harfbuzz-ng roll

third_party/harfbuzz-ng/src/hb-icu-le.cc

+/*
+ * Copyright © 2012  Google, Inc.
+ *
+ *  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.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#define HB_SHAPER icu_le
+#define hb_icu_le_shaper_font_data_t PortableFontInstance
+#include "hb-shaper-impl-private.hh"
+
+#include "hb-icu-le/PortableFontInstance.h"
+
+#include "layout/LayoutEngine.h"
+#include "unicode/unistr.h"
+
+#include "hb-icu.h"
+
+
+/*
+ * shaper face data
+ */
+
+struct hb_icu_le_shaper_face_data_t {};
+
+hb_icu_le_shaper_face_data_t *
+_hb_icu_le_shaper_face_data_create (hb_face_t *face)
+{
+  return (hb_icu_le_shaper_face_data_t *) HB_SHAPER_DATA_SUCCEEDED;
+}
+
+void
+_hb_icu_le_shaper_face_data_destroy (hb_icu_le_shaper_face_data_t *data)
+{
+}
+
+
+/*
+ * shaper font data
+ */
+
+hb_icu_le_shaper_font_data_t *
+_hb_icu_le_shaper_font_data_create (hb_font_t *font)
+{
+  LEErrorCode status = LE_NO_ERROR;
+  hb_icu_le_shaper_font_data_t *data = new PortableFontInstance (font->face,
+                                                                 font->x_scale,
+                                                                 font->y_scale,
+                                                                 status);
+  if (status != LE_NO_ERROR) {
+    delete (data);
+    return NULL;
+  }
+
+  return data;
+}
+
+void
+_hb_icu_le_shaper_font_data_destroy (hb_icu_le_shaper_font_data_t *data)
+{
+  delete (data);
+}
+
+
+/*
+ * shaper shape_plan data
+ */
+
+struct hb_icu_le_shaper_shape_plan_data_t {};
+
+hb_icu_le_shaper_shape_plan_data_t *
+_hb_icu_le_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan,
+                                          const hb_feature_t *user_features,
+                                          unsigned int        num_user_features)
+{
+  return (hb_icu_le_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
+}
+
+void
+_hb_icu_le_shaper_shape_plan_data_destroy (hb_icu_le_shaper_shape_plan_data_t *data)
+{
+}
+
+
+/*
+ * shaper
+ */
+
+hb_bool_t
+_hb_icu_le_shape (hb_shape_plan_t    *shape_plan,
+                  hb_font_t          *font,
+                  hb_buffer_t        *buffer,
+                  const hb_feature_t *features,
+                  unsigned int        num_features)
+{
+  LEFontInstance *font_instance = HB_SHAPER_DATA_GET (font);
+  le_int32 script_code = hb_icu_script_from_script (shape_plan->props.script);
+  le_int32 language_code = -1 /* TODO */;
+  le_int32 typography_flags = 3; // essential for ligatures and kerning
+  LEErrorCode status = LE_NO_ERROR;
+  LayoutEngine *le = LayoutEngine::layoutEngineFactory (font_instance,
+                                                        script_code,
+                                                        language_code,
+                                                        typography_flags,
+                                                        status);
+  if (status != LE_NO_ERROR)
+  { delete (le); return false; }
+
+retry:
+
+  unsigned int scratch_size;
+  char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
+
+#define ALLOCATE_ARRAY(Type, name, len) \
+  Type *name = (Type *) scratch; \
+  scratch += (len) * sizeof ((name)[0]); \
+  scratch_size -= (len) * sizeof ((name)[0]);
+
+  ALLOCATE_ARRAY (LEUnicode, chars, buffer->len);
+  ALLOCATE_ARRAY (unsigned int, clusters, buffer->len);
+
+  for (unsigned int i = 0; i < buffer->len; i++) {
+    chars[i] = buffer->info[i].codepoint;
+    clusters[i] = buffer->info[i].cluster;
+  }
+
+  unsigned int glyph_count = le->layoutChars(chars,
+                                             0,
+                                             buffer->len,
+                                             buffer->len,
+                                             HB_DIRECTION_IS_BACKWARD (buffer->props.direction),
+                                             0., 0.,
+                                             status);
+  if (status != LE_NO_ERROR)
+  { delete (le); return false; }
+
+  unsigned int num_glyphs = scratch_size / (sizeof (LEGlyphID) +
+                                            sizeof (le_int32) +
+                                            sizeof (float) * 2);
+
+  if (unlikely (glyph_count >= num_glyphs || glyph_count > buffer->allocated)) {
+    buffer->ensure (buffer->allocated * 2);
+    if (buffer->in_error)
+    { delete (le); return false; }
+    goto retry;
+  }
+
+  ALLOCATE_ARRAY (LEGlyphID, glyphs, glyph_count);
+  ALLOCATE_ARRAY (le_int32, indices, glyph_count);
+  ALLOCATE_ARRAY (float, positions, glyph_count * 2 + 2);
+
+  le->getGlyphs(glyphs, status);
+  le->getCharIndices(indices, status);
+  le->getGlyphPositions(positions, status);
+
+#undef ALLOCATE_ARRAY
+
+  /* Ok, we've got everything we need, now compose output buffer,
+   * very, *very*, carefully! */
+
+  unsigned int j = 0;
+  hb_glyph_info_t *info = buffer->info;
+  for (unsigned int i = 0; i < glyph_count; i++)
+  {
+    if (glyphs[i] >= 0xFFFE)
+        continue;
+
+    info[j].codepoint = glyphs[i];
+    info[j].cluster = clusters[indices[i]];
+
+    /* icu-le doesn't seem to have separapte advance values. */
+    info[j].mask = positions[2 * i + 2] - positions[2 * i];
+    info[j].var1.u32 = 0;
+    info[j].var2.u32 = -positions[2 * i + 1];
+
+    j++;
+  }
+  buffer->len = j;
+
+  buffer->clear_positions ();
+
+  for (unsigned int i = 0; i < buffer->len; i++) {
+    hb_glyph_info_t *info = &buffer->info[i];
+    hb_glyph_position_t *pos = &buffer->pos[i];
+
+    /* TODO vertical */
+    pos->x_advance = info->mask;
+    pos->x_offset = info->var1.u32;
+    pos->y_offset = info->var2.u32;
+  }
+
+  delete (le);
+  return true;
+}