Remove experimental auto-hinting 'warp' mode.

This feature was always experimental, and probably nevery worked
properly. This patch completely removes it from the source code,
except for a documentation block describing it for historical
purpose.

16 files changed, 18 insertions, 676 deletions

diff --git a/ChangeLog b/ChangeLog
index 48ab91859..648101aba 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,19 @@
 2021-07-12  David Turner  <david@freetype.org>
 
+	Remove experimental auto-hinting 'warp' mode.
+
+	This feature was always experimental, and probably nevery worked
+	properly. This patch completely removes it from the source code,
+	except for a documentation block describing it for historical
+	purpose.
+
+	* devel/ftoption.h: Remove AF_CONFIG_OPTION_USE_WARPER.
+	* include/freetype/config/ftoption.h: Remove AF_CONFIG_OPTION_USE_WARPER.
+	* include/freetype/ftdriver.h: Document 'warping' property as obsolete.
+	* src/autofit/*: Remove any warp mode related code.
+
+2021-07-12  David Turner  <david@freetype.org>
+
 	Remove experimental "Latin2" writing system (FT_OPTION_AUTOFIT2)
 
 	This code has always been experimental and was never compiled anyway
diff --git a/devel/ftoption.h b/devel/ftoption.h
index 3cb04debd..ab7bbbd6a 100644
--- a/devel/ftoption.h
+++ b/devel/ftoption.h
@@ -909,24 +909,6 @@ FT_BEGIN_HEADER
 
   /**************************************************************************
    *
-   * Compile 'autofit' module with warp hinting.  The idea of the warping
-   * code is to slightly scale and shift a glyph within a single dimension so
-   * that as much of its segments are aligned (more or less) on the grid.  To
-   * find out the optimal scaling and shifting value, various parameter
-   * combinations are tried and scored.
-   *
-   * You can switch warping on and off with the `warping` property of the
-   * auto-hinter (see file `ftdriver.h` for more information; by default it
-   * is switched off).
-   *
-   * This experimental option is not active if the rendering mode is
-   * `FT_RENDER_MODE_LIGHT`.
-   */
-#define AF_CONFIG_OPTION_USE_WARPER
-
-
-  /**************************************************************************
-   *
    * Use TrueType-like size metrics for 'light' auto-hinting.
    *
    * It is strongly recommended to avoid this option, which exists only to
diff --git a/include/freetype/config/ftoption.h b/include/freetype/config/ftoption.h
index da4250b08..ab5ab5f9f 100644
--- a/include/freetype/config/ftoption.h
+++ b/include/freetype/config/ftoption.h
@@ -911,24 +911,6 @@ FT_BEGIN_HEADER
 
   /**************************************************************************
    *
-   * Compile 'autofit' module with warp hinting.  The idea of the warping
-   * code is to slightly scale and shift a glyph within a single dimension so
-   * that as much of its segments are aligned (more or less) on the grid.  To
-   * find out the optimal scaling and shifting value, various parameter
-   * combinations are tried and scored.
-   *
-   * You can switch warping on and off with the `warping` property of the
-   * auto-hinter (see file `ftdriver.h` for more information; by default it
-   * is switched off).
-   *
-   * This experimental option is not active if the rendering mode is
-   * `FT_RENDER_MODE_LIGHT`.
-   */
-#define AF_CONFIG_OPTION_USE_WARPER
-
-
-  /**************************************************************************
-   *
    * Use TrueType-like size metrics for 'light' auto-hinting.
    *
    * It is strongly recommended to avoid this option, which exists only to
diff --git a/include/freetype/ftdriver.h b/include/freetype/ftdriver.h
index 59ae8431f..6b13d92e6 100644
--- a/include/freetype/ftdriver.h
+++ b/include/freetype/ftdriver.h
@@ -1162,11 +1162,11 @@ FT_BEGIN_HEADER
    *   warping
    *
    * @description:
-   *   **Experimental only**
+   *   **Obsolete**
    *
-   *   If FreeType gets compiled with option `AF_CONFIG_OPTION_USE_WARPER` to
-   *   activate the warp hinting code in the auto-hinter, this property
-   *   switches warping on and off.
+   *   This property was always experimental and probably never worked
+   *   correctly. It was entirely removed from the FreeType 2 sources.
+   *   This entry is only here for historical reference.
    *
    *   Warping only works in 'normal' auto-hinting mode replacing it.  The
    *   idea of the code is to slightly scale and shift a glyph along the
@@ -1175,36 +1175,6 @@ FT_BEGIN_HEADER
    *   out a glyph's optimal scaling and shifting value, various parameter
    *   combinations are tried and scored.
    *
-   *   By default, warping is off.
-   *
-   * @note:
-   *   This property can be used with @FT_Property_Get also.
-   *
-   *   This property can be set via the `FREETYPE_PROPERTIES` environment
-   *   variable (using values 1 and 0 for 'on' and 'off', respectively).
-   *
-   *   The warping code can also change advance widths.  Have a look at the
-   *   `lsb_delta` and `rsb_delta` fields in the @FT_GlyphSlotRec structure
-   *   for details on improving inter-glyph distances while rendering.
-   *
-   *   Since warping is a global property of the auto-hinter it is best to
-   *   change its value before rendering any face.  Otherwise, you should
-   *   reload all faces that get auto-hinted in 'normal' hinting mode.
-   *
-   * @example:
-   *   This example shows how to switch on warping (omitting the error
-   *   handling).
-   *
-   *   ```
-   *     FT_Library  library;
-   *     FT_Bool     warping = 1;
-   *
-   *
-   *     FT_Init_FreeType( &library );
-   *
-   *     FT_Property_Set( library, "autofitter", "warping", &warping );
-   *   ```
-   *
    * @since:
    *   2.6
    *
diff --git a/src/autofit/afcjk.c b/src/autofit/afcjk.c
index ba15f2c55..7e46b6b1e 100644
--- a/src/autofit/afcjk.c
+++ b/src/autofit/afcjk.c
@@ -37,11 +37,6 @@
 #include "aferrors.h"
 
 
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-#include "afwarp.h"
-#endif
-
-
   /**************************************************************************
    *
    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
@@ -1400,11 +1395,6 @@
     /* compute flags depending on render mode, etc. */
     mode = metrics->root.scaler.render_mode;
 
-#if 0 /* AF_CONFIG_OPTION_USE_WARPER */
-    if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
-      metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
-#endif
-
     scaler_flags = hints->scaler_flags;
     other_flags  = 0;
 
@@ -1433,12 +1423,6 @@
 
     scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE;
 
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-    /* get (global) warper flag */
-    if ( !metrics->root.globals->module->warping )
-      scaler_flags |= AF_SCALER_FLAG_NO_WARPER;
-#endif
-
     hints->scaler_flags = scaler_flags;
     hints->other_flags  = other_flags;
 
@@ -2321,25 +2305,6 @@
       if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
            ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) )   )
       {
-
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-        if ( dim == AF_DIMENSION_HORZ                                  &&
-             metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL &&
-             AF_HINTS_DO_WARP( hints )                                 )
-        {
-          AF_WarperRec  warper;
-          FT_Fixed      scale;
-          FT_Pos        delta;
-
-
-          af_warper_compute( &warper, hints, (AF_Dimension)dim,
-                             &scale, &delta );
-          af_glyph_hints_scale_dim( hints, (AF_Dimension)dim,
-                                    scale, delta );
-          continue;
-        }
-#endif /* AF_CONFIG_OPTION_USE_WARPER */
-
         af_cjk_hint_edges( hints, (AF_Dimension)dim );
         af_cjk_align_edge_points( hints, (AF_Dimension)dim );
         af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
diff --git a/src/autofit/afhints.c b/src/autofit/afhints.c
index 6e5af1ecb..08b5daff1 100644
--- a/src/autofit/afhints.c
+++ b/src/autofit/afhints.c
@@ -1688,33 +1688,4 @@
   }
 
 
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-
-  /* Apply (small) warp scale and warp delta for given dimension. */
-
-  FT_LOCAL_DEF( void )
-  af_glyph_hints_scale_dim( AF_GlyphHints  hints,
-                            AF_Dimension   dim,
-                            FT_Fixed       scale,
-                            FT_Pos         delta )
-  {
-    AF_Point  points       = hints->points;
-    AF_Point  points_limit = points + hints->num_points;
-    AF_Point  point;
-
-
-    if ( dim == AF_DIMENSION_HORZ )
-    {
-      for ( point = points; point < points_limit; point++ )
-        point->x = FT_MulFix( point->fx, scale ) + delta;
-    }
-    else
-    {
-      for ( point = points; point < points_limit; point++ )
-        point->y = FT_MulFix( point->fy, scale ) + delta;
-    }
-  }
-
-#endif /* AF_CONFIG_OPTION_USE_WARPER */
-
 /* END */
diff --git a/src/autofit/afhints.h b/src/autofit/afhints.h
index 0ce0aa32a..9f3639261 100644
--- a/src/autofit/afhints.h
+++ b/src/autofit/afhints.h
@@ -408,10 +408,6 @@ FT_BEGIN_HEADER
 #define AF_HINTS_DO_ADVANCE( h )                                \
           !AF_HINTS_TEST_SCALER( h, AF_SCALER_FLAG_NO_ADVANCE )
 
-#define AF_HINTS_DO_WARP( h )                                  \
-          !AF_HINTS_TEST_SCALER( h, AF_SCALER_FLAG_NO_WARPER )
-
-
 
   FT_LOCAL( AF_Direction )
   af_direction_compute( FT_Pos  dx,
@@ -459,14 +455,6 @@ FT_BEGIN_HEADER
   af_glyph_hints_align_weak_points( AF_GlyphHints  hints,
                                     AF_Dimension   dim );
 
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-  FT_LOCAL( void )
-  af_glyph_hints_scale_dim( AF_GlyphHints  hints,
-                            AF_Dimension   dim,
-                            FT_Fixed       scale,
-                            FT_Pos         delta );
-#endif
-
   FT_LOCAL( void )
   af_glyph_hints_done( AF_GlyphHints  hints );
 
diff --git a/src/autofit/afindic.c b/src/autofit/afindic.c
index e1eeb7448..064c300ed 100644
--- a/src/autofit/afindic.c
+++ b/src/autofit/afindic.c
@@ -27,11 +27,6 @@
 #include "aferrors.h"
 
 
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-#include "afwarp.h"
-#endif
-
-
   static FT_Error
   af_indic_metrics_init( AF_CJKMetrics  metrics,
                          FT_Face        face )
diff --git a/src/autofit/aflatin.c b/src/autofit/aflatin.c
index 8ca6ac29d..b8af228a4 100644
--- a/src/autofit/aflatin.c
+++ b/src/autofit/aflatin.c
@@ -24,11 +24,6 @@
 #include "aferrors.h"
 
 
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-#include "afwarp.h"
-#endif
-
-
   /**************************************************************************
    *
    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
@@ -2636,11 +2631,6 @@
     /* compute flags depending on render mode, etc. */
     mode = metrics->root.scaler.render_mode;
 
-#if 0 /* #ifdef AF_CONFIG_OPTION_USE_WARPER */
-    if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
-      metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
-#endif
-
     scaler_flags = hints->scaler_flags;
     other_flags  = 0;
 
@@ -2678,12 +2668,6 @@
          ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0          )
       scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL;
 
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-    /* get (global) warper flag */
-    if ( !metrics->root.globals->module->warping )
-      scaler_flags |= AF_SCALER_FLAG_NO_WARPER;
-#endif
-
     hints->scaler_flags = scaler_flags;
     hints->other_flags  = other_flags;
 
@@ -3600,24 +3584,6 @@
     /* grid-fit the outline */
     for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
     {
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-      if ( dim == AF_DIMENSION_HORZ                                  &&
-           metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL &&
-           AF_HINTS_DO_WARP( hints )                                 )
-      {
-        AF_WarperRec  warper;
-        FT_Fixed      scale;
-        FT_Pos        delta;
-
-
-        af_warper_compute( &warper, hints, (AF_Dimension)dim,
-                           &scale, &delta );
-        af_glyph_hints_scale_dim( hints, (AF_Dimension)dim,
-                                  scale, delta );
-        continue;
-      }
-#endif /* AF_CONFIG_OPTION_USE_WARPER */
-
       if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
            ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) )   )
       {
diff --git a/src/autofit/afmodule.c b/src/autofit/afmodule.c
index f892268cb..76f9b3733 100644
--- a/src/autofit/afmodule.c
+++ b/src/autofit/afmodule.c
@@ -190,35 +190,6 @@
 
       return error;
     }
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-    else if ( !ft_strcmp( property_name, "warping" ) )
-    {
-#ifdef FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES
-      if ( value_is_string )
-      {
-        const char*  s = (const char*)value;
-        long         w = ft_strtol( s, NULL, 10 );
-
-
-        if ( w == 0 )
-          module->warping = 0;
-        else if ( w == 1 )
-          module->warping = 1;
-        else
-          return FT_THROW( Invalid_Argument );
-      }
-      else
-#endif
-      {
-        FT_Bool*  warping = (FT_Bool*)value;
-
-
-        module->warping = *warping;
-      }
-
-      return error;
-    }
-#endif /* AF_CONFIG_OPTION_USE_WARPER */
     else if ( !ft_strcmp( property_name, "darkening-parameters" ) )
     {
       FT_Int*  darken_params;
@@ -322,9 +293,6 @@
     AF_Module  module         = (AF_Module)ft_module;
     FT_UInt    fallback_style = module->fallback_style;
     FT_UInt    default_script = module->default_script;
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-    FT_Bool    warping        = module->warping;
-#endif
 
 
     if ( !ft_strcmp( property_name, "glyph-to-script-map" ) )
@@ -371,17 +339,6 @@
 
       return error;
     }
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-    else if ( !ft_strcmp( property_name, "warping" ) )
-    {
-      FT_Bool*  val = (FT_Bool*)value;
-
-
-      *val = warping;
-
-      return error;
-    }
-#endif /* AF_CONFIG_OPTION_USE_WARPER */
     else if ( !ft_strcmp( property_name, "darkening-parameters" ) )
     {
       FT_Int*  darken_params = module->darken_params;
@@ -447,9 +404,6 @@
 
     module->fallback_style    = AF_STYLE_FALLBACK;
     module->default_script    = AF_SCRIPT_DEFAULT;
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-    module->warping           = 0;
-#endif
     module->no_stem_darkening = TRUE;
 
     module->darken_params[0]  = CFF_CONFIG_OPTION_DARKENING_PARAMETER_X1;
diff --git a/src/autofit/afmodule.h b/src/autofit/afmodule.h
index 5d1d9ca5c..c5bd46820 100644
--- a/src/autofit/afmodule.h
+++ b/src/autofit/afmodule.h
@@ -37,9 +37,6 @@ FT_BEGIN_HEADER
 
     FT_UInt       fallback_style;
     FT_UInt       default_script;
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-    FT_Bool       warping;
-#endif
     FT_Bool       no_stem_darkening;
     FT_Int        darken_params[8];
 
diff --git a/src/autofit/aftypes.h b/src/autofit/aftypes.h
index 6e63314a8..02a83dac3 100644
--- a/src/autofit/aftypes.h
+++ b/src/autofit/aftypes.h
@@ -172,7 +172,6 @@ extern void*  _af_debug_hints;
 #define AF_SCALER_FLAG_NO_HORIZONTAL  1U /* disable horizontal hinting */
 #define AF_SCALER_FLAG_NO_VERTICAL    2U /* disable vertical hinting   */
 #define AF_SCALER_FLAG_NO_ADVANCE     4U /* disable advance hinting    */
-#define AF_SCALER_FLAG_NO_WARPER      8U /* disable warper             */
 
 
   typedef struct  AF_ScalerRec_
diff --git a/src/autofit/afwarp.c b/src/autofit/afwarp.c
deleted file mode 100644
index 8d6760f28..000000000
--- a/src/autofit/afwarp.c
+++ /dev/null
@@ -1,373 +0,0 @@
-/****************************************************************************
- *
- * afwarp.c
- *
- *   Auto-fitter warping algorithm (body).
- *
- * Copyright (C) 2006-2021 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.
- *
- */
-
-
-  /*
-   * The idea of the warping code is to slightly scale and shift a glyph
-   * within a single dimension so that as much of its segments are aligned
-   * (more or less) on the grid.  To find out the optimal scaling and
-   * shifting value, various parameter combinations are tried and scored.
-   */
-
-#include "afwarp.h"
-
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-
-  /**************************************************************************
-   *
-   * 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  afwarp
-
-
-  /* The weights cover the range 0/64 - 63/64 of a pixel.  Obviously, */
-  /* values around a half pixel (which means exactly between two grid */
-  /* lines) gets the worst weight.                                    */
-#if 1
-  static const AF_WarpScore
-  af_warper_weights[64] =
-  {
-    35, 32, 30, 25, 20, 15, 12, 10,  5,  1,  0,  0,  0,  0,  0,  0,
-     0,  0,  0,  0,  0,  0, -1, -2, -5, -8,-10,-10,-20,-20,-30,-30,
-
-   -30,-30,-20,-20,-10,-10, -8, -5, -2, -1,  0,  0,  0,  0,  0,  0,
-     0,  0,  0,  0,  0,  0,  0,  1,  5, 10, 12, 15, 20, 25, 30, 32,
-  };
-#else
-  static const AF_WarpScore
-  af_warper_weights[64] =
-  {
-    30, 20, 10,  5,  4,  4,  3,  2,  1,  0,  0,  0,  0,  0,  0,  0,
-     0,  0,  0,  0,  0,  0,  0, -1, -2, -2, -5, -5,-10,-10,-15,-20,
-
-   -20,-15,-15,-10,-10, -5, -5, -2, -2, -1,  0,  0,  0,  0,  0,  0,
-     0,  0,  0,  0,  0,  0,  0,  0,  1,  2,  3,  4,  4,  5, 10, 20,
-  };
-#endif
-
-
-  /* Score segments for a given `scale' and `delta' in the range */
-  /* `xx1' to `xx2', and store the best result in `warper'.  If  */
-  /* the new best score is equal to the old one, prefer the      */
-  /* value with a smaller distortion (around `base_distort').    */
-
-  static void
-  af_warper_compute_line_best( AF_Warper     warper,
-                               FT_Fixed      scale,
-                               FT_Pos        delta,
-                               FT_Pos        xx1,
-                               FT_Pos        xx2,
-                               AF_WarpScore  base_distort,
-                               AF_Segment    segments,
-                               FT_Int        num_segments )
-  {
-    FT_Int        idx_min, idx_max, idx0;
-    FT_Int        nn;
-    AF_WarpScore  scores[65];
-
-
-    for ( nn = 0; nn < 65; nn++ )
-      scores[nn] = 0;
-
-    idx0 = xx1 - warper->t1;
-
-    /* compute minimum and maximum indices */
-    {
-      FT_Pos  xx1min = warper->x1min;
-      FT_Pos  xx1max = warper->x1max;
-      FT_Pos  w      = xx2 - xx1;
-
-
-      if ( xx1min + w < warper->x2min )
-        xx1min = warper->x2min - w;
-
-      if ( xx1max + w > warper->x2max )
-        xx1max = warper->x2max - w;
-
-      idx_min = xx1min - warper->t1;
-      idx_max = xx1max - warper->t1;
-
-      if ( idx_min < 0 || idx_min > idx_max || idx_max > 64 )
-      {
-        FT_TRACE5(( "invalid indices:\n" ));
-        FT_TRACE5(( "  min=%d max=%d, xx1=%ld xx2=%ld,\n",
-                    idx_min, idx_max, xx1, xx2 ));
-        FT_TRACE5(( "  x1min=%ld x1max=%ld, x2min=%ld x2max=%ld\n",
-                    warper->x1min, warper->x1max,
-                    warper->x2min, warper->x2max ));
-        return;
-      }
-    }
-
-    for ( nn = 0; nn < num_segments; nn++ )
-    {
-      FT_Pos  len = segments[nn].max_coord - segments[nn].min_coord;
-      FT_Pos  y0  = FT_MulFix( segments[nn].pos, scale ) + delta;
-      FT_Pos  y   = y0 + ( idx_min - idx0 );
-      FT_Int  idx;
-
-
-      /* score the length of the segments for the given range */
-      for ( idx = idx_min; idx <= idx_max; idx++, y++ )
-        scores[idx] += af_warper_weights[y & 63] * len;
-    }
-
-    /* find best score */
-    {
-      FT_Int  idx;
-
-
-      for ( idx = idx_min; idx <= idx_max; idx++ )
-      {
-        AF_WarpScore  score = scores[idx];
-        AF_WarpScore  distort = base_distort + ( idx - idx0 );
-
-
-        if ( score > warper->best_score         ||
-             ( score == warper->best_score    &&
-               distort < warper->best_distort ) )
-        {
-          warper->best_score   = score;
-          warper->best_distort = distort;
-          warper->best_scale   = scale;
-          warper->best_delta   = delta + ( idx - idx0 );
-        }
-      }
-    }
-  }
-
-
-  /* Compute optimal scaling and delta values for a given glyph and */
-  /* dimension.                                                     */
-
-  FT_LOCAL_DEF( void )
-  af_warper_compute( AF_Warper      warper,
-                     AF_GlyphHints  hints,
-                     AF_Dimension   dim,
-                     FT_Fixed      *a_scale,
-                     FT_Pos        *a_delta )
-  {
-    AF_AxisHints  axis;
-    AF_Point      points;
-
-    FT_Fixed      org_scale;
-    FT_Pos        org_delta;
-
-    FT_Int        nn, num_points, num_segments;
-    FT_Int        X1, X2;
-    FT_Int        w;
-
-    AF_WarpScore  base_distort;
-    AF_Segment    segments;
-
-
-    /* get original scaling transformation */
-    if ( dim == AF_DIMENSION_VERT )
-    {
-      org_scale = hints->y_scale;
-      org_delta = hints->y_delta;
-    }
-    else
-    {
-      org_scale = hints->x_scale;
-      org_delta = hints->x_delta;
-    }
-
-    warper->best_scale   = org_scale;
-    warper->best_delta   = org_delta;
-    warper->best_score   = FT_INT_MIN;
-    warper->best_distort = 0;
-
-    axis         = &hints->axis[dim];
-    segments     = axis->segments;
-    num_segments = axis->num_segments;
-    points       = hints->points;
-    num_points   = hints->num_points;
-
-    *a_scale = org_scale;
-    *a_delta = org_delta;
-
-    /* get X1 and X2, minimum and maximum in original coordinates */
-    if ( num_segments < 1 )
-      return;
-
-#if 1
-    X1 = X2 = points[0].fx;
-    for ( nn = 1; nn < num_points; nn++ )
-    {
-      FT_Int  X = points[nn].fx;
-
-
-      if ( X < X1 )
-        X1 = X;
-      if ( X > X2 )
-        X2 = X;
-    }
-#else
-    X1 = X2 = segments[0].pos;
-    for ( nn = 1; nn < num_segments; nn++ )
-    {
-      FT_Int  X = segments[nn].pos;
-
-
-      if ( X < X1 )
-        X1 = X;
-      if ( X > X2 )
-        X2 = X;
-    }
-#endif
-
-    if ( X1 >= X2 )
-      return;
-
-    warper->x1 = FT_MulFix( X1, org_scale ) + org_delta;
-    warper->x2 = FT_MulFix( X2, org_scale ) + org_delta;
-
-    warper->t1 = AF_WARPER_FLOOR( warper->x1 );
-    warper->t2 = AF_WARPER_CEIL( warper->x2 );
-
-    /* examine a half pixel wide range around the maximum coordinates */
-    warper->x1min = warper->x1 & ~31;
-    warper->x1max = warper->x1min + 32;
-    warper->x2min = warper->x2 & ~31;
-    warper->x2max = warper->x2min + 32;
-
-    if ( warper->x1max > warper->x2 )
-      warper->x1max = warper->x2;
-
-    if ( warper->x2min < warper->x1 )
-      warper->x2min = warper->x1;
-
-    warper->w0 = warper->x2 - warper->x1;
-
-    if ( warper->w0 <= 64 )
-    {
-      warper->x1max = warper->x1;
-      warper->x2min = warper->x2;
-    }
-
-    /* examine (at most) a pixel wide range around the natural width */
-    warper->wmin = warper->x2min - warper->x1max;
-    warper->wmax = warper->x2max - warper->x1min;
-
-#if 1
-    /* some heuristics to reduce the number of widths to be examined */
-    {
-      int  margin = 16;
-
-
-      if ( warper->w0 <= 128 )
-      {
-         margin = 8;
-         if ( warper->w0 <= 96 )
-           margin = 4;
-      }
-
-      if ( warper->wmin < warper->w0 - margin )
-        warper->wmin = warper->w0 - margin;
-
-      if ( warper->wmax > warper->w0 + margin )
-        warper->wmax = warper->w0 + margin;
-    }
-
-    if ( warper->wmin < warper->w0 * 3 / 4 )
-      warper->wmin = warper->w0 * 3 / 4;
-
-    if ( warper->wmax > warper->w0 * 5 / 4 )
-      warper->wmax = warper->w0 * 5 / 4;
-#else
-    /* no scaling, just translation */
-    warper->wmin = warper->wmax = warper->w0;
-#endif
-
-    for ( w = warper->wmin; w <= warper->wmax; w++ )
-    {
-      FT_Fixed  new_scale;
-      FT_Pos    new_delta;
-      FT_Pos    xx1, xx2;
-
-
-      /* compute min and max positions for given width,       */
-      /* assuring that they stay within the coordinate ranges */
-      xx1 = warper->x1;
-      xx2 = warper->x2;
-      if ( w >= warper->w0 )
-      {
-        xx1 -= w - warper->w0;
-        if ( xx1 < warper->x1min )
-        {
-          xx2 += warper->x1min - xx1;
-          xx1  = warper->x1min;
-        }
-      }
-      else
-      {
-        xx1 -= w - warper->w0;
-        if ( xx1 > warper->x1max )
-        {
-          xx2 -= xx1 - warper->x1max;
-          xx1  = warper->x1max;
-        }
-      }
-
-      if ( xx1 < warper->x1 )
-        base_distort = warper->x1 - xx1;
-      else
-        base_distort = xx1 - warper->x1;
-
-      if ( xx2 < warper->x2 )
-        base_distort += warper->x2 - xx2;
-      else
-        base_distort += xx2 - warper->x2;
-
-      /* give base distortion a greater weight while scoring */
-      base_distort *= 10;
-
-      new_scale = org_scale + FT_DivFix( w - warper->w0, X2 - X1 );
-      new_delta = xx1 - FT_MulFix( X1, new_scale );
-
-      af_warper_compute_line_best( warper, new_scale, new_delta, xx1, xx2,
-                                   base_distort,
-                                   segments, num_segments );
-    }
-
-    {
-      FT_Fixed  best_scale = warper->best_scale;
-      FT_Pos    best_delta = warper->best_delta;
-
-
-      hints->xmin_delta = FT_MulFix( X1, best_scale - org_scale )
-                          + best_delta;
-      hints->xmax_delta = FT_MulFix( X2, best_scale - org_scale )
-                          + best_delta;
-
-      *a_scale = best_scale;
-      *a_delta = best_delta;
-    }
-  }
-
-#else /* !AF_CONFIG_OPTION_USE_WARPER */
-
-  /* ANSI C doesn't like empty source files */
-  typedef int  _af_warp_dummy;
-
-#endif /* !AF_CONFIG_OPTION_USE_WARPER */
-
-/* END */
diff --git a/src/autofit/afwarp.h b/src/autofit/afwarp.h
deleted file mode 100644
index 53e50d690..000000000
--- a/src/autofit/afwarp.h
+++ /dev/null
@@ -1,66 +0,0 @@
-/****************************************************************************
- *
- * afwarp.h
- *
- *   Auto-fitter warping algorithm (specification).
- *
- * Copyright (C) 2006-2021 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.
- *
- */
-
-
-#ifndef AFWARP_H_
-#define AFWARP_H_
-
-#include "afhints.h"
-
-FT_BEGIN_HEADER
-
-#define AF_WARPER_SCALE
-
-#define AF_WARPER_FLOOR( x )  ( (x) & ~FT_TYPEOF( x )63 )
-#define AF_WARPER_CEIL( x )   AF_WARPER_FLOOR( (x) + 63 )
-
-
-  typedef FT_Int32  AF_WarpScore;
-
-  typedef struct  AF_WarperRec_
-  {
-    FT_Pos        x1, x2;
-    FT_Pos        t1, t2;
-    FT_Pos        x1min, x1max;
-    FT_Pos        x2min, x2max;
-    FT_Pos        w0, wmin, wmax;
-
-    FT_Fixed      best_scale;
-    FT_Pos        best_delta;
-    AF_WarpScore  best_score;
-    AF_WarpScore  best_distort;
-
-  } AF_WarperRec, *AF_Warper;
-
-
-#ifdef AF_CONFIG_OPTION_USE_WARPER
-  FT_LOCAL( void )
-  af_warper_compute( AF_Warper      warper,
-                     AF_GlyphHints  hints,
-                     AF_Dimension   dim,
-                     FT_Fixed      *a_scale,
-                     FT_Pos        *a_delta );
-#endif
-
-
-FT_END_HEADER
-
-
-#endif /* AFWARP_H_ */
-
-
-/* END */
diff --git a/src/autofit/autofit.c b/src/autofit/autofit.c
index dc81f9ffa..665234f4f 100644
--- a/src/autofit/autofit.c
+++ b/src/autofit/autofit.c
@@ -30,7 +30,6 @@
 #include "afmodule.c"
 #include "afranges.c"
 #include "afshaper.c"
-#include "afwarp.c"
 
 
 /* END */
diff --git a/src/autofit/rules.mk b/src/autofit/rules.mk
index 74ed121ca..9d82a5add 100644
--- a/src/autofit/rules.mk
+++ b/src/autofit/rules.mk
@@ -40,7 +40,6 @@ AUTOF_DRV_SRC := $(AUTOF_DIR)/afangles.c \
                  $(AUTOF_DIR)/afmodule.c \
                  $(AUTOF_DIR)/afranges.c \
                  $(AUTOF_DIR)/afshaper.c \
-                 $(AUTOF_DIR)/afwarp.c
 
 # AUTOF driver headers
 #