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, 125 insertions, 0 deletions

diff --git a/source/blender/functions/FN_multi_function_data_type.hh b/source/blender/functions/FN_multi_function_data_type.hh
new file mode 100644
index 00000000000..856d1cc7253
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+++ b/source/blender/functions/FN_multi_function_data_type.hh
@@ -0,0 +1,125 @@
+/*
+ * 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_DATA_TYPE_HH__
+#define __FN_MULTI_FUNCTION_DATA_TYPE_HH__
+
+/** \file
+ * \ingroup fn
+ *
+ * A MFDataType describes what type of data a multi-function gets as input, outputs or mutates.
+ * Currently, only individual elements or vectors of elements are supported. Adding more data types
+ * is possible when necessary.
+ */
+
+#include "FN_cpp_type.hh"
+
+namespace blender {
+namespace fn {
+
+class MFDataType {
+ public:
+  enum Category {
+    Single,
+    Vector,
+  };
+
+ private:
+  Category m_category;
+  const CPPType *m_type;
+
+  MFDataType(Category category, const CPPType &type) : m_category(category), m_type(&type)
+  {
+  }
+
+ public:
+  static MFDataType ForSingle(const CPPType &type)
+  {
+    return MFDataType(Single, type);
+  }
+
+  static MFDataType ForVector(const CPPType &type)
+  {
+    return MFDataType(Vector, type);
+  }
+
+  template<typename T> static MFDataType ForSingle()
+  {
+    return MFDataType::ForSingle(CPPType::get<T>());
+  }
+
+  template<typename T> static MFDataType ForVector()
+  {
+    return MFDataType::ForVector(CPPType::get<T>());
+  }
+
+  bool is_single() const
+  {
+    return m_category == Single;
+  }
+
+  bool is_vector() const
+  {
+    return m_category == Vector;
+  }
+
+  Category category() const
+  {
+    return m_category;
+  }
+
+  const CPPType &single_type() const
+  {
+    BLI_assert(this->is_single());
+    return *m_type;
+  }
+
+  const CPPType &vector_base_type() const
+  {
+    BLI_assert(this->is_vector());
+    return *m_type;
+  }
+
+  friend bool operator==(const MFDataType &a, const MFDataType &b);
+  friend bool operator!=(const MFDataType &a, const MFDataType &b);
+
+  std::string to_string() const
+  {
+    switch (m_category) {
+      case Single:
+        return m_type->name();
+      case Vector:
+        return m_type->name() + " Vector";
+    }
+    BLI_assert(false);
+    return "";
+  }
+};
+
+inline bool operator==(const MFDataType &a, const MFDataType &b)
+{
+  return a.m_category == b.m_category && a.m_type == b.m_type;
+}
+
+inline bool operator!=(const MFDataType &a, const MFDataType &b)
+{
+  return !(a == b);
+}
+
+}  // namespace fn
+}  // namespace blender
+
+#endif /* __FN_MULTI_FUNCTION_DATA_TYPE_HH__ */