Functions: add generic functions that output constants

source/blender/functions/CMakeLists.txt

@@ -30,6 +30,7 @@ set(SRC
   intern/attributes_ref.cc
   intern/cpp_types.cc
   intern/multi_function.cc
+  intern/multi_function_builder.cc
   intern/multi_function_network.cc
   intern/multi_function_network_evaluation.cc
 

source/blender/functions/FN_multi_function_builder.hh

@@ -225,6 +225,33 @@ template<typename T> class CustomMF_Constant : public MultiFunction {
   }
 };
 
+/**
+ * A multi-function that outputs the same value every time. The value is not owned by an instance
+ * of this function. The caller is responsible for destructing and freeing the value.
+ */
+class CustomMF_GenericConstant : public MultiFunction {
+ private:
+  const CPPType &type_;
+  const void *value_;
+
+ public:
+  CustomMF_GenericConstant(const CPPType &type, const void *value);
+  void call(IndexMask mask, MFParams params, MFContext context) const override;
+};
+
+/**
+ * A multi-function that outputs the same array every time. The array is not owned by in instance
+ * of this function. The caller is responsible for destructing and freeing the values.
+ */
+class CustomMF_GenericConstantArray : public MultiFunction {
+ private:
+  GSpan array_;
+
+ public:
+  CustomMF_GenericConstantArray(GSpan array);
+  void call(IndexMask mask, MFParams params, MFContext context) const override;
+};
+
 }  // namespace blender::fn
 
 #endif /* __FN_MULTI_FUNCTION_BUILDER_HH__ */

source/blender/functions/intern/multi_function_builder.cc

@@ -0,0 +1,71 @@
+/*
+ * 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 "FN_multi_function_builder.hh"
+
+namespace blender::fn {
+
+CustomMF_GenericConstant::CustomMF_GenericConstant(const CPPType &type, const void *value)
+    : type_(type), value_(value)
+{
+  MFSignatureBuilder signature = this->get_builder("Constant " + type.name());
+  std::stringstream ss;
+  type.debug_print(value, ss);
+  signature.single_output(ss.str(), type);
+}
+
+void CustomMF_GenericConstant::call(IndexMask mask,
+                                    MFParams params,
+                                    MFContext UNUSED(context)) const
+{
+  GMutableSpan output = params.uninitialized_single_output(0);
+  type_.fill_uninitialized_indices(value_, output.buffer(), mask);
+}
+
+static std::string gspan_to_string(GSpan array)
+{
+  std::stringstream ss;
+  ss << "[";
+  uint max_amount = 5;
+  for (uint i : IndexRange(std::min(max_amount, array.size()))) {
+    array.type().debug_print(array[i], ss);
+    ss << ", ";
+  }
+  if (max_amount < array.size()) {
+    ss << "...";
+  }
+  ss << "]";
+  return ss.str();
+}
+
+CustomMF_GenericConstantArray::CustomMF_GenericConstantArray(GSpan array) : array_(array)
+{
+  const CPPType &type = array.type();
+  MFSignatureBuilder signature = this->get_builder("Constant " + type.name() + " Vector");
+  signature.vector_output(gspan_to_string(array), type);
+}
+
+void CustomMF_GenericConstantArray::call(IndexMask mask,
+                                         MFParams params,
+                                         MFContext UNUSED(context)) const
+{
+  GVectorArray &vectors = params.vector_output(0);
+  for (uint i : mask) {
+    vectors.extend(i, array_);
+  }
+}
+
+}  // namespace blender::fn

tests/gtests/functions/FN_multi_function_test.cc

@@ -329,4 +329,53 @@ TEST(multi_function, CustomMF_Constant)
   EXPECT_EQ(outputs[3], 42);
 }
 
+TEST(multi_function, CustomMF_GenericConstant)
+{
+  int value = 42;
+  CustomMF_GenericConstant fn{CPPType_int32, (const void *)&value};
+  EXPECT_EQ(fn.param_name(0), "42");
+
+  Array<int> outputs(4, 0);
+
+  MFParamsBuilder params(fn, outputs.size());
+  params.add_uninitialized_single_output(outputs.as_mutable_span());
+
+  MFContextBuilder context;
+
+  fn.call({0, 1, 2}, params, context);
+
+  EXPECT_EQ(outputs[0], 42);
+  EXPECT_EQ(outputs[1], 42);
+  EXPECT_EQ(outputs[2], 42);
+  EXPECT_EQ(outputs[3], 0);
+}
+
+TEST(multi_function, CustomMF_GenericConstantArray)
+{
+  std::array<int, 4> values = {3, 4, 5, 6};
+  CustomMF_GenericConstantArray fn{GSpan(Span(values))};
+  EXPECT_EQ(fn.param_name(0), "[3, 4, 5, 6, ]");
+
+  GVectorArray g_vector_array{CPPType_int32, 4};
+  GVectorArrayRef<int> vector_array = g_vector_array;
+
+  MFParamsBuilder params(fn, g_vector_array.size());
+  params.add_vector_output(g_vector_array);
+
+  MFContextBuilder context;
+
+  fn.call({1, 2, 3}, params, context);
+
+  EXPECT_EQ(vector_array[0].size(), 0);
+  EXPECT_EQ(vector_array[1].size(), 4);
+  EXPECT_EQ(vector_array[2].size(), 4);
+  EXPECT_EQ(vector_array[3].size(), 4);
+  for (uint i = 1; i < 4; i++) {
+    EXPECT_EQ(vector_array[i][0], 3);
+    EXPECT_EQ(vector_array[i][1], 4);
+    EXPECT_EQ(vector_array[i][2], 5);
+    EXPECT_EQ(vector_array[i][3], 6);
+  }
+}
+
 }  // namespace blender::fn