/***************************************************************************/
/*                                                                         */
/*  pshrec.c                                                               */
/*                                                                         */
/*    FreeType PostScript hints recorder (body).                           */
/*                                                                         */
/*  Copyright 2001, 2002, 2003, 2004 by                                    */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_INTERNAL_OBJECTS_H
#include FT_INTERNAL_DEBUG_H
#include "pshrec.h"
#include "pshalgo.h"

#include "pshnterr.h"

#undef  FT_COMPONENT
#define FT_COMPONENT  trace_pshrec

#ifdef DEBUG_HINTER
  PS_Hints  ps_debug_hints         = 0;
  int       ps_debug_no_horz_hints = 0;
  int       ps_debug_no_vert_hints = 0;
#endif


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                      PS_HINT MANAGEMENT                       *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /* destroy hints table */
  static void
  ps_hint_table_done( PS_Hint_Table  table,
                      FT_Memory      memory )
  {
    FT_FREE( table->hints );
    table->num_hints = 0;
    table->max_hints = 0;
  }


  /* ensure that a table can contain "count" elements */
  static FT_Error
  ps_hint_table_ensure( PS_Hint_Table  table,
                        FT_UInt        count,
                        FT_Memory      memory )
  {
    FT_UInt   old_max = table->max_hints;
    FT_UInt   new_max = count;
    FT_Error  error   = 0;


    if ( new_max > old_max )
    {
      /* try to grow the table */
      new_max = FT_PAD_CEIL( new_max, 8 );
      if ( !FT_RENEW_ARRAY( table->hints, old_max, new_max ) )
        table->max_hints = new_max;
    }
    return error;
  }


  static FT_Error
  ps_hint_table_alloc( PS_Hint_Table  table,
                       FT_Memory      memory,
                       PS_Hint       *ahint )
  {
    FT_Error  error = 0;
    FT_UInt   count;
    PS_Hint   hint = 0;


    count = table->num_hints;
    count++;

    if ( count >= table->max_hints )
    {
      error = ps_hint_table_ensure( table, count, memory );
      if ( error )
        goto Exit;
    }

    hint        = table->hints + count - 1;
    hint->pos   = 0;
    hint->len   = 0;
    hint->flags = 0;

    table->num_hints = count;

  Exit:
    *ahint = hint;
    return error;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                      PS_MASK MANAGEMENT                       *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /* destroy mask */
  static void
  ps_mask_done( PS_Mask    mask,
                FT_Memory  memory )
  {
    FT_FREE( mask->bytes );
    mask->num_bits  = 0;
    mask->max_bits  = 0;
    mask->end_point = 0;
  }


  /* ensure that a mask can contain "count" bits */
  static FT_Error
  ps_mask_ensure( PS_Mask    mask,
                  FT_UInt    count,
                  FT_Memory  memory )
  {
    FT_UInt   old_max = ( mask->max_bits + 7 ) >> 3;
    FT_UInt   new_max = ( count          + 7 ) >> 3;
    FT_Error  error   = 0;


    if ( new_max > old_max )
    {
      new_max = FT_PAD_CEIL( new_max, 8 );
      if ( !FT_RENEW_ARRAY( mask->bytes, old_max, new_max ) )
        mask->max_bits = new_max * 8;
    }
    return error;
  }


  /* test a bit value in a given mask */
  static FT_Int
  ps_mask_test_bit( PS_Mask  mask,
                    FT_Int   idx )
  {
    if ( (FT_UInt)idx >= mask->num_bits )
      return 0;

    return mask->bytes[idx >> 3] & ( 0x80 >> ( idx & 7 ) );
  }


  /* clear a given bit */
  static void
  ps_mask_clear_bit( PS_Mask  mask,
                     FT_Int   idx )
  {
    FT_Byte*  p;


    if ( (FT_UInt)idx >= mask->num_bits )
      return;

    p    = mask->bytes + ( idx >> 3 );
    p[0] = (FT_Byte)( p[0] & ~( 0x80 >> ( idx & 7 ) ) );
  }


  /* set a given bit, possibly grow the mask */
  static FT_Error
  ps_mask_set_bit( PS_Mask    mask,
                   FT_Int     idx,
                   FT_Memory  memory )
  {
    FT_Error  error = 0;
    FT_Byte*  p;


    if ( idx < 0 )
      goto Exit;

    if ( (FT_UInt)idx >= mask->num_bits )
    {
      error = ps_mask_ensure( mask, idx + 1, memory );
      if ( error )
        goto Exit;

      mask->num_bits = idx + 1;
    }

    p    = mask->bytes + ( idx >> 3 );
    p[0] = (FT_Byte)( p[0] | ( 0x80 >> ( idx & 7 ) ) );

  Exit:
    return error;
  }


  /* destroy mask table */
  static void
  ps_mask_table_done( PS_Mask_Table  table,
                      FT_Memory      memory )
  {
    FT_UInt  count = table->max_masks;
    PS_Mask  mask  = table->masks;


    for ( ; count > 0; count--, mask++ )
      ps_mask_done( mask, memory );

    FT_FREE( table->masks );
    table->num_masks = 0;
    table->max_masks = 0;
  }


  /* ensure that a mask table can contain "count" masks */
  static FT_Error
  ps_mask_table_ensure( PS_Mask_Table  table,
                        FT_UInt        count,
                        FT_Memory      memory )
  {
    FT_UInt   old_max = table->max_masks;
    FT_UInt   new_max = count;
    FT_Error  error   = 0;


    if ( new_max > old_max )
    {
      new_max = FT_PAD_CEIL( new_max, 8 );
      if ( !FT_RENEW_ARRAY( table->masks, old_max, new_max ) )
        table->max_masks = new_max;
    }
    return error;
  }


  /* allocate a new mask in a table */
  static FT_Error
  ps_mask_table_alloc( PS_Mask_Table  table,
                       FT_Memory      memory,
                       PS_Mask       *amask )
  {
    FT_UInt   count;
    FT_Error  error = 0;
    PS_Mask   mask  = 0;


    count = table->num_masks;
    count++;

    if ( count > table->max_masks )
    {
      error = ps_mask_table_ensure( table, count, memory );
      if ( error )
        goto Exit;
    }

    mask             = table->masks + count - 1;
    mask->num_bits   = 0;
    mask->end_point  = 0;
    table->num_masks = count;

  Exit:
    *amask = mask;
    return error;
  }


  /* return last hint mask in a table, create one if the table is empty */
  static FT_Error
  ps_mask_table_last( PS_Mask_Table  table,
                      FT_Memory      memory,
                      PS_Mask       *amask )
  {
    FT_Error  error = 0;
    FT_UInt   count;
    PS_Mask   mask;


    count = table->num_masks;
    if ( count == 0 )
    {
      error = ps_mask_table_alloc( table, memory, &mask );
      if ( error )
        goto Exit;
    }
    else
      mask = table->masks + count - 1;

  Exit:
    *amask = mask;
    return error;
  }


  /* set a new mask to a given bit range */
  static FT_Error
  ps_mask_table_set_bits( PS_Mask_Table  table,
                          FT_Byte*       source,
                          FT_UInt        bit_pos,
                          FT_UInt        bit_count,
                          FT_Memory      memory )
  {
    FT_Error  error = 0;
    PS_Mask   mask;


    error = ps_mask_table_last( table, memory, &mask );
    if ( error )
      goto Exit;

    error = ps_mask_ensure( mask, bit_count, memory );
    if ( error )
      goto Exit;

    mask->num_bits = bit_count;

    /* now, copy bits */
    {
      FT_Byte*  read  = source + ( bit_pos >> 3 );
      FT_Int    rmask = 0x80 >> ( bit_pos & 7 );
      FT_Byte*  write = mask->bytes;
      FT_Int    wmask = 0x80;
      FT_Int    val;


      for ( ; bit_count > 0; bit_count-- )
      {
        val = write[0] & ~wmask;

        if ( read[0] & rmask )
          val |= wmask;

        write[0] = (FT_Byte)val;

        rmask >>= 1;
        if ( rmask == 0 )
        {
          read++;
          rmask = 0x80;
        }

        wmask >>= 1;
        if ( wmask == 0 )
        {
          write++;
          wmask = 0x80;
        }
      }
    }

  Exit:
    return error;
  }


  /* test whether two masks in a table intersect */
  static FT_Int
  ps_mask_table_test_intersect( PS_Mask_Table  table,
                                FT_Int         index1,
                                FT_Int         index2 )
  {
    PS_Mask   mask1  = table->masks + index1;
    PS_Mask   mask2  = table->masks + index2;
    FT_Byte*  p1     = mask1->bytes;
    FT_Byte*  p2     = mask2->bytes;
    FT_UInt   count1 = mask1->num_bits;
    FT_UInt   count2 = mask2->num_bits;
    FT_UInt   count;


    count = ( count1 <= count2 ) ? count1 : count2;
    for ( ; count >= 8; count -= 8 )
    {
      if ( p1[0] & p2[0] )
        return 1;

      p1++;
      p2++;
    }

    if ( count == 0 )
      return 0;

    return ( p1[0] & p2[0] ) & ~( 0xFF >> count );
  }


  /* merge two masks, used by ps_mask_table_merge_all */
  static FT_Error
  ps_mask_table_merge( PS_Mask_Table  table,
                       FT_Int         index1,
                       FT_Int         index2,