text: /****************************************************************************
   *
   * pshglob.c
   *
   *   PostScript hinter global hinting management (body).
   *   Inspired by the new auto-hinter module.
   *
   * Copyright (C) 2001-2020 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 <freetype/freetype.h>
  #include <freetype/internal/ftobjs.h>
  #include <freetype/internal/ftcalc.h>
  #include "pshglob.h"
  
  #ifdef DEBUG_HINTER
    PSH_Globals  ps_debug_globals = NULL;
  #endif
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*****                                                               *****/
    /*****                       STANDARD WIDTHS                         *****/
    /*****                                                               *****/
    /*************************************************************************/
    /*************************************************************************/
  
  
    /* scale the widths/heights table */
    static void
    psh_globals_scale_widths( PSH_Globals  globals,
                              FT_UInt      direction )
    {
      PSH_Dimension  dim   = &globals->dimension[direction];
      PSH_Widths     stdw  = &dim->stdw;
      FT_UInt        count = stdw->count;
      PSH_Width      width = stdw->widths;
      PSH_Width      stand = width;               /* standard width/height */
      FT_Fixed       scale = dim->scale_mult;
  
  
      if ( count > 0 )
      {
        width->cur = FT_MulFix( width->org, scale );
        width->fit = FT_PIX_ROUND( width->cur );
  
        width++;
        count--;
  
        for ( ; count > 0; count--, width++ )
        {
          FT_Pos  w, dist;
  
  
          w    = FT_MulFix( width->org, scale );
          dist = w - stand->cur;
  
          if ( dist < 0 )
            dist = -dist;
  
          if ( dist < 128 )
            w = stand->cur;
  
          width->cur = w;
          width->fit = FT_PIX_ROUND( w );
        }
      }
    }
  
  
  #if 0
  
    /* org_width is in font units, result in device pixels, 26.6 format */
    FT_LOCAL_DEF( FT_Pos )
    psh_dimension_snap_width( PSH_Dimension  dimension,
                              FT_Int         org_width )
    {
      FT_UInt  n;
      FT_Pos   width     = FT_MulFix( org_width, dimension->scale_mult );
      FT_Pos   best      = 64 + 32 + 2;
      FT_Pos   reference = width;
  
  
      for ( n = 0; n < dimension->stdw.count; n++ )
      {
        FT_Pos  w;
        FT_Pos  dist;
  
  
        w = dimension->stdw.widths[n].cur;
        dist = width - w;
        if ( dist < 0 )
          dist = -dist;
        if ( dist < best )
        {
          best      = dist;
          reference = w;
        }
      }
  
      if ( width >= reference )
      {
        width -= 0x21;
        if ( width < reference )
          width = reference;
      }
      else
      {
        width += 0x21;
        if ( width > reference )
          width = reference;
      }
  
      return width;
    }
  
  #endif /* 0 */
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*****                                                               *****/
    /*****                       BLUE ZONES                              *****/
    /*****                                                               *****/
    /*************************************************************************/
    /*************************************************************************/
  
    static void
    psh_blues_set_zones_0( PSH_Blues       target,
                           FT_Bool         is_others,
                           FT_UInt         read_count,
                           FT_Short*       read,
                           PSH_Blue_Table  top_table,
                           PSH_Blue_Table  bot_table )
    {
      FT_UInt  count_top = top_table->count;
      FT_UInt  count_bot = bot_table->count;
      FT_Bool  first     = 1;
  
      FT_UNUSED( target );
  
  
      for ( ; read_count > 1; read_count -= 2 )
      {
        FT_Int         reference, delta;
        FT_UInt        count;
        PSH_Blue_Zone  zones, zone;
        FT_Bool        top;
  
  
        /* read blue zone entry, and select target top/bottom zone */
        top = 0;
        if ( first || is_others )
        {
          reference = read[1];
          delta     = read[0] - reference;
  
          zones = bot_table->zones;
          count = count_bot;
          first = 0;
        }
        else
        {
          reference = read[0];
          delta     = read[1] - reference;
  
          zones = top_table->zones;
          count = count_top;
          top   = 1;
        }
  
        /* insert into sorted table */
        zone = zones;
        for ( ; count > 0; count--, zone++ )
        {
          if ( reference < zone->org_ref )
            break;
  
          if ( reference == zone->org_ref )
          {
            FT_Int  delta0 = zone->org_delta;
  
  
            /* we have two zones on the same reference position -- */
            /* only keep the largest one                           */
            if ( delta < 0 )
            {
              if ( delta < delta0 )
                zone->org_delta = delta;
            }
            else
            {
              if ( delta > delta0 )
                zone->org_delta = delta;
            }
            goto Skip;
          }
        }
  
        for ( ; count > 0; count-- )
          zone[count] = zone[count-1];
  
        zone->org_ref   = reference;
        zone->org_delta = delta;
  
        if ( top )
          count_top++;
        else
          count_bot++;
  
      Skip:
        read += 2;
      }
  
      top_table->count = count_top;
      bot_table->count = count_bot;
    }
  
  
    /* Re-read blue zones from the original fonts and store them into our */
    /* private structure.  This function re-orders, sanitizes, and        */
    /* fuzz-expands the zones as well.                                    */
    static void
    psh_blues_set_zones( PSH_Blues  target,
                         FT_UInt    count,
                         FT_Short*  blues,
                         FT_UInt    count_others,
                         FT_Short*  other_blues,
                         FT_Int     fuzz,
                         FT_Int     family )
    {
      PSH_Blue_Table  top_table, bot_table;
      FT_UInt         count_top, count_bot;
  
  
      if ( family )
      {
        top_table = &target->family_top;
        bot_table = &target->family_bottom;
      }
      else
      {
        top_table = &target->normal_top;
        bot_table = &target->normal_bottom;
      }
  
      /* read the input blue zones, and build two sorted tables  */
      /* (one for the top zones, the other for the bottom zones) */
      top_table->count = 0;
      bot_table->count = 0;
  
      /* first, the blues */
      psh_blues_set_zones_0( target, 0,
                             count, blues, top_table, bot_table );
      psh_blues_set_zones_0( target, 1,
                             count_others, other_blues, top_table, bot_table );
  
      count_top = top_table->count;
      count_bot = bot_table->count;
  
      /* sanitize top table */
      if ( count_top > 0 )
      {
        PSH_Blue_Zone  zone = top_table->zones;
  
  
        for ( count = count_top; count > 0; count--, zone++ )
        {
          FT_Int  delta;
  
  
          if ( count > 1 )
          {
            delta = zone[1].org_ref - zone[0].org_ref;
            if ( zone->org_delta > delta )
              zone->org_delta = delta;
          }
  
          zone->org_bottom = zone->org_ref;
          zone->org_top    = zone->org_delta + zone->org_ref;
        }
      }
  
      /* sanitize bottom table */
      if ( count_bot > 0 )
      {
        PSH_Blue_Zone  zone = bot_table->zones;
  
  
        for ( count = count_bot; count > 0; count--, zone++ )
        {
          FT_Int  delta;
  
  
          if ( count > 1 )
          {
            delta = zone[0].org_ref - zone[1].org_ref;
            if ( zone->org_delta < delta )
              zone->org_delta = delta;
          }
  
          zone->org_top    = zone->org_ref;
          zone->org_bottom = zone->org_delta + zone->org_ref;
        }
      }
  
      /* expand top and bottom tables with blue fuzz */
      {
        FT_Int         dim, top, bot, delta;
        PSH_Blue_Zone  zone;
  
  
        zone  = top_table->zones;
        count = count_top;
  
        for ( dim = 1; dim >= 0; dim-- )
        {
          if ( count > 0 )
          {
            /* expand the bottom of the lowest zone normally */
            zone->org_bottom -= fuzz;
  
            /* expand the top and bottom of intermediate zones;    */
            /* checking that the interval is smaller than the fuzz */
            top = zone->org_top;
  
            for ( count--; count > 0; count-- )
            {
              bot   = zone[1].org_bottom;
              delta = bot - top;
  
              if ( delta / 2 < fuzz )
                zone[0].org_top = zone[1].org_bottom = top + delta / 2;
              else
              {
                zone[0].org_top    = top + fuzz;
                zone[1].org_bottom = bot - fuzz;
              }
  
              zone++;
              top = zone->org_top;
            }
  
            /* expand the top of the highest zone normally */
            zone->org_top = top + fuzz;
          }
          zone  = bot_table->zones;
          count = count_bot;
        }
      }
    }
  
  
    /* reset the blues table when the device transform changes */
    static void
    psh_blues_scale_zones( PSH_Blues  blues,
                           FT_Fixed   scale,
                           FT_Pos     delta )
    {
      FT_UInt         count;
      FT_UInt         num;
      PSH_Blue_Table  table = NULL;
  
      /*                                                        */
      /* Determine whether we need to suppress overshoots or    */
      /* not.  We simply need to compare the vertical scale     */
      /* parameter to the raw bluescale value.  Here is why:    */
      /*                                                        */
      /*   We need to suppress overshoots for all pointsizes.   */
      /*   At 300dpi that satisfies:                            */
      /*                                                        */
      /*      pointsize < 240*bluescale + 0.49                  */
      /*                                                        */
      /*   This corresponds to:                                 */
      /*                                                        */
      /*      pixelsize < 1000*bluescale + 49/24                */
      /*                                                        */
      /*      scale*EM_Size < 1000*bluescale + 49/24            */
      /*                                                        */
      /*   However, for normal Type 1 fonts, EM_Size is 1000!   */
      /*   We thus only check:                                  */
      /*                                                        */
      /*      scale < bluescale + 49/24000                      */
      /*                                                        */
      /*   which we shorten to                                  */
      /*                                                        */
      /*      "scale < bluescale"                               */
      /*                                                        */
      /* Note that `blue_scale' is stored 1000 times its real   */
      /* value, and that `scale' converts from font units to    */
      /* fractional pixels.                                     */
      /*                                                        */
  
      /* 1000 / 64 = 125 / 8 */
      if ( scale >= 0x20C49BAL )
        blues->no_overshoots = FT_BOOL( scale < blues->blue_scale * 8 / 125 );
      else
        blues->no_overshoots = FT_BOOL( scale * 125 < blues->blue_scale * 8 );
  
      /*                                                        */
      /*  The blue threshold is the font units distance under   */
      /*  which overshoots are suppressed due to the BlueShift  */
      /*  even if the scale is greater than BlueScale.          */
      /*                                                        */
      /*  It is the smallest distance such that                 */
      /*                                                        */
      /*    dist <= BlueShift && dist*scale <= 0.5 pixels       */
      /*                                                        */
      {
        FT_Int  threshold = blues->blue_shift;
  
  
        while ( threshold > 0 && FT_MulFix( threshold, scale ) > 32 )
          threshold--;
  
        blues->blue_threshold = threshold;
      }
  
      for ( num = 0; num < 4; num++ )
      {
        PSH_Blue_Zone  zone;
  
  
        switch ( num )
        {
        case 0:
          table = &blues->normal_top;
          break;
        case 1:
          table = &blues->normal_bottom;
          break;
        case 2:
          table = &blues->family_top;
          break;
        default:
          table = &blues->family_bottom;
          break;
        }
  
        zone  = table->zones;
        count = table->count;
        for ( ; count > 0; count--, zone++ )
        {
          zone->cur_top    = FT_MulFix( zone->org_top,    scale ) + delta;
          zone->cur_bottom = FT_MulFix( zone->org_bottom, scale ) + delta;
          zone->cur_ref    = FT_MulFix( zone->org_ref,    scale ) + delta;
          zone->cur_delta  = FT_MulFix( zone->org_delta,  scale );
  
          /* round scaled reference position */
          zone->cur_ref = FT_PIX_ROUND( zone->cur_ref );
  
  #if 0
          if ( zone->cur_ref > zone->cur_top )
            zone->cur_ref -= 64;
          else if ( zone->cur_ref < zone->cur_bottom )
            zone->cur_ref += 64;
  #endif
        }
      }
  
      /* process the families now */
  
      for ( num = 0; num < 2; num++ )
      {
        PSH_Blue_Zone   zone1, zone2;
        FT_UInt         count1, count2;
        PSH_Blue_Table  normal, family;
  
  
        switch ( num )
        {
        case 0:
          normal = &blues->normal_top;
          family = &blues->family_top;
          break;
  
        default:
          normal = &blues->normal_bottom;
          family = &blues->family_bottom;
        }
  
        zone1  = normal->zones;
        count1 = normal->count;
  
        for ( ; count1 > 0; count1--, zone1++ )
        {
          /* try to find a family zone whose reference position is less */
          /* than 1 pixel far from the current zone                     */
          zone2  = family->zones;
          count2 = family->count;
  
          for ( ; count2 > 0; count2--, zone2++ )
          {
            FT_Pos  Delta;
  
  
            Delta = zone1->org_ref - zone2->org_ref;
            if ( Delta < 0 )
              Delta = -Delta;
  
            if ( FT_MulFix( Delta, scale ) < 64 )
            {
              zone1->cur_top    = zone2->cur_top;
              zone1->cur_bottom = zone2->cur_bottom;
              zone1->cur_ref    = zone2->cur_ref;
              zone1->cur_delta  = zone2->cur_delta;
              break;
            }
          }
        }
      }
    }
  
  
    /* calculate the maximum height of given blue zones */
    static FT_Short
    psh_calc_max_height( FT_UInt          num,
                         const FT_Short*  values,
                         FT_Short         cur_max )
    {
      FT_UInt  count;
  
  
      for ( count = 0; count < num; count += 2 )
      {
        FT_Short  cur_height = values[count + 1] - values[count];
  
  
        if ( cur_height > cur_max )
          cur_max = cur_height;
      }
  
      return cur_max;
    }
  
  
    FT_LOCAL_DEF( void )
    psh_blues_snap_stem( PSH_Blues      blues,
                         FT_Int         stem_top,
                         FT_Int         stem_bot,
                         PSH_Alignment  alignment )
    {
      PSH_Blue_Table  table;
      FT_UInt         count;
      FT_Pos          delta;
      PSH_Blue_Zone   zone;
      FT_Int          no_shoots;
  
  
      alignment->align = PSH_BLUE_ALIGN_NONE;
  
      no_shoots = blues->no_overshoots;
  
      /* look up stem top in top zones table */
      table = &blues->normal_top;
      count = table->count;
      zone  = table->zones;
  
      for ( ; count > 0; count--, zone++ )
      {
        delta = SUB_LONG( stem_top, zone->org_bottom );
        if ( delta < -blues->blue_fuzz )
          break;
  
        if ( stem_top <= zone->org_top + blues->blue_fuzz )
        {
          if ( no_shoots || delta <= blues->blue_threshold )
          {
            alignment->align    |= PSH_BLUE_ALIGN_TOP;
            alignment->align_top = zone->cur_ref;
          }
          break;
        }
      }
  
      /* look up stem bottom in bottom zones table */
      table = &blues->normal_bottom;
      count = table->count;
      zone  = table->zones + count-1;
  
      for ( ; count > 0; count--, zone-- )
      {
        delta = SUB_LONG( zone->org_top, stem_bot );
        if ( delta < -blues->blue_fuzz )
          break;
  
        if ( stem_bot >= zone->org_bottom - blues->blue_fuzz )
        {
          if ( no_shoots || delta < blues->blue_threshold )
          {
            alignment->align    |= PSH_BLUE_ALIGN_BOT;
            alignment->align_bot = zone->cur_ref;
          }
          break;
        }
      }
    }
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*****                                                               *****/
    /*****                        GLOBAL HINTS                           *****/
    /*****                                                               *****/
    /*************************************************************************/
    /*************************************************************************/
  
    static void
    psh_globals_destroy( PSH_Globals  globals )
    {
      if ( globals )
      {
        FT_Memory  memory;
  
  
        memory = globals->memory;
        globals->dimension[0].stdw.count = 0;
        globals->dimension[1].stdw.count = 0;
  
        globals->blues.normal_top.count    = 0;
        globals->blues.normal_bottom.count = 0;
        globals->blues.family_top.count    = 0;
        globals->blues.family_bottom.count = 0;
  
        FT_FREE( globals );
  
  #ifdef DEBUG_HINTER
        ps_debug_globals = NULL;
  #endif
      }
    }
  
  
    static FT_Error
    psh_globals_new( FT_Memory     memory,
                     T1_Private*   priv,
                     PSH_Globals  *aglobals )
    {
      PSH_Globals  globals = NULL;
      FT_Error     error;
  
  
      if ( !FT_NEW( globals ) )
      {
        FT_UInt    count;
        FT_Short*  read;
  
  
        globals->memory = memory;
  
        /* copy standard widths */
        {
          PSH_Dimension  dim   = &globals->dimension[1];
          PSH_Width      write = dim->stdw.widths;
  
  
          write->org = priv->standard_width[0];
          write++;
  
          read = priv->snap_widths;
          for ( count = priv->num_snap_widths; count > 0; count-- )
          {
            write->org = *read;
            write++;
            read++;
          }
  
          dim->stdw.count = priv->num_snap_widths + 1;
        }
  
        /* copy standard heights */
        {
          PSH_Dimension  dim = &globals->dimension[0];
          PSH_Width      write = dim->stdw.widths;
  
  
          write->org = priv->standard_height[0];
          write++;
          read = priv->snap_heights;
          for ( count = priv->num_snap_heights; count > 0; count-- )
          {
            write->org = *read;
            write++;
            read++;
          }
  
          dim->stdw.count = priv->num_snap_heights + 1;
        }
  
        /* copy blue zones */
        psh_blues_set_zones( &globals->blues, priv->num_blue_values,
                             priv->blue_values, priv->num_other_blues,
                             priv->other_blues, priv->blue_fuzz, 0 );
  
        psh_blues_set_zones( &globals->blues, priv->num_family_blues,
                             priv->family_blues, priv->num_family_other_blues,
                             priv->family_other_blues, priv->blue_fuzz, 1 );
  
        /* limit the BlueScale value to `1 / max_of_blue_zone_heights' */
        {
          FT_Fixed  max_scale;
          FT_Short  max_height = 1;
  
  
          max_height = psh_calc_max_height( priv->num_blue_values,
                                            priv->blue_values,
                                            max_height );
          max_height = psh_calc_max_height( priv->num_other_blues,
                                            priv->other_blues,
                                            max_height );
          max_height = psh_calc_max_height( priv->num_family_blues,
                                            priv->family_blues,
                                            max_height );
          max_height = psh_calc_max_height( priv->num_family_other_blues,
                                            priv->family_other_blues,
                                            max_height );
  
          /* BlueScale is scaled 1000 times */
          max_scale = FT_DivFix( 1000, max_height );
          globals->blues.blue_scale = priv->blue_scale < max_scale
                                        ? priv->blue_scale
                                        : max_scale;
        }
  
        globals->blues.blue_shift = priv->blue_shift;
        globals->blues.blue_fuzz  = priv->blue_fuzz;
  
        globals->dimension[0].scale_mult  = 0;
        globals->dimension[0].scale_delta = 0;
        globals->dimension[1].scale_mult  = 0;
        globals->dimension[1].scale_delta = 0;
  
  #ifdef DEBUG_HINTER
        ps_debug_globals = globals;
  #endif
      }
  
      *aglobals = globals;
      return error;
    }
  
  
    FT_LOCAL_DEF( void )
    psh_globals_set_scale( PSH_Globals  globals,
                           FT_Fixed     x_scale,
                           FT_Fixed     y_scale,
                           FT_Fixed     x_delta,
                           FT_Fixed     y_delta )
    {
      PSH_Dimension  dim;
  
  
      dim = &globals->dimension[0];
      if ( x_scale != dim->scale_mult  ||
           x_delta != dim->scale_delta )
      {
        dim->scale_mult  = x_scale;
        dim->scale_delta = x_delta;
  
        psh_globals_scale_widths( globals, 0 );
      }
  
      dim = &globals->dimension[1];
      if ( y_scale != dim->scale_mult  ||
           y_delta != dim->scale_delta )
      {
        dim->scale_mult  = y_scale;
        dim->scale_delta = y_delta;
  
        psh_globals_scale_widths( globals, 1 );
        psh_blues_scale_zones( &globals->blues, y_scale, y_delta );
      }
    }
  
  
    FT_LOCAL_DEF( void )
    psh_globals_funcs_init( PSH_Globals_FuncsRec*  funcs )
    {
      funcs->create    = psh_globals_new;
      funcs->set_scale = psh_globals_set_scale;
      funcs->destroy   = psh_globals_destroy;
    }
  
  
  /* END */
  