(dumpglyphs): Set a clipping region when we draw glyphs

with a font of inappropriate size.
(x_list_fonts): Try alternate fonts if we can't find a font of an
appropriate size.

1 files changed, 183 insertions, 111 deletions

diff --git a/src/xterm.c b/src/xterm.c
index 47161855862..386aa54599a 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -550,7 +550,7 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
   Window window = FRAME_X_WINDOW (f);
   int orig_left = left;
   int gidx = 0;
-  int pixel_width;
+  int i;
 
   while (n > 0)
     {
@@ -619,11 +619,6 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
 
       /* LEN gets the length of the run.  */
       len = cp - buf;
-      /* PIXEL_WIDTH get the pixcel width of the run.  */
-      pixel_width
-        = (FONT_WIDTH (f->output_data.x->font)
-           * (cmpcharp ? cmpcharp->width : len * CHARSET_WIDTH (charset)));
-
       /* Now output this run of chars, with the font and pixel values
          determined by the face code CF.  */
       {
@@ -631,10 +626,18 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
         XFontStruct *font = NULL;
         GC gc;
         int stippled = 0;
+        int line_height = f->output_data.x->line_height;
+        /* Pixel width of each glyph in this run.  */
+        int glyph_width
+          = FONT_WIDTH (f->output_data.x->font) * CHARSET_WIDTH (charset);
+        /* Overall pixel width of this run.  */
+        int run_width
+          = (FONT_WIDTH (f->output_data.x->font)
+             * (cmpcharp ? cmpcharp->width : len * CHARSET_WIDTH (charset)));
         /* A flag to tell if we have already filled background.  We
            fill background in advance in the following cases:
            1) A face has stipple.
-           2) A height of font is different from that of the current line.
+           2) A height of font is shorter than LINE_HEIGHT.
            3) Drawing a composite character.
            4) Font has non-zero _MULE_BASELINE_OFFSET property.
            After filling background, we draw glyphs by XDrawString16.  */
@@ -644,6 +647,8 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
         /* The property value of `_MULE_RELATIVE_COMPOSE' and
            `_MULE_DEFAULT_ASCENT'.  */
         int relative_compose = 0, default_ascent = 0;
+        /* 1 if we find no font or a font of inappropriate size.  */
+        int require_clipping;
 
         /* HL = 3 means use a mouse face previously chosen.  */
         if (hl == 3)
@@ -691,12 +696,10 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
             font = (XFontStruct *) (fontp->font);
             gc = FACE_NON_ASCII_GC (face);
             XSetFont (FRAME_X_DISPLAY (f), gc, font->fid);
-            if (font->max_byte1 != 0)
-              baseline = (f->output_data.x->line_height
-                          + font->ascent - font->descent) / 2;
-            else
-              baseline = (f->output_data.x->font_baseline
-                          - fontp->baseline_offset);
+            baseline
+              = (font->max_byte1 != 0
+                 ? (line_height + font->ascent - font->descent) / 2
+                 : f->output_data.x->font_baseline - fontp->baseline_offset);
             if (cmpcharp && cmpcharp->cmp_rule == NULL)
               {
                 relative_compose = fontp->relative_compose;
@@ -755,10 +758,8 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
             /* The cursor overrides stippling.  */
             stippled = 0;
 
-            if (!cmpcharp
-                && (!font
-                    || font == (XFontStruct *) FACE_DEFAULT
-                    || font == f->output_data.x->font)
+            if ((font == (XFontStruct *) FACE_DEFAULT
+                 || font == f->output_data.x->font)
                 && face->background == f->output_data.x->background_pixel
                 && face->foreground == f->output_data.x->foreground_pixel)
               {
@@ -813,30 +814,53 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
         if (font == (XFontStruct *) FACE_DEFAULT)
           font = f->output_data.x->font;
 
+        if (font)
+          require_clipping = (FONT_HEIGHT (font) > line_height
+                              || FONT_WIDTH (font) > glyph_width
+                              || baseline != f->output_data.x->font_baseline);
+
         if (font && (just_foreground || (cmpcharp && gidx > 0)))
           background_filled = 1;
-        else if (!font
-                 || stippled
-                 || f->output_data.x->line_height != FONT_HEIGHT (font)
-                 || cmpcharp
-                 || baseline != f->output_data.x->font_baseline)
+        else if (stippled)
           {
-            if (!stippled)
-              /* This is to fill a rectangle with background color.  */
-              XSetStipple (FRAME_X_DISPLAY (f), gc,
-                           FRAME_X_DISPLAY_INFO (f)->null_pixel);
             /* Turn stipple on.  */
             XSetFillStyle (FRAME_X_DISPLAY (f), gc, FillOpaqueStippled);
 
             /* Draw stipple or background color on background.  */
             XFillRectangle (FRAME_X_DISPLAY (f), window, gc,
-                            left, top, pixel_width,
-                            f->output_data.x->line_height);
+                            left, top, run_width, line_height);
 
             /* Turn stipple off.  */
             XSetFillStyle (FRAME_X_DISPLAY (f), gc, FillSolid);
 
             background_filled = 1;
+          }
+        else if (!font
+                 || FONT_HEIGHT (font) < line_height
+                 || FONT_WIDTH (font) < glyph_width
+                 || baseline != f->output_data.x->font_baseline
+                 || cmpcharp)
+          {
+            /* Fill a area for the current run in background pixle of GC.  */
+            XGCValues xgcv;
+            unsigned long mask = GCForeground | GCBackground;
+            unsigned long fore, back;
+
+            /* The current code at first exchange foreground and
+              background of GC, fill the area, then recover the
+              original foreground and background of GC.
+              Aren't there more smart ways?  */
+
+            XGetGCValues (FRAME_X_DISPLAY (f), gc, mask, &xgcv);
+            fore = xgcv.foreground, back = xgcv.background;
+            xgcv.foreground = back, xgcv.background = fore;
+            XChangeGC (FRAME_X_DISPLAY (f), gc, mask, &xgcv);
+            XFillRectangle (FRAME_X_DISPLAY (f), window, gc,
+                            left, top, run_width, line_height);
+            xgcv.foreground = fore, xgcv.background = back;
+            XChangeGC (FRAME_X_DISPLAY (f), gc, mask, &xgcv);
+
+            background_filled = 1;
             if (cmpcharp)
               /* To assure not to fill background while drawing
                  remaining components.  */
@@ -847,10 +871,48 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
 
         if (font)
           {
-            if (cmpcharp)
+            if (require_clipping)
+              {
+                Region region;  /* Region used for setting clip mask to GC.  */
+                XPoint x[4];    /* Data used for creating REGION.  */
+
+                x[0].x = x[3].x = left, x[1].x = x[2].x = left + glyph_width;
+                x[0].y = x[1].y = top,  x[2].y = x[3].y = top + line_height;
+                region = XPolygonRegion (x, 4, EvenOddRule);
+                XSetRegion (FRAME_X_DISPLAY (f), gc, region);
+                XDestroyRegion (region);
+              }
+
+            if (!cmpcharp)
+              {
+                if (require_clipping)
+                  for (i = 0; i < len; i++)
+                    {
+                      if (i > 0) 
+                        XSetClipOrigin (FRAME_X_DISPLAY (f), gc,
+                                        glyph_width * i, 0);
+                      if (background_filled)
+                        XDrawString16 (FRAME_X_DISPLAY (f), window, gc,
+                                       left + glyph_width * i,
+                                       top + baseline, buf + i, 1);
+                      else
+                        XDrawImageString16 (FRAME_X_DISPLAY (f), window, gc,
+                                            left + glyph_width * i,
+                                            top + baseline, buf + i, 1);
+                    }
+                else
+                  {
+                    if (background_filled)
+                      XDrawString16 (FRAME_X_DISPLAY (f), window, gc,
+                                     left, top + baseline, buf, len);
+                    else
+                      XDrawImageString16 (FRAME_X_DISPLAY (f), window, gc,
+                                          left, top + baseline, buf, len);
+                  }
+              }
+            else
               {
                 XCharStruct *pcm; /* Pointer to per char metric info.  */
-                int i;
 
                 if ((cmpcharp->cmp_rule || relative_compose)
                     && gidx == 0)
@@ -939,22 +1001,8 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
                                    buf + i, 1);
                   }
               }
-            else if (background_filled)
-              XDrawString16 (FRAME_X_DISPLAY (f), window, gc,
-                             left, top + baseline, buf, len);
-            else
-              XDrawImageString16 (FRAME_X_DISPLAY (f), window, gc,
-                                  left, top + baseline, buf, len);
-
-            /* Clear the rest of the line's height.  */
-            if (f->output_data.x->line_height > FONT_HEIGHT (font))
-              XClearArea (FRAME_X_DISPLAY (f), window, left,
-                          top + FONT_HEIGHT (font),
-                          FONT_WIDTH (font) * len,
-                          /* This is how many pixels of height
-                             we have to clear.  */
-                          f->output_data.x->line_height - FONT_HEIGHT (font),
-                          False);
+            if (require_clipping)
+              XSetClipMask (FRAME_X_DISPLAY (f), gc, None);
 
 #if 0 /* Doesn't work, because it uses FRAME_CURRENT_GLYPHS,
          which often is not up to date yet.  */
@@ -969,29 +1017,20 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
               }
 #endif
           }
-        else
+        if (!font || require_clipping)
           {
-            /* There's no appropriate font for this glyph.  Just show
-               rectangles.  */
+            /* Show rectangles to show that we found no font or a font
+               of inappropriate size.  */
 
             if (cmpcharp)
               XDrawRectangle
                 (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
-                 left, top + 1,
-                 pixel_width - 2, f->output_data.x->line_height - 3);
+                 left, top, run_width - 1, line_height - 1);
             else
-              {
-                int left_offset;
-                int left_skip_step = (FONT_WIDTH (f->output_data.x->font)
-                                      * CHARSET_WIDTH (charset));
-
-                for (left_offset = 0; left_offset < pixel_width;
-                     left_offset += left_skip_step)
-                  XDrawRectangle
-                    (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
-                     left + left_offset, top + 1,
-                     left_skip_step - 2, f->output_data.x->line_height - 3);
-              }
+              for (i = 0; i < len; i++)
+                XDrawRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
+                                left + glyph_width * i, top,
+                                glyph_width -1, line_height - 1);
           }
         
         /* We should probably check for XA_UNDERLINE_POSITION and
@@ -1004,17 +1043,17 @@ dumpglyphs (f, left, top, gp, n, hl, just_foreground, cmpcharp)
              on the default font of this frame.  */
           int underline_position = f->output_data.x->font_baseline + 1;
 
-          if (underline_position >= f->output_data.x->line_height)
-            underline_position = f->output_data.x->line_height - 1;
+          if (underline_position >= line_height)
+            underline_position = line_height - 1;
 
           if (face->underline)
             XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
                             FACE_GC (face),
-                            left, top + underline_position, pixel_width, 1);
+                            left, top + underline_position, run_width, 1);
         }
 
         if (!cmpcharp)
-          left += pixel_width;
+          left += run_width;
       }
     }
 
@@ -5171,8 +5210,8 @@ x_new_font (f, fontname)
 
 /* Give frame F the fontset named FONTSETNAME as its default font, and
    return the full name of that fontset.  FONTSETNAME may be a wildcard
-   pattern; in that case, we choose some font that fits the pattern.
-   The return value shows which font we chose.  */
+   pattern; in that case, we choose some fontset that fits the pattern.
+   The return value shows which fontset we chose.  */
 
 Lisp_Object
 x_new_fontset (f, fontsetname)
@@ -6128,30 +6167,39 @@ x_list_fonts (f, pattern, size, maxnames)
      int size;
      int maxnames;
 {
-  Lisp_Object list, newlist, key;
+  Lisp_Object list, patterns = Qnil, newlist = Qnil, key, tem, second_best;
   Display *dpy = f != NULL ? FRAME_X_DISPLAY (f) : x_display_list->display;
 
-  key = Fcons (pattern, make_number (maxnames));
-
-  if (f == NULL)
-    list = Qnil;
-  else
-    /* See if we cached the result for this particular query.  */
-    list = Fassoc (key,
-                   XCONS (FRAME_X_DISPLAY_INFO (f)->name_list_element)->cdr);
-
-  /* Now LIST has the form (KEY . FONT-DATA-LIST), where KEY is a
-    pattern which matches font names in FONT-DATA-LIST, FONT-DATA-LIST
-    is a list of cons cells for the form (FONTNAME . FONTWIDTH).  */
+  for (list = Valternative_fontname_alist; CONSP (list);
+       list = XCONS (list)->cdr)
+    {
+      tem = XCONS (list)->car;
+      if (CONSP (tem)
+          && STRINGP (XCONS (tem)->car)
+          && !NILP (Fstring_equal (XCONS (tem)->car, pattern)))
+        {
+          patterns = XCONS (tem)->cdr;
+          break;
+        }
+    }
 
-  if (!NILP (list))
-    list = XCONS (list)->cdr;
-  else
+  for (patterns = Fcons (pattern, patterns); CONSP (patterns);
+       patterns = XCONS (patterns)->cdr, pattern = XCONS (patterns)->car)
     {
-      /* At first, put PATTERN in the cache.  */
       int num_fonts;
       char **names;
 
+      /* See if we cached the result for this particular query.  */
+      if (f && (tem = XCONS (FRAME_X_DISPLAY_INFO (f)->name_list_element)->cdr,
+                key = Fcons (pattern, make_number (maxnames)),
+                !NILP (list = Fassoc (key, tem))))
+        {
+          list = Fcdr_safe (list);
+          /* We have a cashed list.  Don't have to get the list again.  */
+          goto label_cached;
+        }
+
+      /* At first, put PATTERN in the cache.  */
       BLOCK_INPUT;
       names = XListFonts (dpy, XSTRING (pattern)->data, maxnames, &num_fonts);
       UNBLOCK_INPUT;
@@ -6159,7 +6207,6 @@ x_list_fonts (f, pattern, size, maxnames)
       if (names)
         {
           int i;
-          Lisp_Object tem;
 
           /* Make a list of all the fonts we got back.
              Store that in the font cache for the display.  */
@@ -6169,10 +6216,10 @@ x_list_fonts (f, pattern, size, maxnames)
               int average_width = -1, dashes = 0, width = 0;
 
               /* Count the number of dashes in NAMES[I].  If there are
-                 14 dashes, and the field value following 12th dash
-                 (AVERAGE_WIDTH) is 0, this is a auto-scaled font
-                 which is usually too ugly to be used for editing.
-                 Let's ignore it.  */
+                14 dashes, and the field value following 12th dash
+                (AVERAGE_WIDTH) is 0, this is a auto-scaled font which
+                is usually too ugly to be used for editing.  Let's
+                ignore it.  */
               while (*p)
                 if (*p++ == '-')
                   {
@@ -6192,7 +6239,7 @@ x_list_fonts (f, pattern, size, maxnames)
                               (Vx_pixel_size_width_font_regexp, names[i])
                               >= 0))
                         /* We can set the value of PIXEL_SIZE to the
-                           width of this font.  */
+                          width of this font.  */
                         list = Fcons (Fcons (tem, make_number (width)), list);
                       else
                         /* For the moment, width is not known.  */
@@ -6203,31 +6250,33 @@ x_list_fonts (f, pattern, size, maxnames)
           XFreeFontNames (names);
         }
 
+      /* Now store the result in the cache.  */
       if (f != NULL)
         XCONS (FRAME_X_DISPLAY_INFO (f)->name_list_element)->cdr
           = Fcons (Fcons (key, list),
                    XCONS (FRAME_X_DISPLAY_INFO (f)->name_list_element)->cdr);
-    }
 
-  if (NILP (list))
-    return Qnil;
+    label_cached:
+      if (NILP (list)) continue; /* Try the remaining alternatives.  */
 
-  newlist = Qnil;
+      newlist = second_best = Qnil;
+      /* Make a list of the fonts that have the right width.  */
+      for (; CONSP (list); list = XCONS (list)->cdr)
+        {
+          tem = XCONS (list)->car;
 
-  /* Make a list of the fonts that have the right width.  */
-  for (; CONSP (list); list = XCONS (list)->cdr)
-    {
-      Lisp_Object tem = XCONS (list)->car;
-      int keeper;
+          if (!CONSP (tem) || NILP (XCONS (tem)->car))
+            continue;
+          if (!size)
+            {
+              newlist = Fcons (XCONS (tem)->car, newlist);
+              continue;
+            }
 
-      if (!CONSP (tem) || NILP (XCONS (tem)->car))
-        continue;
-      if (!size)
-        keeper = 1;
-      else
-        {
           if (!INTEGERP (XCONS (tem)->cdr))
             {
+              /* Since we have not yet known the size of this font, we
+                must try slow function call XLoadQueryFont.  */
               XFontStruct *thisinfo;
 
               BLOCK_INPUT;
@@ -6241,12 +6290,35 @@ x_list_fonts (f, pattern, size, maxnames)
                   XFreeFont (dpy, thisinfo);
                 }
               else
+                /* For unknown reason, the previous call of XListFont had
+                  retruned a font which can't be opened.  Record the size
+                  as 0 not to try to open it again.  */
                 XCONS (tem)->cdr = make_number (0);
             }
-          keeper = XINT (XCONS (tem)->cdr) == size;
+          if (XINT (XCONS (tem)->cdr) == size)
+            newlist = Fcons (XCONS (tem)->car, newlist);
+          else if (NILP (second_best))
+            second_best = tem;
+          else if (XINT (XCONS (tem)->cdr) < size)
+            {
+              if (XINT (XCONS (second_best)->cdr) > size
+                  || XINT (XCONS (second_best)->cdr) < XINT (XCONS (tem)->cdr))
+                second_best = tem;
+            }
+          else
+            {
+              if (XINT (XCONS (second_best)->cdr) > size
+                  && XINT (XCONS (second_best)->cdr) > XINT (XCONS (tem)->cdr))
+                second_best = tem;
+            }
+        }
+      if (!NILP (newlist))
+        break;
+      else if (!NILP (second_best))
+        {
+          newlist = Fcons (XCONS (second_best)->car, Qnil);
+          break;
         }
-      if (keeper)
-        newlist = Fcons (XCONS (tem)->car, newlist);
     }
 
   return newlist;
@@ -6298,7 +6370,7 @@ x_load_font (f, fontname, size)
     BLOCK_INPUT;
     font = (XFontStruct *) XLoadQueryFont (FRAME_X_DISPLAY (f), fontname);
     UNBLOCK_INPUT;
-    if (!font || (size && font->max_bounds.width != size))
+    if (!font)
       return NULL;
 
     /* Do we need to create the table?  */