diff --git a/ChangeLog b/ChangeLog
index 9fa54eb..bc4d291 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2021-03-10  Alexei Podtelezhnikov  <apodtele@gmail.com>
+
+	* src/smooth/ftgrays.c (FT_INTEGRATE): New convenience macro.
+	(gray_render_line, gray_render_scanline): Use it.
+
 2021-03-09  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	* src/smooth/ftgrays.c (gray_render_line): Rearrange conditionals.
diff --git a/src/smooth/ftgrays.c b/src/smooth/ftgrays.c
index 74fe3ff..5e3d453 100644
--- a/src/smooth/ftgrays.c
+++ b/src/smooth/ftgrays.c
@@ -483,6 +483,9 @@
   static gray_TWorker  ras;
 #endif
 
+#define FT_INTEGRATE( ras, a, b )                         \
+           ras.cover += (a), ras.area += (a) * (TArea)(b)
+
 
   typedef struct gray_TRaster_
   {
@@ -655,10 +658,9 @@
     /* XXX: y-delta and x-delta below should be related.            */
     FT_DIV_MOD( TCoord, p, dx, delta, mod );
 
-    ras.area  += (TArea)( ( fx1 + first ) * delta );
-    ras.cover += delta;
-    y1        += delta;
-    ex1       += incr;
+    FT_INTEGRATE( ras, delta, fx1 + first );
+    y1  += delta;
+    ex1 += incr;
     gray_set_cell( RAS_VAR_ ex1, ey );
 
     if ( ex1 != ex2 )
@@ -679,10 +681,9 @@
           delta++;
         }
 
-        ras.area  += (TArea)( ONE_PIXEL * delta );
-        ras.cover += delta;
-        y1        += delta;
-        ex1       += incr;
+        FT_INTEGRATE( ras, delta, ONE_PIXEL );
+        y1  += delta;
+        ex1 += incr;
         gray_set_cell( RAS_VAR_ ex1, ey );
       } while ( ex1 != ex2 );
     }
@@ -690,10 +691,7 @@
     fx1 = ONE_PIXEL - first;
 
   End:
-    dy = y2 - y1;
-
-    ras.area  += (TArea)( ( fx1 + fx2 ) * dy );
-    ras.cover += dy;
+    FT_INTEGRATE( ras, y2 - y1, fx1 + fx2 );
   }
 
 
@@ -736,7 +734,6 @@
     {
       TCoord  ex     = TRUNC( ras.x );
       TCoord  two_fx = FRACT( ras.x ) << 1;
-      TArea   area;
 
 
       if ( dy > 0)
@@ -750,27 +747,23 @@
         incr  = -1;
       }
 
-      delta      = first - fy1;
-      ras.area  += (TArea)two_fx * delta;
-      ras.cover += delta;
-      ey1       += incr;
+      delta = first - fy1;
+      FT_INTEGRATE( ras, delta, two_fx);
+      ey1 += incr;
 
       gray_set_cell( RAS_VAR_ ex, ey1 );
 
       delta = first + first - ONE_PIXEL;
-      area  = (TArea)two_fx * delta;
       while ( ey1 != ey2 )
       {
-        ras.area  += area;
-        ras.cover += delta;
-        ey1       += incr;
+        FT_INTEGRATE( ras, delta, two_fx);
+        ey1 += incr;
 
         gray_set_cell( RAS_VAR_ ex, ey1 );
       }
 
-      delta      = fy2 - ONE_PIXEL + first;
-      ras.area  += (TArea)two_fx * delta;
-      ras.cover += delta;
+      delta = fy2 - ONE_PIXEL + first;
+      FT_INTEGRATE( ras, delta, two_fx);
 
       goto End;
     }
@@ -883,8 +876,7 @@
         do
         {
           fy2 = ONE_PIXEL;
-          ras.cover += ( fy2 - fy1 );
-          ras.area  += ( fy2 - fy1 ) * fx1 * 2;
+          FT_INTEGRATE( ras, fy2 - fy1, fx1 * 2 );
           fy1 = 0;
           ey1++;
           gray_set_cell( RAS_VAR_ ex1, ey1 );
@@ -893,8 +885,7 @@
         do
         {
           fy2 = 0;
-          ras.cover += ( fy2 - fy1 );
-          ras.area  += ( fy2 - fy1 ) * fx1 * 2;
+          FT_INTEGRATE( ras, fy2 - fy1, fx1 * 2 );
           fy1 = ONE_PIXEL;
           ey1--;
           gray_set_cell( RAS_VAR_ ex1, ey1 );
@@ -918,8 +909,7 @@
           fx2 = 0;
           fy2 = FT_UDIV( -prod, -dx );
           prod -= dy * ONE_PIXEL;
-          ras.cover += ( fy2 - fy1 );
-          ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
+          FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
           fx1 = ONE_PIXEL;
           fy1 = fy2;
           ex1--;
@@ -930,8 +920,7 @@
           prod -= dx * ONE_PIXEL;
           fx2 = FT_UDIV( -prod, dy );
           fy2 = ONE_PIXEL;
-          ras.cover += ( fy2 - fy1 );
-          ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
+          FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
           fx1 = fx2;
           fy1 = 0;
           ey1++;
@@ -942,8 +931,7 @@
           prod += dy * ONE_PIXEL;
           fx2 = ONE_PIXEL;
           fy2 = FT_UDIV( prod, dx );
-          ras.cover += ( fy2 - fy1 );
-          ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
+          FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
           fx1 = 0;
           fy1 = fy2;
           ex1++;
@@ -954,8 +942,7 @@
           fx2 = FT_UDIV( prod, -dy );
           fy2 = 0;
           prod += dx * ONE_PIXEL;
-          ras.cover += ( fy2 - fy1 );
-          ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
+          FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
           fx1 = fx2;
           fy1 = ONE_PIXEL;
           ey1--;
@@ -968,8 +955,7 @@
     fx2 = FRACT( to_x );
     fy2 = FRACT( to_y );
 
-    ras.cover += ( fy2 - fy1 );
-    ras.area  += ( fy2 - fy1 ) * ( fx1 + fx2 );
+    FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 );
 
   End:
     ras.x       = to_x;