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/* $Id: xfonts.c,v 1.8 1997/05/24 12:11:25 brianp Exp $ */
/* xfonts.c -- glXUseXFont() for Mesa
Copyright (C) 1995 Thorsten.Ohl @ Physik.TH-Darmstadt.de
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* $Log: xfonts.c,v $
* Revision 1.8 1997/05/24 12:11:25 brianp
* renamed glXUseXFont() to Fake_glXUseXFont()
*
* Revision 1.7 1997/03/13 03:14:34 brianp
* removed unused variable 'c' from dump_font_struct()
*
* Revision 1.6 1996/11/20 03:05:14 brianp
* added #include "GL/glx.h"
*
* Revision 1.5 1996/10/22 01:02:46 brianp
* call XFreeFontInfo instead of XFreeFont (again)
*
* Revision 1.4 1996/10/09 03:07:42 brianp
* replaced XFreeFontInfo with XFreeFont
*
* Revision 1.3 1996/09/19 03:41:48 brianp
* updated for new X/Mesa changes
*
* Revision 1.2 1996/09/15 01:50:05 brianp
* fixed #includes
*
* Revision 1.1 1996/09/13 01:38:16 brianp
* Initial revision
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include "GL/gl.h"
#include "GL/glx.h"
#include "GL/xmesa.h"
#include "macros.h"
/* Some debugging info. */
#ifdef DEBUG
#include <ctype.h>
int debug_xfonts = 0;
static void
dump_char_struct (XCharStruct *ch, char *prefix)
{
printf ("%slbearing = %d, rbearing = %d, width = %d\n",
prefix, ch->lbearing, ch->rbearing, ch->width);
printf ("%sascent = %d, descent = %d, attributes = %u\n",
prefix, ch->ascent, ch->descent, ch->attributes);
}
static void
dump_font_struct (XFontStruct *font)
{
printf ("ascent = %d, descent = %d\n", font->ascent, font->descent);
printf ("char_or_byte2 = (%d,%d)\n",
font->min_char_or_byte2, font->max_char_or_byte2);
printf ("byte1 = (%d,%d)\n", font->min_byte1, font->max_byte1);
printf ("all_chars_exist = %s\n", font->all_chars_exist ? "True" : "False");
printf ("default_char = %c (\\%03o)\n",
isprint (font->default_char) ? font->default_char : ' ',
font->default_char);
dump_char_struct (&font->min_bounds, "min> ");
dump_char_struct (&font->max_bounds, "max> ");
#if 0
for (c = font->min_char_or_byte2; c <= font->max_char_or_byte2; c++)
{
char prefix[8];
sprintf (prefix, "%d> ", c);
dump_char_struct (&font->per_char[c], prefix);
}
#endif
}
static void
dump_bitmap (unsigned int width, unsigned int height, GLubyte *bitmap)
{
int x, y;
printf (" ");
for (x = 0; x < 8*width; x++)
printf ("%o", 7 - (x % 8));
putchar ('\n');
for (y = 0; y < height; y++)
{
printf ("%3o:", y);
for (x = 0; x < 8*width; x++)
putchar ((bitmap[width*(height - y - 1) + x/8] & (1 << (7 - (x % 8))))
? '*' : '.');
printf (" ");
for (x = 0; x < width; x++)
printf ("0x%02x, ", bitmap[width*(height - y - 1) + x]);
putchar ('\n');
}
}
#endif /* DEBUG */
/* Implementation. */
/* Fill a BITMAP with a character C from thew current font
in the graphics context GC. WIDTH is the width in bytes
and HEIGHT is the height in bits.
Note that the generated bitmaps must be used with
glPixelStorei (GL_UNPACK_SWAP_BYTES, GL_FALSE);
glPixelStorei (GL_UNPACK_LSB_FIRST, GL_FALSE);
glPixelStorei (GL_UNPACK_ROW_LENGTH, 0);
glPixelStorei (GL_UNPACK_SKIP_ROWS, 0);
glPixelStorei (GL_UNPACK_SKIP_PIXELS, 0);
glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
Possible optimizations:
* use only one reusable pixmap with the maximum dimensions.
* draw the entire font into a single pixmap (careful with
proportional fonts!).
*/
static void
fill_bitmap (Display *dpy, Window win, GC gc,
unsigned int width, unsigned int height,
int x0, int y0, char c, GLubyte *bitmap)
{
XImage *image;
int x, y;
Pixmap pixmap;
pixmap = XCreatePixmap (dpy, win, 8*width, height, 1);
XSetForeground(dpy, gc, 0);
XFillRectangle (dpy, pixmap, gc, 0, 0, 8*width, height);
XSetForeground(dpy, gc, 1);
XDrawString (dpy, pixmap, gc, x0, y0, &c, 1);
image = XGetImage (dpy, pixmap, 0, 0, 8*width, height, 1, XYPixmap);
/* Fill the bitmap (X11 and OpenGL are upside down wrt each other). */
for (y = 0; y < height; y++)
for (x = 0; x < 8*width; x++)
if (XGetPixel (image, x, y))
bitmap[width*(height - y - 1) + x/8] |= (1 << (7 - (x % 8)));
XFreePixmap (dpy, pixmap);
XDestroyImage (image);
}
#include "xmesaP.h"
#include "context.h"
#include "fakeglx.h"
void Fake_glXUseXFont( Font font, int first, int count, int listbase )
{
XMesaContext CC;
Display *dpy;
Window win;
Pixmap pixmap;
GC gc;
XGCValues values;
unsigned long valuemask;
XFontStruct *fs;
GLint swapbytes, lsbfirst, rowlength;
GLint skiprows, skippixels, alignment;
unsigned int max_width, max_height, max_bm_width, max_bm_height;
GLubyte *bm;
int i;
CC = XMesaGetCurrentContext();
dpy = CC->display;
win = CC->xm_buffer->frontbuffer;
fs = XQueryFont (dpy, font);
if (!fs)
{
gl_error (CC->gl_ctx, GL_INVALID_VALUE,
"Couldn't get font structure information");
return;
}
/* Allocate a bitmap that can fit all characters. */
max_width = fs->max_bounds.rbearing - fs->min_bounds.lbearing;
max_height = fs->max_bounds.ascent + fs->max_bounds.descent;
max_bm_width = (max_width + 7) / 8;
max_bm_height = max_height;
bm = (GLubyte *) malloc ((max_bm_width * max_bm_height) * sizeof (GLubyte));
if (!bm)
{
gl_error (CC->gl_ctx, GL_OUT_OF_MEMORY,
"Couldn't allocate bitmap in glXUseXFont()");
return;
}
/* Save the current packing mode for bitmaps. */
glGetIntegerv (GL_UNPACK_SWAP_BYTES, &swapbytes);
glGetIntegerv (GL_UNPACK_LSB_FIRST, &lsbfirst);
glGetIntegerv (GL_UNPACK_ROW_LENGTH, &rowlength);
glGetIntegerv (GL_UNPACK_SKIP_ROWS, &skiprows);
glGetIntegerv (GL_UNPACK_SKIP_PIXELS, &skippixels);
glGetIntegerv (GL_UNPACK_ALIGNMENT, &alignment);
/* Enforce a standard packing mode which is compatible with
fill_bitmap() from above. This is actually the default mode,
except for the (non)alignment. */
glPixelStorei (GL_UNPACK_SWAP_BYTES, GL_FALSE);
glPixelStorei (GL_UNPACK_LSB_FIRST, GL_FALSE);
glPixelStorei (GL_UNPACK_ROW_LENGTH, 0);
glPixelStorei (GL_UNPACK_SKIP_ROWS, 0);
glPixelStorei (GL_UNPACK_SKIP_PIXELS, 0);
glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
pixmap = XCreatePixmap (dpy, win, 10, 10, 1);
values.foreground = BlackPixel (dpy, DefaultScreen (dpy));
values.background = WhitePixel (dpy, DefaultScreen (dpy));
values.font = fs->fid;
valuemask = GCForeground | GCBackground | GCFont;
gc = XCreateGC (dpy, pixmap, valuemask, &values);
XFreePixmap (dpy, pixmap);
#ifdef DEBUG
if (debug_xfonts)
dump_font_struct (fs);
#endif
for (i = 0; i < count; i++)
{
unsigned int width, height, bm_width, bm_height;
GLfloat x0, y0, dx, dy;
XCharStruct *ch;
int x, y;
int c = first + i;
int list = listbase + i;
if (fs->per_char
&& (c >= fs->min_char_or_byte2) && (c <= fs->max_char_or_byte2))
ch = &fs->per_char[c-fs->min_char_or_byte2];
else
ch = &fs->max_bounds;
#ifdef DEBUG
if (debug_xfonts)
{
char s[7];
sprintf (s, isprint (c) ? "%c> " : "\\%03o> ", c);
dump_char_struct (ch, s);
}
#endif
/* glBitmap()' parameters:
straight from the glXUseXFont(3) manpage. */
width = ch->rbearing - ch->lbearing;
height = ch->ascent + ch->descent;
x0 = - ch->lbearing;
y0 = ch->descent - 1;
dx = ch->width;
dy = 0;
/* X11's starting point. */
x = - ch->lbearing;
y = ch->ascent;
/* Round the width to a multiple of eight. We will use this also
for the pixmap for capturing the X11 font. This is slightly
inefficient, but it makes the OpenGL part real easy. */
bm_width = (width + 7) / 8;
bm_height = height;
glNewList (list, GL_COMPILE);
if ((c >= fs->min_char_or_byte2) && (c <= fs->max_char_or_byte2)
&& (bm_width > 0) && (bm_height > 0))
{
MEMSET (bm, '\0', bm_width * bm_height);
fill_bitmap (dpy, win, gc, bm_width, bm_height, x, y, c, bm);
glBitmap (width, height, x0, y0, dx, dy, bm);
#ifdef DEBUG
if (debug_xfonts)
{
printf ("width/height = %d/%d\n", width, height);
printf ("bm_width/bm_height = %d/%d\n", bm_width, bm_height);
dump_bitmap (bm_width, bm_height, bm);
}
#endif
}
else
glBitmap (0, 0, 0.0, 0.0, dx, dy, NULL);
glEndList ();
}
free (bm);
XFreeFontInfo( NULL, fs, 0 );
XFreeGC (dpy, gc);
/* Restore saved packing modes. */
glPixelStorei(GL_UNPACK_SWAP_BYTES, swapbytes);
glPixelStorei(GL_UNPACK_LSB_FIRST, lsbfirst);
glPixelStorei(GL_UNPACK_ROW_LENGTH, rowlength);
glPixelStorei(GL_UNPACK_SKIP_ROWS, skiprows);
glPixelStorei(GL_UNPACK_SKIP_PIXELS, skippixels);
glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
}
/* The End. */
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