[freetype2] svg_metrics 88dbfb53c: [cff, truetype] Simplify SVG metrics scaling.

[Werner Lemberg]

branch: svg_metrics
commit 88dbfb53cb890a6c955ab2815070959d2bf2b5bf
Author: Alexei Podtelezhnikov <apodtele@gmail.com>
Commit: Alexei Podtelezhnikov <apodtele@gmail.com>

    [cff, truetype] Simplify SVG metrics scaling.
    
    Use pre-calculated scaling factors. Previously, the advance widths
    were incorrectly rounded to pixels.
    
    * src/cff/cffgload.c (cff_slot_load): Use `x_scale` and `y_scale`.
    * src/truetype/ttgload.c (TT_Load_Glyph): Ditto.
---
 src/cff/cffgload.c     | 30 ++++++++++++------------------
 src/truetype/ttgload.c | 28 +++++++++++-----------------
 2 files changed, 23 insertions(+), 35 deletions(-)

diff --git a/src/cff/cffgload.c b/src/cff/cffgload.c
index d8fc31857..23318d9ab 100644
--- a/src/cff/cffgload.c
+++ b/src/cff/cffgload.c
@@ -356,18 +356,14 @@
 
 #ifdef FT_CONFIG_OPTION_SVG
     /* check for OT-SVG */
-    if ( ( load_flags & FT_LOAD_COLOR )     &&
-         ( (TT_Face)glyph->root.face )->svg )
+    if ( ( load_flags & FT_LOAD_COLOR ) && face->svg )
     {
       /*
        * We load the SVG document and try to grab the advances from the
        * table.  For the bearings we rely on the presetting hook to do that.
        */
 
-      FT_Short      dummy;
-      FT_UShort     advanceX;
-      FT_UShort     advanceY;
-      SFNT_Service  sfnt;
+      SFNT_Service  sfnt  = (SFNT_Service)face->sfnt;
 
 
       if ( size && (size->root.metrics.x_ppem < 1 ||
@@ -379,10 +375,17 @@
 
       FT_TRACE3(( "Trying to load SVG glyph\n" ));
 
-      sfnt  = (SFNT_Service)((TT_Face)glyph->root.face)->sfnt;
       error = sfnt->load_svg_doc( (FT_GlyphSlot)glyph, glyph_index );
       if ( !error )
       {
+        FT_Fixed  x_scale = size->root.metrics.x_scale;
+        FT_Fixed  y_scale = size->root.metrics.y_scale;
+
+        FT_Short   dummy;
+        FT_UShort  advanceX;
+        FT_UShort  advanceY;
+
+
         FT_TRACE3(( "Successfully loaded SVG glyph\n" ));
 
         glyph->root.format = FT_GLYPH_FORMAT_SVG;
@@ -407,17 +410,8 @@
         glyph->root.linearHoriAdvance = advanceX;
         glyph->root.linearVertAdvance = advanceY;
 
-        advanceX =
-          (FT_UShort)FT_MulDiv( advanceX,
-                                glyph->root.face->size->metrics.x_ppem,
-                                glyph->root.face->units_per_EM );
-        advanceY =
-          (FT_UShort)FT_MulDiv( advanceY,
-                                glyph->root.face->size->metrics.y_ppem,
-                                glyph->root.face->units_per_EM );
-
-        glyph->root.metrics.horiAdvance = advanceX << 6;
-        glyph->root.metrics.vertAdvance = advanceY << 6;
+        glyph->root.metrics.horiAdvance = FT_MulFix( advanceX, x_scale );
+        glyph->root.metrics.vertAdvance = FT_MulFix( advanceY, y_scale );
 
         return error;
       }
diff --git a/src/truetype/ttgload.c b/src/truetype/ttgload.c
index 68698df14..a92b4c17a 100644
--- a/src/truetype/ttgload.c
+++ b/src/truetype/ttgload.c
@@ -2871,21 +2871,22 @@
     /* check for OT-SVG */
     if ( ( load_flags & FT_LOAD_COLOR ) && ( (TT_Face)glyph->face )->svg )
     {
-      SFNT_Service  sfnt;
-
-      FT_Short   leftBearing;
-      FT_Short   topBearing;
-      FT_UShort  advanceX;
-      FT_UShort  advanceY;
+      TT_Face       face = (TT_Face)glyph->face;
+      SFNT_Service  sfnt = (SFNT_Service)face->sfnt;
 
 
       FT_TRACE3(( "Trying to load SVG glyph\n" ));
-      sfnt = (SFNT_Service)( (TT_Face)glyph->face )->sfnt;
 
       error = sfnt->load_svg_doc( glyph, glyph_index );
       if ( !error )
       {
-        TT_Face  face = (TT_Face)glyph->face;
+        FT_Fixed  x_scale = size->root.metrics.x_scale;
+        FT_Fixed  y_scale = size->root.metrics.y_scale;
+
+        FT_Short   leftBearing;
+        FT_Short   topBearing;
+        FT_UShort  advanceX;
+        FT_UShort  advanceY;
 
 
         FT_TRACE3(( "Successfully loaded SVG glyph\n" ));
@@ -2906,15 +2907,8 @@
         glyph->linearHoriAdvance = advanceX;
         glyph->linearVertAdvance = advanceY;
 
-        advanceX = (FT_UShort)FT_MulDiv( advanceX,
-                                         glyph->face->size->metrics.x_ppem,
-                                         glyph->face->units_per_EM );
-        advanceY = (FT_UShort)FT_MulDiv( advanceY,
-                                         glyph->face->size->metrics.y_ppem,
-                                         glyph->face->units_per_EM );
-
-        glyph->metrics.horiAdvance = advanceX << 6;
-        glyph->metrics.vertAdvance = advanceY << 6;
+        glyph->metrics.horiAdvance = FT_MulFix( advanceX, x_scale );
+        glyph->metrics.vertAdvance = FT_MulFix( advanceY, y_scale );
 
         return error;
       }