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