[HarfBuzz] harfbuzz-ng: Branch 'master' - 5 commits

Behdad Esfahbod behdad at kemper.freedesktop.org
Sat Aug 11 15:35:27 PDT 2012


 TODO                               |    4 +
 src/hb-ot-shape-complex-arabic.cc  |  110 +++++++++++++++++++++++++------------
 src/hb-ot-shape-complex-indic.cc   |    1 
 src/hb-ot-shape-complex-misc.cc    |   12 ++--
 src/hb-ot-shape-complex-private.hh |   15 ++++-
 src/hb-ot-shape-fallback.cc        |   22 ++++++-
 src/hb-ot-shape.cc                 |    3 +
 7 files changed, 123 insertions(+), 44 deletions(-)

New commits:
commit 9f9f04c2229227bb0712166e824157bbbf5cef80
Author: Behdad Esfahbod <behdad at behdad.org>
Date:   Sat Aug 11 18:34:13 2012 -0400

    [OT] Unbreak Thai shaping and fallback Arabic shaping
    
    The merger of normalizer and glyph-mapping broke shapers that
    modified text stream.  Unbreak them by adding a new preprocess_text
    shaping stage that happens before normalizing/cmap and disallow
    setup_mask modification of actual text.

diff --git a/src/hb-ot-shape-complex-arabic.cc b/src/hb-ot-shape-complex-arabic.cc
index e0db41c..e1a2791 100644
--- a/src/hb-ot-shape-complex-arabic.cc
+++ b/src/hb-ot-shape-complex-arabic.cc
@@ -274,12 +274,8 @@ arabic_fallback_shape (hb_font_t *font, hb_buffer_t *buffer)
 }
 
 static void
-setup_masks_arabic (const hb_ot_shape_plan_t *plan,
-		    hb_buffer_t              *buffer,
-		    hb_font_t                *font)
+arabic_joining (hb_buffer_t *buffer)
 {
-  const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
-
   unsigned int count = buffer->len;
   unsigned int prev = 0, state = 0;
 
@@ -305,14 +301,37 @@ setup_masks_arabic (const hb_ot_shape_plan_t *plan,
     state = entry->next_state;
   }
 
-  if (likely (!arabic_plan->do_fallback)) {
-    /* Has OpenType tables */
-    for (unsigned int i = 0; i < count; i++)
-      buffer->info[i].mask |= arabic_plan->mask_array[buffer->info[i].arabic_shaping_action()];
-  } else
+  HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);
+}
+
+static void
+preprocess_text_arabic (const hb_ot_shape_plan_t *plan,
+			hb_buffer_t              *buffer,
+			hb_font_t                *font)
+{
+  const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
+
+  if (unlikely (arabic_plan->do_fallback))
+  {
+    arabic_joining (buffer);
     arabic_fallback_shape (font, buffer);
+  }
+}
 
-  HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);
+static void
+setup_masks_arabic (const hb_ot_shape_plan_t *plan,
+		    hb_buffer_t              *buffer,
+		    hb_font_t                *font)
+{
+  const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
+
+  if (likely (!arabic_plan->do_fallback))
+  {
+    arabic_joining (buffer);
+    unsigned int count = buffer->len;
+    for (unsigned int i = 0; i < count; i++)
+      buffer->info[i].mask |= arabic_plan->mask_array[buffer->info[i].arabic_shaping_action()];
+  }
 }
 
 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic =
@@ -322,6 +341,7 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic =
   NULL, /* override_features */
   data_create_arabic,
   data_destroy_arabic,
+  preprocess_text_arabic,
   NULL, /* normalization_preference */
   setup_masks_arabic,
   true, /* zero_width_attached_marks */
diff --git a/src/hb-ot-shape-complex-indic.cc b/src/hb-ot-shape-complex-indic.cc
index 4f9a5af..6fbd5c8 100644
--- a/src/hb-ot-shape-complex-indic.cc
+++ b/src/hb-ot-shape-complex-indic.cc
@@ -1134,6 +1134,7 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_indic =
   override_features_indic,
   data_create_indic,
   data_destroy_indic,
+  NULL, /* preprocess_text */
   NULL, /* normalization_preference */
   setup_masks_indic,
   false, /* zero_width_attached_marks */
diff --git a/src/hb-ot-shape-complex-misc.cc b/src/hb-ot-shape-complex-misc.cc
index 4f1dd5b..13bc22b 100644
--- a/src/hb-ot-shape-complex-misc.cc
+++ b/src/hb-ot-shape-complex-misc.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright © 2010  Google, Inc.
+ * Copyright © 2010,2012  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
@@ -90,6 +90,7 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_default =
   NULL, /* override_features */
   NULL, /* data_create */
   NULL, /* data_destroy */
+  NULL, /* preprocess_text */
   normalization_preference_default,
   NULL, /* setup_masks */
   true, /* zero_width_attached_marks */
@@ -99,9 +100,9 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_default =
 /* Thai / Lao shaper */
 
 static void
-setup_masks_thai (const hb_ot_shape_plan_t *plan HB_UNUSED,
-		  hb_buffer_t              *buffer,
-		  hb_font_t                *font HB_UNUSED)
+preprocess_text_thai (const hb_ot_shape_plan_t *plan HB_UNUSED,
+		      hb_buffer_t              *buffer,
+		      hb_font_t                *font HB_UNUSED)
 {
   /* The following is NOT specified in the MS OT Thai spec, however, it seems
    * to be what Uniscribe and other engines implement.  According to Eric Muller:
@@ -200,7 +201,8 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_thai =
   NULL, /* override_features */
   NULL, /* data_create */
   NULL, /* data_destroy */
+  preprocess_text_thai,
   NULL, /* normalization_preference */
-  setup_masks_thai,
+  NULL, /* setup_masks */
   true, /* zero_width_attached_marks */
 };
diff --git a/src/hb-ot-shape-complex-private.hh b/src/hb-ot-shape-complex-private.hh
index efff325..e84c490 100644
--- a/src/hb-ot-shape-complex-private.hh
+++ b/src/hb-ot-shape-complex-private.hh
@@ -56,7 +56,6 @@ struct hb_ot_complex_shaper_t
   /* collect_features()
    * Called during shape_plan().
    * Shapers should use plan->map to add their features and callbacks.
-   * May be NULL.
    */
   void (*collect_features) (hb_ot_shape_planner_t *plan);
 
@@ -64,7 +63,6 @@ struct hb_ot_complex_shaper_t
    * Called during shape_plan().
    * Shapers should use plan->map to override features and add callbacks after
    * common features are added.
-   * May be NULL.
    */
   void (*override_features) (hb_ot_shape_planner_t *plan);
 
@@ -73,7 +71,7 @@ struct hb_ot_complex_shaper_t
    * Called at the end of shape_plan().
    * Whatever shapers return will be accessible through plan->data later.
    * If NULL is returned, means a plan failure.
-   * May be NULL. */
+   */
   void *(*data_create) (const hb_ot_shape_plan_t *plan);
 
   /* data_destroy()
@@ -83,6 +81,16 @@ struct hb_ot_complex_shaper_t
    * May be NULL. */
   void (*data_destroy) (void *data);
 
+
+  /* preprocess_text()
+   * Called during shape().
+   * Shapers can use to modify text before shaping starts.
+   */
+  void (*preprocess_text) (const hb_ot_shape_plan_t *plan,
+			   hb_buffer_t              *buffer,
+			   hb_font_t                *font);
+
+
   /* normalization_preference()
    * Called during shape().
    */
@@ -92,6 +100,7 @@ struct hb_ot_complex_shaper_t
   /* setup_masks()
    * Called during shape().
    * Shapers should use map to get feature masks and set on buffer.
+   * Shapers may NOT modify characters.
    */
   void (*setup_masks) (const hb_ot_shape_plan_t *plan,
 		       hb_buffer_t              *buffer,
diff --git a/src/hb-ot-shape.cc b/src/hb-ot-shape.cc
index 823eced..29076cf 100644
--- a/src/hb-ot-shape.cc
+++ b/src/hb-ot-shape.cc
@@ -319,6 +319,9 @@ hb_ot_map_glyphs_fast (hb_buffer_t  *buffer)
 static inline void
 hb_ot_substitute_default (hb_ot_shape_context_t *c)
 {
+  if (c->plan->shaper->preprocess_text)
+    c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
+
   hb_ot_mirror_chars (c);
 
   HB_BUFFER_ALLOCATE_VAR (c->buffer, glyph_index);
commit e9f28a38f54b98fa59f9159ccaaa3be6027e1378
Author: Behdad Esfahbod <behdad at behdad.org>
Date:   Sat Aug 11 18:20:28 2012 -0400

    [OT] Add shape_plan to Arabic shaper

diff --git a/src/hb-ot-shape-complex-arabic.cc b/src/hb-ot-shape-complex-arabic.cc
index 2a96b7d..e0db41c 100644
--- a/src/hb-ot-shape-complex-arabic.cc
+++ b/src/hb-ot-shape-complex-arabic.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright © 2010  Google, Inc.
+ * Copyright © 2010,2012  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
@@ -99,7 +99,7 @@ static uint16_t get_ligature (hb_codepoint_t first, hb_codepoint_t second)
   return 0;
 }
 
-static const hb_tag_t arabic_syriac_features[] =
+static const hb_tag_t arabic_features[] =
 {
   HB_TAG('i','n','i','t'),
   HB_TAG('m','e','d','i'),
@@ -127,9 +127,7 @@ enum {
 
   NONE,
 
-  COMMON_NUM_FEATURES = 4,
-  SYRIAC_NUM_FEATURES = 7,
-  TOTAL_NUM_FEATURES = NONE
+  ARABIC_NUM_FEATURES = NONE
 };
 
 static const struct arabic_state_table_entry {
@@ -184,9 +182,8 @@ collect_features_arabic (hb_ot_shape_planner_t *plan)
 
   map->add_gsub_pause (NULL);
 
-  unsigned int num_features = plan->props.script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES;
-  for (unsigned int i = 0; i < num_features; i++)
-    map->add_bool_feature (arabic_syriac_features[i], false);
+  for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++)
+    map->add_bool_feature (arabic_features[i], false);
 
   map->add_gsub_pause (NULL);
 
@@ -200,10 +197,51 @@ collect_features_arabic (hb_ot_shape_planner_t *plan)
   map->add_bool_feature (HB_TAG('c','s','w','h'));
 }
 
+struct arabic_shape_plan_t
+{
+  ASSERT_POD ();
+
+  bool do_fallback;
+  hb_mask_t mask_array[ARABIC_NUM_FEATURES];
+};
+
+static void *
+data_create_arabic (const hb_ot_shape_plan_t *plan)
+{
+  arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) calloc (1, sizeof (arabic_shape_plan_t));
+  if (unlikely (!arabic_plan))
+    return NULL;
+
+  hb_mask_t total_masks = 0;
+  for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) {
+    arabic_plan->mask_array[i] = plan->map.get_1_mask (arabic_features[i]);
+    total_masks |= arabic_plan->mask_array[i];
+  }
+
+  /* Pitfalls:
+   * - This path fires if user force-set init/medi/fina/isol off,
+   * - If font does not declare script 'arab', well, what to do?
+   *   Most probably it's safe to assume that init/medi/fina/isol
+   *   still mean Arabic shaping, although they do not have to.
+   */
+  arabic_plan->do_fallback = 0 == total_masks;
+
+  return arabic_plan;
+}
+
+static void
+data_destroy_arabic (void *data)
+{
+  free (data);
+}
 
 static void
 arabic_fallback_shape (hb_font_t *font, hb_buffer_t *buffer)
 {
+  /* Only Arabic has presentation forms encoded in Unicode. */
+  if (buffer->props.script != HB_SCRIPT_ARABIC)
+    return;
+
   unsigned int count = buffer->len;
   hb_codepoint_t glyph;
 
@@ -240,6 +278,8 @@ setup_masks_arabic (const hb_ot_shape_plan_t *plan,
 		    hb_buffer_t              *buffer,
 		    hb_font_t                *font)
 {
+  const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
+
   unsigned int count = buffer->len;
   unsigned int prev = 0, state = 0;
 
@@ -265,28 +305,12 @@ setup_masks_arabic (const hb_ot_shape_plan_t *plan,
     state = entry->next_state;
   }
 
-  hb_mask_t mask_array[TOTAL_NUM_FEATURES + 1] = {0};
-  hb_mask_t total_masks = 0;
-  unsigned int num_masks = buffer->props.script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES;
-  for (unsigned int i = 0; i < num_masks; i++) {
-    mask_array[i] = plan->map.get_1_mask (arabic_syriac_features[i]);
-    total_masks |= mask_array[i];
-  }
-
-  if (total_masks) {
+  if (likely (!arabic_plan->do_fallback)) {
     /* Has OpenType tables */
     for (unsigned int i = 0; i < count; i++)
-      buffer->info[i].mask |= mask_array[buffer->info[i].arabic_shaping_action()];
-  } else if (buffer->props.script == HB_SCRIPT_ARABIC) {
-    /* Fallback Arabic shaping to Presentation Forms */
-    /* Pitfalls:
-     * - This path fires if user force-set init/medi/fina/isol off,
-     * - If font does not declare script 'arab', well, what to do?
-     *   Most probably it's safe to assume that init/medi/fina/isol
-     *   still mean Arabic shaping, although they do not have to.
-     */
+      buffer->info[i].mask |= arabic_plan->mask_array[buffer->info[i].arabic_shaping_action()];
+  } else
     arabic_fallback_shape (font, buffer);
-  }
 
   HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);
 }
@@ -296,8 +320,8 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic =
   "arabic",
   collect_features_arabic,
   NULL, /* override_features */
-  NULL, /* data_create */
-  NULL, /* data_destroy */
+  data_create_arabic,
+  data_destroy_arabic,
   NULL, /* normalization_preference */
   setup_masks_arabic,
   true, /* zero_width_attached_marks */
commit 344cc56698a8c84c4c1a05a71d829e5171aa3a60
Author: Behdad Esfahbod <behdad at behdad.org>
Date:   Sat Aug 11 17:36:23 2012 -0400

    Add TODO

diff --git a/TODO b/TODO
index 71e5b4d..0c09f00 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,10 @@
 General fixes:
 =============
 
+- Ligature matching and match_input() of (Chain)Context should use the
+  same logic.  Right now the Ligature logic is more involved.  Possibly
+  merge, or duplicate.
+
 - mask propagation? (when ligation, "or" the masks).
 
 - Warn at compile time (and runtime with HB_DEBUG?) if no Unicode / font
commit daf13afb0801740dcc7900c4af190e24b80a05c0
Author: Behdad Esfahbod <behdad at behdad.org>
Date:   Fri Aug 10 16:38:44 2012 -0400

    [OT] Implement fallback mark positioning for "double" combining marks

diff --git a/src/hb-ot-shape-fallback.cc b/src/hb-ot-shape-fallback.cc
index a6e5b16..56a3e7a 100644
--- a/src/hb-ot-shape-fallback.cc
+++ b/src/hb-ot-shape-fallback.cc
@@ -162,7 +162,14 @@ position_mark (const hb_ot_shape_plan_t *plan,
   {
     case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
     case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
-      /* TODO Do something...  For now, fall through. */
+      if (buffer->props.direction == HB_DIRECTION_LTR) {
+	pos.x_offset += base_extents.x_bearing - mark_extents.width / 2 - mark_extents.x_bearing;
+        break;
+      } else if (buffer->props.direction == HB_DIRECTION_RTL) {
+	pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing;
+        break;
+      }
+      /* Fall through */
 
     case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
     case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
commit d345313104d9e3c8a8533ccdebd74e0648d0bee3
Author: Behdad Esfahbod <behdad at behdad.org>
Date:   Fri Aug 10 16:34:04 2012 -0400

    [OT] Fix fallback mark positioning with left-to-right text
    
    Ouch!

diff --git a/src/hb-ot-shape-fallback.cc b/src/hb-ot-shape-fallback.cc
index abc7e2b..a6e5b16 100644
--- a/src/hb-ot-shape-fallback.cc
+++ b/src/hb-ot-shape-fallback.cc
@@ -242,6 +242,10 @@ position_around_base (const hb_ot_shape_plan_t *plan,
   HB_UNUSED bool is_ligature = is_a_ligature (buffer->info[base]);
 
   hb_position_t x_offset = 0, y_offset = 0;
+  if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
+    x_offset -= buffer->pos[base].x_advance;
+    y_offset -= buffer->pos[base].y_advance;
+  }
   unsigned int last_combining_class = 255;
   hb_glyph_extents_t cluster_extents;
   for (unsigned int i = base + 1; i < end; i++)
@@ -262,8 +266,13 @@ position_around_base (const hb_ot_shape_plan_t *plan,
 
       last_combining_class = this_combining_class;
     } else {
-      x_offset -= buffer->pos[i].x_advance;
-      y_offset -= buffer->pos[i].y_advance;
+      if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
+	x_offset -= buffer->pos[i].x_advance;
+	y_offset -= buffer->pos[i].y_advance;
+      } else {
+	x_offset += buffer->pos[i].x_advance;
+	y_offset += buffer->pos[i].y_advance;
+      }
     }
 
 



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