diff options
author | Jacques Lucke <jacques@blender.org> | 2020-07-17 14:47:57 +0300 |
---|---|---|
committer | Jacques Lucke <jacques@blender.org> | 2020-07-17 14:49:18 +0300 |
commit | 3ef59121a49b986700747469850e02f6420ee8aa (patch) | |
tree | 9a6dc6b823ebd355e227ce0ad0427f8d1a4c8e39 /source/blender/simulation | |
parent | 9582797d4b50a18040e96ae07aa8c7643cbcc25a (diff) |
Simulation: move initial simulation code from bf_blenkernel to bf_simulation
I removed bf_blenkernel from `nodes/CMakeLists.txt` again (added it yesterday),
because now this was causing me unresolved symbol errors... Without it, cmake
seems to link the libraries bf_simulation, bf_blenkernel and bf_nodes in the right
order. Not sure if that is just luck or if it is guaranteed.
It was possible to fix the issue by using cmakes `LINK_INTERFACE_MULTIPLICITY`,
but that is probably bad style.
Diffstat (limited to 'source/blender/simulation')
-rw-r--r-- | source/blender/simulation/CMakeLists.txt | 7 | ||||
-rw-r--r-- | source/blender/simulation/SIM_simulation_update.hh | 32 | ||||
-rw-r--r-- | source/blender/simulation/intern/simulation_update.cc | 678 |
3 files changed, 717 insertions, 0 deletions
diff --git a/source/blender/simulation/CMakeLists.txt b/source/blender/simulation/CMakeLists.txt index c87d9330f2d..f9fc0b5c798 100644 --- a/source/blender/simulation/CMakeLists.txt +++ b/source/blender/simulation/CMakeLists.txt @@ -24,8 +24,11 @@ set(INC ../blenkernel ../blenlib ../depsgraph + ../functions ../imbuf ../makesdna + ../makesrna + ../nodes ../../../intern/guardedalloc ) @@ -41,11 +44,15 @@ set(SRC intern/implicit.h intern/implicit_blender.c intern/implicit_eigen.cpp + intern/simulation_update.cc SIM_mass_spring.h + SIM_simulation_update.hh ) set(LIB + bf_blenkernel + bf_nodes ) if(WITH_OPENMP_STATIC) diff --git a/source/blender/simulation/SIM_simulation_update.hh b/source/blender/simulation/SIM_simulation_update.hh new file mode 100644 index 00000000000..40b62bfb58a --- /dev/null +++ b/source/blender/simulation/SIM_simulation_update.hh @@ -0,0 +1,32 @@ +/* + * 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. + */ + +#ifndef __SIM_SIMULATION_UPDATE_HH__ +#define __SIM_SIMULATION_UPDATE_HH__ + +struct Depsgraph; +struct Scene; +struct Simulation; + +namespace blender::sim { + +void update_simulation_in_depsgraph(Depsgraph *depsgraph, + Scene *scene_cow, + Simulation *simulation_cow); + +} + +#endif /* __SIM_SIMULATION_UPDATE_HH__ */ diff --git a/source/blender/simulation/intern/simulation_update.cc b/source/blender/simulation/intern/simulation_update.cc new file mode 100644 index 00000000000..918d433cb3d --- /dev/null +++ b/source/blender/simulation/intern/simulation_update.cc @@ -0,0 +1,678 @@ +/* + * 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. + */ + +#include "SIM_simulation_update.hh" + +#include "BKE_customdata.h" +#include "BKE_simulation.h" + +#include "DNA_scene_types.h" +#include "DNA_simulation_types.h" + +#include "DEG_depsgraph_query.h" + +#include "BLI_array.hh" +#include "BLI_float3.hh" +#include "BLI_listbase.h" +#include "BLI_map.hh" +#include "BLI_rand.h" +#include "BLI_vector.hh" + +#include "NOD_node_tree_multi_function.hh" + +#include "FN_attributes_ref.hh" +#include "FN_cpp_types.hh" +#include "FN_multi_function_network_evaluation.hh" +#include "FN_multi_function_network_optimization.hh" + +extern "C" { +void WM_clipboard_text_set(const char *buf, bool selection); +} + +namespace blender::sim { + +static void ensure_attributes_exist(ParticleSimulationState *state) +{ + if (CustomData_get_layer_named(&state->attributes, CD_PROP_FLOAT3, "Position") == nullptr) { + CustomData_add_layer_named( + &state->attributes, CD_PROP_FLOAT3, CD_CALLOC, nullptr, state->tot_particles, "Position"); + } + if (CustomData_get_layer_named(&state->attributes, CD_PROP_FLOAT3, "Velocity") == nullptr) { + CustomData_add_layer_named( + &state->attributes, CD_PROP_FLOAT3, CD_CALLOC, nullptr, state->tot_particles, "Velocity"); + } + if (CustomData_get_layer_named(&state->attributes, CD_PROP_INT32, "ID") == nullptr) { + CustomData_add_layer_named( + &state->attributes, CD_PROP_INT32, CD_CALLOC, nullptr, state->tot_particles, "ID"); + } +} + +static void copy_states_to_cow(Simulation *simulation_orig, Simulation *simulation_cow) +{ + BKE_simulation_state_remove_all(simulation_cow); + simulation_cow->current_frame = simulation_orig->current_frame; + + LISTBASE_FOREACH (SimulationState *, state_orig, &simulation_orig->states) { + switch ((eSimulationStateType)state_orig->type) { + case SIM_STATE_TYPE_PARTICLES: { + ParticleSimulationState *particle_state_orig = (ParticleSimulationState *)state_orig; + ParticleSimulationState *particle_state_cow = (ParticleSimulationState *) + BKE_simulation_state_add(simulation_cow, SIM_STATE_TYPE_PARTICLES, state_orig->name); + particle_state_cow->tot_particles = particle_state_orig->tot_particles; + CustomData_copy(&particle_state_orig->attributes, + &particle_state_cow->attributes, + CD_MASK_ALL, + CD_DUPLICATE, + particle_state_orig->tot_particles); + break; + } + } + } +} + +static Map<const fn::MFOutputSocket *, std::string> deduplicate_attribute_nodes( + fn::MFNetwork &network, + nodes::MFNetworkTreeMap &network_map, + const nodes::DerivedNodeTree &tree) +{ + Span<const nodes::DNode *> attribute_dnodes = tree.nodes_by_type( + "SimulationNodeParticleAttribute"); + uint amount = attribute_dnodes.size(); + if (amount == 0) { + return {}; + } + + Vector<fn::MFInputSocket *> name_sockets; + for (const nodes::DNode *dnode : attribute_dnodes) { + fn::MFInputSocket &name_socket = network_map.lookup_dummy(dnode->input(0)); + name_sockets.append(&name_socket); + } + + fn::MFNetworkEvaluator network_fn{{}, name_sockets.as_span()}; + + fn::MFParamsBuilder params{network_fn, 1}; + + Array<std::string> attribute_names{amount, NoInitialization()}; + for (uint i : IndexRange(amount)) { + params.add_uninitialized_single_output( + fn::GMutableSpan(fn::CPPType_string, attribute_names.data() + i, 1)); + } + + fn::MFContextBuilder context; + /* Todo: Check that the names don't depend on dummy nodes. */ + network_fn.call({0}, params, context); + + Map<std::pair<std::string, fn::MFDataType>, Vector<fn::MFNode *>> + attribute_nodes_by_name_and_type; + for (uint i : IndexRange(amount)) { + attribute_nodes_by_name_and_type + .lookup_or_add_default({attribute_names[i], name_sockets[i]->node().output(0).data_type()}) + .append(&name_sockets[i]->node()); + } + + Map<const fn::MFOutputSocket *, std::string> attribute_inputs; + for (auto item : attribute_nodes_by_name_and_type.items()) { + StringRef attribute_name = item.key.first; + fn::MFDataType data_type = item.key.second; + Span<fn::MFNode *> nodes = item.value; + + fn::MFOutputSocket &new_attribute_socket = network.add_input( + "Attribute '" + attribute_name + "'", data_type); + for (fn::MFNode *node : nodes) { + network.relink(node->output(0), new_attribute_socket); + } + network.remove(nodes); + + attribute_inputs.add_new(&new_attribute_socket, attribute_name); + } + + return attribute_inputs; +} + +class CustomDataAttributesRef { + private: + Vector<void *> buffers_; + uint size_; + std::unique_ptr<fn::AttributesInfo> info_; + + public: + CustomDataAttributesRef(CustomData &custom_data, uint size) + { + fn::AttributesInfoBuilder builder; + for (const CustomDataLayer &layer : Span(custom_data.layers, custom_data.totlayer)) { + buffers_.append(layer.data); + switch (layer.type) { + case CD_PROP_INT32: { + builder.add<int32_t>(layer.name, 0); + break; + } + case CD_PROP_FLOAT3: { + builder.add<float3>(layer.name, {0, 0, 0}); + break; + } + } + } + info_ = std::make_unique<fn::AttributesInfo>(builder); + size_ = size; + } + + operator fn::MutableAttributesRef() + { + return fn::MutableAttributesRef(*info_, buffers_, size_); + } + + operator fn::AttributesRef() const + { + return fn::AttributesRef(*info_, buffers_, size_); + } +}; + +static std::string dnode_to_path(const nodes::DNode &dnode) +{ + std::string path; + for (const nodes::DParentNode *parent = dnode.parent(); parent; parent = parent->parent()) { + path = parent->node_ref().name() + "/" + path; + } + path = path + dnode.name(); + return path; +} + +static void remove_unused_states(Simulation *simulation, const VectorSet<std::string> &state_names) +{ + LISTBASE_FOREACH_MUTABLE (SimulationState *, state, &simulation->states) { + if (!state_names.contains(state->name)) { + BKE_simulation_state_remove(simulation, state); + } + } +} + +static void reset_states(Simulation *simulation) +{ + LISTBASE_FOREACH (SimulationState *, state, &simulation->states) { + switch ((eSimulationStateType)state->type) { + case SIM_STATE_TYPE_PARTICLES: { + ParticleSimulationState *particle_state = (ParticleSimulationState *)state; + CustomData_free(&particle_state->attributes, particle_state->tot_particles); + particle_state->tot_particles = 0; + break; + } + } + } +} + +static SimulationState *try_find_state_by_name(Simulation *simulation, StringRef name) +{ + LISTBASE_FOREACH (SimulationState *, state, &simulation->states) { + if (state->name == name) { + return state; + } + } + return nullptr; +} + +static void add_missing_particle_states(Simulation *simulation, Span<std::string> state_names) +{ + for (StringRefNull name : state_names) { + SimulationState *state = try_find_state_by_name(simulation, name); + if (state != nullptr) { + BLI_assert(state->type == SIM_STATE_TYPE_PARTICLES); + continue; + } + + BKE_simulation_state_add(simulation, SIM_STATE_TYPE_PARTICLES, name.c_str()); + } +} + +static void reinitialize_empty_simulation_states(Simulation *simulation, + const nodes::DerivedNodeTree &tree) +{ + VectorSet<std::string> state_names; + for (const nodes::DNode *dnode : tree.nodes_by_type("SimulationNodeParticleSimulation")) { + state_names.add(dnode_to_path(*dnode)); + } + + remove_unused_states(simulation, state_names); + reset_states(simulation); + add_missing_particle_states(simulation, state_names); +} + +static void update_simulation_state_list(Simulation *simulation, + const nodes::DerivedNodeTree &tree) +{ + VectorSet<std::string> state_names; + for (const nodes::DNode *dnode : tree.nodes_by_type("SimulationNodeParticleSimulation")) { + state_names.add(dnode_to_path(*dnode)); + } + + remove_unused_states(simulation, state_names); + add_missing_particle_states(simulation, state_names); +} + +class ParticleFunctionInput { + public: + virtual ~ParticleFunctionInput() = default; + virtual void add_input(fn::AttributesRef attributes, + fn::MFParamsBuilder ¶ms, + ResourceCollector &resources) const = 0; +}; + +class ParticleFunction { + private: + const fn::MultiFunction *global_fn_; + const fn::MultiFunction *per_particle_fn_; + Array<const ParticleFunctionInput *> global_inputs_; + Array<const ParticleFunctionInput *> per_particle_inputs_; + Array<bool> output_is_global_; + Vector<uint> global_output_indices_; + Vector<uint> per_particle_output_indices_; + Vector<fn::MFDataType> output_types_; + Vector<StringRefNull> output_names_; + + friend class ParticleFunctionEvaluator; + + public: + ParticleFunction(const fn::MultiFunction *global_fn, + const fn::MultiFunction *per_particle_fn, + Span<const ParticleFunctionInput *> global_inputs, + Span<const ParticleFunctionInput *> per_particle_inputs, + Span<bool> output_is_global) + : global_fn_(global_fn), + per_particle_fn_(per_particle_fn), + global_inputs_(global_inputs), + per_particle_inputs_(per_particle_inputs), + output_is_global_(output_is_global) + { + for (uint i : output_is_global_.index_range()) { + if (output_is_global_[i]) { + uint param_index = global_inputs_.size() + global_output_indices_.size(); + fn::MFParamType param_type = global_fn_->param_type(param_index); + BLI_assert(param_type.is_output()); + output_types_.append(param_type.data_type()); + output_names_.append(global_fn_->param_name(param_index)); + global_output_indices_.append(i); + } + else { + uint param_index = per_particle_inputs_.size() + per_particle_output_indices_.size(); + fn::MFParamType param_type = per_particle_fn_->param_type(param_index); + BLI_assert(param_type.is_output()); + output_types_.append(param_type.data_type()); + output_names_.append(per_particle_fn_->param_name(param_index)); + per_particle_output_indices_.append(i); + } + } + } +}; + +class ParticleFunctionEvaluator { + private: + ResourceCollector resources_; + const ParticleFunction &particle_fn_; + IndexMask mask_; + fn::MFContextBuilder global_context_; + fn::MFContextBuilder per_particle_context_; + fn::AttributesRef particle_attributes_; + Vector<void *> outputs_; + bool is_computed_ = false; + + public: + ParticleFunctionEvaluator(const ParticleFunction &particle_fn, + IndexMask mask, + fn::AttributesRef particle_attributes) + : particle_fn_(particle_fn), + mask_(mask), + particle_attributes_(particle_attributes), + outputs_(particle_fn_.output_types_.size(), nullptr) + { + } + + ~ParticleFunctionEvaluator() + { + for (uint output_index : outputs_.index_range()) { + void *buffer = outputs_[output_index]; + fn::MFDataType data_type = particle_fn_.output_types_[output_index]; + BLI_assert(data_type.is_single()); /* For now. */ + const fn::CPPType &type = data_type.single_type(); + + if (particle_fn_.output_is_global_[output_index]) { + type.destruct(buffer); + } + else { + type.destruct_indices(outputs_[0], mask_); + } + } + } + + void compute() + { + BLI_assert(!is_computed_); + this->compute_globals(); + this->compute_per_particle(); + is_computed_ = true; + } + + template<typename T> fn::VSpan<T> get(uint output_index, StringRef expected_name) const + { + return this->get(output_index, expected_name).typed<T>(); + } + + fn::GVSpan get(uint output_index, StringRef expected_name) const + { +#ifdef DEBUG + StringRef real_name = particle_fn_.output_names_[output_index]; + BLI_assert(expected_name == real_name); + BLI_assert(is_computed_); +#endif + UNUSED_VARS_NDEBUG(expected_name); + const void *buffer = outputs_[output_index]; + const fn::CPPType &type = particle_fn_.output_types_[output_index].single_type(); + if (particle_fn_.output_is_global_[output_index]) { + return fn::GVSpan::FromSingleWithMaxSize(type, buffer); + } + else { + return fn::GVSpan(fn::GSpan(type, buffer, mask_.min_array_size())); + } + } + + private: + void compute_globals() + { + if (particle_fn_.global_fn_ == nullptr) { + return; + } + + fn::MFParamsBuilder params(*particle_fn_.global_fn_, mask_.min_array_size()); + + /* Add input parameters. */ + for (const ParticleFunctionInput *input : particle_fn_.global_inputs_) { + input->add_input(particle_attributes_, params, resources_); + } + + /* Add output parameters. */ + for (uint output_index : particle_fn_.global_output_indices_) { + fn::MFDataType data_type = particle_fn_.output_types_[output_index]; + BLI_assert(data_type.is_single()); /* For now. */ + + const fn::CPPType &type = data_type.single_type(); + void *buffer = resources_.linear_allocator().allocate(type.size(), type.alignment()); + params.add_uninitialized_single_output(fn::GMutableSpan(type, buffer, 1)); + outputs_[output_index] = buffer; + } + + particle_fn_.global_fn_->call({0}, params, global_context_); + } + + void compute_per_particle() + { + if (particle_fn_.per_particle_fn_ == nullptr) { + return; + } + + fn::MFParamsBuilder params(*particle_fn_.per_particle_fn_, mask_.min_array_size()); + + /* Add input parameters. */ + for (const ParticleFunctionInput *input : particle_fn_.per_particle_inputs_) { + input->add_input(particle_attributes_, params, resources_); + } + + /* Add output parameters. */ + for (uint output_index : particle_fn_.per_particle_output_indices_) { + fn::MFDataType data_type = particle_fn_.output_types_[output_index]; + BLI_assert(data_type.is_single()); /* For now. */ + + const fn::CPPType &type = data_type.single_type(); + void *buffer = resources_.linear_allocator().allocate(type.size() * mask_.min_array_size(), + type.alignment()); + params.add_uninitialized_single_output( + fn::GMutableSpan(type, buffer, mask_.min_array_size())); + outputs_[output_index] = buffer; + } + + particle_fn_.per_particle_fn_->call(mask_, params, global_context_); + } +}; + +class ParticleAttributeInput : public ParticleFunctionInput { + private: + std::string attribute_name_; + const fn::CPPType &attribute_type_; + + public: + ParticleAttributeInput(std::string attribute_name, const fn::CPPType &attribute_type) + : attribute_name_(std::move(attribute_name)), attribute_type_(attribute_type) + { + } + + void add_input(fn::AttributesRef attributes, + fn::MFParamsBuilder ¶ms, + ResourceCollector &UNUSED(resources)) const override + { + std::optional<fn::GSpan> span = attributes.try_get(attribute_name_, attribute_type_); + if (span.has_value()) { + params.add_readonly_single_input(*span); + } + else { + params.add_readonly_single_input(fn::GVSpan::FromDefault(attribute_type_)); + } + } +}; + +static const ParticleFunction *create_particle_function_for_inputs( + Span<const fn::MFInputSocket *> sockets_to_compute, + ResourceCollector &resources, + const Map<const fn::MFOutputSocket *, std::string> &attribute_inputs) +{ + BLI_assert(sockets_to_compute.size() >= 1); + const fn::MFNetwork &network = sockets_to_compute[0]->node().network(); + + VectorSet<const fn::MFOutputSocket *> dummy_deps; + VectorSet<const fn::MFInputSocket *> unlinked_input_deps; + network.find_dependencies(sockets_to_compute, dummy_deps, unlinked_input_deps); + BLI_assert(unlinked_input_deps.size() == 0); + + Vector<const ParticleFunctionInput *> per_particle_inputs; + for (const fn::MFOutputSocket *socket : dummy_deps) { + const std::string *attribute_name = attribute_inputs.lookup_ptr(socket); + if (attribute_name == nullptr) { + return nullptr; + } + per_particle_inputs.append(&resources.construct<ParticleAttributeInput>( + AT, *attribute_name, socket->data_type().single_type())); + } + + const fn::MultiFunction &per_particle_fn = resources.construct<fn::MFNetworkEvaluator>( + AT, dummy_deps.as_span(), sockets_to_compute); + + Array<bool> output_is_global(sockets_to_compute.size(), false); + + const ParticleFunction &particle_fn = resources.construct<ParticleFunction>( + AT, + nullptr, + &per_particle_fn, + Span<const ParticleFunctionInput *>(), + per_particle_inputs.as_span(), + output_is_global.as_span()); + + return &particle_fn; +} + +class ParticleForce { + public: + virtual ~ParticleForce() = default; + virtual void add_force(fn::AttributesRef attributes, + MutableSpan<float3> r_combined_force) const = 0; +}; + +class ParticleFunctionForce : public ParticleForce { + private: + const ParticleFunction &particle_fn_; + + public: + ParticleFunctionForce(const ParticleFunction &particle_fn) : particle_fn_(particle_fn) + { + } + + void add_force(fn::AttributesRef attributes, MutableSpan<float3> r_combined_force) const override + { + IndexMask mask = IndexRange(attributes.size()); + ParticleFunctionEvaluator evaluator{particle_fn_, mask, attributes}; + evaluator.compute(); + fn::VSpan<float3> forces = evaluator.get<float3>(0, "Force"); + for (uint i : mask) { + r_combined_force[i] += forces[i]; + } + } +}; + +static Vector<const ParticleForce *> create_forces_for_particle_simulation( + const nodes::DNode &simulation_node, + nodes::MFNetworkTreeMap &network_map, + ResourceCollector &resources, + const Map<const fn::MFOutputSocket *, std::string> &attribute_inputs) +{ + Vector<const ParticleForce *> forces; + for (const nodes::DOutputSocket *origin_socket : + simulation_node.input(2, "Forces").linked_sockets()) { + const nodes::DNode &origin_node = origin_socket->node(); + if (origin_node.idname() != "SimulationNodeForce") { + continue; + } + + const fn::MFInputSocket &force_socket = network_map.lookup_dummy( + origin_node.input(0, "Force")); + + const ParticleFunction *particle_fn = create_particle_function_for_inputs( + {&force_socket}, resources, attribute_inputs); + + if (particle_fn == nullptr) { + continue; + } + + const ParticleForce &force = resources.construct<ParticleFunctionForce>(AT, *particle_fn); + forces.append(&force); + } + return forces; +} + +static Map<std::string, Vector<const ParticleForce *>> collect_forces( + nodes::MFNetworkTreeMap &network_map, + ResourceCollector &resources, + const Map<const fn::MFOutputSocket *, std::string> &attribute_inputs) +{ + Map<std::string, Vector<const ParticleForce *>> forces_by_simulation; + for (const nodes::DNode *dnode : + network_map.tree().nodes_by_type("SimulationNodeParticleSimulation")) { + std::string name = dnode_to_path(*dnode); + Vector<const ParticleForce *> forces = create_forces_for_particle_simulation( + *dnode, network_map, resources, attribute_inputs); + forces_by_simulation.add_new(std::move(name), std::move(forces)); + } + return forces_by_simulation; +} + +void update_simulation_in_depsgraph(Depsgraph *depsgraph, + Scene *scene_cow, + Simulation *simulation_cow) +{ + int current_frame = scene_cow->r.cfra; + if (simulation_cow->current_frame == current_frame) { + return; + } + + /* Below we modify the original state/cache. Only the active depsgraph is allowed to do that. */ + if (!DEG_is_active(depsgraph)) { + return; + } + + Simulation *simulation_orig = (Simulation *)DEG_get_original_id(&simulation_cow->id); + + nodes::NodeTreeRefMap tree_refs; + /* TODO: Use simulation_cow, but need to add depsgraph relations before that. */ + const nodes::DerivedNodeTree tree{simulation_orig->nodetree, tree_refs}; + fn::MFNetwork network; + ResourceCollector resources; + nodes::MFNetworkTreeMap network_map = insert_node_tree_into_mf_network(network, tree, resources); + Map<const fn::MFOutputSocket *, std::string> attribute_inputs = deduplicate_attribute_nodes( + network, network_map, tree); + fn::mf_network_optimization::constant_folding(network, resources); + fn::mf_network_optimization::common_subnetwork_elimination(network); + fn::mf_network_optimization::dead_node_removal(network); + // WM_clipboard_text_set(network.to_dot().c_str(), false); + + Map<std::string, Vector<const ParticleForce *>> forces_by_simulation = collect_forces( + network_map, resources, attribute_inputs); + + if (current_frame == 1) { + reinitialize_empty_simulation_states(simulation_orig, tree); + + RNG *rng = BLI_rng_new(0); + + simulation_orig->current_frame = 1; + LISTBASE_FOREACH (ParticleSimulationState *, state, &simulation_orig->states) { + state->tot_particles = 1000; + CustomData_realloc(&state->attributes, state->tot_particles); + ensure_attributes_exist(state); + + CustomDataAttributesRef custom_data_attributes{state->attributes, + (uint)state->tot_particles}; + + fn::MutableAttributesRef attributes = custom_data_attributes; + MutableSpan<float3> positions = attributes.get<float3>("Position"); + MutableSpan<float3> velocities = attributes.get<float3>("Velocity"); + MutableSpan<int32_t> ids = attributes.get<int32_t>("ID"); + + for (uint i : positions.index_range()) { + positions[i] = {i / 100.0f, 0, 0}; + velocities[i] = {0, BLI_rng_get_float(rng) - 0.5f, BLI_rng_get_float(rng) - 0.5f}; + ids[i] = i; + } + } + + BLI_rng_free(rng); + + copy_states_to_cow(simulation_orig, simulation_cow); + } + else if (current_frame == simulation_orig->current_frame + 1) { + update_simulation_state_list(simulation_orig, tree); + float time_step = 1.0f / 24.0f; + simulation_orig->current_frame = current_frame; + + LISTBASE_FOREACH (ParticleSimulationState *, state, &simulation_orig->states) { + ensure_attributes_exist(state); + + CustomDataAttributesRef custom_data_attributes{state->attributes, + (uint)state->tot_particles}; + + fn::MutableAttributesRef attributes = custom_data_attributes; + MutableSpan<float3> positions = attributes.get<float3>("Position"); + MutableSpan<float3> velocities = attributes.get<float3>("Velocity"); + + Array<float3> force_vectors{(uint)state->tot_particles, {0, 0, 0}}; + Span<const ParticleForce *> forces = forces_by_simulation.lookup_as(state->head.name); + for (const ParticleForce *force : forces) { + force->add_force(attributes, force_vectors); + } + + for (uint i : positions.index_range()) { + velocities[i] += force_vectors[i] * time_step; + positions[i] += velocities[i] * time_step; + } + } + + copy_states_to_cow(simulation_orig, simulation_cow); + } +} + +} // namespace blender::sim |