[gimp/gimp-2-10] app: add gimp_tile_handler_validate_validate()

[Ell <ell src gnome org>]

commit a4fb3e11d67792592e9c90719e98a33bc5466295
Author: Ell <ell_se yahoo com>
Date:   Wed Nov 28 13:04:46 2018 -0500

    app: add gimp_tile_handler_validate_validate()
    
    ... which validates a given rectangle directly into the buffer,
    possibly intersecting it with the dirty region.  This is more
    efficient than either invalidating, un-invalidating, and rendering
    a given rect, as we're doing in GimpProjection, or validating the
    buffer tile-by-tile, as we're doing in gimp:buffer-source-validate.
    
    (cherry picked from commit 82a60997d485f4df5f39c97fe10bcae7893dd235)

 app/gegl/gimptilehandlervalidate.c | 74 +++++++++++++++++++++++++++++++++++---
 app/gegl/gimptilehandlervalidate.h |  5 +++
 2 files changed, 74 insertions(+), 5 deletions(-)
---
diff --git a/app/gegl/gimptilehandlervalidate.c b/app/gegl/gimptilehandlervalidate.c
index 9280e3122d..ff15f5786e 100644
--- a/app/gegl/gimptilehandlervalidate.c
+++ b/app/gegl/gimptilehandlervalidate.c
@@ -247,10 +247,10 @@ gimp_tile_handler_validate_real_validate_buffer (GimpTileHandlerValidate *valida
 }
 
 static GeglTile *
-gimp_tile_handler_validate_validate (GeglTileSource *source,
-                                     GeglTile       *tile,
-                                     gint            x,
-                                     gint            y)
+gimp_tile_handler_validate_validate_tile (GeglTileSource *source,
+                                          GeglTile       *tile,
+                                          gint            x,
+                                          gint            y)
 {
   GimpTileHandlerValidate *validate = GIMP_TILE_HANDLER_VALIDATE (source);
   cairo_rectangle_int_t    tile_rect;
@@ -382,7 +382,7 @@ gimp_tile_handler_validate_command (GeglTileSource  *source,
   retval = gegl_tile_handler_source_command (source, command, x, y, z, data);
 
   if (command == GEGL_TILE_GET && z == 0)
-    retval = gimp_tile_handler_validate_validate (source, retval, x, y);
+    retval = gimp_tile_handler_validate_validate_tile (source, retval, x, y);
 
   return retval;
 }
@@ -490,6 +490,70 @@ gimp_tile_handler_validate_end_validate (GimpTileHandlerValidate *validate)
     GIMP_TILE_HANDLER_VALIDATE_GET_CLASS (validate)->end_validate (validate);
 }
 
+void
+gimp_tile_handler_validate_validate (GimpTileHandlerValidate *validate,
+                                     GeglBuffer              *buffer,
+                                     const GeglRectangle     *rect,
+                                     gboolean                 intersect)
+{
+  GimpTileHandlerValidateClass *klass;
+
+  g_return_if_fail (GIMP_IS_TILE_HANDLER_VALIDATE (validate));
+  g_return_if_fail (gimp_tile_handler_validate_get_assigned (buffer) ==
+                    validate);
+
+  klass = GIMP_TILE_HANDLER_VALIDATE_GET_CLASS (validate);
+
+  if (intersect)
+    {
+      cairo_region_t *region = cairo_region_copy (validate->dirty_region);
+
+      cairo_region_intersect_rectangle (region,
+                                        (const cairo_rectangle_int_t *) rect);
+
+      if (! cairo_region_is_empty (region))
+        {
+          gint n_rects;
+          gint i;
+
+          gimp_tile_handler_validate_begin_validate (validate);
+
+          n_rects = cairo_region_num_rectangles (region);
+
+          for (i = 0; i < n_rects; i++)
+            {
+              cairo_rectangle_int_t blit_rect;
+
+              cairo_region_get_rectangle (region, i, &blit_rect);
+
+              klass->validate_buffer (validate,
+                                      (const GeglRectangle *) &blit_rect,
+                                      buffer);
+            }
+
+          gimp_tile_handler_validate_end_validate (validate);
+
+          cairo_region_subtract_rectangle (
+            validate->dirty_region,
+            (const cairo_rectangle_int_t *) rect);
+        }
+
+      cairo_region_destroy (region);
+    }
+  else
+    {
+      gimp_tile_handler_validate_begin_validate (validate);
+
+      klass->validate_buffer (validate, rect, buffer);
+
+      gimp_tile_handler_validate_end_validate (validate);
+
+      cairo_region_subtract_rectangle (
+            validate->dirty_region,
+            (const cairo_rectangle_int_t *) rect);
+    }
+}
+
 void
 gimp_tile_handler_validate_buffer_copy (GeglBuffer          *src_buffer,
                                         const GeglRectangle *src_rect,
diff --git a/app/gegl/gimptilehandlervalidate.h b/app/gegl/gimptilehandlervalidate.h
index b892cf5c4e..63a6e97a47 100644
--- a/app/gegl/gimptilehandlervalidate.h
+++ b/app/gegl/gimptilehandlervalidate.h
@@ -87,6 +87,11 @@ void                      gimp_tile_handler_validate_undo_invalidate (GimpTileHa
 void                      gimp_tile_handler_validate_begin_validate  (GimpTileHandlerValidate *validate);
 void                      gimp_tile_handler_validate_end_validate    (GimpTileHandlerValidate *validate);
 
+void                      gimp_tile_handler_validate_validate        (GimpTileHandlerValidate *validate,
+                                                                      GeglBuffer              *buffer,
+                                                                      const GeglRectangle     *rect,
+                                                                      gboolean                 intersect);
+
 void                      gimp_tile_handler_validate_buffer_copy     (GeglBuffer              *src_buffer,
                                                                       const GeglRectangle     *src_rect,
                                                                       GeglBuffer              *dst_buffer,