[glyf/path-builder] Optimize scaling code

Scale each point once upon entry to function.

This makes our shape fetching code as fast as FreeType for all
benchmark cases now.

src/OT/glyf/path-builder.hh

@@ -42,13 +42,13 @@ struct path_builder_t
   void consume_point (const contour_point_t &point)
   {
     bool is_on_curve = point.flag & glyf_impl::SimpleGlyph::FLAG_ON_CURVE;
-    optional_point_t p (point.x, point.y);
+    optional_point_t p (font->em_fscalef_x (point.x), font->em_fscalef_y (point.y));
     if (!first_oncurve)
     {
       if (is_on_curve)
       {
 	first_oncurve = p;
-	draw_session->move_to (font->em_fscalef_x (p.x), font->em_fscalef_y (p.y));
+	draw_session->move_to (p.x, p.y);
       }
       else
       {
@@ -57,7 +57,7 @@ struct path_builder_t
 	  optional_point_t mid = first_offcurve.lerp (p, .5f);
 	  first_oncurve = mid;
 	  last_offcurve = p;
-	  draw_session->move_to (font->em_fscalef_x (mid.x), font->em_fscalef_y (mid.y));
+	  draw_session->move_to (mid.x, mid.y);
 	}
 	else
 	  first_offcurve = p;
@@ -69,22 +69,22 @@ struct path_builder_t
       {
 	if (is_on_curve)
 	{
-	  draw_session->quadratic_to (font->em_fscalef_x (last_offcurve.x), font->em_fscalef_y (last_offcurve.y),
-				     font->em_fscalef_x (p.x), font->em_fscalef_y (p.y));
+	  draw_session->quadratic_to (last_offcurve.x, last_offcurve.y,
+				     p.x, p.y);
 	  last_offcurve = optional_point_t ();
 	}
 	else
 	{
 	  optional_point_t mid = last_offcurve.lerp (p, .5f);
-	  draw_session->quadratic_to (font->em_fscalef_x (last_offcurve.x), font->em_fscalef_y (last_offcurve.y),
-				     font->em_fscalef_x (mid.x), font->em_fscalef_y (mid.y));
+	  draw_session->quadratic_to (last_offcurve.x, last_offcurve.y,
+				     mid.x, mid.y);
 	  last_offcurve = p;
 	}
       }
       else
       {
 	if (is_on_curve)
-	  draw_session->line_to (font->em_fscalef_x (p.x), font->em_fscalef_y (p.y));
+	  draw_session->line_to (p.x, p.y);
 	else
 	  last_offcurve = p;
       }
@@ -95,23 +95,23 @@ struct path_builder_t
       if (first_offcurve && last_offcurve)
       {
 	optional_point_t mid = last_offcurve.lerp (first_offcurve, .5f);
-	draw_session->quadratic_to (font->em_fscalef_x (last_offcurve.x), font->em_fscalef_y (last_offcurve.y),
-				   font->em_fscalef_x (mid.x), font->em_fscalef_y (mid.y));
+	draw_session->quadratic_to (last_offcurve.x, last_offcurve.y,
+				   mid.x, mid.y);
 	last_offcurve = optional_point_t ();
 	/* now check the rest */
       }
 
       if (first_offcurve && first_oncurve)
-	draw_session->quadratic_to (font->em_fscalef_x (first_offcurve.x), font->em_fscalef_y (first_offcurve.y),
-				   font->em_fscalef_x (first_oncurve.x), font->em_fscalef_y (first_oncurve.y));
+	draw_session->quadratic_to (first_offcurve.x, first_offcurve.y,
+				   first_oncurve.x, first_oncurve.y);
       else if (last_offcurve && first_oncurve)
-	draw_session->quadratic_to (font->em_fscalef_x (last_offcurve.x), font->em_fscalef_y (last_offcurve.y),
-				   font->em_fscalef_x (first_oncurve.x), font->em_fscalef_y (first_oncurve.y));
+	draw_session->quadratic_to (last_offcurve.x, last_offcurve.y,
+				   first_oncurve.x, first_oncurve.y);
       else if (first_oncurve)
-	draw_session->line_to (font->em_fscalef_x (first_oncurve.x), font->em_fscalef_y (first_oncurve.y));
+	draw_session->line_to (first_oncurve.x, first_oncurve.y);
       else if (first_offcurve)
       {
-	float x = font->em_fscalef_x (first_offcurve.x), y = font->em_fscalef_x (first_offcurve.y);
+	float x = first_offcurve.x, y = first_offcurve.y;
 	draw_session->move_to (x, y);
 	draw_session->quadratic_to (x, y, x, y);
       }