michael@0: /*
michael@0:  * Copyright © 2012  Google, Inc.
michael@0:  *
michael@0:  *  This is part of HarfBuzz, a text shaping library.
michael@0:  *
michael@0:  * Permission is hereby granted, without written agreement and without
michael@0:  * license or royalty fees, to use, copy, modify, and distribute this
michael@0:  * software and its documentation for any purpose, provided that the
michael@0:  * above copyright notice and the following two paragraphs appear in
michael@0:  * all copies of this software.
michael@0:  *
michael@0:  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
michael@0:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
michael@0:  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
michael@0:  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
michael@0:  * DAMAGE.
michael@0:  *
michael@0:  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
michael@0:  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
michael@0:  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
michael@0:  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
michael@0:  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
michael@0:  *
michael@0:  * Google Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #define HB_SHAPER old
michael@0: #define hb_old_shaper_face_data_t HB_FaceRec_
michael@0: #define hb_old_shaper_font_data_t HB_Font_
michael@0: #include "hb-shaper-impl-private.hh"
michael@0: 
michael@0: #include <harfbuzz.h>
michael@0: 
michael@0: 
michael@0: #ifndef HB_DEBUG_OLD
michael@0: #define HB_DEBUG_OLD (HB_DEBUG+0)
michael@0: #endif
michael@0: 
michael@0: 
michael@0: static HB_Script
michael@0: hb_old_script_from_script (hb_script_t script)
michael@0: {
michael@0:   switch ((hb_tag_t) script)
michael@0:   {
michael@0:     default:
michael@0:     case HB_SCRIPT_COMMON:		return HB_Script_Common;
michael@0:     case HB_SCRIPT_GREEK:		return HB_Script_Greek;
michael@0:     case HB_SCRIPT_CYRILLIC:		return HB_Script_Cyrillic;
michael@0:     case HB_SCRIPT_ARMENIAN:		return HB_Script_Armenian;
michael@0:     case HB_SCRIPT_HEBREW:		return HB_Script_Hebrew;
michael@0:     case HB_SCRIPT_ARABIC:		return HB_Script_Arabic;
michael@0:     case HB_SCRIPT_SYRIAC:		return HB_Script_Syriac;
michael@0:     case HB_SCRIPT_THAANA:		return HB_Script_Thaana;
michael@0:     case HB_SCRIPT_DEVANAGARI:		return HB_Script_Devanagari;
michael@0:     case HB_SCRIPT_BENGALI:		return HB_Script_Bengali;
michael@0:     case HB_SCRIPT_GURMUKHI:		return HB_Script_Gurmukhi;
michael@0:     case HB_SCRIPT_GUJARATI:		return HB_Script_Gujarati;
michael@0:     case HB_SCRIPT_ORIYA:		return HB_Script_Oriya;
michael@0:     case HB_SCRIPT_TAMIL:		return HB_Script_Tamil;
michael@0:     case HB_SCRIPT_TELUGU:		return HB_Script_Telugu;
michael@0:     case HB_SCRIPT_KANNADA:		return HB_Script_Kannada;
michael@0:     case HB_SCRIPT_MALAYALAM:		return HB_Script_Malayalam;
michael@0:     case HB_SCRIPT_SINHALA:		return HB_Script_Sinhala;
michael@0:     case HB_SCRIPT_THAI:		return HB_Script_Thai;
michael@0:     case HB_SCRIPT_LAO:			return HB_Script_Lao;
michael@0:     case HB_SCRIPT_TIBETAN:		return HB_Script_Tibetan;
michael@0:     case HB_SCRIPT_MYANMAR:		return HB_Script_Myanmar;
michael@0:     case HB_SCRIPT_GEORGIAN:		return HB_Script_Georgian;
michael@0:     case HB_SCRIPT_HANGUL:		return HB_Script_Hangul;
michael@0:     case HB_SCRIPT_OGHAM:		return HB_Script_Ogham;
michael@0:     case HB_SCRIPT_RUNIC:		return HB_Script_Runic;
michael@0:     case HB_SCRIPT_KHMER:		return HB_Script_Khmer;
michael@0:     case HB_SCRIPT_NKO:			return HB_Script_Nko;
michael@0:     case HB_SCRIPT_INHERITED:		return HB_Script_Inherited;
michael@0:   }
michael@0: }
michael@0: 
michael@0: 
michael@0: static HB_Bool
michael@0: hb_old_convertStringToGlyphIndices (HB_Font old_font,
michael@0: 				    const HB_UChar16 *string,
michael@0: 				    hb_uint32 length,
michael@0: 				    HB_Glyph *glyphs,
michael@0: 				    hb_uint32 *numGlyphs,
michael@0: 				    HB_Bool rightToLeft)
michael@0: {
michael@0:   hb_font_t *font = (hb_font_t *) old_font->userData;
michael@0: 
michael@0:   for (unsigned int i = 0; i < length; i++)
michael@0:   {
michael@0:     hb_codepoint_t u;
michael@0: 
michael@0:     /* XXX Handle UTF-16.  Ugh */
michael@0:     u = string[i];
michael@0: 
michael@0:     if (rightToLeft)
michael@0:       u = hb_unicode_funcs_get_default ()->mirroring (u);
michael@0: 
michael@0:     font->get_glyph (u, 0, &u); /* TODO Variation selectors */
michael@0: 
michael@0:     glyphs[i] = u;
michael@0:   }
michael@0:   *numGlyphs = length; /* XXX */
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static void
michael@0: hb_old_getGlyphAdvances (HB_Font old_font,
michael@0: 			 const HB_Glyph *glyphs,
michael@0: 			 hb_uint32 numGlyphs,
michael@0: 			 HB_Fixed *advances,
michael@0: 			 int flags /*HB_ShaperFlag*/ HB_UNUSED)
michael@0: {
michael@0:   hb_font_t *font = (hb_font_t *) old_font->userData;
michael@0: 
michael@0:   for (unsigned int i = 0; i < numGlyphs; i++)
michael@0:     advances[i] = font->get_glyph_h_advance (glyphs[i]);
michael@0: }
michael@0: 
michael@0: static HB_Bool
michael@0: hb_old_canRender (HB_Font old_font,
michael@0: 		  const HB_UChar16 *string,
michael@0: 		  hb_uint32 length)
michael@0: {
michael@0:   return true; /* TODO */
michael@0: }
michael@0: 
michael@0: static HB_Error
michael@0: hb_old_getPointInOutline (HB_Font old_font,
michael@0: 			  HB_Glyph glyph,
michael@0: 			  int flags /*HB_ShaperFlag*/,
michael@0: 			  hb_uint32 point,
michael@0: 			  HB_Fixed *xpos,
michael@0: 			  HB_Fixed *ypos,
michael@0: 			  hb_uint32 *nPoints)
michael@0: {
michael@0:   return HB_Err_Ok; /* TODO */
michael@0: }
michael@0: 
michael@0: static void
michael@0: hb_old_getGlyphMetrics (HB_Font old_font,
michael@0: 			HB_Glyph glyph,
michael@0: 			HB_GlyphMetrics *metrics)
michael@0: {
michael@0:   hb_font_t *font = (hb_font_t *) old_font->userData;
michael@0: 
michael@0:   hb_glyph_extents_t extents;
michael@0: 
michael@0:   font->get_glyph_extents (glyph, &extents);
michael@0: 
michael@0:   metrics->x       = extents.x_bearing;
michael@0:   metrics->y       = extents.y_bearing;
michael@0:   metrics->width   = extents.width;
michael@0:   metrics->height  = extents.height;
michael@0:   metrics->xOffset = font->get_glyph_h_advance (glyph);
michael@0:   metrics->yOffset = 0;
michael@0: }
michael@0: 
michael@0: static HB_Fixed
michael@0: hb_old_getFontMetric (HB_Font old_font,
michael@0: 		      HB_FontMetric metric)
michael@0: {
michael@0:   hb_font_t *font = (hb_font_t *) old_font->userData;
michael@0: 
michael@0:   switch (metric)
michael@0:   {
michael@0:     case HB_FontAscent:
michael@0:        return font->y_scale; /* XXX We don't have ascent data yet. */
michael@0: 
michael@0:     default:
michael@0:       return 0;
michael@0:   }
michael@0: }
michael@0: 
michael@0: static const HB_FontClass hb_old_font_class = {
michael@0:   hb_old_convertStringToGlyphIndices,
michael@0:   hb_old_getGlyphAdvances,
michael@0:   hb_old_canRender,
michael@0:   hb_old_getPointInOutline,
michael@0:   hb_old_getGlyphMetrics,
michael@0:   hb_old_getFontMetric
michael@0: };
michael@0: 
michael@0: 
michael@0: 
michael@0: static HB_Error
michael@0: table_func (void *font, HB_Tag tag, HB_Byte *buffer, HB_UInt *length)
michael@0: {
michael@0:   hb_face_t *face = (hb_face_t *) font;
michael@0:   hb_blob_t *blob = face->reference_table ((hb_tag_t) tag);
michael@0:   unsigned int capacity = *length;
michael@0:   *length = hb_blob_get_length (blob);
michael@0:   memcpy (buffer, hb_blob_get_data (blob, NULL), MIN (capacity, *length));
michael@0:   hb_blob_destroy (blob);
michael@0:  return HB_Err_Ok;
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper face data
michael@0:  */
michael@0: 
michael@0: hb_old_shaper_face_data_t *
michael@0: _hb_old_shaper_face_data_create (hb_face_t *face)
michael@0: {
michael@0:   return HB_NewFace (face, table_func);
michael@0: }
michael@0: 
michael@0: void
michael@0: _hb_old_shaper_face_data_destroy (hb_old_shaper_face_data_t *data)
michael@0: {
michael@0:   HB_FreeFace (data);
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper font data
michael@0:  */
michael@0: 
michael@0: hb_old_shaper_font_data_t *
michael@0: _hb_old_shaper_font_data_create (hb_font_t *font)
michael@0: {
michael@0:   HB_FontRec *data = (HB_FontRec *) calloc (1, sizeof (HB_FontRec));
michael@0:   if (unlikely (!data)) {
michael@0:     DEBUG_MSG (OLD, font, "malloc()ing HB_Font failed");
michael@0:     return NULL;
michael@0:   }
michael@0: 
michael@0:   data->klass = &hb_old_font_class;
michael@0:   data->x_ppem = font->x_ppem;
michael@0:   data->y_ppem = font->y_ppem;
michael@0:   data->x_scale = font->x_scale; /* XXX */
michael@0:   data->y_scale = font->y_scale; /* XXX */
michael@0:   data->userData = font;
michael@0: 
michael@0:   return data;
michael@0: }
michael@0: 
michael@0: void
michael@0: _hb_old_shaper_font_data_destroy (hb_old_shaper_font_data_t *data)
michael@0: {
michael@0:   free (data);
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper shape_plan data
michael@0:  */
michael@0: 
michael@0: struct hb_old_shaper_shape_plan_data_t {};
michael@0: 
michael@0: hb_old_shaper_shape_plan_data_t *
michael@0: _hb_old_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
michael@0: 				       const hb_feature_t *user_features HB_UNUSED,
michael@0: 				       unsigned int        num_user_features HB_UNUSED)
michael@0: {
michael@0:   return (hb_old_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
michael@0: }
michael@0: 
michael@0: void
michael@0: _hb_old_shaper_shape_plan_data_destroy (hb_old_shaper_shape_plan_data_t *data HB_UNUSED)
michael@0: {
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper
michael@0:  */
michael@0: 
michael@0: hb_bool_t
michael@0: _hb_old_shape (hb_shape_plan_t    *shape_plan HB_UNUSED,
michael@0: 	       hb_font_t          *font,
michael@0: 	       hb_buffer_t        *buffer,
michael@0: 	       const hb_feature_t *features,
michael@0: 	       unsigned int        num_features)
michael@0: {
michael@0:   hb_face_t *face = font->face;
michael@0:   HB_Face old_face = HB_SHAPER_DATA_GET (face);
michael@0:   HB_Font old_font = HB_SHAPER_DATA_GET (font);
michael@0: 
michael@0:   bool backward = HB_DIRECTION_IS_BACKWARD (buffer->props.direction);
michael@0: 
michael@0: retry:
michael@0: 
michael@0:   unsigned int scratch_size;
michael@0:   char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
michael@0: 
michael@0: #define utf16_index() var1.u32
michael@0:   HB_UChar16 *pchars = (HB_UChar16 *) scratch;
michael@0:   unsigned int chars_len = 0;
michael@0:   for (unsigned int i = 0; i < buffer->len; i++) {
michael@0:     hb_codepoint_t c = buffer->info[i].codepoint;
michael@0:     buffer->info[i].utf16_index() = chars_len;
michael@0:     if (likely (c < 0x10000))
michael@0:       pchars[chars_len++] = c;
michael@0:     else if (unlikely (c >= 0x110000))
michael@0:       pchars[chars_len++] = 0xFFFD;
michael@0:     else {
michael@0:       pchars[chars_len++] = 0xD800 + ((c - 0x10000) >> 10);
michael@0:       pchars[chars_len++] = 0xDC00 + ((c - 0x10000) & ((1 << 10) - 1));
michael@0:     }
michael@0:   }
michael@0: 
michael@0: 
michael@0: #define ALLOCATE_ARRAY(Type, name, len) \
michael@0:   name = (Type *) scratch; \
michael@0:   scratch += (len) * sizeof ((name)[0]); \
michael@0:   scratch_size -= (len) * sizeof ((name)[0]);
michael@0: 
michael@0: 
michael@0:   HB_ShaperItem item = {0};
michael@0: 
michael@0:   ALLOCATE_ARRAY (const HB_UChar16, item.string, chars_len);
michael@0:   ALLOCATE_ARRAY (unsigned short, item.log_clusters, chars_len + 2);
michael@0:   item.stringLength = chars_len;
michael@0:   item.item.pos = 0;
michael@0:   item.item.length = item.stringLength;
michael@0:   item.item.script = hb_old_script_from_script (buffer->props.script);
michael@0:   item.item.bidiLevel = backward ? 1 : 0;
michael@0: 
michael@0:   item.font = old_font;
michael@0:   item.face = old_face;
michael@0:   item.shaperFlags = 0;
michael@0: 
michael@0:   item.glyphIndicesPresent = false;
michael@0: 
michael@0:   /* TODO Alignment. */
michael@0:   unsigned int num_glyphs = scratch_size / (sizeof (HB_Glyph) +
michael@0: 					    sizeof (HB_GlyphAttributes) +
michael@0: 					    sizeof (HB_Fixed) +
michael@0: 					    sizeof (HB_FixedPoint) +
michael@0: 					    sizeof (uint32_t));
michael@0: 
michael@0:   item.num_glyphs = num_glyphs;
michael@0:   ALLOCATE_ARRAY (HB_Glyph, item.glyphs, num_glyphs);
michael@0:   ALLOCATE_ARRAY (HB_GlyphAttributes, item.attributes, num_glyphs);
michael@0:   ALLOCATE_ARRAY (HB_Fixed, item.advances, num_glyphs);
michael@0:   ALLOCATE_ARRAY (HB_FixedPoint, item.offsets, num_glyphs);
michael@0:   /* Apparently in some cases the offsets array will not be fully assigned to.
michael@0:    * Clear it. */
michael@0:   memset (item.offsets, 0, num_glyphs * sizeof (item.offsets[0]));
michael@0:   uint32_t *vis_clusters;
michael@0:   ALLOCATE_ARRAY (uint32_t, vis_clusters, num_glyphs);
michael@0: 
michael@0: #undef ALLOCATE_ARRAY
michael@0: 
michael@0:   if (!HB_ShapeItem (&item))
michael@0:   {
michael@0:     if (unlikely (item.num_glyphs > num_glyphs))
michael@0:     {
michael@0:       buffer->ensure (buffer->allocated * 2);
michael@0:       if (buffer->in_error)
michael@0:         return false;
michael@0:       goto retry;
michael@0:     }
michael@0:     return false;
michael@0:   }
michael@0:   num_glyphs = item.num_glyphs;
michael@0: 
michael@0:   /* Ok, we've got everything we need, now compose output buffer,
michael@0:    * very, *very*, carefully! */
michael@0: 
michael@0:   /* Calculate visual-clusters.  That's what we ship. */
michael@0:   for (unsigned int i = 0; i < num_glyphs; i++)
michael@0:     vis_clusters[i] = -1;
michael@0:   for (unsigned int i = 0; i < buffer->len; i++) {
michael@0:     uint32_t *p = &vis_clusters[item.log_clusters[buffer->info[i].utf16_index()]];
michael@0:     *p = MIN (*p, buffer->info[i].cluster);
michael@0:   }
michael@0:   for (unsigned int i = 1; i < num_glyphs; i++)
michael@0:     if (vis_clusters[i] == (uint32_t) -1)
michael@0:       vis_clusters[i] = vis_clusters[i - 1];
michael@0: 
michael@0: #undef utf16_index
michael@0: 
michael@0:   buffer->ensure (num_glyphs);
michael@0:   if (buffer->in_error)
michael@0:     return false;
michael@0: 
michael@0: 
michael@0:   buffer->len = num_glyphs;
michael@0:   hb_glyph_info_t *info = buffer->info;
michael@0:   for (unsigned int i = 0; i < num_glyphs; i++)
michael@0:   {
michael@0:     info[i].codepoint = item.glyphs[i];
michael@0:     info[i].cluster = vis_clusters[i];
michael@0: 
michael@0:     info[i].mask = item.advances[i];
michael@0:     info[i].var1.u32 = item.offsets[i].x;
michael@0:     info[i].var2.u32 = item.offsets[i].y;
michael@0:   }
michael@0: 
michael@0:   buffer->clear_positions ();
michael@0: 
michael@0:   for (unsigned int i = 0; i < num_glyphs; ++i) {
michael@0:     hb_glyph_info_t *info = &buffer->info[i];
michael@0:     hb_glyph_position_t *pos = &buffer->pos[i];
michael@0: 
michael@0:     /* TODO vertical */
michael@0:     pos->x_advance = info->mask;
michael@0:     pos->x_offset = info->var1.u32;
michael@0:     pos->y_offset = info->var2.u32;
michael@0:   }
michael@0: 
michael@0:   if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
michael@0:     buffer->reverse ();
michael@0: 
michael@0:   return true;
michael@0: }