[color] Round extents when scaling

src/hb-ot-color-cbdt-table.hh

@@ -443,11 +443,13 @@ struct CBDT
 	}
       }
 
-      /* Convert to the font units. */
-      extents->x_bearing *= upem / (float) x_ppem;
-      extents->y_bearing *= upem / (float) y_ppem;
-      extents->width *= upem / (float) x_ppem;
-      extents->height *= upem / (float) y_ppem;
+      /* Convert to font units. */
+      double x_scale = upem / (double) x_ppem;
+      double y_scale = upem / (double) y_ppem;
+      extents->x_bearing = round (extents->x_bearing * x_scale);
+      extents->y_bearing = round (extents->y_bearing * y_scale);
+      extents->width = round (extents->width * x_scale);
+      extents->height = round (extents->height * y_scale);
 
       return true;
     }

src/hb-ot-color-sbix-table.hh

@@ -252,14 +252,14 @@ struct sbix
       extents->width     = png.IHDR.width;
       extents->height    = png.IHDR.height;
 
-      /* Convert to the font units. */
+      /* Convert to font units. */
       if (strike_ppem)
       {
-	unsigned int upem = font->face->upem;
-	extents->x_bearing *= upem / (float) strike_ppem;
-	extents->y_bearing *= upem / (float) strike_ppem;
-	extents->width *= upem / (float) strike_ppem;
-	extents->height *= upem / (float) strike_ppem;
+	double scale = font->face->upem / (double) strike_ppem;
+	extents->x_bearing = round (extents->x_bearing * scale);
+	extents->y_bearing = round (extents->y_bearing * scale);
+	extents->width = round (extents->width * scale);
+	extents->height = round (extents->height * scale);
       }
 
       hb_blob_destroy (blob);