[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.

1 files changed, 25 insertions, 71 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;