[pango] [HB] Round instead of trunc

[Behdad Esfahbod <behdad src gnome org>]

commit 0d0cbf451613c301ae358cc4dbe54fb63ae5fc9e
Author: Behdad Esfahbod <behdad behdad org>
Date:   Mon Apr 19 02:34:10 2010 -0400

    [HB] Round instead of trunc

 pango/opentype/hb-ot-layout-gpos-private.hh |   20 ++++++++++----------
 pango/opentype/hb-private.h                 |    2 +-
 2 files changed, 11 insertions(+), 11 deletions(-)
---
diff --git a/pango/opentype/hb-ot-layout-gpos-private.hh b/pango/opentype/hb-ot-layout-gpos-private.hh
index e4ec9fc..dcbbf0f 100644
--- a/pango/opentype/hb-ot-layout-gpos-private.hh
+++ b/pango/opentype/hb-ot-layout-gpos-private.hh
@@ -104,13 +104,13 @@ struct ValueRecord {
     y_scale = context->font->y_scale;
     /* design units -> fractional pixel */
     if (format & xPlacement)
-      glyph_pos->x_pos += _hb_16dot16_mul_trunc (x_scale, *(SHORT*)values++);
+      glyph_pos->x_pos += _hb_16dot16_mul_round (x_scale, *(SHORT*)values++);
     if (format & yPlacement)
-      glyph_pos->y_pos += _hb_16dot16_mul_trunc (y_scale, *(SHORT*)values++);
+      glyph_pos->y_pos += _hb_16dot16_mul_round (y_scale, *(SHORT*)values++);
     if (format & xAdvance)
-      glyph_pos->x_advance += _hb_16dot16_mul_trunc (x_scale, *(SHORT*)values++);
+      glyph_pos->x_advance += _hb_16dot16_mul_round (x_scale, *(SHORT*)values++);
     if (format & yAdvance)
-      glyph_pos->y_advance += _hb_16dot16_mul_trunc (y_scale, *(SHORT*)values++);
+      glyph_pos->y_advance += _hb_16dot16_mul_round (y_scale, *(SHORT*)values++);
 
     x_ppem = context->font->x_ppem;
     y_ppem = context->font->y_ppem;
@@ -152,8 +152,8 @@ struct AnchorFormat1
   inline void get_anchor (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id HB_GNUC_UNUSED,
 			  hb_position_t *x, hb_position_t *y) const
   {
-      *x = _hb_16dot16_mul_trunc (context->font->x_scale, xCoordinate);
-      *y = _hb_16dot16_mul_trunc (context->font->y_scale, yCoordinate);
+      *x = _hb_16dot16_mul_round (context->font->x_scale, xCoordinate);
+      *y = _hb_16dot16_mul_round (context->font->y_scale, yCoordinate);
   }
 
   inline bool sanitize (SANITIZE_ARG_DEF) {
@@ -177,8 +177,8 @@ struct AnchorFormat2
 			  hb_position_t *x, hb_position_t *y) const
   {
       /* TODO Contour */
-      *x = _hb_16dot16_mul_trunc (context->font->x_scale, xCoordinate);
-      *y = _hb_16dot16_mul_trunc (context->font->y_scale, yCoordinate);
+      *x = _hb_16dot16_mul_round (context->font->x_scale, xCoordinate);
+      *y = _hb_16dot16_mul_round (context->font->y_scale, yCoordinate);
   }
 
   inline bool sanitize (SANITIZE_ARG_DEF) {
@@ -202,8 +202,8 @@ struct AnchorFormat3
   inline void get_anchor (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id HB_GNUC_UNUSED,
 			  hb_position_t *x, hb_position_t *y) const
   {
-      *x = _hb_16dot16_mul_trunc (context->font->x_scale, xCoordinate);
-      *y = _hb_16dot16_mul_trunc (context->font->y_scale, yCoordinate);
+      *x = _hb_16dot16_mul_round (context->font->x_scale, xCoordinate);
+      *y = _hb_16dot16_mul_round (context->font->y_scale, yCoordinate);
 
       /* pixel -> fractional pixel */
       if (context->font->x_ppem)
diff --git a/pango/opentype/hb-private.h b/pango/opentype/hb-private.h
index b17b24a..92e514f 100644
--- a/pango/opentype/hb-private.h
+++ b/pango/opentype/hb-private.h
@@ -207,7 +207,7 @@ _hb_popcount32 (uint32_t mask)
 
 
 /* Multiplies a 16dot16 value by another value, then truncates the result */
-#define _hb_16dot16_mul_trunc(A,B) ((int64_t) (A) * (B) / 0x10000)
+#define _hb_16dot16_mul_round(A,B) (((int64_t) (A) * (B) + 0x8000) / 0x10000)
 
 #include "hb-object-private.h"