Remove now-inaccurate bytecode comments

[gnu-emacs] / src / xftfont.c

diff --git a/src/xftfont.c b/src/xftfont.c
index 0e8b876f1d33bd1cb3e90c522532254360a95ba6..34c6f7d3e42acbd0bd578c7b6dd6c9765723132f 100644 (file)
--- a/src/xftfont.c
+++ b/src/xftfont.c
@@ -1,5 +1,5 @@
 /* xftfont.c -- XFT font driver.
-   Copyright (C) 2006-2015 Free Software Foundation, Inc.
+   Copyright (C) 2006-2016 Free Software Foundation, Inc.
    Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011
      National Institute of Advanced Industrial Science and Technology (AIST)
      Registration Number H13PRO009
@@ -8,8 +8,8 @@ This file is part of GNU Emacs.
 
 GNU Emacs 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 3 of the License, or
-(at your option) any later version.
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.
 
 GNU Emacs is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -25,14 +25,11 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <X11/Xft/Xft.h>
 
 #include "lisp.h"
-#include "dispextern.h"
 #include "xterm.h"
 #include "frame.h"
 #include "blockinput.h"
-#include "character.h"
 #include "charset.h"
 #include "composite.h"
-#include "fontset.h"
 #include "font.h"
 #include "ftfont.h"
 
@@ -111,8 +108,7 @@ xftfont_get_colors (struct frame *f, struct face *face, GC gc,
          colors[0].pixel = fg->pixel = xgcv.foreground;
          if (bg)
            colors[1].pixel = bg->pixel = xgcv.background;
-         XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), colors,
-                       bg ? 2 : 1);
+         x_query_colors (f, colors, bg ? 2 : 1);
          fg->color.alpha = 0xFFFF;
          fg->color.red = colors[0].red;
          fg->color.green = colors[0].green;
@@ -399,7 +395,15 @@ xftfont_open (struct frame *f, Lisp_Object entity, int pixel_size)
 
   font->ascent = xftfont->ascent;
   font->descent = xftfont->descent;
-  if (pixel_size >= 5)
+  /* The following workaround is unnecessary on most systems, and
+     causes annoying differences in glyph height between regular and
+     bold fonts (see bug#22383).  However, with some fonts, such as
+     monaco, removing the workaround results in overlapping vertical
+     space of a line, see bug#23360.  As long as the way to reconcile
+     these opposites is not known, we provide a user option to work
+     around the problem.  */
+  if (pixel_size >= 5
+      && xft_font_ascent_descent_override)
     {
       /* The above condition is a dirty workaround because
         XftTextExtents8 behaves strangely for some fonts
@@ -617,8 +621,26 @@ xftfont_draw (struct glyph_string *s, int from, int to, int x, int y,
     XftDrawSetClip (xft_draw, NULL);
 
   if (with_background)
-    XftDrawRect (xft_draw, &bg,
-                x, y - s->font->ascent, s->width, s->font->height);
+    {
+      int height = FONT_HEIGHT (s->font), ascent = FONT_BASE (s->font);
+
+      /* Font's global height and ascent values might be
+        preposterously large for some fonts.  We fix here the case
+        when those fonts are used for display of glyphless
+        characters, because drawing background with font dimensions
+        in those cases makes the display illegible.  There's only one
+        more call to the draw method with with_background set to
+        true, and that's in x_draw_glyph_string_foreground, when
+        drawing the cursor, where we have no such heuristics
+        available.  FIXME.  */
+      if (s->first_glyph->type == GLYPHLESS_GLYPH
+         && (s->first_glyph->u.glyphless.method == GLYPHLESS_DISPLAY_HEX_CODE
+             || s->first_glyph->u.glyphless.method == GLYPHLESS_DISPLAY_ACRONYM))
+       height = ascent =
+         s->first_glyph->slice.glyphless.lower_yoff
+         - s->first_glyph->slice.glyphless.upper_yoff;
+      XftDrawRect (xft_draw, &bg, x, y - ascent, s->width, height);
+    }
   code = alloca (sizeof (FT_UInt) * len);
   for (i = 0; i < len; i++)
     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
@@ -729,6 +751,12 @@ syms_of_xftfont (void)
   DEFSYM (QCembolden, ":embolden");
   DEFSYM (QClcdfilter, ":lcdfilter");
 
+  DEFVAR_BOOL ("xft-font-ascent-descent-override",
+              xft_font_ascent_descent_override,
+              doc:  /* Non-nil means override the ascent and descent values for Xft font driver.
+This is needed with some fonts to correct vertical overlap of glyphs.  */);
+  xft_font_ascent_descent_override = 0;
+
   ascii_printable[0] = 0;
 
   xftfont_driver = ftfont_driver;