Cope with TrueType fonts without a 'post' table or with a format 3 'post'

table (which doesn't specify glyph names), constructing an arbitrary list
of glyph names for ourselves.

git-svn-id: svn://svn.tartarus.org/sgt/halibut@7276 cda61777-01e9-0310-a592-d414129be87e

diff --git a/in_sfnt.c b/in_sfnt.c
index 0d51ff9..f29590b 100644 (file)
--- a/in_sfnt.c
+++ b/in_sfnt.c
@@ -132,6 +132,7 @@ sfnt_decode offsubdir_decode[] = {
 #define TAG_hmtx       0x686d7478
 #define TAG_kern       0x6b65726e
 #define TAG_loca       0x6c6f6361
+#define TAG_maxp       0x6d617870
 #define TAG_name       0x6e616d65
 #define TAG_post       0x706f7374
 #define sfnt_true      0x74727565
@@ -364,6 +365,18 @@ sfnt_decode kern_f0_pair_decode[] = {
     { d_end }
 };
 
+/* Maximum profile ('maxp') table */
+typedef struct t_maxp_Tag t_maxp;
+struct t_maxp_Tag {
+    unsigned version;
+    unsigned numGlyphs;
+};
+sfnt_decode t_maxp_decode[] = {
+    { d_uint32, offsetof(t_maxp, version) },
+    { d_uint16, offsetof(t_maxp, numGlyphs) },
+    { d_end }
+};
+
 /* Naming ('name') table  */
 typedef struct t_name_Tag t_name;
 typedef struct namerecord_Tag namerecord;
@@ -503,6 +516,14 @@ static int glyphsbyname_cmp_search(void const *a, void const *b) {
     return 0;
 }
 
+/* Generate an name for a glyph that doesn't have one. */
+static glyph genglyph(unsigned idx) {
+    char buf[11];
+    if (idx == 0) return glyph_intern(".notdef");
+    sprintf(buf, "glyph%u", idx);
+    return glyph_intern(buf);
+}
+
 /*
  * Extract data from the 'post' table (mostly glyph mappings)
  *
@@ -519,59 +540,75 @@ static void sfnt_mapglyphs(font_info *fi) {
     unsigned nextras, i, g;
 
     sf->glyphsbyname = sf->glyphsbyindex = NULL;
-    if (!sfnt_findtable(sf, TAG_post, &ptr, &end)) {
-       error(err_sfntnotable, &sf->pos, "post");
-       return;
-    }
-    ptr = decode(t_post_decode, ptr, end, &post);
-    if (ptr == NULL) {
-       error(err_sfntbadtable, &sf->pos, "post");
-       return;
-    }
+    if (sfnt_findtable(sf, TAG_post, &ptr, &end)) {
+       ptr = decode(t_post_decode, ptr, end, &post);
+       if (ptr == NULL) {
+           error(err_sfntbadtable, &sf->pos, "post");
+           goto noglyphs;
+       }
     
-    sf->minmem = post.minMemType42;
-    sf->maxmem = post.maxMemType42;
-    fi->italicangle = post.italicAngle / 65536.0;
-    switch (post.format) {
-      case 0x00010000:
-       sf->nglyphs = 258;
-       sf->glyphsbyindex = (glyph *)tt_std_glyphs;
-       break;
-      case 0x00020000:
-       if ((char *)ptr + 2 > (char *)end) return;
-       decode_uint16(ptr, &sf->nglyphs);
-       ptr = (char *)ptr + 2;
-       if ((char *)ptr + 2*sf->nglyphs > (char *)end) return;
-       nextras = 0;
-       for (sptr = (unsigned char *)ptr + 2*sf->nglyphs;
-            sptr < (unsigned char *)end;
-            sptr += *sptr+1)
-           nextras++;
-       extraglyphs = snewn(nextras, glyph);
-       i = 0;
-       for (sptr = (unsigned char *)ptr + 2*sf->nglyphs;
-            sptr < (unsigned char *)end;
-            sptr += *sptr+1) {
-           memcpy(tmp, sptr + 1, *sptr);
-           tmp[*sptr] = 0;
-           assert(i < nextras);
-           extraglyphs[i++] = glyph_intern(tmp);
+       sf->minmem = post.minMemType42;
+       sf->maxmem = post.maxMemType42;
+       fi->italicangle = post.italicAngle / 65536.0;
+       switch (post.format) {
+         case 0x00010000:
+           if (sf->nglyphs != 258) {
+               error(err_sfntbadtable, &sf->pos, "post");
+               break;
+           }
+           sf->glyphsbyindex = (glyph *)tt_std_glyphs;
+           break;
+         case 0x00020000:
+           if ((char *)ptr + 2 > (char *)end) {
+               error(err_sfntbadtable, &sf->pos, "post");
+               break;
+           }
+           ptr = (char *)ptr + 2;
+           if ((char *)ptr + 2*sf->nglyphs > (char *)end) {
+               error(err_sfntbadtable, &sf->pos, "post");
+               break;
+           }
+           nextras = 0;
+           for (sptr = (unsigned char *)ptr + 2*sf->nglyphs;
+                sptr < (unsigned char *)end;
+                sptr += *sptr+1)
+               nextras++;
+           extraglyphs = snewn(nextras, glyph);
+           i = 0;
+           for (sptr = (unsigned char *)ptr + 2*sf->nglyphs;
+                sptr < (unsigned char *)end;
+                sptr += *sptr+1) {
+               memcpy(tmp, sptr + 1, *sptr);
+               tmp[*sptr] = 0;
+               assert(i < nextras);
+               extraglyphs[i++] = glyph_intern(tmp);
+           }
+           sf->glyphsbyindex = snewn(sf->nglyphs, glyph);
+           for (i = 0; i < sf->nglyphs; i++) {
+               decode_uint16((char *)ptr + 2*i, &g);
+               if (g <= 257)
+                   sf->glyphsbyindex[i] = tt_std_glyphs[g];
+               else if (g < 258 + nextras)
+                   sf->glyphsbyindex[i] = extraglyphs[g - 258];
+               else {
+                   error(err_sfntbadtable, &sf->pos, "post");
+                   sf->glyphsbyindex[i] = genglyph(i);
+               }
+           }
+           sfree(extraglyphs);
+           break;
+         case 0x00030000:
+           break;
+         default:
+           error(err_sfnttablevers, &sf->pos, "post");
+           break;
        }
+    }
+  noglyphs:
+    if (!sf->glyphsbyindex) {
        sf->glyphsbyindex = snewn(sf->nglyphs, glyph);
-       for (i = 0; i < sf->nglyphs; i++) {
-           decode_uint16((char *)ptr + 2*i, &g);
-           if (g <= 257)
-               sf->glyphsbyindex[i] = tt_std_glyphs[g];
-           else if (g < 258 + nextras)
-               sf->glyphsbyindex[i] = extraglyphs[g - 258];
-           else
-               sf->glyphsbyindex[i] = NOGLYPH;
-       }
-       sfree(extraglyphs);
-       break;
-      default:
-       error(err_sfnttablevers, &sf->pos, "post");
-       return;
+       for (i = 0; i < sf->nglyphs; i++)
+           sf->glyphsbyindex[i] = genglyph(i);
     }
     /* Construct glyphsbyname */
     sf->glyphsbyname = snewn(sf->nglyphs, unsigned short);
@@ -839,6 +876,7 @@ void read_sfnt_file(input *in) {
     FILE *fp = in->currfp;
     font_info *fi = snew(font_info);
     void *ptr, *end;
+    t_maxp maxp;
 
     fi->name = NULL;
     fi->widths = newtree234(width_cmp);
@@ -890,6 +928,19 @@ void read_sfnt_file(input *in) {
        error(err_sfnttablevers, &sf->pos, "head");
        return;
     }
+    if (!sfnt_findtable(sf, TAG_maxp, &ptr, &end)) {
+       error(err_sfntnotable, &sf->pos, "maxp");
+       return;
+    }
+    if (decode(t_maxp_decode, ptr, end, &maxp) == NULL) {
+       error(err_sfntbadtable, &sf->pos, "maxp");
+       return;
+    }
+    if (maxp.version < 0x00005000 || maxp.version > 0x0001ffff) {
+       error(err_sfnttablevers, &sf->pos, "maxp");
+       return;
+    }
+    sf->nglyphs = maxp.numGlyphs;
     fi->name = sfnt_psname(fi);
     if (fi->name == NULL) return;
     sfnt_mapglyphs(fi);