src/mesa/drivers/x11/xfonts.c

   1
   2 /*
   3  * Mesa 3-D graphics library
   4  * Version:  3.5
   5  *
   6  * Copyright (C) 1999-2000  Brian Paul   All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /* xfonts.c -- glXUseXFont() for Mesa written by
  28  * Copyright (C) 1995 Thorsten.Ohl @ Physik.TH-Darmstadt.de
  29  */
  30
  31 #ifdef __VMS
  32 #include <GL/vms_x_fix.h>
  33 #endif
  34
  35 #include "glxheader.h"
  36 #include "main/context.h"
  37 #include "main/imports.h"
  38 #include "xfonts.h"
  39
  40
  41 /* Some debugging info.  */
  42
  43 #ifdef DEBUG
  44 #undef _R
  45 #undef _G
  46 #undef _B
  47 #include <ctype.h>
  48
  49 int debug_xfonts = 0;
  50
  51 static void
  52 dump_char_struct(XCharStruct * ch, char *prefix)
  53 {
  54    printf("%slbearing = %d, rbearing = %d, width = %d\n",
  55           prefix, ch->lbearing, ch->rbearing, ch->width);
  56    printf("%sascent = %d, descent = %d, attributes = %u\n",
  57           prefix, ch->ascent, ch->descent, (unsigned int) ch->attributes);
  58 }
  59
  60 static void
  61 dump_font_struct(XFontStruct * font)
  62 {
  63    printf("ascent = %d, descent = %d\n", font->ascent, font->descent);
  64    printf("char_or_byte2 = (%u,%u)\n",
  65           font->min_char_or_byte2, font->max_char_or_byte2);
  66    printf("byte1 = (%u,%u)\n", font->min_byte1, font->max_byte1);
  67    printf("all_chars_exist = %s\n", font->all_chars_exist ? "True" : "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       char prefix[8];
  76       sprintf(prefix, "%d> ", c);
  77       dump_char_struct(&font->per_char[c], prefix);
  78    }
  79 #endif
  80 }
  81
  82 static void
  83 dump_bitmap(unsigned int width, unsigned int height, GLubyte * bitmap)
  84 {
  85    unsigned int x, y;
  86
  87    printf("    ");
  88    for (x = 0; x < 8 * width; x++)
  89       printf("%o", 7 - (x % 8));
  90    putchar('\n');
  91    for (y = 0; y < height; y++) {
  92       printf("%3o:", y);
  93       for (x = 0; x < 8 * width; x++)
  94          putchar((bitmap[width * (height - y - 1) + x / 8] & (1 << (7 - (x %
  95                                                                          8))))
  96                  ? '*' : '.');
  97       printf("   ");
  98       for (x = 0; x < width; x++)
  99          printf("0x%02x, ", bitmap[width * (height - y - 1) + x]);
 100       putchar('\n');
 101    }
 102 }
 103 #endif /* DEBUG */
 104
 105
 106 /* Implementation.  */
 107
 108 /* Fill a BITMAP with a character C from thew current font
 109    in the graphics context GC.  WIDTH is the width in bytes
 110    and HEIGHT is the height in bits.
 111
 112    Note that the generated bitmaps must be used with
 113
 114         glPixelStorei (GL_UNPACK_SWAP_BYTES, GL_FALSE);
 115         glPixelStorei (GL_UNPACK_LSB_FIRST, GL_FALSE);
 116         glPixelStorei (GL_UNPACK_ROW_LENGTH, 0);
 117         glPixelStorei (GL_UNPACK_SKIP_ROWS, 0);
 118         glPixelStorei (GL_UNPACK_SKIP_PIXELS, 0);
 119         glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
 120
 121    Possible optimizations:
 122
 123      * use only one reusable pixmap with the maximum dimensions.
 124      * draw the entire font into a single pixmap (careful with
 125        proportional fonts!).
 126 */
 127
 128
 129 /*
 130  * Generate OpenGL-compatible bitmap.
 131  */
 132 static void
 133 fill_bitmap(Display * dpy, Window win, GC gc,
 134             unsigned int width, unsigned int height,
 135             int x0, int y0, unsigned int c, GLubyte * bitmap)
 136 {
 137    XImage *image;
 138    unsigned int x, y;
 139    Pixmap pixmap;
 140    XChar2b char2b;
 141
 142    pixmap = XCreatePixmap(dpy, win, 8 * width, height, 1);
 143    XSetForeground(dpy, gc, 0);
 144    XFillRectangle(dpy, pixmap, gc, 0, 0, 8 * width, height);
 145    XSetForeground(dpy, gc, 1);
 146
 147    char2b.byte1 = (c >> 8) & 0xff;
 148    char2b.byte2 = (c & 0xff);
 149
 150    XDrawString16(dpy, pixmap, gc, x0, y0, &char2b, 1);
 151
 152    image = XGetImage(dpy, pixmap, 0, 0, 8 * width, height, 1, XYPixmap);
 153    if (image) {
 154       /* Fill the bitmap (X11 and OpenGL are upside down wrt each other).  */
 155       for (y = 0; y < height; y++)
 156          for (x = 0; x < 8 * width; x++)
 157             if (XGetPixel(image, x, y))
 158                bitmap[width * (height - y - 1) + x / 8] |=
 159                   (1 << (7 - (x % 8)));
 160       XDestroyImage(image);
 161    }
 162
 163    XFreePixmap(dpy, pixmap);
 164 }
 165
 166 /*
 167  * determine if a given glyph is valid and return the
 168  * corresponding XCharStruct.
 169  */
 170 static XCharStruct *
 171 isvalid(XFontStruct * fs, unsigned int which)
 172 {
 173    unsigned int rows, pages;
 174    unsigned 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) || (fs->max_char_or_byte2 < which))
 183          valid = 0;
 184    }
 185    else {
 186       /* "matrix" fonts */
 187       byte2 = which & 0xff;
 188       byte1 = which >> 8;
 189       if ((fs->min_char_or_byte2 > byte2) ||
 190           (fs->max_char_or_byte2 < byte2) ||
 191           (fs->min_byte1 > byte1) || (fs->max_byte1 < byte1))
 192          valid = 0;
 193    }
 194
 195    if (valid) {
 196       if (fs->per_char) {
 197          if (rows == 1) {
 198             /* "linear" fonts */
 199             return (fs->per_char + (which - fs->min_char_or_byte2));
 200          }
 201          else {
 202             /* "matrix" fonts */
 203             i = ((byte1 - fs->min_byte1) * pages) +
 204                (byte2 - fs->min_char_or_byte2);
 205             return (fs->per_char + i);
 206          }
 207       }
 208       else {
 209          return (&fs->min_bounds);
 210       }
 211    }
 212    return (NULL);
 213 }
 214
 215
 216 void
 217 Fake_glXUseXFont(Font font, int first, int count, int listbase)
 218 {
 219    Display *dpy;
 220    Window win;
 221    Pixmap pixmap;
 222    GC gc;
 223    XGCValues values;
 224    unsigned long valuemask;
 225    XFontStruct *fs;
 226    GLint swapbytes, lsbfirst, rowlength;
 227    GLint skiprows, skippixels, alignment;
 228    unsigned int max_width, max_height, max_bm_width, max_bm_height;
 229    GLubyte *bm;
 230    int i;
 231
 232    dpy = glXGetCurrentDisplay();
 233    if (!dpy)
 234       return;                   /* I guess glXMakeCurrent wasn't called */
 235    win = RootWindow(dpy, DefaultScreen(dpy));
 236
 237    fs = XQueryFont(dpy, font);
 238    if (!fs) {
 239       _mesa_error(NULL, GL_INVALID_VALUE,
 240                   "Couldn't get font structure information");
 241       return;
 242    }
 243
 244    /* Allocate a bitmap that can fit all characters.  */
 245    max_width = fs->max_bounds.rbearing - fs->min_bounds.lbearing;
 246    max_height = fs->max_bounds.ascent + fs->max_bounds.descent;
 247    max_bm_width = (max_width + 7) / 8;
 248    max_bm_height = max_height;
 249
 250    bm = (GLubyte *) malloc((max_bm_width * max_bm_height) * sizeof(GLubyte));
 251    if (!bm) {
 252       XFreeFontInfo(NULL, fs, 1);
 253       _mesa_error(NULL, GL_OUT_OF_MEMORY,
 254                   "Couldn't allocate bitmap in glXUseXFont()");
 255       return;
 256    }
 257
 258 #if 0
 259    /* get the page info */
 260    pages = fs->max_char_or_byte2 - fs->min_char_or_byte2 + 1;
 261    firstchar = (fs->min_byte1 << 8) + fs->min_char_or_byte2;
 262    lastchar = (fs->max_byte1 << 8) + fs->max_char_or_byte2;
 263    rows = fs->max_byte1 - fs->min_byte1 + 1;
 264    unsigned int first_char, last_char, pages, rows;
 265 #endif
 266
 267    /* Save the current packing mode for bitmaps.  */
 268    glGetIntegerv(GL_UNPACK_SWAP_BYTES, &swapbytes);
 269    glGetIntegerv(GL_UNPACK_LSB_FIRST, &lsbfirst);
 270    glGetIntegerv(GL_UNPACK_ROW_LENGTH, &rowlength);
 271    glGetIntegerv(GL_UNPACK_SKIP_ROWS, &skiprows);
 272    glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &skippixels);
 273    glGetIntegerv(GL_UNPACK_ALIGNMENT, &alignment);
 274
 275    /* Enforce a standard packing mode which is compatible with
 276       fill_bitmap() from above.  This is actually the default mode,
 277       except for the (non)alignment.  */
 278    glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE);
 279    glPixelStorei(GL_UNPACK_LSB_FIRST, GL_FALSE);
 280    glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 281    glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
 282    glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
 283    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 284
 285    pixmap = XCreatePixmap(dpy, win, 10, 10, 1);
 286    values.foreground = BlackPixel(dpy, DefaultScreen(dpy));
 287    values.background = WhitePixel(dpy, DefaultScreen(dpy));
 288    values.font = fs->fid;
 289    valuemask = GCForeground | GCBackground | GCFont;
 290    gc = XCreateGC(dpy, pixmap, valuemask, &values);
 291    XFreePixmap(dpy, pixmap);
 292
 293 #ifdef DEBUG
 294    if (debug_xfonts)
 295       dump_font_struct(fs);
 296 #endif
 297
 298    for (i = 0; i < count; i++) {
 299       unsigned int width, height, bm_width, bm_height;
 300       GLfloat x0, y0, dx, dy;
 301       XCharStruct *ch;
 302       int x, y;
 303       unsigned int c = first + i;
 304       int list = listbase + i;
 305       int valid;
 306
 307       /* check on index validity and get the bounds */
 308       ch = isvalid(fs, c);
 309       if (!ch) {
 310          ch = &fs->max_bounds;
 311          valid = 0;
 312       }
 313       else {
 314          valid = 1;
 315       }
 316
 317 #ifdef DEBUG
 318       if (debug_xfonts) {
 319          char s[7];
 320          sprintf(s, isprint(c) ? "%c> " : "\\%03o> ", c);
 321          dump_char_struct(ch, s);
 322       }
 323 #endif
 324
 325       /* glBitmap()' parameters:
 326          straight from the glXUseXFont(3) manpage.  */
 327       width = ch->rbearing - ch->lbearing;
 328       height = ch->ascent + ch->descent;
 329       x0 = -ch->lbearing;
 330       y0 = ch->descent - 0;     /* XXX used to subtract 1 here */
 331       /* but that caused a conformace failure */
 332       dx = ch->width;
 333       dy = 0;
 334
 335       /* X11's starting point.  */
 336       x = -ch->lbearing;
 337       y = ch->ascent;
 338
 339       /* Round the width to a multiple of eight.  We will use this also
 340          for the pixmap for capturing the X11 font.  This is slightly
 341          inefficient, but it makes the OpenGL part real easy.  */
 342       bm_width = (width + 7) / 8;
 343       bm_height = height;
 344
 345       glNewList(list, GL_COMPILE);
 346       if (valid && (bm_width > 0) && (bm_height > 0)) {
 347
 348          memset(bm, '\0', bm_width * bm_height);
 349          fill_bitmap(dpy, win, gc, bm_width, bm_height, x, y, c, bm);
 350
 351          glBitmap(width, height, x0, y0, dx, dy, bm);
 352 #ifdef DEBUG
 353          if (debug_xfonts) {
 354             printf("width/height = %u/%u\n", width, height);
 355             printf("bm_width/bm_height = %u/%u\n", bm_width, bm_height);
 356             dump_bitmap(bm_width, bm_height, bm);
 357          }
 358 #endif
 359       }
 360       else {
 361          glBitmap(0, 0, 0.0, 0.0, dx, dy, NULL);
 362       }
 363       glEndList();
 364    }
 365
 366    free(bm);
 367    XFreeFontInfo(NULL, fs, 1);
 368    XFreeGC(dpy, gc);
 369
 370    /* Restore saved packing modes.  */
 371    glPixelStorei(GL_UNPACK_SWAP_BYTES, swapbytes);
 372    glPixelStorei(GL_UNPACK_LSB_FIRST, lsbfirst);
 373    glPixelStorei(GL_UNPACK_ROW_LENGTH, rowlength);
 374    glPixelStorei(GL_UNPACK_SKIP_ROWS, skiprows);
 375    glPixelStorei(GL_UNPACK_SKIP_PIXELS, skippixels);
 376    glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
 377 }