From d0ce3c66e2af2785203f7bbb1d4abca5c226045d Mon Sep 17 00:00:00 2001
From: Rod Sheeter <rsheeter@google.com>
Date: Tue, 6 Feb 2018 16:58:35 -0800
Subject: [PATCH] Resolve codepoints:glyph ids. Does not compile; undefined
 reference to OT::_hb_NullPool

---
 src/hb-subset-plan.cc    | 25 +++++++++++++++++++------
 src/hb-subset-plan.hh    |  2 +-
 src/hb-subset-private.hh | 17 +++++++++++++++--
 src/hb-subset.cc         | 13 ++++---------
 4 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/src/hb-subset-plan.cc b/src/hb-subset-plan.cc
index 8111d519b..5d23f88b2 100644
--- a/src/hb-subset-plan.cc
+++ b/src/hb-subset-plan.cc
@@ -21,17 +21,30 @@
  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
- * Google Author(s): Garret Rieger
+ * Google Author(s): Garret Rieger, Roderick Sheeter
  */
 
 #include "hb-subset-plan.hh"
 #include "hb-subset-private.hh"
 
+// TODO(Q1) map from old:new gid
 hb_set_t *
-get_glyph_ids_from_cmap (hb_face_t *face,
-                         hb_set_t  *codepoints)
+glyph_ids_to_retain (hb_subset_face_t *face,
+                     hb_set_t  *codepoints)
 {
-  return hb_set_get_empty ();
+  hb_codepoint_t cp = -1;
+  hb_set_t *gids = hb_set_create();
+  while (hb_set_next(codepoints, &cp)) {
+    hb_codepoint_t gid;
+    if (face->cmap.get_nominal_glyph(cp, &gid)) {
+      // TODO(Q1) a nice way to turn on/off logs
+      fprintf(stderr, "gid for U+%04X is %d\n", cp, gid);
+      hb_set_add(gids, cp);
+    } else {
+      fprintf(stderr, "Unable to resolve gid for U+%04X\n", cp);
+    }
+  }
+  return gids;
 }
 
 /**
@@ -45,12 +58,12 @@ get_glyph_ids_from_cmap (hb_face_t *face,
  * Since: 1.7.5
  **/
 hb_subset_plan_t *
-hb_subset_plan_create (hb_face_t           *face,
+hb_subset_plan_create (hb_subset_face_t    *face,
                        hb_subset_profile_t *profile,
                        hb_subset_input_t   *input)
 {
   hb_subset_plan_t *plan = hb_object_create<hb_subset_plan_t> ();
-  plan->glyphs_to_retain = get_glyph_ids_from_cmap (face, input->codepoints);
+  plan->glyphs_to_retain = glyph_ids_to_retain (face, input->codepoints);
   return plan;
 }
 
diff --git a/src/hb-subset-plan.hh b/src/hb-subset-plan.hh
index 54b1e651d..6e94a76ff 100644
--- a/src/hb-subset-plan.hh
+++ b/src/hb-subset-plan.hh
@@ -40,7 +40,7 @@ struct hb_subset_plan_t {
 typedef struct hb_subset_plan_t hb_subset_plan_t;
 
 hb_subset_plan_t *
-hb_subset_plan_create (hb_face_t           *face,
+hb_subset_plan_create (hb_subset_face_t    *face,
                        hb_subset_profile_t *profile,
                        hb_subset_input_t   *input);
 
diff --git a/src/hb-subset-private.hh b/src/hb-subset-private.hh
index b38ab0b26..eb4147dce 100644
--- a/src/hb-subset-private.hh
+++ b/src/hb-subset-private.hh
@@ -21,15 +21,21 @@
  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
- * Google Author(s): Garret Rieger
+ * Google Author(s): Garret Rieger, Roderick Sheeter
  */
 
 #ifndef HB_SUBSET_PRIVATE_HH
 #define HB_SUBSET_PRIVATE_HH
 
-#include "hb-object-private.hh"
+
 #include "hb-private.hh"
 
+#include "hb-ot.h"
+
+#include "hb-font-private.hh"
+
+#include "hb-ot-cmap-table.hh"
+
 struct hb_subset_input_t {
   hb_object_header_t header;
   ASSERT_POD ();
@@ -37,4 +43,11 @@ struct hb_subset_input_t {
   hb_set_t *codepoints;
 };
 
+struct hb_subset_face_t {
+  hb_object_header_t header;
+
+  hb_face_t *face;
+  OT::cmap::accelerator_t cmap;
+};
+
 #endif /* HB_SUBSET_PRIVATE_HH */
diff --git a/src/hb-subset.cc b/src/hb-subset.cc
index 7b44d5168..7108eb871 100644
--- a/src/hb-subset.cc
+++ b/src/hb-subset.cc
@@ -27,6 +27,7 @@
 
 #include "hb-object-private.hh"
 #include "hb-private.hh"
+
 #include "hb-subset-glyf.hh"
 #include "hb-subset-private.hh"
 #include "hb-subset-plan.hh"
@@ -38,14 +39,6 @@ struct hb_subset_profile_t {
   ASSERT_POD ();
 };
 
-struct hb_subset_face_t {
-  hb_object_header_t header;
-  ASSERT_POD ();
-
-  hb_face_t *face;
-};
-
-
 /**
  * hb_subset_profile_create:
  *
@@ -119,6 +112,7 @@ hb_subset_face_create (hb_face_t *face)
 
   hb_subset_face_t *subset_face = hb_object_create<hb_subset_face_t> ();
   subset_face->face = hb_face_reference (face);
+  subset_face->cmap.init(face);
 
   return subset_face;
 }
@@ -133,6 +127,7 @@ hb_subset_face_destroy (hb_subset_face_t *subset_face)
 {
   if (!hb_object_destroy (subset_face)) return;
 
+  subset_face->cmap.fini();
   hb_face_destroy(subset_face->face);
   free (subset_face);
 }
@@ -154,7 +149,7 @@ hb_subset (hb_subset_profile_t *profile,
 {
   if (!profile || !input || !face) return false;
 
-  hb_subset_plan_t *plan = hb_subset_plan_create (face->face, profile, input);
+  hb_subset_plan_t *plan = hb_subset_plan_create (face, profile, input);
 
   // TODO:
   // - Create initial header + table directory