commit ab1c98ac183d07e2ac0e38c5a2a6ec607f14aeb0
author Anuj Verma <anujv@posteo.net> Thu Jan 27 15:23:47 2022 +0530
committer Anuj Verma <anujv@posteo.net> Thu Jan 27 18:01:08 2022 +0530
tree 39abc3f9060ffdf9678ca155ffde8a2a59169555
parent 3d77756e73c61ab37eb020a32730cda8efab79ff

Fix sdf computation while `USE_SQUARED_DISTANCES`.

Function `map_fixed_to_sdf` expects spread to be absolute
and not squared.

* src/sdf/ftbsdf.c (finalize_sdf): Pass absolute spread
while `map_fixed_to_sdf`.

* src/sdf/ftsdf.c (sdf_generate_bounding_box): Ditto.

src/sdf/ftbsdf.c

diff --git a/src/sdf/ftbsdf.c b/src/sdf/ftbsdf.c
index f33330f..1328ac4 100644
--- a/src/sdf/ftbsdf.c
+++ b/src/sdf/ftbsdf.c
@@ -1096,7 +1096,7 @@
     FT_Int  i, j;
 
     FT_SDFFormat*  t_buffer;
-    FT_16D16       spread;
+    FT_16D16       sp_sq, spread;
 
 
     if ( !worker || !target )
@@ -1116,11 +1116,13 @@
       goto Exit;
     }
 
-#if USE_SQUARED_DISTANCES
-    spread = FT_INT_16D16( worker->params.spread *
-                           worker->params.spread );
-#else
     spread = FT_INT_16D16( worker->params.spread );
+
+#if USE_SQUARED_DISTANCES
+    sp_sq = FT_INT_16D16( worker->params.spread *
+                          worker->params.spread );
+#else
+    sp_sq = FT_INT_16D16( worker->params.spread );
 #endif
 
     for ( j = 0; j < r; j++ )
@@ -1136,8 +1138,8 @@
         index = j * w + i;
         dist  = worker->distance_map[index].dist;
 
-        if ( dist < 0 || dist > spread )
-          dist = spread;
+        if ( dist < 0 || dist > sp_sq )
+          dist = sp_sq;
 
 #if USE_SQUARED_DISTANCES
         dist = square_root( dist );

src/sdf/ftsdf.c

diff --git a/src/sdf/ftsdf.c b/src/sdf/ftsdf.c
index 46ef7b1..f5e5551 100644
--- a/src/sdf/ftsdf.c
+++ b/src/sdf/ftsdf.c
@@ -3242,7 +3242,7 @@
     buffer   = (FT_SDFFormat*)bitmap->buffer;
 
     if ( USE_SQUARED_DISTANCES )
-      sp_sq = fixed_spread * fixed_spread;
+      sp_sq = FT_INT_16D16( spread * spread );
     else
       sp_sq = fixed_spread;