* src/pshinter/pshalgo.c: slight modification to the Postscript hinter

to slightly increase the contrast of smooth hinting. This is very similar
    to what the auto-hinter does when it comes to stem width computations.
    However, it produces better results with well-hinted fonts..

ChangeLog

@@ -1,12 +1,19 @@
+2002-08-29  David Turner  <david@freetype.org>
+
+    * src/pshinter/pshalgo.c: slight modification to the Postscript hinter
+    to slightly increase the contrast of smooth hinting. This is very similar
+    to what the auto-hinter does when it comes to stem width computations.
+    However, it produces better results with well-hinted fonts..
+
 2002-08-27  David Turner  <david@freetype.org>
 
     * massive re-formatting changes to many, many source files. I don't
     want to list them all here. The operations performed were all logical
     transformations of the sources:
-    
+
       - trying to convert all enums and constants to CAPITALIZED_STYLE, with
         #define definitions like
-        
+
           #define  my_old_constants   MY_NEW_CONSTANT
 
       - big, big update of the documentation comments
@@ -14,7 +21,7 @@
     * include/freetype/freetype.h, src/base/ftobjs.c, src/smooth/ftsmooth.c,
     include/freetype/ftimage.h: adding support for LCD-optimized rendering
     though the new constants/enums:
-    
+
       FT_RENDER_MODE_LCD, FT_RENDER_MODE_LCD_V
       FT_PIXEL_MODE_LCD,  FT_PIXEL_MODE_LCD_V
 
@@ -23,12 +30,12 @@
 
     * adding new FT_LOAD_XXX flags, used to specify both hinting and rendering
     targets:
-    
+
       FT_LOAD_TARGET_NORMAL :: anti-aliased hinting & rendering
       FT_LOAD_TARGET_MONO   :: monochrome bitmaps
       FT_LOAD_TARGET_LCD    :: horizontal RGB/BGR decimated hinting & rendering
       FT_LOAD_TARGET_LCD_V  :: vertical RGB/BGR decimated hinting & rendering
-      
+
     note that FT_LOAD_TARGET_NORMAL is 0, which means that the default
     behaviour of the font engine is _unchanged_.
 
@@ -185,7 +192,7 @@
 
 2002-08-15  Graham Asher  <graham.asher@btinternet.com>
 
-	Implemented the incremental font loading system for the CFF driver. 
+	Implemented the incremental font loading system for the CFF driver.
 	Tested using the GhostScript-to-FreeType bridge (under development).
 
 	* src/cff/cffgload.c (cff_get_glyph_data, cff_free_glyph_data): New
@@ -300,7 +307,7 @@
 
 2002-07-18  Graham Asher  <graham.asher@btinternet.com>
 
-	Added types and structures to support incremental typeface loading. 
+	Added types and structures to support incremental typeface loading.
 	The FT_Incremental_Interface structure, defined in freetype.h, is
 	designed to be passed to FT_Open_Face to provide callback functions
 	to obtain glyph recipes and metrics, for fonts like those passed

src/pshinter/pshalgo3.c

@@ -33,10 +33,8 @@
 #endif
 
 
-#undef  SNAP_STEMS
-#undef  ONLY_ALIGN_Y
-
-#define  COMPUTE_INFLEXS
+#define  COMPUTE_INFLEXS  /* compute inflection points to optimize "S" and others */
+#define  STRONGER         /* slightly increase the contrast of smooth hinting */
 
   /*************************************************************************/
   /*************************************************************************/
@@ -412,7 +410,7 @@
       /* perform stem snapping when requested */
       no_snapping = ( dimension == 0 && !glyph->no_horz_snapping ) ||
                     ( dimension == 1 && !glyph->no_vert_snapping );
-                    
+
       if ( !no_snapping )
       {
         /* compute fitted width/height */
@@ -499,6 +497,58 @@
           }
           else
           {
+#ifdef STRONGER
+            if ( len <= 64 )
+            {
+              /* the stem is less than one pixel, we will center it */
+              /* around the nearest pixel center                    */
+              /*                                                    */
+              pos = ( pos + (len >> 1) & -64 );
+              len = 64;
+            }
+            else
+            {
+              FT_Pos  delta = len - dim->stdw.widths[0].cur;
+
+
+              if ( delta < 0 )
+                delta = -delta;
+
+              if ( delta < 40 )
+              {
+                len = dim->stdw.widths[0].cur;
+                if ( len < 32 )
+                  len = 32;
+              }
+
+              if ( len < 3 * 64 )
+              {
+                delta = ( len & 63 );
+                len &= -64;
+
+                if ( delta < 10 )
+                  len += delta;
+
+                else if ( delta < 32 )
+                  len += 10;
+
+                else if ( delta < 54 )
+                  len += 54;
+
+                else
+                  len += delta;
+              }
+              else
+                len = ( len + 32 ) & -64;
+            }
+
+            /* now that we have a good hinted stem width, try to position */
+            /* the stem along a pixel grid integer coordinate             */
+            hint->cur_pos = pos + psh3_hint_snap_stem_side_delta( pos, len );
+            hint->cur_len = len;
+
+#else /* !STRONGER */
+
             /* Stems less than one pixel wide are easy - we want to
              * make them as dark as possible, so they must fall within
              * one pixel. If the stem is split between two pixels
@@ -541,7 +591,7 @@
               FT_Fixed delta_a, delta_b;
 
 
-              if ( len & 64 )           
+              if ( len & 64 )
               {
                 delta_a = ( center & -64 ) + 32 - center;
                 delta_b = ( ( center + 32 ) & - 64 ) - center;
@@ -573,6 +623,7 @@
                 pos += delta_b;
             }
             hint->cur_pos = pos;
+#endif /* !STRONGER */
           }
         }
       }
@@ -1712,7 +1763,7 @@
 
     glyph->no_horz_hints = 0;
     glyph->no_vert_hints = 0;
-    
+
     glyph->no_horz_snapping = FT_BOOL( hint_mode == FT_RENDER_MODE_NORMAL ||
                                        hint_mode == FT_RENDER_MODE_LCD_V  );