[wasm-graphite] Ensure native direction here too

Binds buffer_get_script and script_get_horizontal_direction.

src/hb-wasm-api-buffer.hh

@@ -132,6 +132,14 @@ HB_WASM_API (direction_t, buffer_get_direction) (HB_WASM_EXEC_ENV
   return (direction_t) hb_buffer_get_direction (buffer);
 }
 
+HB_WASM_API (script_t, buffer_get_script) (HB_WASM_EXEC_ENV
+					   ptr_d(buffer_t, buffer))
+{
+  HB_REF2OBJ (buffer);
+
+  return hb_script_to_iso15924_tag (hb_buffer_get_script (buffer));
+}
+
 HB_WASM_API (void, buffer_reverse) (HB_WASM_EXEC_ENV
 				    ptr_d(buffer_t, buffer))
 {

src/hb-wasm-api-common.hh

@@ -0,0 +1,44 @@
+/*
+ * Copyright © 2023  Behdad Esfahbod
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#ifndef HB_WASM_API_COMMON_HH
+#define HB_WASM_API_COMMON_HH
+
+#include "hb-wasm-api.hh"
+
+namespace hb {
+namespace wasm {
+
+
+HB_WASM_API (direction_t, script_get_horizontal_direction) (HB_WASM_EXEC_ENV
+							    script_t script)
+{
+  return (direction_t)
+	 hb_script_get_horizontal_direction (hb_script_from_iso15924_tag (script));
+}
+
+
+}}
+
+#endif /* HB_WASM_API_COMMON_HH */

src/hb-wasm-api-list.hh

@@ -50,6 +50,8 @@ static void debugprint4 (HB_WASM_EXEC_ENV char *str, int32_t i1, int32_t i2, int
  * https://github.com/bytecodealliance/wasm-micro-runtime/blob/main/doc/export_native_api.md */
 static NativeSymbol _hb_wasm_native_symbols[] =
 {
+  /* common */
+  NATIVE_SYMBOL ("(i)i",	script_get_horizontal_direction),
 
   /* blob */
   NATIVE_SYMBOL ("(i)",		blob_free),
@@ -60,6 +62,7 @@ static NativeSymbol _hb_wasm_native_symbols[] =
   NATIVE_SYMBOL ("(ii)",	buffer_copy_contents),
   NATIVE_SYMBOL ("(ii)i",	buffer_set_contents),
   NATIVE_SYMBOL ("(i)i",	buffer_get_direction),
+  NATIVE_SYMBOL ("(i)i",	buffer_get_script),
   NATIVE_SYMBOL ("(i)",		buffer_reverse),
   NATIVE_SYMBOL ("(i)",		buffer_reverse_clusters),
 

src/hb-wasm-api.cc

@@ -29,6 +29,7 @@
 
 #include "hb-wasm-api-blob.hh"
 #include "hb-wasm-api-buffer.hh"
+#include "hb-wasm-api-common.hh"
 #include "hb-wasm-api-face.hh"
 #include "hb-wasm-api-font.hh"
 #include "hb-wasm-api-shape.hh"

src/hb-wasm-api.h

@@ -92,6 +92,14 @@ typedef enum {
 #define DIRECTION_IS_BACKWARD(dir)	((((unsigned int) (dir)) & ~2U) == 5)
 #define DIRECTION_REVERSE(dir)		((direction_t) (((unsigned int) (dir)) ^ 1))
 
+typedef tag_t script_t; /* ISO 15924 representation of Unicode scripts. */
+
+
+/* common */
+
+HB_WASM_API (direction_t, script_get_horizontal_direction) (HB_WASM_EXEC_ENV
+							    script_t script);
+
 
 /* blob */
 
@@ -151,6 +159,9 @@ HB_WASM_API (bool_t, buffer_set_contents) (HB_WASM_EXEC_ENV
 HB_WASM_API (direction_t, buffer_get_direction) (HB_WASM_EXEC_ENV
 						 ptr_d(buffer_t, buffer));
 
+HB_WASM_API (script_t, buffer_get_script) (HB_WASM_EXEC_ENV
+					   ptr_d(buffer_t, buffer));
+
 HB_WASM_API (void, buffer_reverse) (HB_WASM_EXEC_ENV
 				    ptr_d(buffer_t, buffer));
 

src/meson.build

@@ -329,6 +329,7 @@ hb_wasm_sources = files(
   'hb-wasm-api.hh',
   'hb-wasm-api-blob.hh',
   'hb-wasm-api-buffer.hh',
+  'hb-wasm-api-common.hh',
   'hb-wasm-api-face.hh',
   'hb-wasm-api-font.hh',
   'hb-wasm-api-shape.hh',

src/wasm-graphite/shape.cc

@@ -38,15 +38,24 @@ static void free_table (const void *data, const void *table_data)
 bool_t
 shape (font_t *font, buffer_t *buffer)
 {
-  face_t *face = font_get_face (font);
-
-  blob_t blob = face_reference_table (face, TAG ('c','m','a','p'));
-
-  blob_free (&blob);
+  direction_t direction = buffer_get_direction (buffer);
+  direction_t horiz_dir = script_get_horizontal_direction (buffer_get_script (buffer));
+  /* TODO vertical:
+   * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
+   * Ogham fonts are supposed to be implemented BTT or not.  Need to research that
+   * first. */
+  if ((DIRECTION_IS_HORIZONTAL (direction) &&
+       direction != horiz_dir && horiz_dir != DIRECTION_INVALID) ||
+      (DIRECTION_IS_VERTICAL   (direction) &&
+       direction != DIRECTION_TTB))
+  {
+    buffer_reverse_clusters (buffer);
+    direction = DIRECTION_REVERSE (direction);
+  }
 
   buffer_contents_t contents = buffer_copy_contents (buffer);
-  direction_t direction = buffer_get_direction (buffer);
 
+  face_t *face = font_get_face (font);
   const gr_face_ops ops = {sizeof (gr_face_ops), &copy_table, &free_table};
   gr_face *grface = gr_make_face_with_ops (face, &ops, gr_face_preloadAll);