* src/base/ftcalc.c (FT_CeilFix, FT_FloorFix): Normalize.

This commit makes the functions behave as expected, this is,
rounding towards plus or minus infinity.

ChangeLog

@@ -1,3 +1,10 @@
+2015-09-09  Wojciech Mamrak  <wmamrak@gmail.com>
+
+	* src/base/ftcalc.c (FT_CeilFix, FT_FloorFix): Normalize.
+
+	This commit makes the functions behave as expected, this is,
+	rounding towards plus or minus infinity.
+
 2015-09-07  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	* src/smooth/ftgrays.c (gray_render_line): Simplify clipping.

include/freetype/freetype.h

@@ -3955,7 +3955,8 @@ FT_BEGIN_HEADER
   /*    a :: The number to be rounded.                                     */
   /*                                                                       */
   /* <Return>                                                              */
-  /*    The result of `(a + 0x8000) & -0x10000'.                           */
+  /*    `a' rounded to nearest 16.16 fixed integer, halfway cases away     */
+  /*    from zero.                                                         */
   /*                                                                       */
   FT_EXPORT( FT_Fixed )
   FT_RoundFix( FT_Fixed  a );
@@ -3974,7 +3975,7 @@ FT_BEGIN_HEADER
   /*    a :: The number for which the ceiling function is to be computed.  */
   /*                                                                       */
   /* <Return>                                                              */
-  /*    The result of `(a + 0x10000 - 1) & -0x10000'.                      */
+  /*    `a' rounded towards plus infinity.                                 */
   /*                                                                       */
   FT_EXPORT( FT_Fixed )
   FT_CeilFix( FT_Fixed  a );
@@ -3993,7 +3994,7 @@ FT_BEGIN_HEADER
   /*    a :: The number for which the floor function is to be computed.    */
   /*                                                                       */
   /* <Return>                                                              */
-  /*    The result of `a & -0x10000'.                                      */
+  /*    `a' rounded towards minus infinity.                                */
   /*                                                                       */
   FT_EXPORT( FT_Fixed )
   FT_FloorFix( FT_Fixed  a );

src/base/ftcalc.c

@@ -96,8 +96,7 @@
   FT_EXPORT_DEF( FT_Fixed )
   FT_CeilFix( FT_Fixed  a )
   {
-    return a >= 0 ?   ( a + 0xFFFFL ) & ~0xFFFFL
-                  : -((-a + 0xFFFFL ) & ~0xFFFFL );
+    return ( a + 0xFFFFL ) & ~0xFFFFL;
   }
 
 
@@ -106,8 +105,7 @@
   FT_EXPORT_DEF( FT_Fixed )
   FT_FloorFix( FT_Fixed  a )
   {
-    return a >= 0 ?   a & ~0xFFFFL
-                  : -((-a) & ~0xFFFFL );
+    return a & ~0xFFFFL;
   }
 
 #ifndef FT_MSB