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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 old

 #define hb_old_shaper_face_data_t HB_FaceRec_

 #define hb_old_shaper_font_data_t HB_Font_

 #include "hb-shaper-impl-private.hh"

 #include <harfbuzz.h>

 #ifndef HB_DEBUG_OLD

 #define HB_DEBUG_OLD (HB_DEBUG+0)

 #endif

 static HB_Script

 hb_old_script_from_script (hb_script_t script)

 {

   switch ((hb_tag_t) script)

   {

     default:

     case HB_SCRIPT_COMMON:		return HB_Script_Common;

     case HB_SCRIPT_GREEK:		return HB_Script_Greek;

     case HB_SCRIPT_CYRILLIC:		return HB_Script_Cyrillic;

     case HB_SCRIPT_ARMENIAN:		return HB_Script_Armenian;

     case HB_SCRIPT_HEBREW:		return HB_Script_Hebrew;

     case HB_SCRIPT_ARABIC:		return HB_Script_Arabic;

     case HB_SCRIPT_SYRIAC:		return HB_Script_Syriac;

     case HB_SCRIPT_THAANA:		return HB_Script_Thaana;

     case HB_SCRIPT_DEVANAGARI:		return HB_Script_Devanagari;

     case HB_SCRIPT_BENGALI:		return HB_Script_Bengali;

     case HB_SCRIPT_GURMUKHI:		return HB_Script_Gurmukhi;

     case HB_SCRIPT_GUJARATI:		return HB_Script_Gujarati;

     case HB_SCRIPT_ORIYA:		return HB_Script_Oriya;

     case HB_SCRIPT_TAMIL:		return HB_Script_Tamil;

     case HB_SCRIPT_TELUGU:		return HB_Script_Telugu;

     case HB_SCRIPT_KANNADA:		return HB_Script_Kannada;

     case HB_SCRIPT_MALAYALAM:		return HB_Script_Malayalam;

     case HB_SCRIPT_SINHALA:		return HB_Script_Sinhala;

     case HB_SCRIPT_THAI:		return HB_Script_Thai;

     case HB_SCRIPT_LAO:			return HB_Script_Lao;

     case HB_SCRIPT_TIBETAN:		return HB_Script_Tibetan;

     case HB_SCRIPT_MYANMAR:		return HB_Script_Myanmar;

     case HB_SCRIPT_GEORGIAN:		return HB_Script_Georgian;

     case HB_SCRIPT_HANGUL:		return HB_Script_Hangul;

     case HB_SCRIPT_OGHAM:		return HB_Script_Ogham;

     case HB_SCRIPT_RUNIC:		return HB_Script_Runic;

     case HB_SCRIPT_KHMER:		return HB_Script_Khmer;

     case HB_SCRIPT_NKO:			return HB_Script_Nko;

     case HB_SCRIPT_INHERITED:		return HB_Script_Inherited;

   }

 }

 static HB_Bool

 hb_old_convertStringToGlyphIndices (HB_Font old_font,

 				    const HB_UChar16 *string,

 				    hb_uint32 length,

 				    HB_Glyph *glyphs,

 				    hb_uint32 *numGlyphs,

 				    HB_Bool rightToLeft)

 {

   hb_font_t *font = (hb_font_t *) old_font->userData;

   for (unsigned int i = 0; i < length; i++)

   {

     hb_codepoint_t u;

     /* XXX Handle UTF-16.  Ugh */

     u = string[i];

     if (rightToLeft)

       u = hb_unicode_funcs_get_default ()->mirroring (u);

     font->get_glyph (u, 0, &u); /* TODO Variation selectors */

     glyphs[i] = u;

   }

   *numGlyphs = length; /* XXX */

   return true;

 }

 static void

 hb_old_getGlyphAdvances (HB_Font old_font,

 			 const HB_Glyph *glyphs,

 			 hb_uint32 numGlyphs,

 			 HB_Fixed *advances,

 			 int flags /*HB_ShaperFlag*/ HB_UNUSED)

 {

   hb_font_t *font = (hb_font_t *) old_font->userData;

   for (unsigned int i = 0; i < numGlyphs; i++)

     advances[i] = font->get_glyph_h_advance (glyphs[i]);

 }

 static HB_Bool

 hb_old_canRender (HB_Font old_font,

 		  const HB_UChar16 *string,

 		  hb_uint32 length)

 {

   return true; /* TODO */

 }

 static HB_Error

 hb_old_getPointInOutline (HB_Font old_font,

 			  HB_Glyph glyph,

 			  int flags /*HB_ShaperFlag*/,

 			  hb_uint32 point,

 			  HB_Fixed *xpos,

 			  HB_Fixed *ypos,

 			  hb_uint32 *nPoints)

 {

   return HB_Err_Ok; /* TODO */

 }

 static void

 hb_old_getGlyphMetrics (HB_Font old_font,

 			HB_Glyph glyph,

 			HB_GlyphMetrics *metrics)

 {

   hb_font_t *font = (hb_font_t *) old_font->userData;

   hb_glyph_extents_t extents;

   font->get_glyph_extents (glyph, &extents);

   metrics->x       = extents.x_bearing;

   metrics->y       = extents.y_bearing;

   metrics->width   = extents.width;

   metrics->height  = extents.height;

   metrics->xOffset = font->get_glyph_h_advance (glyph);

   metrics->yOffset = 0;

 }

 static HB_Fixed

 hb_old_getFontMetric (HB_Font old_font,

 		      HB_FontMetric metric)

 {

   hb_font_t *font = (hb_font_t *) old_font->userData;

   switch (metric)

   {

     case HB_FontAscent:

        return font->y_scale; /* XXX We don't have ascent data yet. */

     default:

       return 0;

   }

 }

 static const HB_FontClass hb_old_font_class = {

   hb_old_convertStringToGlyphIndices,

   hb_old_getGlyphAdvances,

   hb_old_canRender,

   hb_old_getPointInOutline,

   hb_old_getGlyphMetrics,

   hb_old_getFontMetric

 };

 static HB_Error

 table_func (void *font, HB_Tag tag, HB_Byte *buffer, HB_UInt *length)

 {

   hb_face_t *face = (hb_face_t *) font;

   hb_blob_t *blob = face->reference_table ((hb_tag_t) tag);

   unsigned int capacity = *length;

   *length = hb_blob_get_length (blob);

   memcpy (buffer, hb_blob_get_data (blob, NULL), MIN (capacity, *length));

   hb_blob_destroy (blob);

  return HB_Err_Ok;

 }

 /*

  * shaper face data

  */

 hb_old_shaper_face_data_t *

 _hb_old_shaper_face_data_create (hb_face_t *face)

 {

   return HB_NewFace (face, table_func);

 }

 void

 _hb_old_shaper_face_data_destroy (hb_old_shaper_face_data_t *data)

 {

   HB_FreeFace (data);

 }

 /*

  * shaper font data

  */

 hb_old_shaper_font_data_t *

 _hb_old_shaper_font_data_create (hb_font_t *font)

 {

   HB_FontRec *data = (HB_FontRec *) calloc (1, sizeof (HB_FontRec));

   if (unlikely (!data)) {

     DEBUG_MSG (OLD, font, "malloc()ing HB_Font failed");

     return NULL;

   }

   data->klass = &hb_old_font_class;

   data->x_ppem = font->x_ppem;

   data->y_ppem = font->y_ppem;

   data->x_scale = font->x_scale; /* XXX */

   data->y_scale = font->y_scale; /* XXX */

   data->userData = font;

   return data;

 }

 void

 _hb_old_shaper_font_data_destroy (hb_old_shaper_font_data_t *data)

 {

   free (data);

 }

 /*

  * shaper shape_plan data

  */

 struct hb_old_shaper_shape_plan_data_t {};

 hb_old_shaper_shape_plan_data_t *

 _hb_old_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,

 				       const hb_feature_t *user_features HB_UNUSED,

 				       unsigned int        num_user_features HB_UNUSED)

 {

   return (hb_old_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;

 }

 void

 _hb_old_shaper_shape_plan_data_destroy (hb_old_shaper_shape_plan_data_t *data HB_UNUSED)

 {

 }

 /*

  * shaper

  */

 hb_bool_t

 _hb_old_shape (hb_shape_plan_t    *shape_plan HB_UNUSED,

 	       hb_font_t          *font,

 	       hb_buffer_t        *buffer,

 	       const hb_feature_t *features,

 	       unsigned int        num_features)

 {

   hb_face_t *face = font->face;

   HB_Face old_face = HB_SHAPER_DATA_GET (face);

   HB_Font old_font = HB_SHAPER_DATA_GET (font);

   bool backward = HB_DIRECTION_IS_BACKWARD (buffer->props.direction);

 retry:

   unsigned int scratch_size;

   char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);

 #define utf16_index() var1.u32

   HB_UChar16 *pchars = (HB_UChar16 *) scratch;

   unsigned int chars_len = 0;

   for (unsigned int i = 0; i < buffer->len; i++) {

     hb_codepoint_t c = buffer->info[i].codepoint;

     buffer->info[i].utf16_index() = chars_len;

     if (likely (c < 0x10000))

       pchars[chars_len++] = c;

     else if (unlikely (c >= 0x110000))

       pchars[chars_len++] = 0xFFFD;

     else {

       pchars[chars_len++] = 0xD800 + ((c - 0x10000) >> 10);

       pchars[chars_len++] = 0xDC00 + ((c - 0x10000) & ((1 << 10) - 1));

     }

   }

 #define ALLOCATE_ARRAY(Type, name, len) \

   name = (Type *) scratch; \

   scratch += (len) * sizeof ((name)[0]); \

   scratch_size -= (len) * sizeof ((name)[0]);

   HB_ShaperItem item = {0};

   ALLOCATE_ARRAY (const HB_UChar16, item.string, chars_len);

   ALLOCATE_ARRAY (unsigned short, item.log_clusters, chars_len + 2);

   item.stringLength = chars_len;

   item.item.pos = 0;

   item.item.length = item.stringLength;

   item.item.script = hb_old_script_from_script (buffer->props.script);

   item.item.bidiLevel = backward ? 1 : 0;

   item.font = old_font;

   item.face = old_face;

   item.shaperFlags = 0;

   item.glyphIndicesPresent = false;

   /* TODO Alignment. */

   unsigned int num_glyphs = scratch_size / (sizeof (HB_Glyph) +

 					    sizeof (HB_GlyphAttributes) +

 					    sizeof (HB_Fixed) +

 					    sizeof (HB_FixedPoint) +

 					    sizeof (uint32_t));

   item.num_glyphs = num_glyphs;

   ALLOCATE_ARRAY (HB_Glyph, item.glyphs, num_glyphs);

   ALLOCATE_ARRAY (HB_GlyphAttributes, item.attributes, num_glyphs);

   ALLOCATE_ARRAY (HB_Fixed, item.advances, num_glyphs);

   ALLOCATE_ARRAY (HB_FixedPoint, item.offsets, num_glyphs);

   /* Apparently in some cases the offsets array will not be fully assigned to.

    * Clear it. */

   memset (item.offsets, 0, num_glyphs * sizeof (item.offsets[0]));

   uint32_t *vis_clusters;

   ALLOCATE_ARRAY (uint32_t, vis_clusters, num_glyphs);

 #undef ALLOCATE_ARRAY

   if (!HB_ShapeItem (&item))

   {

     if (unlikely (item.num_glyphs > num_glyphs))

     {

       buffer->ensure (buffer->allocated * 2);

       if (buffer->in_error)

         return false;

       goto retry;

     }

     return false;

   }

   num_glyphs = item.num_glyphs;

   /* Ok, we've got everything we need, now compose output buffer,

    * very, *very*, carefully! */

   /* Calculate visual-clusters.  That's what we ship. */

   for (unsigned int i = 0; i < num_glyphs; i++)

     vis_clusters[i] = -1;

   for (unsigned int i = 0; i < buffer->len; i++) {

     uint32_t *p = &vis_clusters[item.log_clusters[buffer->info[i].utf16_index()]];

     *p = MIN (*p, buffer->info[i].cluster);

   }

   for (unsigned int i = 1; i < num_glyphs; i++)

     if (vis_clusters[i] == (uint32_t) -1)

       vis_clusters[i] = vis_clusters[i - 1];

 #undef utf16_index

   buffer->ensure (num_glyphs);

   if (buffer->in_error)

     return false;

   buffer->len = num_glyphs;

   hb_glyph_info_t *info = buffer->info;

   for (unsigned int i = 0; i < num_glyphs; i++)

   {

     info[i].codepoint = item.glyphs[i];

     info[i].cluster = vis_clusters[i];

     info[i].mask = item.advances[i];

     info[i].var1.u32 = item.offsets[i].x;

     info[i].var2.u32 = item.offsets[i].y;

   }

   buffer->clear_positions ();

   for (unsigned int i = 0; i < num_glyphs; ++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;

   }

   if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))

     buffer->reverse ();

   return true;

 }