diff options
author | Jacques Lucke <jacques@blender.org> | 2022-07-08 17:16:56 +0300 |
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committer | Jacques Lucke <jacques@blender.org> | 2022-07-08 17:16:56 +0300 |
commit | b876ce2a4a4638142439a7cf265a0780491ae4cc (patch) | |
tree | 871d71eb6d1cf215869fc941c831c81bcacc6433 /source/blender/modifiers | |
parent | f391e8f316bd29b700cef874a59cf3b64203d70c (diff) |
Geometry Nodes: new geometry attribute API
Currently, there are two attribute API. The first, defined in `BKE_attribute.h` is
accessible from RNA and C code. The second is implemented with `GeometryComponent`
and is only accessible in C++ code. The second is widely used, but only being
accessible through the `GeometrySet` API makes it awkward to use, and even impossible
for types that don't correspond directly to a geometry component like `CurvesGeometry`.
This patch adds a new attribute API, designed to replace the `GeometryComponent`
attribute API now, and to eventually replace or be the basis of the other one.
The basic idea is that there is an `AttributeAccessor` class that allows code to
interact with a set of attributes owned by some geometry. The accessor itself has
no ownership. `AttributeAccessor` is a simple type that can be passed around by
value. That makes it easy to return it from functions and to store it in containers.
For const-correctness, there is also a `MutableAttributeAccessor` that allows
changing individual and can add or remove attributes.
Currently, `AttributeAccessor` is composed of two pointers. The first is a pointer
to the owner of the attribute data. The second is a pointer to a struct with
function pointers, that is similar to a virtual function table. The functions
know how to access attributes on the owner.
The actual attribute access for geometries is still implemented with the `AttributeProvider`
pattern, which makes it easy to support different sources of attributes on a
geometry and simplifies dealing with built-in attributes.
There are different ways to get an attribute accessor for a geometry:
* `GeometryComponent.attributes()`
* `CurvesGeometry.attributes()`
* `bke::mesh_attributes(const Mesh &)`
* `bke::pointcloud_attributes(const PointCloud &)`
All of these also have a `_for_write` variant that returns a `MutabelAttributeAccessor`.
Differential Revision: https://developer.blender.org/D15280
Diffstat (limited to 'source/blender/modifiers')
-rw-r--r-- | source/blender/modifiers/intern/MOD_nodes.cc | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/source/blender/modifiers/intern/MOD_nodes.cc b/source/blender/modifiers/intern/MOD_nodes.cc index a63a89e076b..885d2f901ec 100644 --- a/source/blender/modifiers/intern/MOD_nodes.cc +++ b/source/blender/modifiers/intern/MOD_nodes.cc @@ -109,7 +109,7 @@ using blender::Span; using blender::StringRef; using blender::StringRefNull; using blender::Vector; -using blender::bke::OutputAttribute; +using blender::bke::AttributeMetaData; using blender::fn::Field; using blender::fn::GField; using blender::fn::ValueOrField; @@ -999,22 +999,27 @@ static Vector<OutputAttributeToStore> compute_attributes_to_store( continue; } const GeometryComponent &component = *geometry.get_component_for_read(component_type); + if (component.is_empty()) { + continue; + } + const blender::bke::AttributeAccessor attributes = *component.attributes(); for (const auto item : outputs_by_domain.items()) { const eAttrDomain domain = item.key; const Span<OutputAttributeInfo> outputs_info = item.value; - if (!component.attribute_domain_supported(domain)) { + if (!attributes.domain_supported(domain)) { continue; } - const int domain_num = component.attribute_domain_num(domain); + const int domain_size = attributes.domain_size(domain); blender::bke::GeometryComponentFieldContext field_context{component, domain}; - blender::fn::FieldEvaluator field_evaluator{field_context, domain_num}; + blender::fn::FieldEvaluator field_evaluator{field_context, domain_size}; for (const OutputAttributeInfo &output_info : outputs_info) { const CPPType &type = output_info.field.cpp_type(); OutputAttributeToStore store{ component_type, domain, output_info.name, - GMutableSpan{type, MEM_malloc_arrayN(domain_num, type.size(), __func__), domain_num}}; + GMutableSpan{ + type, MEM_malloc_arrayN(domain_size, type.size(), __func__), domain_size}}; field_evaluator.add_with_destination(output_info.field, store.data); attributes_to_store.append(store); } @@ -1029,33 +1034,33 @@ static void store_computed_output_attributes( { for (const OutputAttributeToStore &store : attributes_to_store) { GeometryComponent &component = geometry.get_component_for_write(store.component_type); + blender::bke::MutableAttributeAccessor attributes = *component.attributes_for_write(); + const eCustomDataType data_type = blender::bke::cpp_type_to_custom_data_type( store.data.type()); - const std::optional<AttributeMetaData> meta_data = component.attribute_get_meta_data( - store.name); + const std::optional<AttributeMetaData> meta_data = attributes.lookup_meta_data(store.name); /* Attempt to remove the attribute if it already exists but the domain and type don't match. * Removing the attribute won't succeed if it is built in and non-removable. */ if (meta_data.has_value() && (meta_data->domain != store.domain || meta_data->data_type != data_type)) { - component.attribute_try_delete(store.name); + attributes.remove(store.name); } /* Try to create the attribute reusing the stored buffer. This will only succeed if the * attribute didn't exist before, or if it existed but was removed above. */ - if (component.attribute_try_create( - store.name, - store.domain, - blender::bke::cpp_type_to_custom_data_type(store.data.type()), - AttributeInitMove(store.data.data()))) { + if (attributes.add(store.name, + store.domain, + blender::bke::cpp_type_to_custom_data_type(store.data.type()), + blender::bke::AttributeInitMove(store.data.data()))) { continue; } - OutputAttribute attribute = component.attribute_try_get_for_output_only( + blender::bke::GAttributeWriter attribute = attributes.lookup_or_add_for_write( store.name, store.domain, data_type); if (attribute) { - attribute.varray().set_all(store.data.data()); - attribute.save(); + attribute.varray.set_all(store.data.data()); + attribute.finish(); } /* We were unable to reuse the data, so it must be destructed and freed. */ |