[gegl] transform: add OpTransform::get_abyss_policy() virtual function

[N/A <ell src gnome org>]

commit 51d9797aa44232833de97c7527f688d32d74ef3c
Author: Ell <ell_se yahoo com>
Date:   Thu Mar 22 16:03:51 2018 -0400

    transform: add OpTransform::get_abyss_policy() virtual function
    
    Based on a patch by Téo Mazars.
    
    Add a get_abyss_policy() virtual function to OpTransform, which can
    be used by subclasses to control the abyss policy used when
    sampling the input.  When not overridden, ABYSS_NONE is used, as
    before.

 operations/transform/transform-core.c |   41 +++++++++++++++++++++++---------
 operations/transform/transform-core.h |    5 ++-
 2 files changed, 32 insertions(+), 14 deletions(-)
---
diff --git a/operations/transform/transform-core.c b/operations/transform/transform-core.c
index db0f307..02bafc3 100644
--- a/operations/transform/transform-core.c
+++ b/operations/transform/transform-core.c
@@ -191,7 +191,8 @@ op_transform_class_init (OpTransformClass *klass)
   op_class->no_cache                  = TRUE;
   op_class->threaded                  = TRUE;
 
-  klass->create_matrix = NULL;
+  klass->create_matrix                = NULL;
+  klass->get_abyss_policy             = NULL;
 
   gegl_operation_class_set_key (op_class, "categories", "transform");
 
@@ -326,6 +327,15 @@ gegl_transform_create_composite_matrix (OpTransform *transform,
     }
 }
 
+static GeglAbyssPolicy
+gegl_transform_get_abyss_policy (OpTransform *transform)
+{
+  if (OP_TRANSFORM_GET_CLASS (transform)->get_abyss_policy)
+    return OP_TRANSFORM_GET_CLASS (transform)->get_abyss_policy (transform);
+
+  return GEGL_ABYSS_NONE;
+}
+
 static void
 gegl_transform_bounding_box (const gdouble       *points,
                              const gint           num_points,
@@ -662,7 +672,10 @@ gegl_transform_is_intermediate_node (OpTransform *transform)
         {
           GeglOperation *sink = gegl_node_get_gegl_operation (consumers[i]);
 
-          if (! IS_OP_TRANSFORM (sink) || transform->sampler != OP_TRANSFORM (sink)->sampler)
+          if (! IS_OP_TRANSFORM (sink)                           ||
+              transform->sampler != OP_TRANSFORM (sink)->sampler ||
+              gegl_transform_get_abyss_policy (transform) !=
+              gegl_transform_get_abyss_policy (OP_TRANSFORM (sink)))
             {
               is_intermediate = FALSE;
               break;
@@ -1115,13 +1128,14 @@ transform_affine (GeglOperation       *operation,
                   const GeglRectangle *roi,
                   gint                 level)
 {
-  gint         factor = 1 << level;
-  OpTransform *transform = (OpTransform *) operation;
-  const Babl  *format = babl_format ("RaGaBaA float");
-  GeglMatrix3  inverse;
-  gdouble      inverse_near_z = 1.0 / near_z;
-  GeglMatrix2  inverse_jacobian;
-  GeglSampler *sampler = gegl_buffer_sampler_new_at_level (src,
+  gint             factor = 1 << level;
+  OpTransform     *transform = (OpTransform *) operation;
+  const Babl      *format = babl_format ("RaGaBaA float");
+  GeglMatrix3      inverse;
+  gdouble          inverse_near_z = 1.0 / near_z;
+  GeglMatrix2      inverse_jacobian;
+  GeglAbyssPolicy  abyss_policy = gegl_transform_get_abyss_policy (transform);
+  GeglSampler     *sampler = gegl_buffer_sampler_new_at_level (src,
                                          babl_format("RaGaBaA float"),
                                          level?GEGL_SAMPLER_NEAREST:transform->sampler,
                                          level);
@@ -1236,7 +1250,7 @@ transform_affine (GeglOperation       *operation,
                                    u_float, v_float,
                                    &inverse_jacobian,
                                    dest_ptr,
-                                   GEGL_ABYSS_NONE);
+                                   abyss_policy);
                   dest_ptr += (gint) 4;
 
                   u_float += inverse_jacobian.coeff [0][0];
@@ -1276,6 +1290,7 @@ transform_generic (GeglOperation       *operation,
   GeglBufferIterator  *i;
   GeglMatrix3          inverse;
   gdouble              inverse_near_z = 1.0 / near_z;
+  GeglAbyssPolicy      abyss_policy = gegl_transform_get_abyss_policy (transform);
   GeglSampler *sampler = gegl_buffer_sampler_new_at_level (src,
                                          babl_format("RaGaBaA float"),
                                          level?GEGL_SAMPLER_NEAREST:
@@ -1389,7 +1404,7 @@ transform_generic (GeglOperation       *operation,
                                  u, v,
                                  &inverse_jacobian,
                                  dest_ptr,
-                                 GEGL_ABYSS_NONE);
+                                 abyss_policy);
 
                 dest_ptr += (gint) 4;
                 u_float += inverse.coeff [0][0];
@@ -1423,12 +1438,14 @@ transform_nearest (GeglOperation       *operation,
                    const GeglRectangle *roi,
                    gint                 level)
 {
+  OpTransform         *transform = (OpTransform *) operation;
   const Babl          *format    = gegl_buffer_get_format (dest);
   gint                 factor    = 1 << level;
   gint                 px_size   = babl_format_get_bytes_per_pixel (format);
   GeglBufferIterator  *i;
   GeglMatrix3          inverse;
   gdouble              inverse_near_z = 1.0 / near_z;
+  GeglAbyssPolicy      abyss_policy = gegl_transform_get_abyss_policy (transform);
   GeglSampler *sampler = gegl_buffer_sampler_new_at_level (src, format,
                                          GEGL_SAMPLER_NEAREST,
                                          level);
@@ -1526,7 +1543,7 @@ transform_nearest (GeglOperation       *operation,
                                  u, v,
                                  NULL,
                                  dest_ptr,
-                                 GEGL_ABYSS_NONE);
+                                 abyss_policy);
 
                 dest_ptr += px_size;
                 u_float += inverse.coeff [0][0];
diff --git a/operations/transform/transform-core.h b/operations/transform/transform-core.h
index d0e7941..2c6429b 100644
--- a/operations/transform/transform-core.h
+++ b/operations/transform/transform-core.h
@@ -29,8 +29,9 @@ struct _OpTransformClass
 {
   GeglOperationFilterClass parent_class;
 
-  void (* create_matrix) (OpTransform  *transform,
-                          GeglMatrix3  *matrix);
+  void            (* create_matrix)    (OpTransform *transform,
+                                        GeglMatrix3 *matrix);
+  GeglAbyssPolicy (* get_abyss_policy) (OpTransform *transform);
 };
 
 GType op_transform_get_type (void) G_GNUC_CONST;