Functions: initial hash/equals implementation for constant multi-functions

source/blender/functions/intern/multi_function_builder.cc

@@ -14,8 +14,12 @@
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
+#include "FN_cpp_types.hh"
 #include "FN_multi_function_builder.hh"
 
+#include "BLI_float3.hh"
+#include "BLI_hash.hh"
+
 namespace blender::fn {
 
 CustomMF_GenericConstant::CustomMF_GenericConstant(const CPPType &type, const void *value)
@@ -35,6 +39,47 @@ void CustomMF_GenericConstant::call(IndexMask mask,
   type_.fill_uninitialized_indices(value_, output.buffer(), mask);
 }
 
+uint CustomMF_GenericConstant::hash() const
+{
+  if (type_ == CPPType_float3) {
+    return DefaultHash<float3>{}(*(float3 *)value_);
+  }
+  if (type_ == CPPType_int32) {
+    return DefaultHash<int32_t>{}(*(int32_t *)value_);
+  }
+  if (type_ == CPPType_float) {
+    return DefaultHash<float>{}(*(float *)value_);
+  }
+  return MultiFunction::hash();
+}
+
+/* This should be moved into CPPType. */
+bool generic_values_are_equal(const CPPType &type, const void *a, const void *b)
+{
+  if (type == CPPType_float3) {
+    return *(float3 *)a == *(float3 *)b;
+  }
+  if (type == CPPType_int32) {
+    return *(int *)a == *(int *)b;
+  }
+  if (type == CPPType_float) {
+    return *(float *)a == *(float *)b;
+  }
+  return false;
+}
+
+bool CustomMF_GenericConstant::equals(const MultiFunction &other) const
+{
+  const CustomMF_GenericConstant *_other = dynamic_cast<const CustomMF_GenericConstant *>(&other);
+  if (_other == nullptr) {
+    return false;
+  }
+  if (type_ != _other->type_) {
+    return false;
+  }
+  return generic_values_are_equal(type_, value_, _other->value_);
+}
+
 static std::string gspan_to_string(GSpan array)
 {
   std::stringstream ss;