Re: Margin kerning

[Ludovic Courtès]

Hi,

Michael Piotrowski <address@hidden> writes:

> It seems, however, that it interacts negatively with @OptimizePages;
> if it is set to Yes, Lout dumps core in the second run--at least with
> the one document on which I've tested it.

Good catch!  I must confess that I hadn't tested it...

This comes from the fact that `Promote ()' (in z22.c) creates word
objects that contain the string "w" and whose font number is not a valid
font number (zero).  This is fixed by having the margin kerning code
check a word's font number is valid or not (in `FillObject ()').  The
annoying thing is that this verification is very specific to the "w"
objects: "real" words have a valid font attached to them.

BTW, Jeff, what are those "w" objects about?

Additionally, I augmented `MakeWord ()' so that it explicitly
initializes all the fields of a word, although this is not strictly
necessary.

Let me know if it's ok with the following patch.

Thanks!

Ludovic.



--- orig/z07.c
+++ mod/z07.c
@@ -136,6 +136,17 @@
 { OBJECT res;
   NewWord(res, typ, StringLength(str), pos);
   StringCopy(string(res), str);
+
+  word_font(res) = 0;
+  word_colour(res) = 0;
+  word_texture(res) = 0;
+  word_outline(res) = 0;
+  word_language(res) = 0;
+  word_baselinemark(res) = 0;
+  word_ligatures(res) = 0;
+  word_hyph(res) = 0;
+  underline(res) = 0;
+
   FposCopy(fpos(res), *pos);
   debug4(DOS, DDD, "MakeWord(%s, %s, %s) returning %s",
     Image(typ), str, EchoFilePos(pos), EchoObject(res));


--- orig/z14.c
+++ mod/z14.c
@@ -777,10 +777,10 @@
 
          font = word_font(first_on_line);
          word_content = string(first_on_line);
-         if ((word_content[0]) && (SmallGlyphHeight(font, word_content[0])))
+         if ((font > 0) &&
+             (word_content[0]) && (SmallGlyphHeight(font, word_content[0])))
          { OBJECT z;
-           MAPPING m;
-           FULL_CHAR *unacc;
+           FULL_CHAR *unacc = NULL;
            FULL_CHAR first_word[2];
            FULL_LENGTH gwidth;
 
@@ -788,8 +788,12 @@
                   "(beginning of line)", word_content[0]);
 
            /* Get font information.  */
-           m = font_mapping(finfo[font].font_table);
-           unacc = MapTable[m]->map[MAP_UNACCENTED];
+           if (finfo[font].font_table)
+             {
+               MAPPING m;
+               m = font_mapping(finfo[font].font_table);
+               unacc = MapTable[m]->map[MAP_UNACCENTED];
+             }
 
            /* Add the first character.  */
            first_word[0] = word_content[0];
@@ -818,7 +822,7 @@
            /* Add a zero-width gap object.  */
            New(z, GAP_OBJ);
            vspace(z) = 0;
-           if (word_content[1])
+           if ((word_content[1]) && (unacc))
              hspace(z) = FontKernLength(font, unacc,
                                         word_content[0], word_content[1]);
            else
@@ -878,8 +882,7 @@
       if( mode(gap(lgap)) == ADD_HYPH )
       { OBJECT z, tmp;
         FONT_NUM font;
-        MAPPING m;
-       FULL_CHAR *unacc, *word_content;
+       FULL_CHAR *unacc = NULL, *word_content;
        unsigned word_len;
 
        /* find word hyphen attaches to, since need its underline and font */
@@ -891,16 +894,24 @@
 
        /* get font information */
        font = word_font(tmp);
-       m = font_mapping(finfo[font].font_table);
-       unacc = MapTable[m]->map[MAP_UNACCENTED];
+       if (finfo[font].font_table)
+         {
+           MAPPING m;
+           m = font_mapping(finfo[font].font_table);
+           unacc = MapTable[m]->map[MAP_UNACCENTED];
+         }
 
        /* add zero-width gap object */
         New(z, GAP_OBJ);
        debug0(DOF, DD, "   adding hyphen");
        debug0(DOF, DD, "");
        vspace(z) = 0;
-       hspace(z) = FontKernLength(word_font(tmp), unacc,
-                                  word_content[word_len - 1], CH_HYPHEN);
+       if (unacc)
+         hspace(z) = FontKernLength(font, unacc,
+                                    word_content[word_len - 1], CH_HYPHEN);
+       else
+         hspace(z) = 0;
+
        underline(z) = underline(tmp);
        SetGap(gap(z), TRUE, FALSE, TRUE, FIXED_UNIT, EDGE_MODE, 0);
        Link(x, z);
@@ -945,25 +956,28 @@
          word_content = string(last_on_line);
          word_len = strlen((char *)word_content);
 
-         if (*word_content)
+         if((font > 0) && (*word_content))
          {
            last_char = word_content[word_len - 1];
 
            if(SmallGlyphHeight(font, last_char))
            { OBJECT z;
-             MAPPING m;
-             FULL_CHAR *unacc;
+             FULL_CHAR *unacc = NULL;
 
              /* Get font information.  */
-             m = font_mapping(finfo[font].font_table);
-             unacc = MapTable[m]->map[MAP_UNACCENTED];
+             if (finfo[font].font_table)
+               {
+                 MAPPING m;
+                 m = font_mapping(finfo[font].font_table);
+                 unacc = MapTable[m]->map[MAP_UNACCENTED];
+               }
 
              /* Add a zero-width gap object.  */
              New(z, GAP_OBJ);
              debug1(DOF, DD, "   adding margin-kerned character `%c' "
                     "(end of line)", last_char);
              vspace(z) = 0;
-             if(word_len > 1)
+             if((word_len > 1) && (unacc))
                hspace(z) = FontKernLength(font, unacc,
                                           word_content[word_len - 2],
                                           last_char);


--- orig/z37.c
+++ mod/z37.c
@@ -2001,8 +2001,10 @@
 {
   struct metrics *fnt;
 
+  assert ((fnum >= 1) && (fnum <= font_count), "FontGlyphHeight");
+
   fnt = finfo[fnum].size_table;
-  return (fnt[chr].up - fnt[chr].down);
+  return (fnt ? fnt[chr].up - fnt[chr].down : 0);
 }
 
 /*@::FontGlyphWidth()@*******************************************************/
@@ -2018,6 +2020,8 @@
 {
   struct metrics *fnt;
 
+  assert ((fnum >= 1) && (fnum <= font_count), "FontGlyphWidth");
+
   fnt = finfo[fnum].size_table;
-  return (fnt[chr].right - fnt[chr].left);
+  return (fnt ? fnt[chr].right - fnt[chr].left : 0);
 }