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[smooth] Reduce copying during integration phase.

We now record `cover' and `area' directly into the linked list. This
makes rendering faster by 10% or even more at larger sizes.

* src/smooth/ftgrays.c (FT_INTEGRATE): Write directly.
(gray_TWorker): Add direct cell reference and remove unused fields.
(gray_set_cell): Consolidate the linked list management and pointers.
(gray_convert_glyph, gray_convert_glyph_inner): Updated.

git/fs: mount .git/fs: mount/attach disallowed

--- a/ChangeLog

+++ b/ChangeLog

@@ -1,3 +1,15 @@

+2021-03-11  Alexei Podtelezhnikov  <[email protected]>

+

+	[smooth] Reduce copying during integration phase.

+

+	We now record `cover' and `area' directly into the linked list. This

+	makes rendering faster by 10% or even more at larger sizes.

+

+	* src/smooth/ftgrays.c (FT_INTEGRATE): Write directly.

+	(gray_TWorker): Add direct cell reference and remove unused fields.

+	(gray_set_cell): Consolidate the linked list management and pointers.

+	(gray_convert_glyph, gray_convert_glyph_inner): Updated.

+

 2021-03-10  Alexei Podtelezhnikov  <[email protected]>

 	* src/smooth/ftgrays.c (FT_INTEGRATE): New convenience macro.

--- a/src/smooth/ftgrays.c

+++ b/src/smooth/ftgrays.c

@@ -447,14 +447,10 @@

   {

     ft_jmp_buf  jump_buffer;

-    TCoord  ex, ey;

     TCoord  min_ex, max_ex;

     TCoord  min_ey, max_ey;

-    TArea   area;

-    TCoord  cover;

-    int     invalid;

-

+    PCell       cell;

     PCell*      ycells;

     PCell       cells;

     FT_PtrDist  max_cells;

@@ -483,8 +479,9 @@

   static gray_TWorker  ras;

 #endif

-#define FT_INTEGRATE( ras, a, b )                         \

-           ras.cover += (a), ras.area += (a) * (TArea)(b)

+#define FT_INTEGRATE( ras, a, b )                                       \

+           if ( ras.cell )                                              \

+             ras.cell->cover += (a), ras.cell->area += (a) * (TArea)(b)

   typedef struct gray_TRaster_

@@ -523,50 +520,6 @@

   /**************************************************************************

    *

-   * Record the current cell in the linked list.

-   */

-  static void

-  gray_record_cell( RAS_ARG )

-  {

-    PCell  *pcell, cell;

-    TCoord  x = ras.ex;

-

-

-    pcell = &ras.ycells[ras.ey - ras.min_ey];

-    while ( ( cell = *pcell ) )

-    {

-      if ( cell->x > x )

-        break;

-

-      if ( cell->x == x )

-        goto Found;

-

-      pcell = &cell->next;

-    }

-

-    if ( ras.num_cells >= ras.max_cells )

-      ft_longjmp( ras.jump_buffer, 1 );

-

-    /* insert new cell */

-    cell        = ras.cells + ras.num_cells++;

-    cell->x     = x;

-    cell->area  = ras.area;

-    cell->cover = ras.cover;

-

-    cell->next  = *pcell;

-    *pcell      = cell;

-

-    return;

-

-  Found:

-    /* update old cell */

-    cell->area  += ras.area;

-    cell->cover += ras.cover;

-  }

-

-

-  /**************************************************************************

-   *

    * Set the current cell to a new position.

    */

   static void

@@ -573,9 +526,9 @@

   gray_set_cell( RAS_ARG_ TCoord  ex,

                           TCoord  ey )

   {

-    /* Move the cell pointer to a new position.  We set the `invalid'      */

-    /* flag to indicate that the cell isn't part of those we're interested */

-    /* in during the render phase.  This means that:                       */

+    /* Move the cell pointer to a new position in the linked list. We use  */

+    /* NULL to indicate that the cell is outside of the clipping region    */

+    /* during the render phase.  This means that:                          */

     /*                                                                     */

     /* . the new vertical position must be within min_ey..max_ey-1.        */

     /* . the new horizontal position must be strictly less than max_ex     */

@@ -583,17 +536,42 @@

     /* Note that if a cell is to the left of the clipping region, it is    */

     /* actually set to the (min_ex-1) horizontal position.                 */

-    /* record the current one if it is valid and substantial */

-    if ( !ras.invalid && ( ras.area || ras.cover ) )

-      gray_record_cell( RAS_VAR );

+    if ( ey >= ras.max_ey || ey < ras.min_ey || ex >= ras.max_ex )

+      ras.cell = NULL;

+    else

+    {

+      PCell  *pcell, cell;

-    ras.area  = 0;

-    ras.cover = 0;

-    ras.ex    = FT_MAX( ex, ras.min_ex - 1 );

-    ras.ey    = ey;

-    ras.invalid = ( ey >= ras.max_ey || ey < ras.min_ey ||

-                    ex >= ras.max_ex );

+      ex = FT_MAX( ex, ras.min_ex - 1 );

+

+      pcell = &ras.ycells[ey - ras.min_ey];

+      while ( ( cell = *pcell ) )

+      {

+        if ( cell->x > ex )

+          break;

+

+        if ( cell->x == ex )

+          goto Found;

+

+        pcell = &cell->next;

+      }

+

+      if ( ras.num_cells >= ras.max_cells )

+        ft_longjmp( ras.jump_buffer, 1 );

+

+      /* insert new cell */

+      cell        = ras.cells + ras.num_cells++;

+      cell->x     = ex;

+      cell->area  = 0;

+      cell->cover = 0;

+

+      cell->next  = *pcell;

+      *pcell      = cell;

+

+    Found:

+      ras.cell = cell;

+    }

   }

@@ -1631,9 +1609,6 @@

       if ( continued )

         FT_Trace_Enable();

-      if ( !ras.invalid )

-        gray_record_cell( RAS_VAR );

-

       FT_TRACE7(( "band [%d..%d]: %ld cell%s\n",

                   ras.min_ey,

                   ras.max_ey,

@@ -1702,7 +1677,7 @@

         FT_MEM_ZERO( ras.ycells, height * sizeof ( PCell ) );

         ras.num_cells = 0;

-        ras.invalid   = 1;

+        ras.cell      = NULL;

         ras.min_ey    = band[1];

         ras.max_ey    = band[0];