[freetype2] clean-gxvar 47103b2f1 2/2: [truetype] Clean up phantom point accounting.

[Werner Lemberg]

branch: clean-gxvar
commit 47103b2f195e0f9664c9470182f063cb7d41dc9f
Author: Alexei Podtelezhnikov <apodtele@gmail.com>
Commit: Alexei Podtelezhnikov <apodtele@gmail.com>

    [truetype] Clean up phantom point accounting.
    
    This formalizes that the phantom points appended in the outline
    do not increase its point count, nor are they tagged or included
    in any additional contours.  Only their coordinates are stored.
    They are counted in the glyph zone, however.
    
    * src/truetype/ttgxvar.c (TT_Vary_Apply_Glyph_Deltas): Infer `n_points`
    from the outline size plus four phantom points.
    * src/truetype/ttgxvar.h (TT_Vary_Apply_Glyph_Deltas): Remove this
    argument.
    * src/truetype/ttgload.c (tt_prepare_zone): Add phantom four.
    (TT_Process_Simple_Glyph, load_truetype_glyph): Update all callers.
---
 src/truetype/ttgload.c | 96 +++++++++++++-------------------------------------
 src/truetype/ttgxvar.c |  9 ++---
 src/truetype/ttgxvar.h |  3 +-
 3 files changed, 28 insertions(+), 80 deletions(-)

diff --git a/src/truetype/ttgload.c b/src/truetype/ttgload.c
index d2f7496a1..00b795cda 100644
--- a/src/truetype/ttgload.c
+++ b/src/truetype/ttgload.c
@@ -801,7 +801,7 @@
                    FT_UInt       start_point,
                    FT_UInt       start_contour )
   {
-    zone->n_points    = (FT_UShort)load->outline.n_points -
+    zone->n_points    = (FT_UShort)load->outline.n_points + 4 -
                           (FT_UShort)start_point;
     zone->n_contours  = load->outline.n_contours -
                           (FT_Short)start_contour;
@@ -970,11 +970,6 @@
     outline->points[n_points + 2] = loader->pp3;
     outline->points[n_points + 3] = loader->pp4;
 
-    outline->tags[n_points    ] = 0;
-    outline->tags[n_points + 1] = 0;
-    outline->tags[n_points + 2] = 0;
-    outline->tags[n_points + 3] = 0;
-
     n_points += 4;
 
 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
@@ -987,8 +982,7 @@
       /* Deltas apply to the unscaled data. */
       error = TT_Vary_Apply_Glyph_Deltas( loader,
                                           outline,
-                                          unrounded,
-                                          (FT_UInt)n_points );
+                                          unrounded );
       if ( error )
         goto Exit;
     }
@@ -1000,7 +994,7 @@
       tt_prepare_zone( &loader->zone, &gloader->current, 0, 0 );
 
       FT_ARRAY_COPY( loader->zone.orus, loader->zone.cur,
-                     loader->zone.n_points + 4 );
+                     loader->zone.n_points );
     }
 
     {
@@ -1142,11 +1136,7 @@
     }
 
     if ( IS_HINTED( loader->load_flags ) )
-    {
-      loader->zone.n_points += 4;
-
       error = TT_Hint_Glyph( loader, 0 );
-    }
 
 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
   Exit:
@@ -1359,11 +1349,6 @@
     outline->points[outline->n_points + 2] = loader->pp3;
     outline->points[outline->n_points + 3] = loader->pp4;
 
-    outline->tags[outline->n_points    ] = 0;
-    outline->tags[outline->n_points + 1] = 0;
-    outline->tags[outline->n_points + 2] = 0;
-    outline->tags[outline->n_points + 3] = 0;
-
 #ifdef TT_USE_BYTECODE_INTERPRETER
 
     {
@@ -1422,11 +1407,9 @@
 
     /* Some points are likely touched during execution of  */
     /* instructions on components.  So let's untouch them. */
-    for ( i = 0; i < loader->zone.n_points; i++ )
+    for ( i = 0; i < loader->zone.n_points - 4; i++ )
       loader->zone.tags[i] &= ~FT_CURVE_TAG_TOUCH_BOTH;
 
-    loader->zone.n_points += 4;
-
     return TT_Hint_Glyph( loader, 1 );
   }
 
@@ -1747,35 +1730,27 @@
         /* a small outline structure with four elements for */
         /* communication with `TT_Vary_Apply_Glyph_Deltas'  */
         FT_Vector   points[4];
-        char        tags[4]     = { 1, 1, 1, 1 };
-        short       contours[4] = { 0, 1, 2, 3 };
         FT_Outline  outline;
 
         /* unrounded values */
         FT_Vector  unrounded[4] = { {0, 0}, {0, 0}, {0, 0}, {0, 0} };
 
 
-        points[0].x = loader->pp1.x;
-        points[0].y = loader->pp1.y;
-        points[1].x = loader->pp2.x;
-        points[1].y = loader->pp2.y;
-
-        points[2].x = loader->pp3.x;
-        points[2].y = loader->pp3.y;
-        points[3].x = loader->pp4.x;
-        points[3].y = loader->pp4.y;
+        points[0] = loader->pp1;
+        points[1] = loader->pp2;
+        points[2] = loader->pp3;
+        points[3] = loader->pp4;
 
-        outline.n_points   = 4;
-        outline.n_contours = 4;
+        outline.n_points   = 0;
+        outline.n_contours = 0;
         outline.points     = points;
-        outline.tags       = tags;
-        outline.contours   = contours;
+        outline.tags       = NULL;
+        outline.contours   = NULL;
 
         /* this must be done before scaling */
         error = TT_Vary_Apply_Glyph_Deltas( loader,
                                             &outline,
-                                            unrounded,
-                                            (FT_UInt)outline.n_points );
+                                            unrounded );
         if ( error )
           goto Exit;
       }
@@ -1925,17 +1900,16 @@
 
         /* construct an outline structure for              */
         /* communication with `TT_Vary_Apply_Glyph_Deltas' */
-        outline.n_points   = (short)( gloader->current.num_subglyphs + 4 );
-        outline.n_contours = outline.n_points;
+        outline.n_contours = outline.n_points = limit;
 
         outline.points   = NULL;
         outline.tags     = NULL;
         outline.contours = NULL;
 
-        if ( FT_NEW_ARRAY( points, outline.n_points )    ||
-             FT_NEW_ARRAY( tags, outline.n_points )      ||
-             FT_NEW_ARRAY( contours, outline.n_points )  ||
-             FT_NEW_ARRAY( unrounded, outline.n_points ) )
+        if ( FT_NEW_ARRAY( points, limit + 4 )    ||
+             FT_NEW_ARRAY( tags, limit + 4 )      ||
+             FT_NEW_ARRAY( contours, limit + 4 )  ||
+             FT_NEW_ARRAY( unrounded, limit + 4 ) )
           goto Exit1;
 
         subglyph = gloader->current.subglyphs;
@@ -1951,28 +1925,10 @@
           contours[i] = i;
         }
 
-        points[i].x = loader->pp1.x;
-        points[i].y = loader->pp1.y;
-        tags[i]     = 1;
-        contours[i] = i;
-
-        i++;
-        points[i].x = loader->pp2.x;
-        points[i].y = loader->pp2.y;
-        tags[i]     = 1;
-        contours[i] = i;
-
-        i++;
-        points[i].x = loader->pp3.x;
-        points[i].y = loader->pp3.y;
-        tags[i]     = 1;
-        contours[i] = i;
-
-        i++;
-        points[i].x = loader->pp4.x;
-        points[i].y = loader->pp4.y;
-        tags[i]     = 1;
-        contours[i] = i;
+        points[i++] = loader->pp1;
+        points[i++] = loader->pp2;
+        points[i++] = loader->pp3;
+        points[i  ] = loader->pp4;
 
         outline.points   = points;
         outline.tags     = tags;
@@ -1980,11 +1936,9 @@
 
         /* this call provides additional offsets */
         /* for each component's translation      */
-        if ( FT_SET_ERROR( TT_Vary_Apply_Glyph_Deltas(
-                             loader,
-                             &outline,
-                             unrounded,
-                             (FT_UInt)outline.n_points ) ) )
+        if ( FT_SET_ERROR( TT_Vary_Apply_Glyph_Deltas( loader,
+                                                       &outline,
+                                                       unrounded ) ) )
           goto Exit1;
 
         subglyph = gloader->current.subglyphs;
diff --git a/src/truetype/ttgxvar.c b/src/truetype/ttgxvar.c
index 476f6a2f9..1bf9debb0 100644
--- a/src/truetype/ttgxvar.c
+++ b/src/truetype/ttgxvar.c
@@ -3839,25 +3839,20 @@
    *     An array with `n_points' elements that is filled with unrounded
    *     point coordinates (in 26.6 format).
    *
-   * @Input
-   *   n_points ::
-   *     The number of the points in the glyph, including
-   *     phantom points.
-   *
    * @Return:
    *   FreeType error code.  0 means success.
    */
   FT_LOCAL_DEF( FT_Error )
   TT_Vary_Apply_Glyph_Deltas( TT_Loader    loader,
                               FT_Outline*  outline,
-                              FT_Vector*   unrounded,
-                              FT_UInt      n_points )
+                              FT_Vector*   unrounded )
   {
     FT_Error   error;
     TT_Face    face = loader->face;
     FT_Stream  stream = face->root.stream;
     FT_Memory  memory = stream->memory;
     FT_UInt    glyph_index = loader->glyph_index;
+    FT_UInt    n_points = (FT_UInt)outline->n_points + 4;
 
     FT_Vector*  points_org = NULL;  /* coordinates in 16.16 format */
     FT_Vector*  points_out = NULL;  /* coordinates in 16.16 format */
diff --git a/src/truetype/ttgxvar.h b/src/truetype/ttgxvar.h
index b3db2fcd3..15c26373d 100644
--- a/src/truetype/ttgxvar.h
+++ b/src/truetype/ttgxvar.h
@@ -363,8 +363,7 @@ FT_BEGIN_HEADER
   FT_LOCAL( FT_Error )
   TT_Vary_Apply_Glyph_Deltas( TT_Loader    loader,
                               FT_Outline*  outline,
-                              FT_Vector*   unrounded,
-                              FT_UInt      n_points );
+                              FT_Vector*   unrounded );
 
   FT_LOCAL( FT_Error )
   tt_hadvance_adjust( TT_Face  face,