struct texture_font_data {
Display *dpy;
XFontStruct *font;
- GLuint texid;
- int cell_width, cell_height;
- int tex_width, tex_height;
+ int cell_width, cell_height; /* maximal charcell */
+ int tex_width, tex_height; /* size of each texture */
+
+ int grid_mag; /* 1, 2, 4, or 8 */
+ int ntextures; /* 1, 4, 16, or 64 (grid_mag ^ 2) */
+
+ GLuint texid[32];
};
{
char msg[100];
- sprintf (msg, "%s (%d x %d)",
+ sprintf (msg, "texture font %s (%d x %d)",
mipmap_p ? "gluBuild2DMipmaps" : "glTexImage2D",
w2, h2);
check_gl_error (msg);
const char *def2 = "-*-times-bold-r-normal-*-180-*";
const char *def3 = "fixed";
XFontStruct *f;
+ int which;
+
+ check_gl_error ("stale texture font");
if (!res || !*res) abort();
if (!font) font = def1;
data->dpy = dpy;
data->font = f;
- /* Create a pixmap big enough to fit every character in the font.
- Make it square-ish, since GL likes dimensions to be powers of 2.
+ /* Figure out how many textures to use.
+ E.g., if we need 1024x1024 bits, use four 512x512 textures,
+ to be gentle to machines with low texture size limits.
*/
{
- Screen *screen = DefaultScreenOfDisplay (dpy);
- Window root = RootWindowOfScreen (screen);
- XGCValues gcv;
- GC gc;
- Pixmap p;
- int cw = f->max_bounds.rbearing - f->min_bounds.lbearing;
- int ch = f->max_bounds.ascent + f->max_bounds.descent;
- int w = cw * 16;
- int h = ch * 16;
- int i;
-
- data->cell_width = cw;
- data->cell_height = ch;
-
- p = XCreatePixmap (dpy, root, w, h, 1);
- gcv.font = f->fid;
- gcv.foreground = 0;
- gcv.background = 0;
- gc = XCreateGC (dpy, p, (GCFont|GCForeground|GCBackground), &gcv);
- XFillRectangle (dpy, p, gc, 0, 0, w, h);
- XSetForeground (dpy, gc, 1);
- for (i = 0; i < 256; i++)
- {
- char c = (char) i;
- int x = (i % 16) * cw;
- int y = (i / 16) * ch;
-
- /* See comment in print_texture_string for bit layout explanation. */
-
- int lbearing = (f->per_char
- ? f->per_char[i - f->min_char_or_byte2].lbearing
- : f->min_bounds.lbearing);
- int ascent = (f->per_char
- ? f->per_char[i - f->min_char_or_byte2].ascent
- : f->max_bounds.ascent);
- int width = (f->per_char
- ? f->per_char[i - f->min_char_or_byte2].width
- : f->max_bounds.width);
-
- if (width == 0) continue;
- XDrawString (dpy, p, gc, x - lbearing, y + ascent, &c, 1);
- }
- XFreeGC (dpy, gc);
+ int w = to_pow2 (16 * (f->max_bounds.rbearing - f->min_bounds.lbearing));
+ int h = to_pow2 (16 * (f->max_bounds.ascent + f->max_bounds.descent));
+ int i = (w > h ? w : h);
+
+ if (i <= 512) data->grid_mag = 1; /* 1 tex of 16x16 chars */
+ else if (i <= 1024) data->grid_mag = 2; /* 4 tex of 8x8 chars */
+ else if (i <= 2048) data->grid_mag = 4; /* 16 tex of 4x4 chars */
+ else data->grid_mag = 8; /* 32 tex of 2x2 chars */
+
+ data->ntextures = data->grid_mag * data->grid_mag;
+
+# if 0
+ fprintf (stderr,
+ "%s: %dx%d grid of %d textures of %dx%d chars (%dx%d bits)\n",
+ progname,
+ data->grid_mag, data->grid_mag,
+ data->ntextures,
+ 16 / data->grid_mag, 16 / data->grid_mag,
+ i, i);
+# endif
+ }
+
+ for (which = 0; which < data->ntextures; which++)
+ {
+ /* Create a pixmap big enough to fit every character in the font.
+ (modulo the "ntextures" scaling.)
+ Make it square-ish, since GL likes dimensions to be powers of 2.
+ */
+ Screen *screen = DefaultScreenOfDisplay (dpy);
+ Window root = RootWindowOfScreen (screen);
+ XGCValues gcv;
+ GC gc;
+ Pixmap p;
+ int cw = f->max_bounds.rbearing - f->min_bounds.lbearing;
+ int ch = f->max_bounds.ascent + f->max_bounds.descent;
+ int grid_size = (16 / data->grid_mag);
+ int w = cw * grid_size;
+ int h = ch * grid_size;
+ int i;
+
+ data->cell_width = cw;
+ data->cell_height = ch;
+
+ p = XCreatePixmap (dpy, root, w, h, 1);
+ gcv.font = f->fid;
+ gcv.foreground = 0;
+ gcv.background = 0;
+ gc = XCreateGC (dpy, p, (GCFont|GCForeground|GCBackground), &gcv);
+ XFillRectangle (dpy, p, gc, 0, 0, w, h);
+ XSetForeground (dpy, gc, 1);
+ for (i = 0; i < 256 / data->ntextures; i++)
+ {
+ int ii = (i + (which * 256 / data->ntextures));
+ char c = (char) ii;
+ int x = (i % grid_size) * cw;
+ int y = (i / grid_size) * ch;
- glGenTextures (1, &data->texid);
- glBindTexture (GL_TEXTURE_2D, data->texid);
- data->tex_width = w;
- data->tex_height = h;
+ /* See comment in print_texture_string for bit layout explanation.
+ */
+ int lbearing = (f->per_char
+ ? f->per_char[ii - f->min_char_or_byte2].lbearing
+ : f->min_bounds.lbearing);
+ int ascent = (f->per_char
+ ? f->per_char[ii - f->min_char_or_byte2].ascent
+ : f->max_bounds.ascent);
+ int width = (f->per_char
+ ? f->per_char[ii - f->min_char_or_byte2].width
+ : f->max_bounds.width);
+
+ if (width == 0) continue;
+ XDrawString (dpy, p, gc, x - lbearing, y + ascent, &c, 1);
+ }
+ XFreeGC (dpy, gc);
+
+ glGenTextures (1, &data->texid[which]);
+ glBindTexture (GL_TEXTURE_2D, data->texid[which]);
+ check_gl_error ("texture font load");
+ data->tex_width = w;
+ data->tex_height = h;
#if 0 /* debugging: splat the bitmap onto the desktop root window */
- {
- Window win = RootWindow (dpy, 0);
- GC gc2 = XCreateGC (dpy, win, 0, &gcv);
- XSetForeground (dpy, gc2, BlackPixel (dpy, 0));
- XSetBackground (dpy, gc2, WhitePixel (dpy, 0));
- XCopyPlane (dpy, p, win, gc2, 0, 0, w, h, 0, 0, 1);
- XFreeGC (dpy, gc2);
- XSync(dpy, False);
- }
+ {
+ Window win = RootWindow (dpy, 0);
+ GC gc2 = XCreateGC (dpy, win, 0, &gcv);
+ XSetForeground (dpy, gc2, BlackPixel (dpy, 0));
+ XSetBackground (dpy, gc2, WhitePixel (dpy, 0));
+ XCopyPlane (dpy, p, win, gc2, 0, 0, w, h, 0, 0, 1);
+ XFreeGC (dpy, gc2);
+ XSync(dpy, False);
+ usleep (100000);
+ }
#endif
- bitmap_to_texture (dpy, p, &data->tex_width, &data->tex_height);
- XFreePixmap (dpy, p);
- }
+ bitmap_to_texture (dpy, p, &data->tex_width, &data->tex_height);
+ XFreePixmap (dpy, p);
+ }
return data;
}
int x, y;
unsigned int i;
+ clear_gl_error ();
+
glPushMatrix();
- glBindTexture (GL_TEXTURE_2D, data->texid);
glNormal3f (0, 0, 1);
x = 0;
y = 0;
for (i = 0; i < strlen(string); i++)
{
- char c = string[i];
+ unsigned char c = string[i];
if (c == '\n')
{
y -= line_height;
# endif /* DO_SUBSCRIPTS */
else
{
- /* The texture is divided into 16x16 rectangles whose size are
- the max_bounds charcell of the font. Within each rectangle,
- the individual characters' charcells sit in the upper left.
+ /* For a small font, the texture is divided into 16x16 rectangles
+ whose size are the max_bounds charcell of the font. Within each
+ rectangle, the individual characters' charcells sit in the upper
+ left.
+
+ For a larger font, the texture will itself be subdivided, to
+ keep the texture sizes small (in that case we deal with, e.g.,
+ 4 grids of 8x8 characters instead of 1 grid of 16x16.)
+
+ Within each texture:
[A]----------------------------
| | | | |
? f->per_char[c - f->min_char_or_byte2].width
: f->max_bounds.width);
- int ax = ((int) c % 16) * data->cell_width; /* point A */
- int ay = ((int) c / 16) * data->cell_height;
+ char cc = c % (256 / data->ntextures);
+
+ int gs = (16 / data->grid_mag); /* grid size */
+
+ int ax = ((int) cc % gs) * data->cell_width; /* point A */
+ int ay = ((int) cc / gs) * data->cell_height;
int bx = ax - lbearing; /* point B */
int by = ay + ascent;
if (cwidth > 0 && c != ' ')
{
+ int which = c / (256 / data->ntextures);
+ if (which >= data->ntextures) abort();
+ glBindTexture (GL_TEXTURE_2D, data->texid[which]);
+
glBegin (GL_QUADS);
glTexCoord2f (tax, tay); glVertex3f (qx0, qy0, 0);
glTexCoord2f (tcx, tay); glVertex3f (qx1, qy0, 0);
}
}
glPopMatrix();
+
+ check_gl_error ("texture font print");
}
/* Releases the font and texture.
void
free_texture_font (texture_font_data *data)
{
+ int i;
if (data->font)
XFreeFont (data->dpy, data->font);
- if (data->texid)
- glDeleteTextures (1, &data->texid);
+ for (i = 0; i < data->ntextures; i++)
+ if (data->texid[i])
+ glDeleteTextures (1, &data->texid[i]);
free (data);
}
projects / xscreensaver / blobdiff