/* Pango * pango-ot-buffer.c: Buffer of glyphs for shaping/positioning * * Copyright (C) 2004 Red Hat Software * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */#include <config.h>#include "pango-ot-private.h"#define PANGO_SCALE_26_6 (PANGO_SCALE / (1<<6))#define PANGO_UNITS_26_6(d) (PANGO_SCALE_26_6 * (d))/** * pango_ot_buffer_new * @font: a #PangoFcFont * * Creates a new #PangoOTBuffer for the given OpenType font. * * Return value: the newly allocated #PangoOTBuffer, which should *               be freed with pango_ot_buffer_destroy(). * * Since: 1.4 **/PangoOTBuffer *pango_ot_buffer_new (PangoFcFont *font){  /* We lock the font here immediately for the silly reason   * of getting the FT_Memory; otherwise we'd have to   * add a new operation to PangoFcFontmap; callers will   * probably already have the font locked, however,   * so there is little performance penalty.   */  PangoOTBuffer *buffer = g_slice_new (PangoOTBuffer);  FT_Face face = pango_fc_font_lock_face (font);  if (hb_buffer_new (face->memory, &buffer->buffer) != FT_Err_Ok)    g_warning ("Allocation of HB_Buffer failed"); /* this doesn't happen */  buffer->font = g_object_ref (font);  buffer->applied_gpos = FALSE;  buffer->rtl = FALSE;  buffer->zero_width_marks = FALSE;  pango_fc_font_unlock_face (font);  return buffer;}/** * pango_ot_buffer_destroy * @buffer: a #PangoOTBuffer * * Destroys a #PangoOTBuffer and free all associated memory. * * Since: 1.4 **/voidpango_ot_buffer_destroy (PangoOTBuffer *buffer){  hb_buffer_free (buffer->buffer);  g_object_unref (buffer->font);  g_slice_free (PangoOTBuffer, buffer);}/** * pango_ot_buffer_clear * @buffer: a #PangoOTBuffer * * Empties a #PangoOTBuffer, make it ready to add glyphs to. * * Since: 1.4 **/voidpango_ot_buffer_clear (PangoOTBuffer *buffer){  hb_buffer_clear (buffer->buffer);  buffer->applied_gpos = FALSE;}/** * pango_ot_buffer_add_glyph * @buffer: a #PangoOTBuffer * @glyph: the glyph index to add, like a #PangoGlyph * @properties: the glyph properties * @cluster: the cluster that this glyph belongs to * * Appends a glyph to a #PangoOTBuffer, with @properties identifying which * features should be applied on this glyph.  See pango_ruleset_add_feature(). * * Since: 1.4 **/voidpango_ot_buffer_add_glyph (PangoOTBuffer *buffer,			   guint          glyph,			   guint          properties,			   guint          cluster){  hb_buffer_add_glyph (buffer->buffer,			glyph, properties, cluster);}/** * pango_ot_buffer_set_rtl * @buffer: a #PangoOTBuffer * @rtl: %TRUE for right-to-left text * * Sets whether glyphs will be rendered right-to-left.  This setting * is needed for proper horizontal positioning of right-to-left scripts. * * Since: 1.4 **/voidpango_ot_buffer_set_rtl (PangoOTBuffer *buffer,			 gboolean       rtl){  buffer->rtl = rtl != FALSE;}/** * pango_ot_buffer_set_zero_width_marks * @buffer: a #PangoOTBuffer * @zero_width_marks: %TRUE if characters with a mark class should *  be forced to zero width. * * Sets whether characters with a mark class should be forced to zero width. * This setting is needed for proper positioning of Arabic accents, * but will produce incorrect results with standard OpenType Indic * fonts. * * Since: 1.6 **/voidpango_ot_buffer_set_zero_width_marks (PangoOTBuffer     *buffer,				      gboolean           zero_width_marks){  buffer->zero_width_marks = zero_width_marks != FALSE;}/** * pango_ot_buffer_get_glyphs * @buffer: a #PangoOTBuffer * @glyphs: location to store the array of glyphs, or %NULL * @n_glyphs: location to store the number of glyphs, or %NULL * * Gets the glyph array contained in a #PangoOTBuffer.  The glyphs are * owned by the buffer and should not be freed, and are only valid as long * as buffer is not modified. * * Since: 1.4 **/voidpango_ot_buffer_get_glyphs (PangoOTBuffer  *buffer,			    PangoOTGlyph  **glyphs,			    int            *n_glyphs){  if (glyphs)    *glyphs = (PangoOTGlyph *)buffer->buffer->in_string;  if (n_glyphs)    *n_glyphs = buffer->buffer->in_length;}static voidswap_range (PangoGlyphString *glyphs, int start, int end){  int i, j;  for (i = start, j = end - 1; i < j; i++, j--)    {      PangoGlyphInfo glyph_info;      gint log_cluster;      glyph_info = glyphs->glyphs[i];      glyphs->glyphs[i] = glyphs->glyphs[j];      glyphs->glyphs[j] = glyph_info;      log_cluster = glyphs->log_clusters[i];      glyphs->log_clusters[i] = glyphs->log_clusters[j];      glyphs->log_clusters[j] = log_cluster;    }}static voidapply_gpos_ltr (PangoGlyphString *glyphs,		HB_Position      positions){  int i;  for (i = 0; i < glyphs->num_glyphs; i++)    {      FT_Pos x_pos = positions[i].x_pos;      FT_Pos y_pos = positions[i].y_pos;      int back = i;      int j;      while (positions[back].back != 0)	{	  back  -= positions[back].back;	  x_pos += positions[back].x_pos;	  y_pos += positions[back].y_pos;	}      for (j = back; j < i; j++)	glyphs->glyphs[i].geometry.x_offset -= glyphs->glyphs[j].geometry.width;      glyphs->glyphs[i].geometry.x_offset += PANGO_UNITS_26_6(x_pos);      glyphs->glyphs[i].geometry.y_offset -= PANGO_UNITS_26_6(y_pos);      if (positions[i].new_advance)	glyphs->glyphs[i].geometry.width  = PANGO_UNITS_26_6(positions[i].x_advance);      else	glyphs->glyphs[i].geometry.width += PANGO_UNITS_26_6(positions[i].x_advance);    }}static voidapply_gpos_rtl (PangoGlyphString *glyphs,		HB_Position      positions){  int i;  for (i = 0; i < glyphs->num_glyphs; i++)    {      int i_rev = glyphs->num_glyphs - i - 1;      int back_rev = i_rev;      int back;      FT_Pos x_pos = positions[i_rev].x_pos;      FT_Pos y_pos = positions[i_rev].y_pos;      int j;      while (positions[back_rev].back != 0)	{	  back_rev -= positions[back_rev].back;	  x_pos += positions[back_rev].x_pos;	  y_pos += positions[back_rev].y_pos;	}      back = glyphs->num_glyphs - back_rev - 1;      for (j = i; j < back; j++)	glyphs->glyphs[i].geometry.x_offset += glyphs->glyphs[j].geometry.width;      glyphs->glyphs[i].geometry.x_offset += PANGO_UNITS_26_6(x_pos);      glyphs->glyphs[i].geometry.y_offset -= PANGO_UNITS_26_6(y_pos);      if (positions[i_rev].new_advance)	glyphs->glyphs[i].geometry.width  = PANGO_UNITS_26_6(positions[i_rev].x_advance);      else	glyphs->glyphs[i].geometry.width += PANGO_UNITS_26_6(positions[i_rev].x_advance);    }}/** * pango_ot_buffer_output * @buffer: a #PangoOTBuffer * @glyphs: a #PangoGlyphString * * Exports the glyphs in a #PangoOTBuffer into a #PangoGlyphString.  This is * typically used after the OpenType layout processing is over, to convert the * resulting glyphs into a generic Pango glyph string. * * Since: 1.4 **/voidpango_ot_buffer_output (PangoOTBuffer    *buffer,			PangoGlyphString *glyphs){  FT_Face face;  PangoOTInfo *info;  HB_GDEF gdef = NULL;  unsigned int i;  int last_cluster;  face = pango_fc_font_lock_face (buffer->font);  g_assert (face);  /* Copy glyphs into output glyph string */  pango_glyph_string_set_size (glyphs, buffer->buffer->in_length);  last_cluster = -1;  for (i = 0; i < buffer->buffer->in_length; i++)    {      HB_GlyphItem item = &buffer->buffer->in_string[i];      glyphs->glyphs[i].glyph = item->gindex;      glyphs->log_clusters[i] = item->cluster;      if (glyphs->log_clusters[i] != last_cluster)	glyphs->glyphs[i].attr.is_cluster_start = 1;      else	glyphs->glyphs[i].attr.is_cluster_start = 0;      last_cluster = glyphs->log_clusters[i];    }  info = pango_ot_info_get (face);  gdef = pango_ot_info_get_gdef (info);  /* Apply default positioning */  for (i = 0; i < (unsigned int)glyphs->num_glyphs; i++)    {      if (glyphs->glyphs[i].glyph)	{	  PangoRectangle logical_rect;	  FT_UShort property;	  if (buffer->zero_width_marks &&	      gdef &&	      HB_GDEF_Get_Glyph_Property (gdef, glyphs->glyphs[i].glyph, &property) == FT_Err_Ok &&	      (property == HB_GDEF_MARK || (property & HB_LOOKUP_FLAG_IGNORE_SPECIAL_MARKS) != 0))	    {	      glyphs->glyphs[i].geometry.width = 0;	    }	  else	    {	      pango_font_get_glyph_extents ((PangoFont *)buffer->font, glyphs->glyphs[i].glyph, NULL, &logical_rect);	      glyphs->glyphs[i].geometry.width = logical_rect.width;	    }	}      else	glyphs->glyphs[i].geometry.width = 0;      glyphs->glyphs[i].geometry.x_offset = 0;      glyphs->glyphs[i].geometry.y_offset = 0;    }  if (buffer->rtl)    {      /* Swap all glyphs */      swap_range (glyphs, 0, glyphs->num_glyphs);    }  if (buffer->applied_gpos)    {      if (buffer->rtl)	apply_gpos_rtl (glyphs, buffer->buffer->positions);      else	apply_gpos_ltr (glyphs, buffer->buffer->positions);    }  else    pango_fc_font_kern_glyphs (buffer->font, glyphs);  pango_fc_font_unlock_face (buffer->font);}