From 1299f5593751a39174051b59f77ecefc618f42ef Mon Sep 17 00:00:00 2001
From: Werner Lemberg <wl@gnu.org>
Date: Sat, 17 Dec 2011 08:17:19 +0100
Subject: [PATCH] Add code to adjust `hmtx' table.

---
 src/Makefile.am |  1 +
 src/ta.h        |  5 +++++
 src/tahmtx.c    | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/tasfnt.c    |  3 +++
 4 files changed, 68 insertions(+)
 create mode 100644 src/tahmtx.c

diff --git a/src/Makefile.am b/src/Makefile.am
index 51faaa7..a0314f6 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -29,6 +29,7 @@ libttfautohint_a_SOURCES = ta.h \
                            taglyf.c \
                            tagpos.c \
                            tahints.c tahints.h \
+                           tahmtx.c \
                            talatin.c talatin.h \
                            taloader.c taloader.h \
                            taloca.c \
diff --git a/src/ta.h b/src/ta.h
index c4bd7ff..554954e 100644
--- a/src/ta.h
+++ b/src/ta.h
@@ -138,6 +138,7 @@ typedef struct SFNT_ {
   FT_ULong glyf_idx;
   FT_ULong loca_idx;
   FT_ULong head_idx;
+  FT_ULong hmtx_idx;
   FT_ULong maxp_idx;
   FT_ULong OS2_idx;
   FT_ULong GPOS_idx;
@@ -246,6 +247,10 @@ TA_sfnt_create_glyf_data(SFNT* sfnt,
                          FONT* font);
 
 FT_Error
+TA_sfnt_update_hmtx_table(SFNT* sfnt,
+                          FONT* font);
+
+FT_Error
 TA_sfnt_build_loca_table(SFNT* sfnt,
                          FONT* font);
 
diff --git a/src/tahmtx.c b/src/tahmtx.c
new file mode 100644
index 0000000..80886d8
--- /dev/null
+++ b/src/tahmtx.c
@@ -0,0 +1,59 @@
+/* tahmtx.c */
+
+/*
+ * Copyright (C) 2011 by Werner Lemberg.
+ *
+ * This file is part of the ttfautohint library, and may only be used,
+ * modified, and distributed under the terms given in `COPYING'.  By
+ * continuing to use, modify, or distribute this file you indicate that you
+ * have read `COPYING' and understand and accept it fully.
+ *
+ * The file `COPYING' mentioned in the previous paragraph is distributed
+ * with the ttfautohint library.
+ */
+
+
+#include "ta.h"
+
+
+FT_Error
+TA_sfnt_update_hmtx_table(SFNT* sfnt,
+                          FONT* font)
+{
+  SFNT_Table* hmtx_table = &font->tables[sfnt->hmtx_idx];
+  FT_Byte* buf_new;
+  FT_ULong buf_len;
+  FT_ULong i;
+
+
+  if (hmtx_table->processed)
+    return TA_Err_Ok;
+
+  /* the metrics of the added composite element doesn't matter; */
+  /* for this reason, we simply append two zero bytes, */
+  /* indicating a zero value in the `leftSideBearing' array */
+  /* (this works because we don't increase the `numberOfHMetrics' field) */
+
+  hmtx_table->len += 2;
+  /* make the allocated buffer length a multiple of 4 */
+  buf_len = (hmtx_table->len + 3) & ~3;
+  buf_new = (FT_Byte*)realloc(hmtx_table->buf, hmtx_table->len);
+  if (!buf_new)
+  {
+    hmtx_table->len -= 2;
+    return FT_Err_Out_Of_Memory;
+  }
+
+  /* pad end of buffer with zeros */
+  for (i = hmtx_table->len - 2; i < buf_len; i++)
+    buf_new[i] = 0x00;
+
+  hmtx_table->buf = buf_new;
+  hmtx_table->checksum = TA_table_compute_checksum(hmtx_table->buf,
+                                                   hmtx_table->len);
+  hmtx_table->processed = 1;
+
+  return TA_Err_Ok;
+}
+
+/* end of tahmtx.c */
diff --git a/src/tasfnt.c b/src/tasfnt.c
index 2598d07..2c27b5f 100644
--- a/src/tasfnt.c
+++ b/src/tasfnt.c
@@ -41,6 +41,7 @@ TA_sfnt_split_into_SFNT_tables(SFNT* sfnt,
   sfnt->glyf_idx = MISSING;
   sfnt->loca_idx = MISSING;
   sfnt->head_idx = MISSING;
+  sfnt->hmtx_idx = MISSING;
   sfnt->maxp_idx = MISSING;
   sfnt->OS2_idx = MISSING;
   sfnt->GPOS_idx = MISSING;
@@ -117,6 +118,8 @@ TA_sfnt_split_into_SFNT_tables(SFNT* sfnt,
       sfnt->head_idx = j;
     else if (tag == TTAG_glyf)
       sfnt->glyf_idx = j;
+    else if (tag == TTAG_hmtx)
+      sfnt->hmtx_idx = j;
     else if (tag == TTAG_loca)
       sfnt->loca_idx = j;
     else if (tag == TTAG_maxp)
-- 
2.11.4.GIT