[gegl/openmp: 4/4] buffer: wrap gegl_buffer_get babl conversions in openmp

[Øyvind Kolås <ok src gnome org>]

commit 9ad024c8e595eeada734641a035db27b6fe82d76
Author: Øyvind Kolås <pippin gimp org>
Date:   Tue Jun 3 22:48:25 2014 +0200

    buffer: wrap gegl_buffer_get babl conversions in openmp

 gegl/buffer/gegl-buffer-access.c |   55 +++++++++++++++++++++++++------------
 1 files changed, 37 insertions(+), 18 deletions(-)
---
diff --git a/gegl/buffer/gegl-buffer-access.c b/gegl/buffer/gegl-buffer-access.c
index fae90c2..c4bb19a 100644
--- a/gegl/buffer/gegl-buffer-access.c
+++ b/gegl/buffer/gegl-buffer-access.c
@@ -27,6 +27,7 @@
 
 #include "gegl.h"
 #include "gegl-debug.h"
+#include "gegl-config.h"
 #include "gegl-types-internal.h"
 #include "gegl-algorithms.h"
 #include "gegl-buffer-types.h"
@@ -310,10 +311,8 @@ gegl_buffer_iterate_write (GeglBuffer          *buffer,
 
                   if (buffer_y + y >= buffer_abyss_y &&
                       buffer_y + y < abyss_y_total)
-                    {
-                      babl_process (fish, bp + lskip * bpx_size, tp + lskip * px_size,
-                                    pixels - lskip - rskip);
-                    }
+                    babl_process (fish, bp + lskip * bpx_size, tp + lskip * px_size,
+                                  pixels - lskip - rskip);
 
                   tp += tile_stride;
                   bp += buf_stride;
@@ -328,11 +327,8 @@ gegl_buffer_iterate_write (GeglBuffer          *buffer,
 
                   if (buffer_y + y >= buffer_abyss_y &&
                       buffer_y + y < abyss_y_total)
-                    {
-
-                      memcpy (tp + lskip * px_size, bp + lskip * px_size,
-                              (pixels - lskip - rskip) * px_size);
-                    }
+                    memcpy (tp + lskip * px_size, bp + lskip * px_size,
+                            (pixels - lskip - rskip) * px_size);
 
                   tp += tile_stride;
                   bp += buf_stride;
@@ -386,7 +382,8 @@ gegl_buffer_iterate_read_simple (GeglBuffer          *buffer,
           gint      tiledx  = buffer_x + bufx;
           gint      offsetx = gegl_tile_offset (tiledx, tile_width);
           guchar   *bp, *tile_base, *tp;
-          gint      pixels, row, y;
+          gint      pixels, y;
+          gint      y2, yd;
           GeglTile *tile;
 
           bp = buf + bufy * buf_stride + bufx * bpx_size;
@@ -412,18 +409,40 @@ gegl_buffer_iterate_read_simple (GeglBuffer          *buffer,
           tp        = ((guchar *) tile_base) + (offsety * tile_width + offsetx) * px_size;
 
           y = bufy;
-          for (row = offsety;
-               row < tile_height && y < height;
-               row++, y++)
+          y2 = 0;
+          yd = tile_height - offsety;
+          if (height - y < yd)
+            yd = height - y;
+ 
+#ifdef HAVE_OPENMP
+          if (gegl_config()->use_openmp)
             {
               if (fish)
-                babl_process (fish, tp, bp, pixels);
+#pragma omp parallel for
+                for (y2 = 0; y2 < yd; y2 ++)
+                   babl_process (fish, tp + y2 * tile_stride,
+                                       bp + y2 * buf_stride, pixels);
               else
-                memcpy (bp, tp, pixels * px_size);
-
-              tp += tile_stride;
-              bp += buf_stride;
+#pragma omp parallel for
+                for (y2 = 0; y2 < yd; y2 ++)
+                   memcpy (bp + y2 * buf_stride,
+                           tp + y2 * tile_stride, pixels * px_size);
             }
+          else
+#endif
+            {
+              if (fish)
+                for (y2 = 0; y2 < yd; y2 ++)
+                   babl_process (fish, tp + y2 * tile_stride,
+                                       bp + y2 * buf_stride, pixels);
+              else
+                for (y2 = 0; y2 < yd; y2 ++)
+                   memcpy (bp + y2 * buf_stride,
+                           tp + y2 * tile_stride, pixels * px_size);
+            }
+
+          tp += tile_stride * y2;
+          bp += buf_stride * y2;
 
           gegl_tile_unref (tile);
           bufx += (tile_width - offsetx);