Functions: Multi Function

This adds the `MultiFunction` type and some smallish utility types that it uses.
A `MultiFunction` encapsulates a function that is optimized for throughput by
always processing many elements at once.

This is an important part of the new particle system, because it allows us to
execute user generated node trees for many particles efficiently.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D8030

1 files changed, 161 insertions, 0 deletions

diff --git a/source/blender/functions/FN_multi_function_signature.hh b/source/blender/functions/FN_multi_function_signature.hh
new file mode 100644
index 00000000000..64bbd7be5c8
--- /dev/null
+++ b/source/blender/functions/FN_multi_function_signature.hh
@@ -0,0 +1,161 @@
+/*
+ * 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 __FN_MULTI_FUNCTION_SIGNATURE_HH__
+#define __FN_MULTI_FUNCTION_SIGNATURE_HH__
+
+/** \file
+ * \ingroup fn
+ *
+ * The signature of a multi-function contains the functions name and expected parameters. New
+ * signatures should be build using the MFSignatureBuilder class.
+ */
+
+#include "FN_multi_function_param_type.hh"
+
+#include "BLI_vector.hh"
+
+namespace blender {
+namespace fn {
+
+struct MFSignature {
+  std::string function_name;
+  Vector<std::string> param_names;
+  Vector<MFParamType> param_types;
+  Vector<uint> param_data_indices;
+
+  uint data_index(uint param_index) const
+  {
+    return param_data_indices[param_index];
+  }
+};
+
+class MFSignatureBuilder {
+ private:
+  MFSignature &m_data;
+  uint m_span_count = 0;
+  uint m_virtual_span_count = 0;
+  uint m_virtual_array_span_count = 0;
+  uint m_vector_array_count = 0;
+
+ public:
+  MFSignatureBuilder(MFSignature &data) : m_data(data)
+  {
+    BLI_assert(data.param_names.is_empty());
+    BLI_assert(data.param_types.is_empty());
+    BLI_assert(data.param_data_indices.is_empty());
+  }
+
+  /* Input Param Types */
+
+  template<typename T> void single_input(StringRef name)
+  {
+    this->single_input(name, CPPType::get<T>());
+  }
+  void single_input(StringRef name, const CPPType &type)
+  {
+    this->input(name, MFDataType::ForSingle(type));
+  }
+  template<typename T> void vector_input(StringRef name)
+  {
+    this->vector_input(name, CPPType::get<T>());
+  }
+  void vector_input(StringRef name, const CPPType &base_type)
+  {
+    this->input(name, MFDataType::ForVector(base_type));
+  }
+  void input(StringRef name, MFDataType data_type)
+  {
+    m_data.param_names.append(name);
+    m_data.param_types.append(MFParamType(MFParamType::Input, data_type));
+
+    switch (data_type.category()) {
+      case MFDataType::Single:
+        m_data.param_data_indices.append(m_virtual_span_count++);
+        break;
+      case MFDataType::Vector:
+        m_data.param_data_indices.append(m_virtual_array_span_count++);
+        break;
+    }
+  }
+
+  /* Output Param Types */
+
+  template<typename T> void single_output(StringRef name)
+  {
+    this->single_output(name, CPPType::get<T>());
+  }
+  void single_output(StringRef name, const CPPType &type)
+  {
+    this->output(name, MFDataType::ForSingle(type));
+  }
+  template<typename T> void vector_output(StringRef name)
+  {
+    this->vector_output(name, CPPType::get<T>());
+  }
+  void vector_output(StringRef name, const CPPType &base_type)
+  {
+    this->output(name, MFDataType::ForVector(base_type));
+  }
+  void output(StringRef name, MFDataType data_type)
+  {
+    m_data.param_names.append(name);
+    m_data.param_types.append(MFParamType(MFParamType::Output, data_type));
+
+    switch (data_type.category()) {
+      case MFDataType::Single:
+        m_data.param_data_indices.append(m_span_count++);
+        break;
+      case MFDataType::Vector:
+        m_data.param_data_indices.append(m_vector_array_count++);
+        break;
+    }
+  }
+
+  /* Mutable Param Types */
+
+  template<typename T> void single_mutable(StringRef name)
+  {
+    this->single_mutable(name, CPPType::get<T>());
+  }
+  void single_mutable(StringRef name, const CPPType &type)
+  {
+    this->mutable_(name, MFDataType::ForSingle(type));
+  }
+  void vector_mutable(StringRef name, const CPPType &base_type)
+  {
+    this->mutable_(name, MFDataType::ForVector(base_type));
+  }
+  void mutable_(StringRef name, MFDataType data_type)
+  {
+    m_data.param_names.append(name);
+    m_data.param_types.append(MFParamType(MFParamType::Mutable, data_type));
+
+    switch (data_type.category()) {
+      case MFDataType::Single:
+        m_data.param_data_indices.append(m_span_count++);
+        break;
+      case MFDataType::Vector:
+        m_data.param_data_indices.append(m_vector_array_count++);
+        break;
+    }
+  }
+};
+
+}  // namespace fn
+}  // namespace blender
+
+#endif /* __FN_MULTI_FUNCTION_SIGNATURE_HH__ */