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 /*

  * 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/loengine.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 HB_UNUSED)

 {

   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 HB_UNUSED)

 {

 }

 /*

  * 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 HB_UNUSED,

 					  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; /* Needed for ligatures and kerning */

   LEErrorCode status = LE_NO_ERROR;

   le_engine *le = le_create ((const le_font *) font_instance,

 			     script_code,

 			     language_code,

 			     typography_flags,

 			     &status);

   if (status != LE_NO_ERROR)

   { le_close (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);

   /* XXX Use UTF-16 decoder! */

   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 (le,

 					     chars,

 					     0,

 					     buffer->len,

 					     buffer->len,

 					     HB_DIRECTION_IS_BACKWARD (buffer->props.direction),

 					     0., 0.,

 					     &status);

   if (status != LE_NO_ERROR)

   { le_close (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)

     { le_close (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 (le, glyphs, &status);

   le_getCharIndices (le, indices, &status);

   le_getGlyphPositions (le, 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 separate 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;

   }

   le_close (le);

   return true;

 }