Files
test2/source/blender/nodes/NOD_geometry_exec.hh
Jacques Lucke 5cf6f570c6 Geometry Nodes: use virtual arrays in internal attribute api
A virtual array is a data structure that is similar to a normal array
in that its elements can be accessed by an index. However, a virtual
array does not have to be a contiguous array internally. Instead, its
elements can be layed out arbitrarily while element access happens
through a virtual function call. However, the virtual array data
structures are designed so that the virtual function call can be avoided
in cases where it could become a bottleneck.

Most commonly, a virtual array is backed by an actual array/span or
is a single value internally, that is the same for every index.
Besides those, there are many more specialized virtual arrays like the
ones that provides vertex positions based on the `MVert` struct or
vertex group weights.

Not all attributes used by geometry nodes are stored in simple contiguous
arrays. To provide uniform access to all kinds of attributes, the attribute
API has to provide virtual array functionality that hides the implementation
details of attributes.

Before this refactor, the attribute API provided its own virtual array
implementation as part of the `ReadAttribute` and `WriteAttribute` types.
That resulted in unnecessary code duplication with the virtual array system.
Even worse, it bound many algorithms used by geometry nodes to the specifics
of the attribute API, even though they could also use different data sources
(such as data from sockets, default values, later results of expressions, ...).

This refactor removes the `ReadAttribute` and `WriteAttribute` types and
replaces them with `GVArray` and `GVMutableArray` respectively. The `GV`
stands for "generic virtual". The "generic" means that the data type contained
in those virtual arrays is only known at run-time. There are the corresponding
statically typed types `VArray<T>` and `VMutableArray<T>` as well.

No regressions are expected from this refactor. It does come with one
improvement for users. The attribute API can convert the data type
on write now. This is especially useful when writing to builtin attributes
like `material_index` with e.g. the Attribute Math node (which usually
just writes to float attributes, while `material_index` is an integer attribute).

Differential Revision: https://developer.blender.org/D10994
2021-04-17 16:41:39 +02:00

258 lines
7.9 KiB
C++

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#pragma once
#include "FN_generic_value_map.hh"
#include "BKE_attribute_access.hh"
#include "BKE_geometry_set.hh"
#include "BKE_geometry_set_instances.hh"
#include "BKE_node_ui_storage.hh"
#include "BKE_persistent_data_handle.hh"
#include "DNA_node_types.h"
#include "NOD_derived_node_tree.hh"
struct Depsgraph;
struct ModifierData;
namespace blender::nodes {
using bke::geometry_set_realize_instances;
using bke::OutputAttribute;
using bke::OutputAttribute_Typed;
using bke::PersistentDataHandleMap;
using bke::PersistentObjectHandle;
using bke::ReadAttributeLookup;
using bke::WriteAttributeLookup;
using fn::CPPType;
using fn::GMutablePointer;
using fn::GMutableSpan;
using fn::GPointer;
using fn::GSpan;
using fn::GValueMap;
using fn::GVArray;
using fn::GVArray_GSpan;
using fn::GVArray_Span;
using fn::GVArray_Typed;
using fn::GVArrayPtr;
using fn::GVMutableArray;
using fn::GVMutableArray_GSpan;
using fn::GVMutableArray_Typed;
using fn::GVMutableArrayPtr;
class GeoNodeExecParams {
private:
const DNode node_;
GValueMap<StringRef> &input_values_;
GValueMap<StringRef> &output_values_;
const PersistentDataHandleMap &handle_map_;
const Object *self_object_;
const ModifierData *modifier_;
Depsgraph *depsgraph_;
public:
GeoNodeExecParams(const DNode node,
GValueMap<StringRef> &input_values,
GValueMap<StringRef> &output_values,
const PersistentDataHandleMap &handle_map,
const Object *self_object,
const ModifierData *modifier,
Depsgraph *depsgraph)
: node_(node),
input_values_(input_values),
output_values_(output_values),
handle_map_(handle_map),
self_object_(self_object),
modifier_(modifier),
depsgraph_(depsgraph)
{
}
/**
* Get the input value for the input socket with the given identifier.
*
* The node calling becomes responsible for destructing the value before it is done
* executing. This method can only be called once for each identifier.
*/
GMutablePointer extract_input(StringRef identifier)
{
#ifdef DEBUG
this->check_extract_input(identifier);
#endif
return input_values_.extract(identifier);
}
/**
* Get the input value for the input socket with the given identifier.
*
* This method can only be called once for each identifier.
*/
template<typename T> T extract_input(StringRef identifier)
{
#ifdef DEBUG
this->check_extract_input(identifier, &CPPType::get<T>());
#endif
return input_values_.extract<T>(identifier);
}
/**
* Get input as vector for multi input socket with the given identifier.
*
* This method can only be called once for each identifier.
*/
template<typename T> Vector<T> extract_multi_input(StringRef identifier)
{
Vector<T> values;
int index = 0;
while (true) {
std::string sub_identifier = identifier;
if (index > 0) {
sub_identifier += "[" + std::to_string(index) + "]";
}
if (!input_values_.contains(sub_identifier)) {
break;
}
values.append(input_values_.extract<T, StringRef>(sub_identifier));
index++;
}
return values;
}
/**
* Get the input value for the input socket with the given identifier.
*/
template<typename T> const T &get_input(StringRef identifier) const
{
#ifdef DEBUG
this->check_extract_input(identifier, &CPPType::get<T>());
#endif
return input_values_.lookup<T>(identifier);
}
/**
* Move-construct a new value based on the given value and store it for the given socket
* identifier.
*/
void set_output_by_move(StringRef identifier, GMutablePointer value)
{
#ifdef DEBUG
BLI_assert(value.type() != nullptr);
BLI_assert(value.get() != nullptr);
this->check_set_output(identifier, *value.type());
#endif
output_values_.add_new_by_move(identifier, value);
}
void set_output_by_copy(StringRef identifier, GPointer value)
{
#ifdef DEBUG
BLI_assert(value.type() != nullptr);
BLI_assert(value.get() != nullptr);
this->check_set_output(identifier, *value.type());
#endif
output_values_.add_new_by_copy(identifier, value);
}
/**
* Store the output value for the given socket identifier.
*/
template<typename T> void set_output(StringRef identifier, T &&value)
{
#ifdef DEBUG
this->check_set_output(identifier, CPPType::get<std::decay_t<T>>());
#endif
output_values_.add_new(identifier, std::forward<T>(value));
}
/**
* Get the node that is currently being executed.
*/
const bNode &node() const
{
return *node_->bnode();
}
const PersistentDataHandleMap &handle_map() const
{
return handle_map_;
}
const Object *self_object() const
{
return self_object_;
}
Depsgraph *depsgraph() const
{
return depsgraph_;
}
/**
* Add an error message displayed at the top of the node when displaying the node tree,
* and potentially elsewhere in Blender.
*/
void error_message_add(const NodeWarningType type, std::string message) const;
/**
* Creates a read-only attribute based on node inputs. The method automatically detects which
* input socket with the given name is available.
*
* \note This will add an error message if the string socket is active and
* the input attribute does not exist.
*/
GVArrayPtr get_input_attribute(const StringRef name,
const GeometryComponent &component,
const AttributeDomain domain,
const CustomDataType type,
const void *default_value) const;
template<typename T>
GVArray_Typed<T> get_input_attribute(const StringRef name,
const GeometryComponent &component,
const AttributeDomain domain,
const T &default_value) const
{
const CustomDataType type = bke::cpp_type_to_custom_data_type(CPPType::get<T>());
GVArrayPtr varray = this->get_input_attribute(name, component, domain, type, &default_value);
return GVArray_Typed<T>(std::move(varray));
}
/**
* Get the type of an input property or the associated constant socket types with the
* same names. Fall back to the default value if no attribute exists with the name.
*/
CustomDataType get_input_attribute_data_type(const StringRef name,
const GeometryComponent &component,
const CustomDataType default_type) const;
AttributeDomain get_highest_priority_input_domain(Span<std::string> names,
const GeometryComponent &component,
const AttributeDomain default_domain) const;
private:
/* Utilities for detecting common errors at when using this class. */
void check_extract_input(StringRef identifier, const CPPType *requested_type = nullptr) const;
void check_set_output(StringRef identifier, const CPPType &value_type) const;
/* Find the active socket socket with the input name (not the identifier). */
const bNodeSocket *find_available_socket(const StringRef name) const;
};
} // namespace blender::nodes