src/glx/x11/xfont.c

   1 /* -*- mode: c; tab-width: 3; indent-tabs-mode: nil; c-basic-offset: 3; coding: utf-8-unix -*- */
   2 /*
   3  * Mesa 3-D graphics library
   4  * Version:  3.1
   5  *
   6  * Copyright (C) 1999  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 /*
  32   This was take from Mesa and modified to work in the real GLX structure.
  33   It provides a fully client side implementation of glXUseXFont and is
  34   called by that routine when direct rendering is enabled.
  35 */
  36
  37 #ifdef GLX_DIRECT_RENDERING
  38
  39 #include "glxclient.h"
  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, 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) || (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 _X_HIDDEN void
 216 DRI_glXUseXFont(Font font, int first, int count, int listbase)
 217 {
 218    GLXContext CC;
 219    Display *dpy;
 220    Window win;
 221    Pixmap pixmap;
 222    GC gc;
 223    XGCValues values;
 224    unsigned long valuemask;
 225    XFontStruct *fs;
 226
 227    GLint swapbytes, lsbfirst, rowlength;
 228    GLint skiprows, skippixels, alignment;
 229
 230    unsigned int max_width, max_height, max_bm_width, max_bm_height;
 231    GLubyte *bm;
 232
 233    int i;
 234
 235    CC = __glXGetCurrentContext();
 236    dpy = CC->currentDpy;
 237    win = CC->currentDrawable;
 238
 239    fs = XQueryFont(dpy, font);
 240    if (!fs) {
 241       __glXSetError(CC, GL_INVALID_VALUE);
 242       return;
 243    }
 244
 245    /* Allocate a bitmap that can fit all characters.  */
 246    max_width = fs->max_bounds.rbearing - fs->min_bounds.lbearing;
 247    max_height = fs->max_bounds.ascent + fs->max_bounds.descent;
 248    max_bm_width = (max_width + 7) / 8;
 249    max_bm_height = max_height;
 250
 251    bm = (GLubyte *) Xmalloc((max_bm_width * max_bm_height) * sizeof(GLubyte));
 252    if (!bm) {
 253       XFreeFontInfo(NULL, fs, 1);
 254       __glXSetError(CC, GL_OUT_OF_MEMORY);
 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 - 1;
 331       dx = ch->width;
 332       dy = 0;
 333
 334       /* X11's starting point.  */
 335       x = -ch->lbearing;
 336       y = ch->ascent;
 337
 338       /* Round the width to a multiple of eight.  We will use this also
 339          for the pixmap for capturing the X11 font.  This is slightly
 340          inefficient, but it makes the OpenGL part real easy.  */
 341       bm_width = (width + 7) / 8;
 342       bm_height = height;
 343
 344       glNewList(list, GL_COMPILE);
 345       if (valid && (bm_width > 0) && (bm_height > 0)) {
 346
 347          memset(bm, '\0', bm_width * bm_height);
 348          fill_bitmap(dpy, win, gc, bm_width, bm_height, x, y, c, bm);
 349
 350          glBitmap(width, height, x0, y0, dx, dy, bm);
 351 #ifdef DEBUG
 352          if (debug_xfonts) {
 353             printf("width/height = %u/%u\n", width, height);
 354             printf("bm_width/bm_height = %u/%u\n", bm_width, bm_height);
 355             dump_bitmap(bm_width, bm_height, bm);
 356          }
 357 #endif
 358       }
 359       else {
 360          glBitmap(0, 0, 0.0, 0.0, dx, dy, NULL);
 361       }
 362       glEndList();
 363    }
 364
 365    Xfree(bm);
 366    XFreeFontInfo(NULL, fs, 1);
 367    XFreeGC(dpy, gc);
 368
 369    /* Restore saved packing modes.  */
 370    glPixelStorei(GL_UNPACK_SWAP_BYTES, swapbytes);
 371    glPixelStorei(GL_UNPACK_LSB_FIRST, lsbfirst);
 372    glPixelStorei(GL_UNPACK_ROW_LENGTH, rowlength);
 373    glPixelStorei(GL_UNPACK_SKIP_ROWS, skiprows);
 374    glPixelStorei(GL_UNPACK_SKIP_PIXELS, skippixels);
 375    glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
 376 }
 377
 378 #endif