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+/***************************************************************************/
+/*                                                                         */
+/*  psfont.c                                                               */
+/*                                                                         */
+/*    Adobe's code for font instances (body).                              */
+/*                                                                         */
+/*  Copyright 2007-2014 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 "ft2build.h"
+#include FT_INTERNAL_CALC_H
+
+#include "psft.h"
+
+#include "psglue.h"
+#include "psfont.h"
+#include "pserror.h"
+#include "psintrp.h"
+
+
+  /* Compute a stem darkening amount in character space. */
+  static void
+  cf2_computeDarkening( CF2_Fixed   emRatio,
+                        CF2_Fixed   ppem,
+                        CF2_Fixed   stemWidth,
+                        CF2_Fixed*  darkenAmount,
+                        CF2_Fixed   boldenAmount,
+                        FT_Bool     stemDarkened,
+                        FT_Int*     darkenParams )
+  {
+    /*
+     * Total darkening amount is computed in 1000 unit character space
+     * using the modified 5 part curve as Adobe's Avalon rasterizer.
+     * The darkening amount is smaller for thicker stems.
+     * It becomes zero when the stem is thicker than 2.333 pixels.
+     *
+     * By default, we use
+     *
+     *   darkenAmount = 0.4 pixels   if scaledStem <= 0.5 pixels,
+     *   darkenAmount = 0.275 pixels if 1 <= scaledStem <= 1.667 pixels,
+     *   darkenAmount = 0 pixel      if scaledStem >= 2.333 pixels,
+     *
+     * and piecewise linear in-between:
+     *
+     *
+     *   darkening
+     *       ^
+     *       |
+     *       |      (x1,y1)
+     *       |--------+
+     *       |         \
+     *       |          \
+     *       |           \          (x3,y3)
+     *       |            +----------+
+     *       |        (x2,y2)         \
+     *       |                         \
+     *       |                          \
+     *       |                           +-----------------
+     *       |                         (x4,y4)
+     *       +--------------------------------------------->   stem
+     *                                                       thickness
+     *
+     *
+     * This corresponds to the following values for the
+     * `darkening-parameters' property:
+     *
+     *   (x1, y1) = (500, 400)
+     *   (x2, y2) = (1000, 275)
+     *   (x3, y3) = (1667, 275)
+     *   (x4, y4) = (2333, 0)
+     *
+     */
+
+    /* Internal calculations are done in units per thousand for */
+    /* convenience. The x axis is scaled stem width in          */
+    /* thousandths of a pixel. That is, 1000 is 1 pixel.        */
+    /* The y axis is darkening amount in thousandths of a pixel.*/
+    /* In the code, below, dividing by ppem and                 */
+    /* adjusting for emRatio converts darkenAmount to character */
+    /* space (font units).                                      */
+    CF2_Fixed  stemWidthPer1000, scaledStem;
+    FT_Int     logBase2;
+
+
+    *darkenAmount = 0;
+
+    if ( boldenAmount == 0 && !stemDarkened )
+      return;
+
+    /* protect against range problems and divide by zero */
+    if ( emRatio < cf2_doubleToFixed( .01 ) )
+      return;
+
+    if ( stemDarkened )
+    {
+      FT_Int  x1 = darkenParams[0];
+      FT_Int  y1 = darkenParams[1];
+      FT_Int  x2 = darkenParams[2];
+      FT_Int  y2 = darkenParams[3];
+      FT_Int  x3 = darkenParams[4];
+      FT_Int  y3 = darkenParams[5];
+      FT_Int  x4 = darkenParams[6];
+      FT_Int  y4 = darkenParams[7];
+
+
+      /* convert from true character space to 1000 unit character space; */
+      /* add synthetic emboldening effect                                */
+
+      /* `stemWidthPer1000' will not overflow for a legitimate font      */
+
+      stemWidthPer1000 = FT_MulFix( stemWidth + boldenAmount, emRatio );
+
+      /* `scaledStem' can easily overflow, so we must clamp its maximum  */
+      /* value; the test doesn't need to be precise, but must be         */
+      /* conservative.  The clamp value (default 2333) where             */
+      /* `darkenAmount' is zero is well below the overflow value of      */
+      /* 32767.                                                          */
+      /*                                                                 */
+      /* FT_MSB computes the integer part of the base 2 logarithm.  The  */
+      /* number of bits for the product is 1 or 2 more than the sum of   */
+      /* logarithms; remembering that the 16 lowest bits of the fraction */
+      /* are dropped this is correct to within a factor of almost 4.     */
+      /* For example, 0x80.0000 * 0x80.0000 = 0x4000.0000 is 23+23 and   */
+      /* is flagged as possible overflow because 0xFF.FFFF * 0xFF.FFFF = */
+      /* 0xFFFF.FE00 is also 23+23.                                      */
+
+      logBase2 = FT_MSB( (FT_UInt32)stemWidthPer1000 ) +
+                   FT_MSB( (FT_UInt32)ppem );
+
+      if ( logBase2 >= 46 )
+        /* possible overflow */
+        scaledStem = cf2_intToFixed( x4 );
+      else
+        scaledStem = FT_MulFix( stemWidthPer1000, ppem );
+
+      /* now apply the darkening parameters */
+
+      if ( scaledStem < cf2_intToFixed( x1 ) )
+        *darkenAmount = FT_DivFix( cf2_intToFixed( y1 ), ppem );
+
+      else if ( scaledStem < cf2_intToFixed( x2 ) )
+      {
+        FT_Int  xdelta = x2 - x1;
+        FT_Int  ydelta = y2 - y1;
+        FT_Int  x      = stemWidthPer1000 -
+                           FT_DivFix( cf2_intToFixed( x1 ), ppem );
+
+
+        if ( !xdelta )
+          goto Try_x3;
+
+        *darkenAmount = FT_MulDiv( x, ydelta, xdelta ) +
+                          FT_DivFix( cf2_intToFixed( y1 ), ppem );
+      }
+
+      else if ( scaledStem < cf2_intToFixed( x3 ) )
+      {
+      Try_x3:
+        {
+          FT_Int  xdelta = x3 - x2;
+          FT_Int  ydelta = y3 - y2;
+          FT_Int  x      = stemWidthPer1000 -
+                             FT_DivFix( cf2_intToFixed( x2 ), ppem );
+
+
+          if ( !xdelta )
+            goto Try_x4;
+
+          *darkenAmount = FT_MulDiv( x, ydelta, xdelta ) +
+                            FT_DivFix( cf2_intToFixed( y2 ), ppem );
+        }
+      }
+
+      else if ( scaledStem < cf2_intToFixed( x4 ) )
+      {
+      Try_x4:
+        {
+          FT_Int  xdelta = x4 - x3;
+          FT_Int  ydelta = y4 - y3;
+          FT_Int  x      = stemWidthPer1000 -
+                             FT_DivFix( cf2_intToFixed( x3 ), ppem );
+
+
+          if ( !xdelta )
+            goto Use_y4;
+
+          *darkenAmount = FT_MulDiv( x, ydelta, xdelta ) +
+                            FT_DivFix( cf2_intToFixed( y3 ), ppem );
+        }
+      }
+
+      else
+      {
+      Use_y4:
+        *darkenAmount = FT_DivFix( cf2_intToFixed( y4 ), ppem );
+      }
+
+      /* use half the amount on each side and convert back to true */
+      /* character space                                           */
+      *darkenAmount = FT_DivFix( *darkenAmount, 2 * emRatio );
+    }
+
+    /* add synthetic emboldening effect in character space */
+    *darkenAmount += boldenAmount / 2;
+  }
+
+
+  /* set up values for the current FontDict and matrix; */
+  /* called for each glyph to be rendered               */
+
+  /* caller's transform is adjusted for subpixel positioning */
+  static void
+  cf2_font_setup( CF2_Font           font,
+                  const CF2_Matrix*  transform )
+  {
+    /* pointer to parsed font object */
+    PS_Decoder*  decoder = font->decoder;
+
+    FT_Bool  needExtraSetup = FALSE;
+
+    CFF_VStoreRec*  vstore;
+    FT_Bool         hasVariations = FALSE;
+
+    /* character space units */
+    CF2_Fixed  boldenX = font->syntheticEmboldeningAmountX;
+    CF2_Fixed  boldenY = font->syntheticEmboldeningAmountY;
+
+    CFF_SubFont  subFont;
+    CF2_Fixed    ppem;
+
+    CF2_UInt   lenNormalizedV = 0;
+    FT_Fixed*  normalizedV    = NULL;
+
+    /* clear previous error */
+    font->error = FT_Err_Ok;
+
+    /* if a CID fontDict has changed, we need to recompute some cached */
+    /* data                                                            */
+    subFont = cf2_getSubfont( decoder );
+    if ( font->lastSubfont != subFont )
+    {
+      font->lastSubfont = subFont;
+      needExtraSetup    = TRUE;
+    }
+
+    if ( !font->isT1 )
+    {
+      FT_Service_CFFLoad  cffload = (FT_Service_CFFLoad)font->cffload;
+
+
+      /* check for variation vectors */
+      vstore        = cf2_getVStore( decoder );
+      hasVariations = ( vstore->dataCount != 0 );
+
+      if ( hasVariations )
+      {
+#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
+        /* check whether Private DICT in this subfont needs to be reparsed */
+        font->error = cf2_getNormalizedVector( decoder,
+                                               &lenNormalizedV,
+                                               &normalizedV );
+        if ( font->error )
+          return;
+
+        if ( cffload->blend_check_vector( &subFont->blend,
+                                          subFont->private_dict.vsindex,
+                                          lenNormalizedV,
+                                          normalizedV ) )
+        {
+          /* blend has changed, reparse */
+          cffload->load_private_dict( decoder->cff,
+                                      subFont,
+                                      lenNormalizedV,
+                                      normalizedV );
+          needExtraSetup = TRUE;
+        }
+#endif
+
+        /* copy from subfont */
+        font->blend.font = subFont->blend.font;
+
+        /* clear state of charstring blend */
+        font->blend.usedBV = FALSE;
+
+        /* initialize value for charstring */
+        font->vsindex = subFont->private_dict.vsindex;
+
+        /* store vector inputs for blends in charstring */
+        font->lenNDV = lenNormalizedV;
+        font->NDV    = normalizedV;
+      }
+    }
+
+    /* if ppem has changed, we need to recompute some cached data         */
+    /* note: because of CID font matrix concatenation, ppem and transform */
+    /*       do not necessarily track.                                    */
+    ppem = cf2_getPpemY( decoder );
+    if ( font->ppem != ppem )
+    {
+      font->ppem     = ppem;
+      needExtraSetup = TRUE;
+    }
+
+    /* copy hinted flag on each call */
+    font->hinted = (FT_Bool)( font->renderingFlags & CF2_FlagsHinted );
+
+    /* determine if transform has changed;       */
+    /* include Fontmatrix but ignore translation */
+    if ( ft_memcmp( transform,
+                    &font->currentTransform,
+                    4 * sizeof ( CF2_Fixed ) ) != 0 )
+    {
+      /* save `key' information for `cache of one' matrix data; */
+      /* save client transform, without the translation         */
+      font->currentTransform    = *transform;
+      font->currentTransform.tx =
+      font->currentTransform.ty = cf2_intToFixed( 0 );
+
+      /* TODO: FreeType transform is simple scalar; for now, use identity */
+      /*       for outer                                                  */
+      font->innerTransform   = *transform;
+      font->outerTransform.a =
+      font->outerTransform.d = cf2_intToFixed( 1 );
+      font->outerTransform.b =
+      font->outerTransform.c = cf2_intToFixed( 0 );
+
+      needExtraSetup = TRUE;
+    }
+
+    /*
+     * font->darkened is set to true if there is a stem darkening request or
+     * the font is synthetic emboldened.
+     * font->darkened controls whether to adjust blue zones, winding order,
+     * and hinting.
+     *
+     */
+    if ( font->stemDarkened != ( font->renderingFlags & CF2_FlagsDarkened ) )
+    {
+      font->stemDarkened =
+        (FT_Bool)( font->renderingFlags & CF2_FlagsDarkened );
+
+      /* blue zones depend on darkened flag */
+      needExtraSetup = TRUE;
+    }
+
+    /* recompute variables that are dependent on transform or FontDict or */
+    /* darken flag                                                        */
+    if ( needExtraSetup )
+    {
+      /* StdVW is found in the private dictionary;                       */
+      /* recompute darkening amounts whenever private dictionary or      */
+      /* transform change                                                */
+      /* Note: a rendering flag turns darkening on or off, so we want to */
+      /*       store the `on' amounts;                                   */
+      /*       darkening amount is computed in character space           */
+      /* TODO: testing size-dependent darkening here;                    */
+      /*       what to do for rotations?                                 */
+
+      CF2_Fixed  emRatio;
+      CF2_Fixed  stdHW;
+      CF2_Int    unitsPerEm = font->unitsPerEm;
+
+
+      if ( unitsPerEm == 0 )
+        unitsPerEm = 1000;
+
+      ppem = FT_MAX( cf2_intToFixed( 4 ),
+                     font->ppem ); /* use minimum ppem of 4 */
+
+#if 0
+      /* since vstem is measured in the x-direction, we use the `a' member */
+      /* of the fontMatrix                                                 */
+      emRatio = cf2_fixedFracMul( cf2_intToFixed( 1000 ), fontMatrix->a );
+#endif
+
+      /* Freetype does not preserve the fontMatrix when parsing; use */
+      /* unitsPerEm instead.                                         */
+      /* TODO: check precision of this                               */
+      emRatio     = cf2_intToFixed( 1000 ) / unitsPerEm;
+      font->stdVW = cf2_getStdVW( decoder );
+
+      if ( font->stdVW <= 0 )
+        font->stdVW = FT_DivFix( cf2_intToFixed( 75 ), emRatio );
+
+      if ( boldenX > 0 )
+      {
+        /* Ensure that boldenX is at least 1 pixel for synthetic bold font */
+        /* (similar to what Avalon does)                                   */
+        boldenX = FT_MAX( boldenX,
+                          FT_DivFix( cf2_intToFixed( unitsPerEm ), ppem ) );
+
+        /* Synthetic emboldening adds at least 1 pixel to darkenX, while */
+        /* stem darkening adds at most half pixel.  Since the purpose of */
+        /* stem darkening (readability at small sizes) is met with       */
+        /* synthetic emboldening, no need to add stem darkening for a    */
+        /* synthetic bold font.                                          */
+        cf2_computeDarkening( emRatio,
+                              ppem,
+                              font->stdVW,
+                              &font->darkenX,
+                              boldenX,
+                              FALSE,
+                              font->darkenParams );
+      }
+      else
+        cf2_computeDarkening( emRatio,
+                              ppem,
+                              font->stdVW,
+                              &font->darkenX,
+                              0,
+                              font->stemDarkened,
+                              font->darkenParams );
+
+#if 0
+      /* since hstem is measured in the y-direction, we use the `d' member */
+      /* of the fontMatrix                                                 */
+      /* TODO: use the same units per em as above; check this              */
+      emRatio = cf2_fixedFracMul( cf2_intToFixed( 1000 ), fontMatrix->d );
+#endif
+
+      /* set the default stem width, because it must be the same for all */
+      /* family members;                                                 */
+      /* choose a constant for StdHW that depends on font contrast       */
+      stdHW = cf2_getStdHW( decoder );
+
+      if ( stdHW > 0 && font->stdVW > MUL_INT32( 2, stdHW ) )
+        font->stdHW = FT_DivFix( cf2_intToFixed( 75 ), emRatio );
+      else
+      {
+        /* low contrast font gets less hstem darkening */
+        font->stdHW = FT_DivFix( cf2_intToFixed( 110 ), emRatio );
+      }
+
+      cf2_computeDarkening( emRatio,
+                            ppem,
+                            font->stdHW,
+                            &font->darkenY,
+                            boldenY,
+                            font->stemDarkened,
+                            font->darkenParams );
+
+      if ( font->darkenX != 0 || font->darkenY != 0 )
+        font->darkened = TRUE;
+      else
+        font->darkened = FALSE;
+
+      font->reverseWinding = FALSE; /* initial expectation is CCW */
+
+      /* compute blue zones for this instance */
+      cf2_blues_init( &font->blues, font );
+
+    } /* needExtraSetup */
+  }
+
+
+  /* equivalent to AdobeGetOutline */
+  FT_LOCAL_DEF( FT_Error )
+  cf2_getGlyphOutline( CF2_Font           font,
+                       CF2_Buffer         charstring,
+                       const CF2_Matrix*  transform,
+                       CF2_F16Dot16*      glyphWidth )
+  {
+    FT_Error  lastError = FT_Err_Ok;
+
+    FT_Vector  translation;
+
+#if 0
+    FT_Vector  advancePoint;
+#endif
+
+    CF2_Fixed  advWidth = 0;
+    FT_Bool    needWinding;
+
+
+    /* Note: use both integer and fraction for outlines.  This allows bbox */
+    /*       to come out directly.                                         */
+
+    translation.x = transform->tx;
+    translation.y = transform->ty;
+
+    /* set up values based on transform */
+    cf2_font_setup( font, transform );
+    if ( font->error )
+      goto exit;                      /* setup encountered an error */
+
+    /* reset darken direction */
+    font->reverseWinding = FALSE;
+
+    /* winding order only affects darkening */
+    needWinding = font->darkened;
+
+    while ( 1 )
+    {
+      /* reset output buffer */
+      cf2_outline_reset( &font->outline );
+
+      /* build the outline, passing the full translation */
+      cf2_interpT2CharString( font,
+                              charstring,
+                              (CF2_OutlineCallbacks)&font->outline,
+                              &translation,
+                              FALSE,
+                              0,
+                              0,
+                              &advWidth );
+
+      if ( font->error )
+        goto exit;
+
+      if ( !needWinding )
+        break;
+
+      /* check winding order */
+      if ( font->outline.root.windingMomentum >= 0 ) /* CFF is CCW */
+        break;
+
+      /* invert darkening and render again                            */
+      /* TODO: this should be a parameter to getOutline-computeOffset */
+      font->reverseWinding = TRUE;
+
+      needWinding = FALSE;    /* exit after next iteration */
+    }
+
+    /* finish storing client outline */
+    cf2_outline_close( &font->outline );
+
+  exit:
+    /* FreeType just wants the advance width; there is no translation */
+    *glyphWidth = advWidth;
+
+    /* free resources and collect errors from objects we've used */
+    cf2_setError( &font->error, lastError );
+
+    return font->error;
+  }
+
+
+/* END */