From 44778bdf4196e153a1951117a33cd999a5387c82 Mon Sep 17 00:00:00 2001
From: Omar Emara <mail@OmarEmara.dev>
Date: Wed, 21 Feb 2024 13:23:04 +0100
Subject: [PATCH] Compositor: Unify Denoise node between CPU and GPU

The CPU compositor always adds a filter for normal and albedo even if
they don't contain any data, that is, when they are not connected to
anything, by inflating a buffer with the editor value, which is not even
accesible to the user. In anycase, such a solid color will not help do
anything in the denoise operation.

This patch aligns the implementation by only adding the abeldo and
normal filter if they contain actual data, speeding up the operation in
the process.

Pull Request: https://projects.blender.org/blender/blender/pulls/118553
---
 .../operations/COM_DenoiseOperation.cc        | 49 ++++++-------------
 1 file changed, 16 insertions(+), 33 deletions(-)

diff --git a/source/blender/compositor/operations/COM_DenoiseOperation.cc b/source/blender/compositor/operations/COM_DenoiseOperation.cc
index d6315e2dbf8..0c8b94c7612 100644
--- a/source/blender/compositor/operations/COM_DenoiseOperation.cc
+++ b/source/blender/compositor/operations/COM_DenoiseOperation.cc
@@ -114,6 +114,7 @@ class DenoiseFilter {
 DenoiseBaseOperation::DenoiseBaseOperation()
 {
   flags_.is_fullframe_operation = true;
+  flags_.can_be_constant = true;
   output_rendered_ = false;
 }
 
@@ -203,27 +204,23 @@ void DenoiseOperation::generate_denoise(MemoryBuffer *output,
                                         MemoryBuffer *input_albedo,
                                         const NodeDenoise *settings)
 {
-  BLI_assert(input_color->get_buffer());
-  if (!input_color->get_buffer()) {
+  if (input_color->is_a_single_elem()) {
+    output->fill(output->get_rect(), input_color->get_elem(0, 0));
     return;
   }
 
   BLI_assert(COM_is_denoise_supported());
-  /* OpenImageDenoise needs full buffers. */
-  MemoryBuffer *buf_color = input_color->is_a_single_elem() ? input_color->inflate() : input_color;
-  MemoryBuffer *buf_normal = input_normal && input_normal->is_a_single_elem() ?
-                                 input_normal->inflate() :
-                                 input_normal;
-  MemoryBuffer *buf_albedo = input_albedo && input_albedo->is_a_single_elem() ?
-                                 input_albedo->inflate() :
-                                 input_albedo;
 
   DenoiseFilter filter;
   filter.init_and_lock_denoiser(this, output);
 
-  filter.set_image("color", buf_color);
-  filter.set_image("normal", buf_normal);
-  filter.set_image("albedo", buf_albedo);
+  filter.set_image("color", input_color);
+  if (!input_albedo->is_a_single_elem()) {
+    filter.set_image("albedo", input_albedo);
+    if (!input_normal->is_a_single_elem()) {
+      filter.set_image("normal", input_normal);
+    }
+  }
 
   BLI_assert(settings);
   if (settings) {
@@ -237,17 +234,6 @@ void DenoiseOperation::generate_denoise(MemoryBuffer *output,
 
   /* Copy the alpha channel, OpenImageDenoise currently only supports RGB. */
   output->copy_from(input_color, input_color->get_rect(), 3, COM_DATA_TYPE_VALUE_CHANNELS, 3);
-
-  /* Delete inflated buffers. */
-  if (input_color->is_a_single_elem()) {
-    delete buf_color;
-  }
-  if (input_normal && input_normal->is_a_single_elem()) {
-    delete buf_normal;
-  }
-  if (input_albedo && input_albedo->is_a_single_elem()) {
-    delete buf_albedo;
-  }
 }
 
 void DenoiseOperation::update_memory_buffer(MemoryBuffer *output,
@@ -286,21 +272,18 @@ MemoryBuffer *DenoisePrefilterOperation::create_memory_buffer(rcti *rect2)
 
 void DenoisePrefilterOperation::generate_denoise(MemoryBuffer *output, MemoryBuffer *input)
 {
-  BLI_assert(COM_is_denoise_supported());
+  if (input->is_a_single_elem()) {
+    copy_v4_v4(output->get_elem(0, 0), input->get_elem(0, 0));
+    return;
+  }
 
-  /* Denoising needs full buffers. */
-  MemoryBuffer *input_buf = input->is_a_single_elem() ? input->inflate() : input;
+  BLI_assert(COM_is_denoise_supported());
 
   DenoiseFilter filter;
   filter.init_and_lock_denoiser(this, output);
-  filter.set_image(image_name_, input_buf);
+  filter.set_image(image_name_, input);
   filter.execute();
   filter.deinit_and_unlock_denoiser();
-
-  /* Delete inflated buffers. */
-  if (input->is_a_single_elem()) {
-    delete input_buf;
-  }
 }
 
 void DenoisePrefilterOperation::update_memory_buffer(MemoryBuffer *output,