Update freetype to latest version of ASOP.

src/cff/cf2blues.c

+/***************************************************************************/
+/*                                                                         */
+/*  cf2blues.c                                                             */
+/*                                                                         */
+/*    Adobe's code for handling Blue Zones (body).                         */
+/*                                                                         */
+/*  Copyright 2009-2013 Adobe Systems Incorporated.                        */
+/*                                                                         */
+/*  This software, and all works of authorship, whether in source or       */
+/*  object code form as indicated by the copyright notice(s) included      */
+/*  herein (collectively, the "Work") is made available, and may only be   */
+/*  used, modified, and distributed under the FreeType Project License,    */
+/*  LICENSE.TXT.  Additionally, subject to the terms and conditions of the */
+/*  FreeType Project License, each contributor to the Work hereby grants   */
+/*  to any individual or legal entity exercising permissions granted by    */
+/*  the FreeType Project License and this section (hereafter, "You" or     */
+/*  "Your") a perpetual, worldwide, non-exclusive, no-charge,              */
+/*  royalty-free, irrevocable (except as stated in this section) patent    */
+/*  license to make, have made, use, offer to sell, sell, import, and      */
+/*  otherwise transfer the Work, where such license applies only to those  */
+/*  patent claims licensable by such contributor that are necessarily      */
+/*  infringed by their contribution(s) alone or by combination of their    */
+/*  contribution(s) with the Work to which such contribution(s) was        */
+/*  submitted.  If You institute patent litigation against any entity      */
+/*  (including a cross-claim or counterclaim in a lawsuit) alleging that   */
+/*  the Work or a contribution incorporated within the Work constitutes    */
+/*  direct or contributory patent infringement, then any patent licenses   */
+/*  granted to You under this License for that Work shall terminate as of  */
+/*  the date such litigation is filed.                                     */
+/*                                                                         */
+/*  By using, modifying, or distributing the Work you indicate that you    */
+/*  have read and understood the terms and conditions of the               */
+/*  FreeType Project License as well as those provided in this section,    */
+/*  and you accept them fully.                                             */
+/*                                                                         */
+/***************************************************************************/
+
+
+#include "cf2ft.h"
+#include FT_INTERNAL_DEBUG_H
+
+#include "cf2blues.h"
+#include "cf2hints.h"
+#include "cf2font.h"
+
+
+  /*************************************************************************/
+  /*                                                                       */
+  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
+  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
+  /* messages during execution.                                            */
+  /*                                                                       */
+#undef  FT_COMPONENT
+#define FT_COMPONENT  trace_cf2blues
+
+
+  /*
+   * For blue values, the FreeType parser produces an array of integers,
+   * while the Adobe CFF engine produces an array of fixed.
+   * Define a macro to convert FreeType to fixed.
+   */
+#define cf2_blueToFixed( x )  cf2_intToFixed( x )
+
+
+  FT_LOCAL_DEF( void )
+  cf2_blues_init( CF2_Blues  blues,
+                  CF2_Font   font )
+  {
+    /* pointer to parsed font object */
+    CFF_Decoder*  decoder = font->decoder;
+
+    CF2_Fixed  zoneHeight;
+    CF2_Fixed  maxZoneHeight = 0;
+    CF2_Fixed  csUnitsPerPixel;
+
+    size_t  numBlueValues;
+    size_t  numOtherBlues;
+    size_t  numFamilyBlues;
+    size_t  numFamilyOtherBlues;
+
+    FT_Pos*  blueValues;
+    FT_Pos*  otherBlues;
+    FT_Pos*  familyBlues;
+    FT_Pos*  familyOtherBlues;
+
+    size_t     i;
+    CF2_Fixed  emBoxBottom, emBoxTop;
+
+    CF2_Int  unitsPerEm = font->unitsPerEm;
+
+
+    if ( unitsPerEm == 0 )
+      unitsPerEm = 1000;
+
+    FT_ZERO( blues );
+    blues->scale = font->innerTransform.d;
+
+    cf2_getBlueMetrics( decoder,
+                        &blues->blueScale,
+                        &blues->blueShift,
+                        &blues->blueFuzz );
+
+    cf2_getBlueValues( decoder, &numBlueValues, &blueValues );
+    cf2_getOtherBlues( decoder, &numOtherBlues, &otherBlues );
+    cf2_getFamilyBlues( decoder, &numFamilyBlues, &familyBlues );
+    cf2_getFamilyOtherBlues( decoder, &numFamilyOtherBlues, &familyOtherBlues );
+
+    /*
+     * synthetic em box hint heuristic
+     *
+     * Apply this when ideographic dictionary (LanguageGroup 1) has no
+     * real alignment zones.  Adobe tools generate dummy zones at -250 and
+     * 1100 for a 1000 unit em.  Fonts with ICF-based alignment zones
+     * should not enable the heuristic.  When the heuristic is enabled,
+     * the font's blue zones are ignored.
+     *
+     */
+
+    /* get em box from OS/2 typoAscender/Descender                      */
+    /* TODO: FreeType does not parse these metrics.  Skip them for now. */
+#if 0
+    FCM_getHorizontalLineMetrics( &e,
+                                  font->font,
+                                  &ascender,
+                                  &descender,
+                                  &linegap );
+    if ( ascender - descender == unitsPerEm )
+    {
+      emBoxBottom = cf2_intToFixed( descender );
+      emBoxTop    = cf2_intToFixed( ascender );
+    }
+    else
+#endif
+    {
+      emBoxBottom = CF2_ICF_Bottom;
+      emBoxTop    = CF2_ICF_Top;
+    }
+
+    if ( cf2_getLanguageGroup( decoder ) == 1                   &&
+         ( numBlueValues == 0                                 ||
+           ( numBlueValues == 4                             &&
+             cf2_blueToFixed( blueValues[0] ) < emBoxBottom &&
+             cf2_blueToFixed( blueValues[1] ) < emBoxBottom &&
+             cf2_blueToFixed( blueValues[2] ) > emBoxTop    &&
+             cf2_blueToFixed( blueValues[3] ) > emBoxTop    ) ) )
+    {
+      /*
+       * Construct hint edges suitable for synthetic ghost hints at top
+       * and bottom of em box.  +-CF2_MIN_COUNTER allows for unhinted
+       * features above or below the last hinted edge.  This also gives a
+       * net 1 pixel boost to the height of ideographic glyphs.
+       *
+       * Note: Adjust synthetic hints outward by epsilon (0x.0001) to
+       *       avoid interference.  E.g., some fonts have real hints at
+       *       880 and -120.
+       */
+
+      blues->emBoxBottomEdge.csCoord = emBoxBottom - CF2_FIXED_EPSILON;
+      blues->emBoxBottomEdge.dsCoord = cf2_fixedRound(
+                                         FT_MulFix(
+                                           blues->emBoxBottomEdge.csCoord,
+                                           blues->scale ) ) -
+                                       CF2_MIN_COUNTER;
+      blues->emBoxBottomEdge.scale   = blues->scale;
+      blues->emBoxBottomEdge.flags   = CF2_GhostBottom |
+                                       CF2_Locked |
+                                       CF2_Synthetic;
+
+      blues->emBoxTopEdge.csCoord = emBoxTop + CF2_FIXED_EPSILON +
+                                    2 * font->darkenY;
+      blues->emBoxTopEdge.dsCoord = cf2_fixedRound(
+                                      FT_MulFix(
+                                        blues->emBoxTopEdge.csCoord,
+                                        blues->scale ) ) +
+                                    CF2_MIN_COUNTER;
+      blues->emBoxTopEdge.scale   = blues->scale;
+      blues->emBoxTopEdge.flags   = CF2_GhostTop |
+                                    CF2_Locked |
+                                    CF2_Synthetic;
+
+      blues->doEmBoxHints = TRUE;    /* enable the heuristic */
+
+      return;
+    }
+
+    /* copy `BlueValues' and `OtherBlues' to a combined array of top and */
+    /* bottom zones                                                      */
+    for ( i = 0; i < numBlueValues; i += 2 )
+    {
+      blues->zone[blues->count].csBottomEdge =
+        cf2_blueToFixed( blueValues[i] );
+      blues->zone[blues->count].csTopEdge =
+        cf2_blueToFixed( blueValues[i + 1] );
+
+      zoneHeight = blues->zone[blues->count].csTopEdge -
+                   blues->zone[blues->count].csBottomEdge;
+
+      if ( zoneHeight < 0 )
+      {
+        FT_TRACE4(( "cf2_blues_init: ignoring negative zone height\n" ));
+        continue;   /* reject this zone */
+      }
+
+      if ( zoneHeight > maxZoneHeight )
+      {
+        /* take maximum before darkening adjustment      */
+        /* so overshoot suppression point doesn't change */
+        maxZoneHeight = zoneHeight;
+      }
+
+      /* adjust both edges of top zone upward by twice darkening amount */
+      if ( i != 0 )
+      {
+        blues->zone[blues->count].csTopEdge    += 2 * font->darkenY;
+        blues->zone[blues->count].csBottomEdge += 2 * font->darkenY;
+      }
+
+      /* first `BlueValue' is bottom zone; others are top */
+      if ( i == 0 )
+      {
+        blues->zone[blues->count].bottomZone =
+          TRUE;
+        blues->zone[blues->count].csFlatEdge =
+          blues->zone[blues->count].csTopEdge;
+      }
+      else
+      {
+        blues->zone[blues->count].bottomZone =
+          FALSE;
+        blues->zone[blues->count].csFlatEdge =
+          blues->zone[blues->count].csBottomEdge;
+      }
+
+      blues->count += 1;
+    }
+
+    for ( i = 0; i < numOtherBlues; i += 2 )
+    {
+      blues->zone[blues->count].csBottomEdge =
+        cf2_blueToFixed( otherBlues[i] );
+      blues->zone[blues->count].csTopEdge =
+        cf2_blueToFixed( otherBlues[i + 1] );
+
+      zoneHeight = blues->zone[blues->count].csTopEdge -
+                   blues->zone[blues->count].csBottomEdge;
+
+      if ( zoneHeight < 0 )
+      {
+        FT_TRACE4(( "cf2_blues_init: ignoring negative zone height\n" ));
+        continue;   /* reject this zone */
+      }
+
+      if ( zoneHeight > maxZoneHeight )
+      {
+        /* take maximum before darkening adjustment      */
+        /* so overshoot suppression point doesn't change */
+        maxZoneHeight = zoneHeight;
+      }
+
+      /* Note: bottom zones are not adjusted for darkening amount */
+
+      /* all OtherBlues are bottom zone */
+      blues->zone[blues->count].bottomZone =
+        TRUE;
+      blues->zone[blues->count].csFlatEdge =
+        blues->zone[blues->count].csTopEdge;
+
+      blues->count += 1;
+    }
+
+    /* Adjust for FamilyBlues */
+
+    /* Search for the nearest flat edge in `FamilyBlues' or                */
+    /* `FamilyOtherBlues'.  According to the Black Book, any matching edge */
+    /* must be within one device pixel                                     */
+
+    csUnitsPerPixel = FT_DivFix( cf2_intToFixed( 1 ), blues->scale );
+
+    /* loop on all zones in this font */
+    for ( i = 0; i < blues->count; i++ )
+    {
+      size_t     j;
+      CF2_Fixed  minDiff;
+      CF2_Fixed  flatFamilyEdge, diff;
+      /* value for this font */
+      CF2_Fixed  flatEdge = blues->zone[i].csFlatEdge;
+
+
+      if ( blues->zone[i].bottomZone )
+      {
+        /* In a bottom zone, the top edge is the flat edge.             */
+        /* Search `FamilyOtherBlues' for bottom zones; look for closest */
+        /* Family edge that is within the one pixel threshold.          */
+
+        minDiff = CF2_FIXED_MAX;
+
+        for ( j = 0; j < numFamilyOtherBlues; j += 2 )
+        {
+          /* top edge */
+          flatFamilyEdge = cf2_blueToFixed( familyOtherBlues[j + 1] );
+
+          diff = cf2_fixedAbs( flatEdge - flatFamilyEdge );
+
+          if ( diff < minDiff && diff < csUnitsPerPixel )
+          {
+            blues->zone[i].csFlatEdge = flatFamilyEdge;
+            minDiff                   = diff;
+
+            if ( diff == 0 )
+              break;
+          }
+        }
+
+        /* check the first member of FamilyBlues, which is a bottom zone */
+        if ( numFamilyBlues >= 2 )
+        {
+          /* top edge */
+          flatFamilyEdge = cf2_blueToFixed( familyBlues[1] );
+
+          diff = cf2_fixedAbs( flatEdge - flatFamilyEdge );
+
+          if ( diff < minDiff && diff < csUnitsPerPixel )
+            blues->zone[i].csFlatEdge = flatFamilyEdge;
+        }
+      }
+      else
+      {
+        /* In a top zone, the bottom edge is the flat edge.                */
+        /* Search `FamilyBlues' for top zones; skip first zone, which is a */
+        /* bottom zone; look for closest Family edge that is within the    */
+        /* one pixel threshold                                             */
+
+        minDiff = CF2_FIXED_MAX;
+
+        for ( j = 2; j < numFamilyBlues; j += 2 )
+        {
+          /* bottom edge */
+          flatFamilyEdge = cf2_blueToFixed( familyBlues[j] );
+
+          /* adjust edges of top zone upward by twice darkening amount */
+          flatFamilyEdge += 2 * font->darkenY;      /* bottom edge */
+
+          diff = cf2_fixedAbs( flatEdge - flatFamilyEdge );
+
+          if ( diff < minDiff && diff < csUnitsPerPixel )
+          {
+            blues->zone[i].csFlatEdge = flatFamilyEdge;
+            minDiff                   = diff;
+
+            if ( diff == 0 )
+              break;
+          }
+        }
+      }
+    }
+
+    /* TODO: enforce separation of zones, including BlueFuzz */
+
+    /* Adjust BlueScale; similar to AdjustBlueScale() in coretype */
+    /* `bcsetup.c'.                                               */
+
+    if ( maxZoneHeight > 0 )
+    {
+      if ( blues->blueScale > FT_DivFix( cf2_intToFixed( 1 ),
+                                         maxZoneHeight ) )
+      {
+        /* clamp at maximum scale */
+        blues->blueScale = FT_DivFix( cf2_intToFixed( 1 ),
+                                      maxZoneHeight );
+      }
+
+      /*
+       * TODO: Revisit the bug fix for 613448.  The minimum scale
+       *       requirement catches a number of library fonts.  For
+       *       example, with default BlueScale (.039625) and 0.4 minimum,
+       *       the test below catches any font with maxZoneHeight < 10.1.
+       *       There are library fonts ranging from 2 to 10 that get
+       *       caught, including e.g., Eurostile LT Std Medium with
+       *       maxZoneHeight of 6.
+       *
+       */
+#if 0
+      if ( blueScale < .4 / maxZoneHeight )
+      {
+        tetraphilia_assert( 0 );
+        /* clamp at minimum scale, per bug 0613448 fix */
+        blueScale = .4 / maxZoneHeight;
+      }
+#endif
+
+    }
+
+    /*
+     * Suppress overshoot and boost blue zones at small sizes.  Boost
+     * amount varies linearly from 0.5 pixel near 0 to 0 pixel at
+     * blueScale cutoff.
+     * Note: This boost amount is different from the coretype heuristic.
+     *
+     */
+
+    if ( blues->scale < blues->blueScale )
+    {
+      blues->suppressOvershoot = TRUE;
+
+      /* Change rounding threshold for `dsFlatEdge'.                    */
+      /* Note: constant changed from 0.5 to 0.6 to avoid a problem with */
+      /*       10ppem Arial                                             */
+
+      blues->boost = FT_MulFix(
+                       cf2_floatToFixed( .6 ),
+                       ( cf2_intToFixed( 1 ) -
+                         FT_DivFix( blues->scale,
+                                    blues->blueScale ) ) );
+      if ( blues->boost > 0x7FFF )
+      {
+        /* boost must remain less than 0.5, or baseline could go negative */
+        blues->boost = 0x7FFF;
+      }
+    }
+
+    /* boost and darkening have similar effects; don't do both */
+    if ( font->stemDarkened )
+      blues->boost = 0;
+
+    /* set device space alignment for each zone;    */
+    /* apply boost amount before rounding flat edge */
+
+    for ( i = 0; i < blues->count; i++ )
+    {
+      if ( blues->zone[i].bottomZone )
+        blues->zone[i].dsFlatEdge = cf2_fixedRound(
+                                      FT_MulFix(
+                                        blues->zone[i].csFlatEdge,
+                                        blues->scale ) -
+                                      blues->boost );
+      else
+        blues->zone[i].dsFlatEdge = cf2_fixedRound(
+                                      FT_MulFix(
+                                        blues->zone[i].csFlatEdge,
+                                        blues->scale ) +
+                                      blues->boost );
+    }
+  }
+
+
+  /*
+   * Check whether `stemHint' is captured by one of the blue zones.
+   *
+   * Zero, one or both edges may be valid; only valid edges can be
+   * captured.  For compatibility with CoolType, search top and bottom
+   * zones in the same pass (see `BlueLock').  If a hint is captured,
+   * return true and position the edge(s) in one of 3 ways:
+   *
+   *  1) If `BlueScale' suppresses overshoot, position the captured edge
+   *     at the flat edge of the zone.
+   *  2) If overshoot is not suppressed and `BlueShift' requires
+   *     overshoot, position the captured edge a minimum of 1 device pixel
+   *     from the flat edge.
+   *  3) If overshoot is not suppressed or required, position the captured
+   *     edge at the nearest device pixel.
+   *
+   */
+  FT_LOCAL_DEF( FT_Bool )
+  cf2_blues_capture( const CF2_Blues  blues,
+                     CF2_Hint         bottomHintEdge,
+                     CF2_Hint         topHintEdge )
+  {
+    /* TODO: validate? */
+    CF2_Fixed  csFuzz = blues->blueFuzz;
+
+    /* new position of captured edge */
+    CF2_Fixed  dsNew;
+
+    /* amount that hint is moved when positioned */
+    CF2_Fixed  dsMove = 0;
+
+    FT_Bool   captured = FALSE;
+    CF2_UInt  i;
+
+
+    /* assert edge flags are consistent */
+    FT_ASSERT( !cf2_hint_isTop( bottomHintEdge ) &&
+               !cf2_hint_isBottom( topHintEdge ) );
+
+    /* TODO: search once without blue fuzz for compatibility with coretype? */
+    for ( i = 0; i < blues->count; i++ )
+    {
+      if ( blues->zone[i].bottomZone           &&
+           cf2_hint_isBottom( bottomHintEdge ) )
+      {
+        if ( ( blues->zone[i].csBottomEdge - csFuzz ) <=
+               bottomHintEdge->csCoord                   &&
+             bottomHintEdge->csCoord <=
+               ( blues->zone[i].csTopEdge + csFuzz )     )
+        {
+          /* bottom edge captured by bottom zone */
+
+          if ( blues->suppressOvershoot )
+            dsNew = blues->zone[i].dsFlatEdge;
+
+          else if ( ( blues->zone[i].csTopEdge - bottomHintEdge->csCoord ) >=
+                      blues->blueShift )
+          {
+            /* guarantee minimum of 1 pixel overshoot */
+            dsNew = FT_MIN(
+                      cf2_fixedRound( bottomHintEdge->dsCoord ),
+                      blues->zone[i].dsFlatEdge - cf2_intToFixed( 1 ) );
+          }
+
+          else
+          {
+            /* simply round captured edge */
+            dsNew = cf2_fixedRound( bottomHintEdge->dsCoord );
+          }
+
+          dsMove   = dsNew - bottomHintEdge->dsCoord;
+          captured = TRUE;
+
+          break;
+        }
+      }
+
+      if ( !blues->zone[i].bottomZone && cf2_hint_isTop( topHintEdge ) )
+      {
+        if ( ( blues->zone[i].csBottomEdge - csFuzz ) <=
+               topHintEdge->csCoord                      &&
+             topHintEdge->csCoord <=
+               ( blues->zone[i].csTopEdge + csFuzz )     )
+        {
+          /* top edge captured by top zone */
+
+          if ( blues->suppressOvershoot )
+            dsNew = blues->zone[i].dsFlatEdge;
+
+          else if ( ( topHintEdge->csCoord - blues->zone[i].csBottomEdge ) >=
+                      blues->blueShift )
+          {
+            /* guarantee minimum of 1 pixel overshoot */
+            dsNew = FT_MAX(
+                      cf2_fixedRound( topHintEdge->dsCoord ),
+                      blues->zone[i].dsFlatEdge + cf2_intToFixed( 1 ) );
+          }
+
+          else
+          {
+            /* simply round captured edge */
+            dsNew = cf2_fixedRound( topHintEdge->dsCoord );
+          }
+
+          dsMove   = dsNew - topHintEdge->dsCoord;
+          captured = TRUE;
+
+          break;
+        }
+      }
+    }
+
+    if ( captured )
+    {
+      /* move both edges and flag them `locked' */
+      if ( cf2_hint_isValid( bottomHintEdge ) )
+      {
+        bottomHintEdge->dsCoord += dsMove;
+        cf2_hint_lock( bottomHintEdge );
+      }
+
+      if ( cf2_hint_isValid( topHintEdge ) )
+      {
+        topHintEdge->dsCoord += dsMove;
+        cf2_hint_lock( topHintEdge );
+      }
+    }
+
+    return captured;
+  }
+
+
+/* END */