[freetype2] master bdac4cb 1/2: Rendering considerations.

[Alexei Podtelezhnikov]

branch: master
commit bdac4cbe6fb77108a753be859fe73579c5cddc97
Author: Alexei Podtelezhnikov <address@hidden>
Commit: Alexei Podtelezhnikov <address@hidden>

    Rendering considerations.
---
 src/smooth/ftgrays.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/smooth/ftgrays.c b/src/smooth/ftgrays.c
index bab07a1..6a824c4 100644
--- a/src/smooth/ftgrays.c
+++ b/src/smooth/ftgrays.c
@@ -646,6 +646,9 @@ typedef ptrdiff_t  FT_PtrDist;
       dx    = -dx;
     }
 
+    /* the fractional part of y-delta is mod/dx. It is essential to */
+    /* keep track of its accumulation for accurate rendering.       */
+    /* XXX: y-delta and x-delta below should be related.            */
     FT_DIV_MOD( TCoord, p, dx, delta, mod );
 
     ras.area  += (TArea)( ( fx1 + first ) * delta );
@@ -783,6 +786,8 @@ typedef ptrdiff_t  FT_PtrDist;
       dy    = -dy;
     }
 
+    /* the fractional part of x-delta is mod/dy. It is essential to */
+    /* keep track of its accumulation for accurate rendering.       */
     FT_DIV_MOD( TCoord, p, dy, delta, mod );
 
     x = ras.x + delta;