Curves: Remove redundant custom data pointers

These mutable pointers present problems with ownership in relation to
proper copy-on-write for attributes. The simplest solution is to just
remove them and retrieve the layers from  `CustomData` when they are
needed. This also removes the complexity and redundancy of having to
update the pointers as the curves change. A similar change will apply
to meshes and point clouds.

One downside of this change is that it makes random access with RNA
slower. However, it's simple to just use the RNA attribute API instead,
which is unaffected. In this patch I updated Cycles to do that. With
the future attribute CoW changes, this generic approach makes sense
because Cycles can just request ownership of the existing arrays.

Differential Revision: https://developer.blender.org/D15486

1 files changed, 55 insertions, 23 deletions

diff --git a/source/blender/makesrna/intern/rna_curves.c b/source/blender/makesrna/intern/rna_curves.c
index bc3e5203ed0..cb8b36f41d2 100644
--- a/source/blender/makesrna/intern/rna_curves.c
+++ b/source/blender/makesrna/intern/rna_curves.c
@@ -64,7 +64,24 @@ static int rna_CurvePoint_index_get_const(const PointerRNA *ptr)
 {
   const Curves *curves = rna_curves(ptr);
   const float(*co)[3] = ptr->data;
-  return (int)(co - curves->geometry.position);
+  const float(*positions)[3] = (const float(*)[3])CustomData_get_layer_named(
+      &curves->geometry.point_data, CD_PROP_FLOAT3, "position");
+  return (int)(co - positions);
+}
+
+static int rna_Curves_position_data_length(PointerRNA *ptr)
+{
+  const Curves *curves = rna_curves(ptr);
+  return curves->geometry.point_num;
+}
+
+static void rna_Curves_position_data_begin(CollectionPropertyIterator *iter, PointerRNA *ptr)
+{
+  const Curves *curves = rna_curves(ptr);
+  const float(*positions)[3] = (const float(*)[3])CustomData_get_layer_named(
+      &curves->geometry.point_data, CD_PROP_FLOAT3, "position");
+  rna_iterator_array_begin(
+      iter, (void *)positions, sizeof(float[3]), curves->geometry.point_num, false, NULL);
 }
 
 static int rna_CurvePoint_index_get(PointerRNA *ptr)
@@ -85,21 +102,23 @@ static void rna_CurvePoint_location_set(PointerRNA *ptr, const float value[3])
 static float rna_CurvePoint_radius_get(PointerRNA *ptr)
 {
   const Curves *curves = rna_curves(ptr);
-  if (curves->geometry.radius == NULL) {
+  const float *radii = (const float *)CustomData_get_layer_named(
+      &curves->geometry.point_data, CD_PROP_FLOAT, "radius");
+  if (radii == NULL) {
     return 0.0f;
   }
-  const float(*co)[3] = ptr->data;
-  return curves->geometry.radius[co - curves->geometry.position];
+  return radii[rna_CurvePoint_index_get_const(ptr)];
 }
 
 static void rna_CurvePoint_radius_set(PointerRNA *ptr, float value)
 {
   const Curves *curves = rna_curves(ptr);
-  if (curves->geometry.radius == NULL) {
+  float *radii = (float *)CustomData_get_layer_named(
+      &curves->geometry.point_data, CD_PROP_FLOAT, "radius");
+  if (radii == NULL) {
     return;
   }
-  const float(*co)[3] = ptr->data;
-  curves->geometry.radius[co - curves->geometry.position] = value;
+  radii[rna_CurvePoint_index_get_const(ptr)] = value;
 }
 
 static char *rna_CurvePoint_path(const PointerRNA *ptr)
@@ -123,16 +142,6 @@ static char *rna_CurveSlice_path(const PointerRNA *ptr)
   return BLI_sprintfN("curves[%d]", rna_CurveSlice_index_get_const(ptr));
 }
 
-static void rna_CurveSlice_points_begin(CollectionPropertyIterator *iter, PointerRNA *ptr)
-{
-  Curves *curves = rna_curves(ptr);
-  const int *offset_ptr = (int *)ptr->data;
-  const int offset = *offset_ptr;
-  const int size = *(offset_ptr + 1) - offset;
-  float(*co)[3] = curves->geometry.position + *offset_ptr;
-  rna_iterator_array_begin(iter, co, sizeof(float[3]), size, 0, NULL);
-}
-
 static int rna_CurveSlice_first_point_index_get(PointerRNA *ptr)
 {
   const int *offset_ptr = (int *)ptr->data;
@@ -146,6 +155,17 @@ static int rna_CurveSlice_points_length_get(PointerRNA *ptr)
   return *(offset_ptr + 1) - offset;
 }
 
+static void rna_CurveSlice_points_begin(CollectionPropertyIterator *iter, PointerRNA *ptr)
+{
+  Curves *curves = rna_curves(ptr);
+  const int offset = rna_CurveSlice_first_point_index_get(ptr);
+  const int size = rna_CurveSlice_points_length_get(ptr);
+  float(*positions)[3] = (float(*)[3])CustomData_get_layer_named(
+      &curves->geometry.point_data, CD_PROP_FLOAT3, "position");
+  float(*co)[3] = positions + offset;
+  rna_iterator_array_begin(iter, co, sizeof(float[3]), size, 0, NULL);
+}
+
 static void rna_Curves_update_data(struct Main *UNUSED(bmain),
                                    struct Scene *UNUSED(scene),
                                    PointerRNA *ptr)
@@ -252,20 +272,32 @@ static void rna_def_curves(BlenderRNA *brna)
   RNA_def_property_struct_type(prop, "CurveSlice");
   RNA_def_property_ui_text(prop, "Curves", "All curves in the data-block");
 
-  /* TODO: better solution for (*co)[3] parsing issue. */
-
-  RNA_define_verify_sdna(0);
   prop = RNA_def_property(srna, "points", PROP_COLLECTION, PROP_NONE);
-  RNA_def_property_collection_sdna(prop, NULL, "geometry.position", "geometry.point_num");
   RNA_def_property_struct_type(prop, "CurvePoint");
+  RNA_def_property_collection_funcs(prop,
+                                    "rna_Curves_position_data_begin",
+                                    "rna_iterator_array_next",
+                                    "rna_iterator_array_end",
+                                    "rna_iterator_array_get",
+                                    "rna_Curves_position_data_length",
+                                    NULL,
+                                    NULL,
+                                    NULL);
   RNA_def_property_ui_text(prop, "Points", "Control points of all curves");
-  RNA_define_verify_sdna(1);
 
   /* Direct access to built-in attributes. */
 
   RNA_define_verify_sdna(0);
   prop = RNA_def_property(srna, "position_data", PROP_COLLECTION, PROP_NONE);
-  RNA_def_property_collection_sdna(prop, NULL, "geometry.position", "geometry.point_num");
+  RNA_def_property_collection_funcs(prop,
+                                    "rna_Curves_position_data_begin",
+                                    "rna_iterator_array_next",
+                                    "rna_iterator_array_end",
+                                    "rna_iterator_array_get",
+                                    "rna_Curves_position_data_length",
+                                    NULL,
+                                    NULL,
+                                    NULL);
   RNA_def_property_struct_type(prop, "FloatVectorAttributeValue");
   RNA_def_property_update(prop, 0, "rna_Curves_update_data");
   RNA_define_verify_sdna(1);