Some optimizations for the gray-raster (raster engine antialiasing).

Increase the size of the initial memory pool (it's anyways free'd later
on) to improve the performance of the rasterizer and also decrease the
chance of re-allocations.

Also, by combining gray_record_cell and gray_find_cell into one
function, as gray_find_cell is only called from the former, we can skip
some unnecessary operations.

Measured performance improvements range from 58 % to 154 % for rounded
rect filling and stroking.

Reviewed-by: Andreas Kling

2 files changed, 13 insertions, 24 deletions

diff --git a/src/gui/painting/qgrayraster.c b/src/gui/painting/qgrayraster.c
index ec9ebeb71f..536f265f14 100644
--- a/src/gui/painting/qgrayraster.c
+++ b/src/gui/painting/qgrayraster.c
@@ -408,25 +408,31 @@
   /*                                                                       */
   /* Record the current cell in the table.                                 */
   /*                                                                       */
-  static PCell
-  gray_find_cell( RAS_ARG )
+  static void
+  gray_record_cell( RAS_ARG )
   {
     PCell  *pcell, cell;
     int     x = ras.ex;
 
+    if ( ras.invalid || !( ras.area | ras.cover ) )
+        return;
 
     if ( x > ras.max_ex )
       x = ras.max_ex;
 
     pcell = &ras.ycells[ras.ey];
+
     for (;;)
     {
       cell = *pcell;
       if ( cell == NULL || cell->x > x )
         break;
 
-      if ( cell->x == x )
-        goto Exit;
+      if ( cell->x == x ) {
+          cell->area  += ras.area;
+          cell->cover += ras.cover;
+          return;
+      }
 
       pcell = &cell->next;
     }
@@ -436,28 +442,11 @@
 
     cell        = ras.cells + ras.num_cells++;
     cell->x     = x;
-    cell->area  = 0;
-    cell->cover = 0;
+    cell->area  = ras.area;
+    cell->cover = ras.cover;
 
     cell->next  = *pcell;
     *pcell      = cell;
-
-  Exit:
-    return cell;
-  }
-
-
-  static void
-  gray_record_cell( RAS_ARG )
-  {
-    if ( !ras.invalid && ( ras.area | ras.cover ) )
-    {
-      PCell  cell = gray_find_cell( RAS_VAR );
-
-
-      cell->area  += ras.area;
-      cell->cover += ras.cover;
-    }
   }
 
 
diff --git a/src/gui/painting/qgrayraster_p.h b/src/gui/painting/qgrayraster_p.h
index ad595b864a..d610a9a0db 100644
--- a/src/gui/painting/qgrayraster_p.h
+++ b/src/gui/painting/qgrayraster_p.h
@@ -91,7 +91,7 @@
 
 /* Minimum buffer size for raster object, that accounts
    for TWorker and TCell sizes.*/
-#define MINIMUM_POOL_SIZE 4096
+#define MINIMUM_POOL_SIZE 8192
 
   QT_FT_EXPORT_VAR( const QT_FT_Raster_Funcs )  qt_ft_grays_raster;