shithub: freetype+ttf2subf

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[sdf] Fix corner checks and improve performance.

* src/sdf/ftsdf.c (sdf_generate_bounding_box): Always check for a corner if
two distances (for different curves) are very close.

(sdf_conic_to): Check whether the conic curve can be treated as a line
(which happens if the control point coincides with any end point).

git/fs: mount .git/fs: mount/attach disallowed

--- a/src/sdf/ftsdf.c

+++ b/src/sdf/ftsdf.c

@@ -738,6 +738,18 @@

     contour = shape->contours;

+    /* If the control point coincides with any of the end points */

+    /* then it is a line and should be treated as one to avoid   */

+    /* unnecessary complexity later in the algorithm.            */

+    if ( ( contour->last_pos.x == control_1->x &&

+           contour->last_pos.y == control_1->y ) ||

+         ( control_1->x == to->x &&

+           control_1->y == to->y )               )

+    {

+      sdf_line_to( to, user );

+      goto Exit;

+    }

+

     FT_CALL( sdf_edge_new( memory, &edge ) );

     edge->edge_type = SDF_EDGE_CONIC;

@@ -3320,6 +3332,7 @@

             FT_26D6_Vec          grid_point = zero_vector;

             SDF_Signed_Distance  dist       = max_sdf;

             FT_UInt              index      = 0;

+            FT_16D16             diff       = 0;

             if ( x < 0 || x >= width )

@@ -3347,7 +3360,7 @@

             if ( dist.distance > sp_sq )

               continue;

-            /* square_root the values and fit in a 6.10 fixed-point */

+            /* take the square root of the distance if required */

             if ( USE_SQUARED_DISTANCES )

               dist.distance = square_root( dist.distance );

@@ -3359,11 +3372,15 @@

             /* check whether the pixel is set or not */

             if ( dists[index].sign == 0 )

               dists[index] = dist;

-            else if ( dists[index].distance > dist.distance )

-              dists[index] = dist;

-            else if ( FT_ABS( dists[index].distance - dist.distance )

-                        < CORNER_CHECK_EPSILON )

-              dists[index] = resolve_corner( dists[index], dist );

+            else

+            {

+              diff = FT_ABS( dists[index].distance - dist.distance );

+

+              if ( diff <= CORNER_CHECK_EPSILON )

+                dists[index] = resolve_corner( dists[index], dist );

+              else if ( dists[index].distance > dist.distance )

+                dists[index] = dist;

+            }

           }

         }