Compositor: Refactor recursive methods to iterative

In order to reduce stack size this patch converts full frame 
recursive methods into iterative.
- No functional changes.
- No performance changes.
- Memory peak may slightly vary depending on the tree because
 now breadth-first traversal is used instead of depth-first.

Tests in D11113 have same results except for test1 memory peak:
360MBs instead of 329.50MBs.

Reviewed By: Jeroen Bakker (jbakker)

Differential Revision: https://developer.blender.org/D11515

1 files changed, 3 insertions, 4 deletions

diff --git a/source/blender/compositor/intern/COM_FullFrameExecutionModel.h b/source/blender/compositor/intern/COM_FullFrameExecutionModel.h
index 2c0d5e0460a..e68ad93b407 100644
--- a/source/blender/compositor/intern/COM_FullFrameExecutionModel.h
+++ b/source/blender/compositor/intern/COM_FullFrameExecutionModel.h
@@ -67,8 +67,7 @@ class FullFrameExecutionModel : public ExecutionModel {
  private:
   void determine_areas_to_render_and_reads();
   void render_operations(ExecutionSystem &exec_system);
-
-  void ensure_inputs_rendered(NodeOperation *op, ExecutionSystem &exec_system);
+  void render_output_dependencies(NodeOperation *output_op, ExecutionSystem &exec_system);
   Vector<MemoryBuffer *> get_input_buffers(NodeOperation *op);
   MemoryBuffer *create_operation_buffer(NodeOperation *op);
   void render_operation(NodeOperation *op, ExecutionSystem &exec_system);
@@ -76,8 +75,8 @@ class FullFrameExecutionModel : public ExecutionModel {
   void operation_finished(NodeOperation *operation);
 
   void get_output_render_area(NodeOperation *output_op, rcti &r_area);
-  void determine_areas_to_render(NodeOperation *operation, const rcti &render_area);
-  void determine_reads(NodeOperation *operation);
+  void determine_areas_to_render(NodeOperation *output_op, const rcti &output_area);
+  void determine_reads(NodeOperation *output_op);
 
   void update_progress_bar();