/***************************************************************************/
/*                                                                         */
/*  ftcsbits.c                                                             */
/*                                                                         */
/*    FreeType sbits manager (body).                                       */
/*                                                                         */
/*  Copyright 2000-2001, 2002, 2003, 2004, 2005 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 "ftcint.h"
#include FT_CACHE_INTERNAL_SBITS_H
#include FT_INTERNAL_OBJECTS_H
#include FT_INTERNAL_DEBUG_H
#include FT_ERRORS_H

#include "ftcerror.h"


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                     SBIT CACHE NODES                          *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  static FT_Error
  ftc_sbit_copy_bitmap( FTC_SBit    sbit,
                        FT_Bitmap*  bitmap,
                        FT_Memory   memory )
  {
    FT_Error  error;
    FT_Int    pitch = bitmap->pitch;
    FT_ULong  size;


    if ( pitch < 0 )
      pitch = -pitch;

    size = (FT_ULong)( pitch * bitmap->rows );

    if ( !FT_ALLOC( sbit->buffer, size ) )
      FT_MEM_COPY( sbit->buffer, bitmap->buffer, size );

    return error;
  }


  FT_EXPORT_DEF( void )
  FTC_SNode_Free( FTC_SNode   snode,
                  FTC_GCache  cache )
  {
    FTC_SBit   sbit   = snode->sbits;
    FT_UInt    count  = snode->count;
    FT_Memory  memory = FTC_CACHE__MEMORY(cache);


    for ( ; count > 0; sbit++, count-- )
      FT_FREE( sbit->buffer );

    FTC_GNode_Done( FTC_GNODE( snode ) );

    FT_FREE( snode );
  }


  /*
   *  This function tries to load a small bitmap within a given FTC_SNode.
   *  Note that it returns a non-zero error code _only_ in the case of
   *  out-of-memory condition.  For all other errors (e.g., corresponding
   *  to a bad font file), this function will mark the sbit as `unavailable'
   *  and return a value of 0.
   *
   *  You should also read the comment within the @ftc_snode_equal
   *  function below to see how out-of-memory is handled during a lookup.
   */
  static FT_Error
  ftc_snode_load( FTC_SNode    snode,
                  FTC_Manager  manager,
                  FT_UInt      gindex,
                  FT_ULong    *asize )
  {
    FT_Error          error;
    FTC_GNode         gnode  = FTC_GNODE( snode );
    FTC_Family        family = gnode->family;
    FT_Memory         memory = manager->memory;
    FT_Face           face;
    FTC_SBit          sbit;
    FTC_SCacheClass   clazz;


    if ( (FT_UInt)(gindex - gnode->gindex) >= snode->count )
    {
      FT_ERROR(( "ftc_snode_load: invalid glyph index" ));
      return FTC_Err_Invalid_Argument;
    }

    sbit  = snode->sbits + ( gindex - gnode->gindex );
    clazz = FTC_SCACHE__CLASS(FTC_FAMILY__CACHE(family));

    sbit->buffer = 0;

    error = clazz->fam_load_glyph( family, gindex, manager, &face );
    if ( error )
      goto BadGlyph;

    {
      FT_Int        temp;
      FT_GlyphSlot  slot   = face->glyph;
      FT_Bitmap*    bitmap = &slot->bitmap;
      FT_Int        xadvance, yadvance;


      if ( slot->format != FT_GLYPH_FORMAT_BITMAP )
      {
        FT_ERROR(( "%s: glyph loaded didn't return a bitmap!\n",
                   "ftc_snode_load" ));
        goto BadGlyph;
      }

      /* Check that our values fit into 8-bit containers!       */
      /* If this is not the case, our bitmap is too large       */
      /* and we will leave it as `missing' with sbit.buffer = 0 */

#define CHECK_CHAR( d )  ( temp = (FT_Char)d, temp == d )
#define CHECK_BYTE( d )  ( temp = (FT_Byte)d, temp == d )

      /* horizontal advance in pixels */
      xadvance = ( slot->advance.x + 32 ) >> 6;
      yadvance = ( slot->advance.y + 32 ) >> 6;

      if ( !CHECK_BYTE( bitmap->rows  )     ||
           !CHECK_BYTE( bitmap->width )     ||
           !CHECK_CHAR( bitmap->pitch )     ||
           !CHECK_CHAR( slot->bitmap_left ) ||
           !CHECK_CHAR( slot->bitmap_top  ) ||
           !CHECK_CHAR( xadvance )          ||
           !CHECK_CHAR( yadvance )          )
        goto BadGlyph;

      sbit->width     = (FT_Byte)bitmap->width;
      sbit->height    = (FT_Byte)bitmap->rows;
      sbit->pitch     = (FT_Char)bitmap->pitch;
      sbit->left      = (FT_Char)slot->bitmap_left;
      sbit->top       = (FT_Char)slot->bitmap_top;
      sbit->xadvance  = (FT_Char)xadvance;
      sbit->yadvance  = (FT_Char)yadvance;
      sbit->format    = (FT_Byte)bitmap->pixel_mode;
      sbit->max_grays = (FT_Byte)(bitmap->num_grays - 1);

      /* copy the bitmap into a new buffer -- ignore error */
      error = ftc_sbit_copy_bitmap( sbit, bitmap, memory );

      /* now, compute size */
      if ( asize )
        *asize = FT_ABS( sbit->pitch ) * sbit->height;

    } /* glyph loading successful */

    /* ignore the errors that might have occurred --   */
    /* we mark unloaded glyphs with `sbit.buffer == 0' */
    /* and `width == 255', `height == 0'               */
    /*                                                 */
    if ( error && error != FTC_Err_Out_Of_Memory )
    {
    BadGlyph:
      sbit->width  = 255;
      sbit->height = 0;
      sbit->buffer = NULL;
      error        = 0;
      if ( asize )
        *asize = 0;
    }

    return error;
  }


  FT_EXPORT_DEF( FT_Error )
  FTC_SNode_New( FTC_SNode  *psnode,
                 FTC_GNode   gquery,
                 FTC_GCache  cache )
  {
    FT_Memory   memory = FTC_CACHE__MEMORY(cache);
    FT_Error    error;
    FTC_SNode   snode  = NULL;
    FT_UInt     gindex = gquery->gindex;
    FTC_Family  family = gquery->family;

    FTC_SCacheClass   clazz = FTC_SCACHE__CLASS(cache);
    FT_UInt           total;


    total = clazz->fam_get_count( family, FTC_CACHE__MANAGER(cache) );
    if ( total == 0 || gindex >= total )
    {
      error = FT_Err_Invalid_Argument;
      goto Exit;
    }

    if ( !FT_NEW( snode ) )
    {
      FT_UInt  count, start;


      start = gindex - ( gindex % FTC_SBIT_ITEMS_PER_NODE );
      count = total - start;
      if ( count > FTC_SBIT_ITEMS_PER_NODE )
        count = FTC_SBIT_ITEMS_PER_NODE;

      FTC_GNode_Init( FTC_GNODE( snode ), start, family );

      snode->count = count;

      error = ftc_snode_load( snode,
                              FTC_CACHE__MANAGER(cache),
                              gindex,
                              NULL );
      if ( error )
      {
        FTC_SNode_Free( snode, cache );
        snode = NULL;
      }
    }

  Exit:
    *psnode = snode;
    return error;
  }


  FT_EXPORT_DEF( FT_ULong )
  FTC_SNode_Weight( FTC_SNode  snode )
  {
    FT_UInt    count = snode->count;
    FTC_SBit   sbit  = snode->sbits;
    FT_Int     pitch;
    FT_ULong   size;

    FT_ASSERT( snode->count <= FTC_SBIT_ITEMS_PER_NODE );

    /* the node itself */
    size = sizeof ( *snode );

    for ( ; count > 0; count--, sbit++ )
    {
      if ( sbit->buffer )
      {
        pitch = sbit->pitch;
        if ( pitch < 0 )
          pitch = -pitch;

        /* add the size of a given glyph image */
        size += pitch * sbit->height;
      }
    }

    return size;
  }


  FT_EXPORT_DEF( FT_Bool )
  FTC_SNode_Equal( FTC_SNode   snode,
                   FTC_GNode   gquery,
                   FTC_Cache   cache )
  {
    FTC_GNode   gnode  = FTC_GNODE( snode );
    FT_UInt     gindex = gquery->gindex;
    FT_Bool     result;


    result = FT_BOOL( gnode->family == gquery->family                    &&
                      (FT_UInt)( gindex - gnode->gindex ) < snode->count );
    if ( result )
    {
      /* check if we need to load the glyph bitmap now */
      FTC_SBit  sbit = snode->sbits + ( gindex - gnode->gindex );


      if ( sbit->buffer == NULL && sbit->width != 255 )
      {
        FT_ULong  size;
        FT_Error  error;


        FTC_NODE_REF(snode);  /* lock node to prevent flushing */
                              /* in retry loop                 */

        FTC_RETR_LOOP( cache->manager )
        {
          error = ftc_snode_load( snode, cache->manager, gindex, &size );
        }
        FTC_RETRY_END( error );

        FTC_NODE(snode)->ref_count--;  /* unlock the node */

        if ( error )
          result = 0;
        else
          cache->manager->cur_weight += size;
      }
    }

    return result;
  }


/* END */