180   if (rows == 1) {
 181     /* "linear" fonts */
 182     if ((fs->min_char_or_byte2 > which) ||
 183         (fs->max_char_or_byte2 < which)) valid = 0;
 184   } else {
 185     /* "matrix" fonts */
 186     byte2 = which & 0xff;
 187     byte1 = which >> 8;
 188     if ((fs->min_char_or_byte2 > byte2) ||
 189         (fs->max_char_or_byte2 < byte2) ||
 190         (fs->min_byte1 > byte1) ||
 191         (fs->max_byte1 < byte1)) valid = 0;
 192   }
 193
 194   if (valid) {
 195     if (fs->per_char) {
 196       if (rows == 1) {
 197         /* "linear" fonts */
 198         return(fs->per_char + (which-fs->min_char_or_byte2) );
 199       } else {
 200         /* "matrix" fonts */
 201         i = ((byte1 - fs->min_byte1) * pages) +
 202              (byte2 - fs->min_char_or_byte2);
 203         return(fs->per_char + i);
 204       }
 205     } else {
 206         return(&fs->min_bounds);
 207     }
 208   }
 209   return(NULL);
 210 }
 211
 212 _X_HIDDEN void DRI_glXUseXFont( Font font, int first, int count, int listbase )
 213 {
 214   GLXContext CC;
 215   Display *dpy;
 216   Window win;
 217   Pixmap pixmap;
 218   GC gc;
 219   XGCValues values;
 220   unsigned long valuemask;
 221   XFontStruct *fs;
 222
 223   GLint swapbytes, lsbfirst, rowlength;
 224   GLint skiprows, skippixels, alignment;
 225
 226   unsigned int max_width, max_height, max_bm_width, max_bm_height;
 227   GLubyte *bm;
 228
 229   int i;
 230
 231   CC = __glXGetCurrentContext();
 232   dpy = CC->currentDpy;
 233   win = CC->currentDrawable;
 234
 235   fs = XQueryFont (dpy, font);
 236   if (!fs)
 237     {
 238       __glXSetError(CC, GL_INVALID_VALUE);
 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 *) Xmalloc((max_bm_width * max_bm_height) * sizeof
 249 (GLubyte));
 250   if (!bm) {
 251       XFreeFontInfo( NULL, fs, 1 );
 252       __glXSetError(CC, GL_OUT_OF_MEMORY);
 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     {
 298       unsigned int width, height, bm_width, bm_height;
 299       GLfloat x0, y0, dx, dy;
 300       XCharStruct *ch;
 301       int x, y;
 302       unsigned int c = first + i;
 303       int list = listbase + i;
 304       int valid;
 305
 306       /* check on index validity and get the bounds */
 307       ch = isvalid(fs, c);
 308       if (!ch) {
 309         ch = &fs->max_bounds;
 310         valid = 0;
 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 - 1;
 329       dx = ch->width;
 330       dy = 0;
 331
 332       /* X11's starting point.  */
 333       x = - ch->lbearing;
 334       y = ch->ascent;
 335
 336       /* Round the width to a multiple of eight.  We will use this also
 337          for the pixmap for capturing the X11 font.  This is slightly
 338          inefficient, but it makes the OpenGL part real easy.  */
 339       bm_width = (width + 7) / 8;
 340       bm_height = height;
 341
 342       glNewList (list, GL_COMPILE);
 343         if (valid && (bm_width > 0) && (bm_height > 0)) {
 344
 345             memset (bm, '\0', bm_width * bm_height);
 346             fill_bitmap (dpy, win, gc, bm_width, bm_height, x, y, c, bm);
 347
 348             glBitmap (width, height, x0, y0, dx, dy, bm);
 349 #ifdef DEBUG
 350             if (debug_xfonts) {
 351                 printf ("width/height = %u/%u\n", width, height);
 352                 printf ("bm_width/bm_height = %u/%u\n", bm_width,
 353 bm_height);
 354                 dump_bitmap (bm_width, bm_height, bm);
 355               }
 356 #endif
 357           } else {
 358             glBitmap (0, 0, 0.0, 0.0, dx, dy, NULL);
 359           }
 360       glEndList ();
 361     }
 362
 363   Xfree(bm);
 364   XFreeFontInfo( NULL, fs, 1 );
 365   XFreeGC (dpy, gc);
 366
 367   /* Restore saved packing modes.  */
 368   glPixelStorei(GL_UNPACK_SWAP_BYTES, swapbytes);
 369   glPixelStorei(GL_UNPACK_LSB_FIRST, lsbfirst);
 370   glPixelStorei(GL_UNPACK_ROW_LENGTH, rowlength);
 371   glPixelStorei(GL_UNPACK_SKIP_ROWS, skiprows);
 372   glPixelStorei(GL_UNPACK_SKIP_PIXELS, skippixels);
 373   glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
 374 }
 375
 376 #endif