From 98079109e6ebc8f05b6c8de97fcd0ed5667907d1 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Sun, 13 Feb 2022 18:15:32 -0600
Subject: [PATCH] [ot-layout] Add
 +hb_ot_layout_get_horizontal_baseline_tag_for_script()

New API:
+hb_ot_layout_get_horizontal_baseline_tag_for_script()
---
 docs/harfbuzz-sections.txt |  1 +
 src/hb-ot-layout.cc        | 70 ++++++++++++++++++++++++++++++++++++++
 src/hb-ot-layout.h         |  3 ++
 3 files changed, 74 insertions(+)

diff --git a/docs/harfbuzz-sections.txt b/docs/harfbuzz-sections.txt
index acbcf1300..9263994b0 100644
--- a/docs/harfbuzz-sections.txt
+++ b/docs/harfbuzz-sections.txt
@@ -535,6 +535,7 @@ hb_ot_layout_feature_get_lookups
 hb_ot_layout_feature_get_name_ids
 hb_ot_layout_feature_with_variations_get_lookups
 hb_ot_layout_get_attach_points
+hb_ot_layout_get_horizontal_baseline_tag_for_script
 hb_ot_layout_get_baseline
 hb_ot_layout_get_glyph_class
 hb_ot_layout_get_glyphs_in_class
diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index 2d73ab690..aaabc687d 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -1966,6 +1966,76 @@ hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,
 }
 
 #ifndef HB_NO_BASE
+/**
+ * hb_ot_layout_get_horizontal_baseline_tag_for_script:
+ * @script: a script tag.
+ *
+ * Fetches the dominant horizontal baseline tag used by @script.
+ *
+ * Return value: dominant baseline tag for the @script.
+ *
+ * Since: REPLACEME
+ **/
+hb_ot_layout_baseline_tag_t
+hb_ot_layout_get_horizontal_baseline_tag_for_script (hb_script_t script)
+{
+  switch ((int) script)
+  {
+    /* Unicode-1.1 additions */
+    case HB_SCRIPT_BENGALI:
+    case HB_SCRIPT_DEVANAGARI:
+    case HB_SCRIPT_GUJARATI:
+    case HB_SCRIPT_GURMUKHI:
+    /* Unicode-2.0 additions */
+    case HB_SCRIPT_TIBETAN:
+    /* Unicode-4.0 additions */
+    case HB_SCRIPT_LIMBU:
+    /* Unicode-4.1 additions */
+    case HB_SCRIPT_SYLOTI_NAGRI:
+    /* Unicode-5.0 additions */
+    case HB_SCRIPT_PHAGS_PA:
+    /* Unicode-5.2 additions */
+    case HB_SCRIPT_MEETEI_MAYEK:
+    /* Unicode-6.1 additions */
+    case HB_SCRIPT_SHARADA:
+    case HB_SCRIPT_TAKRI:
+    /* Unicode-7.0 additions */
+    case HB_SCRIPT_MODI:
+    case HB_SCRIPT_SIDDHAM:
+    case HB_SCRIPT_TIRHUTA:
+    /* Unicode-9.0 additions */
+    case HB_SCRIPT_MARCHEN:
+    case HB_SCRIPT_NEWA:
+    /* Unicode-10.0 additions */
+    case HB_SCRIPT_SOYOMBO:
+    case HB_SCRIPT_ZANABAZAR_SQUARE:
+    /* Unicode-11.0 additions */
+    case HB_SCRIPT_DOGRA:
+    case HB_SCRIPT_GUNJALA_GONDI:
+    /* Unicode-12.0 additions */
+    case HB_SCRIPT_NANDINAGARI:
+      return HB_OT_LAYOUT_BASELINE_TAG_HANGING;
+
+    /* Unicode-1.1 additions */
+    case HB_SCRIPT_HANGUL:
+    case HB_SCRIPT_HAN:
+    case HB_SCRIPT_HIRAGANA:
+    case HB_SCRIPT_KATAKANA:
+    /* Unicode-3.0 additions */
+    case HB_SCRIPT_BOPOMOFO:
+    /* Unicode-9.0 additions */
+    case HB_SCRIPT_TANGUT:
+    /* Unicode-10.0 additions */
+    case HB_SCRIPT_NUSHU:
+    /* Unicode-13.0 additions */
+    case HB_SCRIPT_KHITAN_SMALL_SCRIPT:
+      return HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT;
+
+    default:
+      return HB_OT_LAYOUT_BASELINE_TAG_ROMAN;
+  }
+}
+
 /**
  * hb_ot_layout_get_baseline:
  * @font: a font
diff --git a/src/hb-ot-layout.h b/src/hb-ot-layout.h
index d47ba0fc9..edbb7b878 100644
--- a/src/hb-ot-layout.h
+++ b/src/hb-ot-layout.h
@@ -511,6 +511,9 @@ typedef enum {
   _HB_OT_LAYOUT_BASELINE_TAG_MAX_VALUE = HB_TAG_MAX_SIGNED /*< skip >*/
 } hb_ot_layout_baseline_tag_t;
 
+HB_EXTERN hb_ot_layout_baseline_tag_t
+hb_ot_layout_get_horizontal_baseline_tag_for_script (hb_script_t script);
+
 HB_EXTERN hb_bool_t
 hb_ot_layout_get_baseline (hb_font_t                   *font,
 			   hb_ot_layout_baseline_tag_t  baseline_tag,