1 files changed, 64 insertions, 0 deletions
diff --git a/source/blender/compositor/realtime_compositor/COM_simple_operation.hh b/source/blender/compositor/realtime_compositor/COM_simple_operation.hh
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index 00000000000..0061986ce42
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+++ b/source/blender/compositor/realtime_compositor/COM_simple_operation.hh
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+#include "BLI_string_ref.hh"
+
+#include "COM_operation.hh"
+#include "COM_result.hh"
+
+namespace blender::realtime_compositor {
+
+/* ------------------------------------------------------------------------------------------------
+ * Simple Operation
+ *
+ * A simple operation is an operation that takes exactly one input and computes exactly one output.
+ * Moreover, the output is guaranteed to only have a single user, that is, its reference count will
+ * be one. Such operations can be attached to the inputs of operations to pre-process the inputs to
+ * prepare them before the operation is executed. */
+class SimpleOperation : public Operation {
+ private:
+  /* The identifier of the output. This is constant for all operations. */
+  static const StringRef output_identifier_;
+  /* The identifier of the input. This is constant for all operations. */
+  static const StringRef input_identifier_;
+
+ public:
+  using Operation::Operation;
+
+  /* Get a reference to the output result of the operation, this essentially calls the super
+   * get_result method with the output identifier of the operation. */
+  Result &get_result();
+
+  /* Map the input of the operation to the given result, this essentially calls the super
+   * map_input_to_result method with the input identifier of the operation. */
+  void map_input_to_result(Result *result);
+
+ protected:
+  /* Simple operations don't need input processors, so override with an empty implementation. */
+  void add_and_evaluate_input_processors() override;
+
+  /* Get a reference to the input result of the operation, this essentially calls the super
+   * get_result method with the input identifier of the operation. */
+  Result &get_input();
+
+  /* Switch the result mapped to the input with the given result, this essentially calls the super
+   * switch_result_mapped_to_input method with the input identifier of the operation. */
+  void switch_result_mapped_to_input(Result *result);
+
+  /* Populate the result of the operation, this essentially calls the super populate_result method
+   * with the output identifier of the operation and sets the initial reference count of the result
+   * to 1, since the result of an operation is guaranteed to have a single user. */
+  void populate_result(Result result);
+
+  /* Declare the descriptor of the input of the operation to be the given descriptor, this
+   * essentially calls the super declare_input_descriptor method with the input identifier of the
+   * operation. */
+  void declare_input_descriptor(InputDescriptor descriptor);
+
+  /* Get a reference to the descriptor of the input, this essentially calls the super
+   * get_input_descriptor method with the input identifier of the operation. */
+  InputDescriptor &get_input_descriptor();
+};
+
+}  // namespace blender::realtime_compositor