From 05576e067b3c72382fa5bffc38cbe15b2644138f Mon Sep 17 00:00:00 2001
From: "georgiy.m.markelov@gmail.com" <georgiy.m.markelov@gmail.com>
Date: Tue, 4 Apr 2023 13:40:16 +0300
Subject: [PATCH 1/9] BLEN-365: Improve creation algorithm of PreviewEngine

---
 scripts/modules/bpy_hydra.py                  | 15 ++++----
 source/blender/render/hydra/engine.cc         |  6 +++
 source/blender/render/hydra/engine.h          |  4 +-
 source/blender/render/hydra/final_engine.cc   |  4 --
 source/blender/render/hydra/preview_engine.cc | 34 +++++++++++++++--
 source/blender/render/hydra/preview_engine.h  |  3 ++
 source/blender/render/hydra/python.cc         | 37 +++++++++++++++++--
 .../render/hydra/render_task_delegate.cc      |  9 +++++
 .../render/hydra/render_task_delegate.h       |  1 +
 .../scene_delegate/blender_scene_delegate.cc  |  6 +++
 .../scene_delegate/blender_scene_delegate.h   |  1 +
 .../blender/render/hydra/viewport_engine.cc   |  6 ---
 12 files changed, 99 insertions(+), 27 deletions(-)

diff --git a/scripts/modules/bpy_hydra.py b/scripts/modules/bpy_hydra.py
index 6b2b0a3e5cd8..b0f1323419b6 100644
--- a/scripts/modules/bpy_hydra.py
+++ b/scripts/modules/bpy_hydra.py
@@ -19,7 +19,7 @@ class CustomHydraRenderEngine(HydraRenderEngine):
     def register(cls):
         super().register()
 
-        bpy_hydra.register_plugins(["/path/to/plugin")], ["/additional/system/path")])
+        bpy_hydra.register_plugins(["/path/to/plugin")])
 
     def get_delegate_settings(self, engine_type):
         return {
@@ -58,6 +58,7 @@ class HydraRenderEngine(bpy.types.RenderEngine):
             return
 
         _bpy_hydra.engine_free(self.engine_ptr)
+        del self.engine_ptr
 
     @classmethod
     def register(cls):
@@ -74,20 +75,18 @@ class HydraRenderEngine(bpy.types.RenderEngine):
 
     # final render
     def update(self, data, depsgraph):
-        pass
-
-    def render(self, depsgraph):
         engine_type = 'PREVIEW' if self.is_preview else 'FINAL'
-
         self.engine_ptr = _bpy_hydra.engine_create(self.as_pointer(), engine_type, self.delegate_id)
         delegate_settings = self.get_delegate_settings(engine_type)
-
         _bpy_hydra.engine_sync(self.engine_ptr, depsgraph.as_pointer(), bpy.context.as_pointer(), delegate_settings)
-        _bpy_hydra.engine_render(self.engine_ptr, depsgraph.as_pointer())
+
+    def render(self, depsgraph):
+        if hasattr(self, 'engine_ptr'):
+            _bpy_hydra.engine_render(self.engine_ptr, depsgraph.as_pointer())
 
     # viewport render
     def view_update(self, context, depsgraph):
-        if not self.engine_ptr:
+        if not hasattr(self, 'engine_ptr'):
             self.engine_ptr = _bpy_hydra.engine_create(self.as_pointer(), 'VIEWPORT', self.delegate_id)
 
         delegate_settings = self.get_delegate_settings('VIEWPORT')
diff --git a/source/blender/render/hydra/engine.cc b/source/blender/render/hydra/engine.cc
index 6452e1ddf866..178909069298 100644
--- a/source/blender/render/hydra/engine.cc
+++ b/source/blender/render/hydra/engine.cc
@@ -42,6 +42,11 @@ Engine::Engine(RenderEngine *bl_engine, const std::string &delegate_id) : bl_eng
   }
 
   engine = std::make_unique<pxr::HdEngine>();
+
+  scene_delegate = std::make_unique<BlenderSceneDelegate>(
+    render_index.get(),
+    pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"),
+    BlenderSceneDelegate::EngineType::PREVIEW);
 }
 
 Engine::~Engine()
@@ -54,6 +59,7 @@ Engine::~Engine()
   render_delegate = nullptr;
   engine = nullptr;
   hgi = nullptr;
+  bl_engine = nullptr;
 }
 
 float Engine::renderer_percent_done()
diff --git a/source/blender/render/hydra/engine.h b/source/blender/render/hydra/engine.h
index 3e6a5ad95056..6cd546bf5424 100644
--- a/source/blender/render/hydra/engine.h
+++ b/source/blender/render/hydra/engine.h
@@ -34,12 +34,12 @@ class Engine {
                     bContext *context,
                     pxr::HdRenderSettingsMap &render_settings) = 0;
   virtual void render(Depsgraph *depsgraph) = 0;
-
+  RenderEngine *bl_engine;
  protected:
   float renderer_percent_done();
 
  protected:
-  RenderEngine *bl_engine;
+  
 
   pxr::HdPluginRenderDelegateUniqueHandle render_delegate;
   std::unique_ptr<pxr::HdRenderIndex> render_index;
diff --git a/source/blender/render/hydra/final_engine.cc b/source/blender/render/hydra/final_engine.cc
index 4052b81fe26e..c0a109d7e137 100644
--- a/source/blender/render/hydra/final_engine.cc
+++ b/source/blender/render/hydra/final_engine.cc
@@ -16,10 +16,6 @@ void FinalEngine::sync(Depsgraph *depsgraph,
                        bContext *context,
                        pxr::HdRenderSettingsMap &render_settings)
 {
-  scene_delegate = std::make_unique<BlenderSceneDelegate>(
-      render_index.get(),
-      pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"),
-      BlenderSceneDelegate::EngineType::FINAL);
   scene_delegate->populate(depsgraph, context);
 
   for (auto const &setting : render_settings) {
diff --git a/source/blender/render/hydra/preview_engine.cc b/source/blender/render/hydra/preview_engine.cc
index d135da4ce785..7970067000ce 100644
--- a/source/blender/render/hydra/preview_engine.cc
+++ b/source/blender/render/hydra/preview_engine.cc
@@ -12,19 +12,37 @@ void PreviewEngine::sync(Depsgraph *depsgraph,
                          bContext *context,
                          pxr::HdRenderSettingsMap &render_settings)
 {
-  scene_delegate = std::make_unique<BlenderSceneDelegate>(
-      render_index.get(),
-      pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"),
-      BlenderSceneDelegate::EngineType::PREVIEW);
+  is_synced = false;
+
+  scene_delegate->clear_data();
+  for (auto &prim : render_index->GetRprimIds()) {
+    render_index->RemoveRprim(prim);
+    render_index->RemoveInstancer(prim);
+    std::cout << "sync RemoveRprim: " << prim.GetText() << " " << render_index->HasRprim(prim)
+              << "\n";
+  }
+
+  for (auto &prim : render_index->GetRprimIds()) {
+    std::cout << "sync after Remove: " << prim.GetText() << "\n";
+  }
+
   scene_delegate->populate(depsgraph, context);
 
+  for (auto &prim : render_index->GetRprimIds()) {
+    std::cout << "sync populate: " << prim.GetText() << "\n";
+  }
+
   for (auto const &setting : render_settings) {
     render_delegate->SetRenderSetting(setting.first, setting.second);
   }
+  is_synced = true;
 }
 
 void PreviewEngine::render(Depsgraph *depsgraph)
 {
+  //if (!is_synced) {
+  //  return;
+  //}
   Scene *scene = DEG_get_input_scene(depsgraph);
   ViewLayer *view_layer = DEG_get_input_view_layer(depsgraph);
 
@@ -35,6 +53,7 @@ void PreviewEngine::render(Depsgraph *depsgraph)
       CameraData(scene->camera, res, pxr::GfVec4f(0, 0, 1, 1)).gf_camera(pxr::GfVec4f(0, 0, 1, 1));
 
   free_camera_delegate->SetCamera(camera);
+  //render_task_delegate->clear_renderer_aovs();
   render_task_delegate->set_camera_and_viewport(free_camera_delegate->GetCameraId(),
                                                 pxr::GfVec4d(0, 0, res[0], res[1]));
   render_task_delegate->set_renderer_aov(pxr::HdAovTokens->color);
@@ -70,6 +89,13 @@ void PreviewEngine::render(Depsgraph *depsgraph)
   update_render_result(layer_name, res[0], res[1], pixels);
 }
 
+void PreviewEngine::stop_renderer()
+{
+  if (render_delegate) {
+    render_delegate->Stop();
+  }
+}
+
 void PreviewEngine::update_render_result(const std::string &layer_name,
                                          int width,
                                          int height,
diff --git a/source/blender/render/hydra/preview_engine.h b/source/blender/render/hydra/preview_engine.h
index a0b38b1d0653..fa5e9a24109a 100644
--- a/source/blender/render/hydra/preview_engine.h
+++ b/source/blender/render/hydra/preview_engine.h
@@ -14,6 +14,9 @@ class PreviewEngine : public FinalEngine {
             bContext *context,
             pxr::HdRenderSettingsMap &render_settings) override;
   void render(Depsgraph *depsgraph) override;
+  void stop_renderer();
+
+  bool is_synced = false;
 
  protected:
   void update_render_result(const std::string &layer_name,
diff --git a/source/blender/render/hydra/python.cc b/source/blender/render/hydra/python.cc
index 9401a76a8f91..64eeec3b150d 100644
--- a/source/blender/render/hydra/python.cc
+++ b/source/blender/render/hydra/python.cc
@@ -16,8 +16,25 @@
 #include "utils.h"
 #include "viewport_engine.h"
 
+#include "BLI_timer.h"
+
 namespace blender::render::hydra {
 
+static double preview_engine_lifetime = 60.0;
+static PreviewEngine *preview_engine;
+
+double timer_func(uintptr_t uuid, void *user_data)
+{
+  if (preview_engine) {
+    preview_engine->stop_renderer();
+    delete preview_engine;
+    preview_engine = nullptr;
+    return -1;
+  }
+
+  return preview_engine_lifetime;
+}
+
 static PyObject *init_func(PyObject * /*self*/, PyObject *args)
 {
   CLOG_INFO(LOG_EN, 1, "Init");
@@ -106,14 +123,22 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
   }
 
   RenderEngine *bl_engine = (RenderEngine *)PyLong_AsVoidPtr(pyengine);
-  
 
   Engine *engine;
   if (STREQ(engine_type, "VIEWPORT")) {
     engine = new ViewportEngine(bl_engine, render_delegate_id);
   }
   else if (STREQ(engine_type, "PREVIEW")) {
-    engine = new PreviewEngine(bl_engine, render_delegate_id);
+    if (!preview_engine) {
+      preview_engine = new PreviewEngine(bl_engine, render_delegate_id);
+    }
+    if (BLI_timer_is_registered(1)) {
+      BLI_timer_unregister(1);
+    }
+    preview_engine->bl_engine = bl_engine;
+
+    CLOG_INFO(LOG_EN, 2, "Engine %016llx %s", engine, engine_type);
+    return PyLong_FromVoidPtr(preview_engine);
   }
   else {
     if (bl_engine->type->flag & RE_USE_GPU_CONTEXT) {
@@ -136,7 +161,13 @@ static PyObject *engine_free_func(PyObject * /*self*/, PyObject *args)
     Py_RETURN_NONE;
   }
 
-  Engine *engine = (Engine *) PyLong_AsVoidPtr(pyengine);
+  Engine *engine = (Engine *)PyLong_AsVoidPtr(pyengine);
+
+  if (preview_engine) {
+    BLI_timer_register(1, timer_func, nullptr, nullptr, preview_engine_lifetime, true);
+    Py_RETURN_NONE;
+  }
+
   delete engine;
 
   CLOG_INFO(LOG_EN, 2, "Engine %016llx", engine);
diff --git a/source/blender/render/hydra/render_task_delegate.cc b/source/blender/render/hydra/render_task_delegate.cc
index 250b86619da8..a853992ac6fd 100644
--- a/source/blender/render/hydra/render_task_delegate.cc
+++ b/source/blender/render/hydra/render_task_delegate.cc
@@ -132,4 +132,13 @@ void RenderTaskDelegate::set_camera_and_viewport(pxr::SdfPath const &camera_id,
   }
 }
 
+void RenderTaskDelegate::clear_renderer_aovs()
+{
+  for (pxr::HdRenderPassAovBinding &binding : task_params.aovBindings) {
+    std::cout << "clear_renderer_aovs: " << binding.renderBufferId.GetText() << "\n";
+    GetRenderIndex().RemoveBprim(pxr::HdPrimTypeTokens->renderBuffer, binding.renderBufferId);
+    buffer_descriptors.erase(binding.renderBufferId);
+  }
+}
+
 }  // namespace blender::render::hydra
diff --git a/source/blender/render/hydra/render_task_delegate.h b/source/blender/render/hydra/render_task_delegate.h
index f7119fc83e2a..8c50072c06e9 100644
--- a/source/blender/render/hydra/render_task_delegate.h
+++ b/source/blender/render/hydra/render_task_delegate.h
@@ -27,6 +27,7 @@ class RenderTaskDelegate : public pxr::HdSceneDelegate {
 
   pxr::HdTaskSharedPtr get_task();
   void set_camera_and_viewport(pxr::SdfPath const &cameraId, pxr::GfVec4d const &viewport);
+  void clear_renderer_aovs();
 
  private:
   pxr::HdxRenderTaskParams task_params;
diff --git a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
index de574193c48e..6b310a10a8b8 100644
--- a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
+++ b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
@@ -477,4 +477,10 @@ pxr::VtValue BlenderSceneDelegate::GetLightParamValue(pxr::SdfPath const &id,
   return pxr::VtValue();
 }
 
+void BlenderSceneDelegate::clear_data()
+{
+  objects.clear();
+  materials.clear();
+}
+
 }  // namespace blender::render::hydra
diff --git a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.h b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.h
index cf03fd74f0c7..0bab7c6e9ddf 100644
--- a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.h
+++ b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.h
@@ -29,6 +29,7 @@ class BlenderSceneDelegate : public pxr::HdSceneDelegate {
   ~BlenderSceneDelegate() override = default;
 
   void populate(Depsgraph *depsgraph, bContext *context);
+  void clear_data();
 
   // delegate methods
   pxr::HdMeshTopology GetMeshTopology(pxr::SdfPath const &id) override;
diff --git a/source/blender/render/hydra/viewport_engine.cc b/source/blender/render/hydra/viewport_engine.cc
index 94f8ab8dad24..b9f7496cb46f 100644
--- a/source/blender/render/hydra/viewport_engine.cc
+++ b/source/blender/render/hydra/viewport_engine.cc
@@ -244,12 +244,6 @@ void ViewportEngine::sync(Depsgraph *depsgraph,
                           bContext *context,
                           pxr::HdRenderSettingsMap &render_settings)
 {
-  if (!scene_delegate) {
-    scene_delegate = std::make_unique<BlenderSceneDelegate>(
-        render_index.get(),
-        pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"),
-        BlenderSceneDelegate::EngineType::VIEWPORT);
-  }
   scene_delegate->populate(depsgraph, context);
 
   for (auto const &setting : render_settings) {
-- 
2.30.2


From cca11e5b171a2a5b7005655742ca1c6a7e1fb7d8 Mon Sep 17 00:00:00 2001
From: "georgiy.m.markelov@gmail.com" <georgiy.m.markelov@gmail.com>
Date: Tue, 4 Apr 2023 13:49:46 +0300
Subject: [PATCH 2/9] clean up code

---
 source/blender/render/hydra/engine.h          |  5 +++--
 source/blender/render/hydra/preview_engine.cc | 18 +-----------------
 source/blender/render/hydra/preview_engine.h  |  2 --
 source/blender/render/hydra/python.cc         |  5 +++--
 4 files changed, 7 insertions(+), 23 deletions(-)

diff --git a/source/blender/render/hydra/engine.h b/source/blender/render/hydra/engine.h
index 6cd546bf5424..7fd868b5efb9 100644
--- a/source/blender/render/hydra/engine.h
+++ b/source/blender/render/hydra/engine.h
@@ -34,13 +34,14 @@ class Engine {
                     bContext *context,
                     pxr::HdRenderSettingsMap &render_settings) = 0;
   virtual void render(Depsgraph *depsgraph) = 0;
+
+ public:
   RenderEngine *bl_engine;
+
  protected:
   float renderer_percent_done();
 
  protected:
-  
-
   pxr::HdPluginRenderDelegateUniqueHandle render_delegate;
   std::unique_ptr<pxr::HdRenderIndex> render_index;
   std::unique_ptr<BlenderSceneDelegate> scene_delegate;
diff --git a/source/blender/render/hydra/preview_engine.cc b/source/blender/render/hydra/preview_engine.cc
index 7970067000ce..4a791af817b0 100644
--- a/source/blender/render/hydra/preview_engine.cc
+++ b/source/blender/render/hydra/preview_engine.cc
@@ -12,37 +12,22 @@ void PreviewEngine::sync(Depsgraph *depsgraph,
                          bContext *context,
                          pxr::HdRenderSettingsMap &render_settings)
 {
-  is_synced = false;
-
   scene_delegate->clear_data();
+
   for (auto &prim : render_index->GetRprimIds()) {
     render_index->RemoveRprim(prim);
     render_index->RemoveInstancer(prim);
-    std::cout << "sync RemoveRprim: " << prim.GetText() << " " << render_index->HasRprim(prim)
-              << "\n";
-  }
-
-  for (auto &prim : render_index->GetRprimIds()) {
-    std::cout << "sync after Remove: " << prim.GetText() << "\n";
   }
 
   scene_delegate->populate(depsgraph, context);
 
-  for (auto &prim : render_index->GetRprimIds()) {
-    std::cout << "sync populate: " << prim.GetText() << "\n";
-  }
-
   for (auto const &setting : render_settings) {
     render_delegate->SetRenderSetting(setting.first, setting.second);
   }
-  is_synced = true;
 }
 
 void PreviewEngine::render(Depsgraph *depsgraph)
 {
-  //if (!is_synced) {
-  //  return;
-  //}
   Scene *scene = DEG_get_input_scene(depsgraph);
   ViewLayer *view_layer = DEG_get_input_view_layer(depsgraph);
 
@@ -53,7 +38,6 @@ void PreviewEngine::render(Depsgraph *depsgraph)
       CameraData(scene->camera, res, pxr::GfVec4f(0, 0, 1, 1)).gf_camera(pxr::GfVec4f(0, 0, 1, 1));
 
   free_camera_delegate->SetCamera(camera);
-  //render_task_delegate->clear_renderer_aovs();
   render_task_delegate->set_camera_and_viewport(free_camera_delegate->GetCameraId(),
                                                 pxr::GfVec4d(0, 0, res[0], res[1]));
   render_task_delegate->set_renderer_aov(pxr::HdAovTokens->color);
diff --git a/source/blender/render/hydra/preview_engine.h b/source/blender/render/hydra/preview_engine.h
index fa5e9a24109a..52f2877f890f 100644
--- a/source/blender/render/hydra/preview_engine.h
+++ b/source/blender/render/hydra/preview_engine.h
@@ -16,8 +16,6 @@ class PreviewEngine : public FinalEngine {
   void render(Depsgraph *depsgraph) override;
   void stop_renderer();
 
-  bool is_synced = false;
-
  protected:
   void update_render_result(const std::string &layer_name,
                             int width,
diff --git a/source/blender/render/hydra/python.cc b/source/blender/render/hydra/python.cc
index 64eeec3b150d..1a6fb7027202 100644
--- a/source/blender/render/hydra/python.cc
+++ b/source/blender/render/hydra/python.cc
@@ -23,7 +23,7 @@ namespace blender::render::hydra {
 static double preview_engine_lifetime = 60.0;
 static PreviewEngine *preview_engine;
 
-double timer_func(uintptr_t uuid, void *user_data)
+double delete_preview_engine(uintptr_t uuid, void *user_data)
 {
   if (preview_engine) {
     preview_engine->stop_renderer();
@@ -164,7 +164,8 @@ static PyObject *engine_free_func(PyObject * /*self*/, PyObject *args)
   Engine *engine = (Engine *)PyLong_AsVoidPtr(pyengine);
 
   if (preview_engine) {
-    BLI_timer_register(1, timer_func, nullptr, nullptr, preview_engine_lifetime, true);
+    BLI_timer_register(1, delete_preview_engine, nullptr, nullptr, preview_engine_lifetime, true);
+    CLOG_INFO(LOG_EN, 2, "Engine %016llx", engine);
     Py_RETURN_NONE;
   }
 
-- 
2.30.2


From a1bf008904e803d183fa80210062c9b85c21cd5f Mon Sep 17 00:00:00 2001
From: "georgiy.m.markelov@gmail.com" <georgiy.m.markelov@gmail.com>
Date: Tue, 4 Apr 2023 13:59:57 +0300
Subject: [PATCH 3/9] clean up code

---
 scripts/modules/bpy_hydra.py                        | 4 ++--
 source/blender/render/hydra/render_task_delegate.cc | 9 ---------
 source/blender/render/hydra/render_task_delegate.h  | 1 -
 3 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/scripts/modules/bpy_hydra.py b/scripts/modules/bpy_hydra.py
index b0f1323419b6..061692873def 100644
--- a/scripts/modules/bpy_hydra.py
+++ b/scripts/modules/bpy_hydra.py
@@ -81,12 +81,12 @@ class HydraRenderEngine(bpy.types.RenderEngine):
         _bpy_hydra.engine_sync(self.engine_ptr, depsgraph.as_pointer(), bpy.context.as_pointer(), delegate_settings)
 
     def render(self, depsgraph):
-        if hasattr(self, 'engine_ptr'):
+        if self.engine_ptr:
             _bpy_hydra.engine_render(self.engine_ptr, depsgraph.as_pointer())
 
     # viewport render
     def view_update(self, context, depsgraph):
-        if not hasattr(self, 'engine_ptr'):
+        if not self.engine_ptr:
             self.engine_ptr = _bpy_hydra.engine_create(self.as_pointer(), 'VIEWPORT', self.delegate_id)
 
         delegate_settings = self.get_delegate_settings('VIEWPORT')
diff --git a/source/blender/render/hydra/render_task_delegate.cc b/source/blender/render/hydra/render_task_delegate.cc
index a853992ac6fd..250b86619da8 100644
--- a/source/blender/render/hydra/render_task_delegate.cc
+++ b/source/blender/render/hydra/render_task_delegate.cc
@@ -132,13 +132,4 @@ void RenderTaskDelegate::set_camera_and_viewport(pxr::SdfPath const &camera_id,
   }
 }
 
-void RenderTaskDelegate::clear_renderer_aovs()
-{
-  for (pxr::HdRenderPassAovBinding &binding : task_params.aovBindings) {
-    std::cout << "clear_renderer_aovs: " << binding.renderBufferId.GetText() << "\n";
-    GetRenderIndex().RemoveBprim(pxr::HdPrimTypeTokens->renderBuffer, binding.renderBufferId);
-    buffer_descriptors.erase(binding.renderBufferId);
-  }
-}
-
 }  // namespace blender::render::hydra
diff --git a/source/blender/render/hydra/render_task_delegate.h b/source/blender/render/hydra/render_task_delegate.h
index 8c50072c06e9..f7119fc83e2a 100644
--- a/source/blender/render/hydra/render_task_delegate.h
+++ b/source/blender/render/hydra/render_task_delegate.h
@@ -27,7 +27,6 @@ class RenderTaskDelegate : public pxr::HdSceneDelegate {
 
   pxr::HdTaskSharedPtr get_task();
   void set_camera_and_viewport(pxr::SdfPath const &cameraId, pxr::GfVec4d const &viewport);
-  void clear_renderer_aovs();
 
  private:
   pxr::HdxRenderTaskParams task_params;
-- 
2.30.2


From d33f8ef37dbe0a41c0b3db27dd45c65a8744c6ff Mon Sep 17 00:00:00 2001
From: "georgiy.m.markelov@gmail.com" <georgiy.m.markelov@gmail.com>
Date: Thu, 6 Apr 2023 16:52:45 +0300
Subject: [PATCH 4/9] fix review comments

---
 source/blender/render/hydra/engine.cc         | 10 +++----
 source/blender/render/hydra/engine.h          |  6 ++--
 source/blender/render/hydra/final_engine.cc   |  4 +++
 source/blender/render/hydra/preview_engine.cc | 28 +++++++++++++------
 source/blender/render/hydra/preview_engine.h  |  6 +++-
 source/blender/render/hydra/python.cc         | 28 +++++++------------
 .../scene_delegate/blender_scene_delegate.cc  | 12 ++++++--
 .../scene_delegate/blender_scene_delegate.h   |  2 +-
 .../render/hydra/scene_delegate/material.cc   |  2 +-
 .../render/hydra/scene_delegate/mesh.cc       |  2 +-
 .../blender/render/hydra/viewport_engine.cc   |  6 ++++
 11 files changed, 65 insertions(+), 41 deletions(-)

diff --git a/source/blender/render/hydra/engine.cc b/source/blender/render/hydra/engine.cc
index 178909069298..8dfc656ce18f 100644
--- a/source/blender/render/hydra/engine.cc
+++ b/source/blender/render/hydra/engine.cc
@@ -42,11 +42,6 @@ Engine::Engine(RenderEngine *bl_engine, const std::string &delegate_id) : bl_eng
   }
 
   engine = std::make_unique<pxr::HdEngine>();
-
-  scene_delegate = std::make_unique<BlenderSceneDelegate>(
-    render_index.get(),
-    pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"),
-    BlenderSceneDelegate::EngineType::PREVIEW);
 }
 
 Engine::~Engine()
@@ -62,6 +57,11 @@ Engine::~Engine()
   bl_engine = nullptr;
 }
 
+bool Engine::is_converged()
+{
+  return render_task_delegate->is_converged();
+}
+
 float Engine::renderer_percent_done()
 {
   pxr::VtDictionary render_stats = render_delegate->GetRenderStats();
diff --git a/source/blender/render/hydra/engine.h b/source/blender/render/hydra/engine.h
index 7fd868b5efb9..5391448e96c3 100644
--- a/source/blender/render/hydra/engine.h
+++ b/source/blender/render/hydra/engine.h
@@ -34,14 +34,14 @@ class Engine {
                     bContext *context,
                     pxr::HdRenderSettingsMap &render_settings) = 0;
   virtual void render(Depsgraph *depsgraph) = 0;
-
- public:
-  RenderEngine *bl_engine;
+  bool is_converged();
 
  protected:
   float renderer_percent_done();
 
  protected:
+  RenderEngine *bl_engine;
+
   pxr::HdPluginRenderDelegateUniqueHandle render_delegate;
   std::unique_ptr<pxr::HdRenderIndex> render_index;
   std::unique_ptr<BlenderSceneDelegate> scene_delegate;
diff --git a/source/blender/render/hydra/final_engine.cc b/source/blender/render/hydra/final_engine.cc
index c0a109d7e137..4052b81fe26e 100644
--- a/source/blender/render/hydra/final_engine.cc
+++ b/source/blender/render/hydra/final_engine.cc
@@ -16,6 +16,10 @@ void FinalEngine::sync(Depsgraph *depsgraph,
                        bContext *context,
                        pxr::HdRenderSettingsMap &render_settings)
 {
+  scene_delegate = std::make_unique<BlenderSceneDelegate>(
+      render_index.get(),
+      pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"),
+      BlenderSceneDelegate::EngineType::FINAL);
   scene_delegate->populate(depsgraph, context);
 
   for (auto const &setting : render_settings) {
diff --git a/source/blender/render/hydra/preview_engine.cc b/source/blender/render/hydra/preview_engine.cc
index 4a791af817b0..77ff6dc8a997 100644
--- a/source/blender/render/hydra/preview_engine.cc
+++ b/source/blender/render/hydra/preview_engine.cc
@@ -12,13 +12,13 @@ void PreviewEngine::sync(Depsgraph *depsgraph,
                          bContext *context,
                          pxr::HdRenderSettingsMap &render_settings)
 {
-  scene_delegate->clear_data();
-
-  for (auto &prim : render_index->GetRprimIds()) {
-    render_index->RemoveRprim(prim);
-    render_index->RemoveInstancer(prim);
+  if (!scene_delegate) {
+    scene_delegate = std::make_unique<BlenderSceneDelegate>(
+        render_index.get(),
+        pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"),
+        BlenderSceneDelegate::EngineType::PREVIEW);
   }
-
+  scene_delegate->clear();
   scene_delegate->populate(depsgraph, context);
 
   for (auto const &setting : render_settings) {
@@ -73,11 +73,21 @@ void PreviewEngine::render(Depsgraph *depsgraph)
   update_render_result(layer_name, res[0], res[1], pixels);
 }
 
-void PreviewEngine::stop_renderer()
+void PreviewEngine::update_bl_engine(RenderEngine *bl_engine)
 {
-  if (render_delegate) {
-    render_delegate->Stop();
+  this->bl_engine = bl_engine;
+}
+
+double PreviewEngine::delete_preview_engine(uintptr_t uuid, void *user_data)
+{
+  std::unique_ptr<PreviewEngine> *preview_engine = static_cast<std::unique_ptr<PreviewEngine>*>(user_data);
+  if (preview_engine && preview_engine->get()->is_converged()) {
+    CLOG_INFO(LOG_EN, 1, "Delete preview engine");
+    preview_engine->reset();
+    return -1;
   }
+
+  return preview_engine_lifetime;
 }
 
 void PreviewEngine::update_render_result(const std::string &layer_name,
diff --git a/source/blender/render/hydra/preview_engine.h b/source/blender/render/hydra/preview_engine.h
index 52f2877f890f..1dffc0c07aaa 100644
--- a/source/blender/render/hydra/preview_engine.h
+++ b/source/blender/render/hydra/preview_engine.h
@@ -14,7 +14,8 @@ class PreviewEngine : public FinalEngine {
             bContext *context,
             pxr::HdRenderSettingsMap &render_settings) override;
   void render(Depsgraph *depsgraph) override;
-  void stop_renderer();
+  void update_bl_engine(RenderEngine *bl_engine);
+  static double delete_preview_engine(uintptr_t uuid, void *user_data);
 
  protected:
   void update_render_result(const std::string &layer_name,
@@ -22,6 +23,9 @@ class PreviewEngine : public FinalEngine {
                             int height,
                             std::vector<float> &pixels);
 
+ public:
+  static inline double preview_engine_lifetime = 180.0;
+
  protected:
   pxr::HdRenderSettingsMap render_settings;
 };
diff --git a/source/blender/render/hydra/python.cc b/source/blender/render/hydra/python.cc
index 1a6fb7027202..c6e43e964b21 100644
--- a/source/blender/render/hydra/python.cc
+++ b/source/blender/render/hydra/python.cc
@@ -20,20 +20,7 @@
 
 namespace blender::render::hydra {
 
-static double preview_engine_lifetime = 60.0;
-static PreviewEngine *preview_engine;
-
-double delete_preview_engine(uintptr_t uuid, void *user_data)
-{
-  if (preview_engine) {
-    preview_engine->stop_renderer();
-    delete preview_engine;
-    preview_engine = nullptr;
-    return -1;
-  }
-
-  return preview_engine_lifetime;
-}
+static std::unique_ptr<PreviewEngine> preview_engine;
 
 static PyObject *init_func(PyObject * /*self*/, PyObject *args)
 {
@@ -130,15 +117,15 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
   }
   else if (STREQ(engine_type, "PREVIEW")) {
     if (!preview_engine) {
-      preview_engine = new PreviewEngine(bl_engine, render_delegate_id);
+      preview_engine = std::make_unique<PreviewEngine>(bl_engine, render_delegate_id);
     }
     if (BLI_timer_is_registered(1)) {
       BLI_timer_unregister(1);
     }
-    preview_engine->bl_engine = bl_engine;
+    preview_engine->update_bl_engine(bl_engine);
 
     CLOG_INFO(LOG_EN, 2, "Engine %016llx %s", engine, engine_type);
-    return PyLong_FromVoidPtr(preview_engine);
+    return PyLong_FromVoidPtr(preview_engine.get());
   }
   else {
     if (bl_engine->type->flag & RE_USE_GPU_CONTEXT) {
@@ -164,7 +151,12 @@ static PyObject *engine_free_func(PyObject * /*self*/, PyObject *args)
   Engine *engine = (Engine *)PyLong_AsVoidPtr(pyengine);
 
   if (preview_engine) {
-    BLI_timer_register(1, delete_preview_engine, nullptr, nullptr, preview_engine_lifetime, true);
+    BLI_timer_register(1,
+                       preview_engine->delete_preview_engine,
+                       &preview_engine,
+                       nullptr,
+                       preview_engine->preview_engine_lifetime,
+                       true);
     CLOG_INFO(LOG_EN, 2, "Engine %016llx", engine);
     Py_RETURN_NONE;
   }
diff --git a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
index 6b310a10a8b8..f1f24f1ea7c6 100644
--- a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
+++ b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
@@ -477,10 +477,18 @@ pxr::VtValue BlenderSceneDelegate::GetLightParamValue(pxr::SdfPath const &id,
   return pxr::VtValue();
 }
 
-void BlenderSceneDelegate::clear_data()
+void BlenderSceneDelegate::clear()
 {
-  objects.clear();
+  for (auto it = materials.begin(); it != materials.end(); ++it) {
+    it->second->remove_prim();
+  }
+
+  for (auto it = objects.begin(); it != objects.end(); ++it) {
+    it->second->remove_prim();
+  }
+
   materials.clear();
+  objects.clear();
 }
 
 }  // namespace blender::render::hydra
diff --git a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.h b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.h
index 0bab7c6e9ddf..bd885c3f0aee 100644
--- a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.h
+++ b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.h
@@ -29,7 +29,7 @@ class BlenderSceneDelegate : public pxr::HdSceneDelegate {
   ~BlenderSceneDelegate() override = default;
 
   void populate(Depsgraph *depsgraph, bContext *context);
-  void clear_data();
+  void clear();
 
   // delegate methods
   pxr::HdMeshTopology GetMeshTopology(pxr::SdfPath const &id) override;
diff --git a/source/blender/render/hydra/scene_delegate/material.cc b/source/blender/render/hydra/scene_delegate/material.cc
index c460b76b651d..4c60531640ef 100644
--- a/source/blender/render/hydra/scene_delegate/material.cc
+++ b/source/blender/render/hydra/scene_delegate/material.cc
@@ -120,7 +120,7 @@ void MaterialData::remove_prim()
 {
   pxr::SdfPath p_id = prim_id(scene_delegate, (Material *)id);
   scene_delegate->GetRenderIndex().RemoveSprim(pxr::HdPrimTypeTokens->material, p_id);
-  CLOG_INFO(LOG_BSD, 2, "Remove: %s", name().c_str());
+  //CLOG_INFO(LOG_BSD, 2, "Remove: %s", name().c_str());
 }
 
 void MaterialData::mark_prim_dirty(DirtyBits dirty_bits)
diff --git a/source/blender/render/hydra/scene_delegate/mesh.cc b/source/blender/render/hydra/scene_delegate/mesh.cc
index 09bbe3828089..a2e4ee062d99 100644
--- a/source/blender/render/hydra/scene_delegate/mesh.cc
+++ b/source/blender/render/hydra/scene_delegate/mesh.cc
@@ -219,7 +219,7 @@ void MeshData::remove_prim()
   }
 
   scene_delegate->GetRenderIndex().RemoveRprim(p_id);
-  CLOG_INFO(LOG_BSD, 2, "Remove: %s", name().c_str());
+  //CLOG_INFO(LOG_BSD, 2, "Remove: %s", name().c_str());
 }
 
 void MeshData::mark_prim_dirty(DirtyBits dirty_bits)
diff --git a/source/blender/render/hydra/viewport_engine.cc b/source/blender/render/hydra/viewport_engine.cc
index b9f7496cb46f..94f8ab8dad24 100644
--- a/source/blender/render/hydra/viewport_engine.cc
+++ b/source/blender/render/hydra/viewport_engine.cc
@@ -244,6 +244,12 @@ void ViewportEngine::sync(Depsgraph *depsgraph,
                           bContext *context,
                           pxr::HdRenderSettingsMap &render_settings)
 {
+  if (!scene_delegate) {
+    scene_delegate = std::make_unique<BlenderSceneDelegate>(
+        render_index.get(),
+        pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"),
+        BlenderSceneDelegate::EngineType::VIEWPORT);
+  }
   scene_delegate->populate(depsgraph, context);
 
   for (auto const &setting : render_settings) {
-- 
2.30.2


From a4286c6fd47c1a1dcbbad681c3e02c37925c3051 Mon Sep 17 00:00:00 2001
From: "georgiy.m.markelov@gmail.com" <georgiy.m.markelov@gmail.com>
Date: Fri, 7 Apr 2023 10:28:24 +0300
Subject: [PATCH 5/9] fix after merge

---
 .../render/hydra/scene_delegate/blender_scene_delegate.cc     | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
index 02dead83349f..e4b43d1fcc05 100644
--- a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
+++ b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
@@ -437,11 +437,11 @@ pxr::VtValue BlenderSceneDelegate::GetLightParamValue(pxr::SdfPath const &id,
 void BlenderSceneDelegate::clear()
 {
   for (auto it = materials.begin(); it != materials.end(); ++it) {
-    it->second->remove_prim();
+    it->second->remove();
   }
 
   for (auto it = objects.begin(); it != objects.end(); ++it) {
-    it->second->remove_prim();
+    it->second->remove();
   }
 
   materials.clear();
-- 
2.30.2


From 5cbc5ff6d4805b04cf322c5930b242e62d83499d Mon Sep 17 00:00:00 2001
From: "georgiy.m.markelov@gmail.com" <georgiy.m.markelov@gmail.com>
Date: Fri, 7 Apr 2023 13:26:45 +0300
Subject: [PATCH 6/9] fix light update

---
 .../render/hydra/scene_delegate/light.cc       | 18 +++++++++++++-----
 .../render/hydra/scene_delegate/light.h        |  2 ++
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/source/blender/render/hydra/scene_delegate/light.cc b/source/blender/render/hydra/scene_delegate/light.cc
index 9d95abb1b218..676270802c9e 100644
--- a/source/blender/render/hydra/scene_delegate/light.cc
+++ b/source/blender/render/hydra/scene_delegate/light.cc
@@ -80,15 +80,17 @@ void LightData::init()
       break;
   }
 
+  p_type = light->type;
+  p_shape = light->area_shape;
+
   /* TODO: temporary value, it should be delivered through Python UI */
   data[pxr::HdLightTokens->exposure] = 1.0f;
 }
 
 pxr::TfToken LightData::prim_type()
 {
-  Light *light = (Light *)((Object *)id)->data;
   pxr::TfToken ret;
-  switch (light->type) {
+  switch (p_type) {
     case LA_LOCAL:
     case LA_SPOT:
       ret = pxr::HdPrimTypeTokens->sphereLight;
@@ -99,7 +101,7 @@ pxr::TfToken LightData::prim_type()
       break;
 
     case LA_AREA:
-      switch (light->area_shape) {
+      switch (p_shape) {
         case LA_AREA_SQUARE:
         case LA_AREA_RECT:
           ret = pxr::HdPrimTypeTokens->rectLight;
@@ -166,10 +168,16 @@ void LightData::remove()
 
 void LightData::update()
 {
-  /* TODO: prim_type was changed we have to do remove..add light */
-
   CLOG_INFO(LOG_BSD, 2, "%s", id->name);
 
+  Light *light = (Light *)((Object *)id)->data;
+  if (light->type != p_type || light->area_shape != p_shape) {
+    remove();
+    init();
+    insert();
+    return;
+  }
+
   pxr::HdDirtyBits bits = pxr::HdLight::Clean;
   if (id->recalc & ID_RECALC_GEOMETRY) {
     init();
diff --git a/source/blender/render/hydra/scene_delegate/light.h b/source/blender/render/hydra/scene_delegate/light.h
index 12d1988e80ed..59733a5d31ca 100644
--- a/source/blender/render/hydra/scene_delegate/light.h
+++ b/source/blender/render/hydra/scene_delegate/light.h
@@ -24,6 +24,8 @@ class LightData : public ObjectData {
 
  private:
   std::map<pxr::TfToken, pxr::VtValue> data;
+  short p_type;
+  short p_shape;
   pxr::TfToken prim_type();
 };
 
-- 
2.30.2


From a439e99ab85e3c70cdb5d2bc90d72ece0824c423 Mon Sep 17 00:00:00 2001
From: "georgiy.m.markelov@gmail.com" <georgiy.m.markelov@gmail.com>
Date: Fri, 7 Apr 2023 18:55:28 +0300
Subject: [PATCH 7/9] fix review comments

---
 source/blender/render/hydra/engine.cc         |  6 ----
 source/blender/render/hydra/engine.h          |  1 -
 source/blender/render/hydra/preview_engine.cc | 33 +++++++++++++++++--
 source/blender/render/hydra/preview_engine.h  |  4 +++
 source/blender/render/hydra/python.cc         | 23 ++-----------
 .../scene_delegate/blender_scene_delegate.cc  |  8 ++---
 .../render/hydra/scene_delegate/light.cc      | 16 ++++-----
 .../render/hydra/scene_delegate/light.h       |  7 ++--
 8 files changed, 53 insertions(+), 45 deletions(-)

diff --git a/source/blender/render/hydra/engine.cc b/source/blender/render/hydra/engine.cc
index 8dfc656ce18f..6452e1ddf866 100644
--- a/source/blender/render/hydra/engine.cc
+++ b/source/blender/render/hydra/engine.cc
@@ -54,12 +54,6 @@ Engine::~Engine()
   render_delegate = nullptr;
   engine = nullptr;
   hgi = nullptr;
-  bl_engine = nullptr;
-}
-
-bool Engine::is_converged()
-{
-  return render_task_delegate->is_converged();
 }
 
 float Engine::renderer_percent_done()
diff --git a/source/blender/render/hydra/engine.h b/source/blender/render/hydra/engine.h
index 5391448e96c3..3e6a5ad95056 100644
--- a/source/blender/render/hydra/engine.h
+++ b/source/blender/render/hydra/engine.h
@@ -34,7 +34,6 @@ class Engine {
                     bContext *context,
                     pxr::HdRenderSettingsMap &render_settings) = 0;
   virtual void render(Depsgraph *depsgraph) = 0;
-  bool is_converged();
 
  protected:
   float renderer_percent_done();
diff --git a/source/blender/render/hydra/preview_engine.cc b/source/blender/render/hydra/preview_engine.cc
index 77ff6dc8a997..041075a72c4a 100644
--- a/source/blender/render/hydra/preview_engine.cc
+++ b/source/blender/render/hydra/preview_engine.cc
@@ -5,9 +5,38 @@
 
 #include "camera.h"
 #include "preview_engine.h"
+#include "BLI_timer.h"
 
 namespace blender::render::hydra {
 
+std::unique_ptr<PreviewEngine> PreviewEngine::preview_engine;
+
+void PreviewEngine::free()
+{
+  if (preview_engine) {
+    BLI_timer_register((uintptr_t)preview_engine.get(),
+                       preview_engine->delete_preview_engine,
+                       &preview_engine,
+                       nullptr,
+                       preview_engine->preview_engine_lifetime,
+                       true);
+  }
+}
+
+std::unique_ptr<PreviewEngine> *PreviewEngine::get(RenderEngine *bl_engine,
+                                                   char *render_delegate_id)
+{
+  if (!preview_engine) {
+    preview_engine = std::make_unique<PreviewEngine>(bl_engine, render_delegate_id);
+  }
+  if (BLI_timer_is_registered((uintptr_t)preview_engine.get())) {
+    BLI_timer_unregister((uintptr_t)preview_engine.get());
+  }
+  preview_engine->update_bl_engine(bl_engine);
+
+  return &preview_engine;
+}
+
 void PreviewEngine::sync(Depsgraph *depsgraph,
                          bContext *context,
                          pxr::HdRenderSettingsMap &render_settings)
@@ -81,8 +110,8 @@ void PreviewEngine::update_bl_engine(RenderEngine *bl_engine)
 double PreviewEngine::delete_preview_engine(uintptr_t uuid, void *user_data)
 {
   std::unique_ptr<PreviewEngine> *preview_engine = static_cast<std::unique_ptr<PreviewEngine>*>(user_data);
-  if (preview_engine && preview_engine->get()->is_converged()) {
-    CLOG_INFO(LOG_EN, 1, "Delete preview engine");
+  if (preview_engine && preview_engine->get()->render_task_delegate->is_converged()) {
+    CLOG_INFO(LOG_EN, uuid, "Delete preview engine");
     preview_engine->reset();
     return -1;
   }
diff --git a/source/blender/render/hydra/preview_engine.h b/source/blender/render/hydra/preview_engine.h
index 1dffc0c07aaa..006d2012f6c2 100644
--- a/source/blender/render/hydra/preview_engine.h
+++ b/source/blender/render/hydra/preview_engine.h
@@ -10,6 +10,9 @@ namespace blender::render::hydra {
 class PreviewEngine : public FinalEngine {
  public:
   using FinalEngine::FinalEngine;
+  static void free();
+  static std::unique_ptr<PreviewEngine> *get(RenderEngine *bl_engine = nullptr,
+                                             char *render_delegate_id = nullptr);
   void sync(Depsgraph *depsgraph,
             bContext *context,
             pxr::HdRenderSettingsMap &render_settings) override;
@@ -27,6 +30,7 @@ class PreviewEngine : public FinalEngine {
   static inline double preview_engine_lifetime = 180.0;
 
  protected:
+  static std::unique_ptr<PreviewEngine> preview_engine;
   pxr::HdRenderSettingsMap render_settings;
 };
 
diff --git a/source/blender/render/hydra/python.cc b/source/blender/render/hydra/python.cc
index c6e43e964b21..cefba258ac69 100644
--- a/source/blender/render/hydra/python.cc
+++ b/source/blender/render/hydra/python.cc
@@ -20,8 +20,6 @@
 
 namespace blender::render::hydra {
 
-static std::unique_ptr<PreviewEngine> preview_engine;
-
 static PyObject *init_func(PyObject * /*self*/, PyObject *args)
 {
   CLOG_INFO(LOG_EN, 1, "Init");
@@ -116,16 +114,7 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
     engine = new ViewportEngine(bl_engine, render_delegate_id);
   }
   else if (STREQ(engine_type, "PREVIEW")) {
-    if (!preview_engine) {
-      preview_engine = std::make_unique<PreviewEngine>(bl_engine, render_delegate_id);
-    }
-    if (BLI_timer_is_registered(1)) {
-      BLI_timer_unregister(1);
-    }
-    preview_engine->update_bl_engine(bl_engine);
-
-    CLOG_INFO(LOG_EN, 2, "Engine %016llx %s", engine, engine_type);
-    return PyLong_FromVoidPtr(preview_engine.get());
+    engine = PreviewEngine::get(bl_engine, render_delegate_id)->get();
   }
   else {
     if (bl_engine->type->flag & RE_USE_GPU_CONTEXT) {
@@ -149,15 +138,9 @@ static PyObject *engine_free_func(PyObject * /*self*/, PyObject *args)
   }
 
   Engine *engine = (Engine *)PyLong_AsVoidPtr(pyengine);
-
+  PreviewEngine *preview_engine = dynamic_cast<PreviewEngine *>(engine);
   if (preview_engine) {
-    BLI_timer_register(1,
-                       preview_engine->delete_preview_engine,
-                       &preview_engine,
-                       nullptr,
-                       preview_engine->preview_engine_lifetime,
-                       true);
-    CLOG_INFO(LOG_EN, 2, "Engine %016llx", engine);
+    preview_engine->free();
     Py_RETURN_NONE;
   }
 
diff --git a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
index e4b43d1fcc05..38346736b41e 100644
--- a/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
+++ b/source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc
@@ -436,12 +436,12 @@ pxr::VtValue BlenderSceneDelegate::GetLightParamValue(pxr::SdfPath const &id,
 
 void BlenderSceneDelegate::clear()
 {
-  for (auto it = materials.begin(); it != materials.end(); ++it) {
-    it->second->remove();
+  for (auto &it : materials) {
+    it.second->remove();
   }
 
-  for (auto it = objects.begin(); it != objects.end(); ++it) {
-    it->second->remove();
+  for (auto &it : objects) {
+    it.second->remove();
   }
 
   materials.clear();
diff --git a/source/blender/render/hydra/scene_delegate/light.cc b/source/blender/render/hydra/scene_delegate/light.cc
index 676270802c9e..3b104e7f11e1 100644
--- a/source/blender/render/hydra/scene_delegate/light.cc
+++ b/source/blender/render/hydra/scene_delegate/light.cc
@@ -7,7 +7,6 @@
 #include <pxr/imaging/hd/tokens.h>
 #include <pxr/usd/usdLux/tokens.h>
 
-#include "BKE_light.h"
 #include "DNA_light_types.h"
 
 #include "blender_scene_delegate.h"
@@ -80,17 +79,16 @@ void LightData::init()
       break;
   }
 
-  p_type = light->type;
-  p_shape = light->area_shape;
+  p_type = prim_type(light);
 
   /* TODO: temporary value, it should be delivered through Python UI */
   data[pxr::HdLightTokens->exposure] = 1.0f;
 }
 
-pxr::TfToken LightData::prim_type()
+pxr::TfToken LightData::prim_type(Light *light)
 {
   pxr::TfToken ret;
-  switch (p_type) {
+  switch (light->type) {
     case LA_LOCAL:
     case LA_SPOT:
       ret = pxr::HdPrimTypeTokens->sphereLight;
@@ -101,7 +99,7 @@ pxr::TfToken LightData::prim_type()
       break;
 
     case LA_AREA:
-      switch (p_shape) {
+      switch (light->area_shape) {
         case LA_AREA_SQUARE:
         case LA_AREA_RECT:
           ret = pxr::HdPrimTypeTokens->rectLight;
@@ -157,13 +155,13 @@ bool LightData::update_visibility(View3D *view3d)
 void LightData::insert()
 {
   CLOG_INFO(LOG_BSD, 2, "%s", id->name);
-  scene_delegate->GetRenderIndex().InsertSprim(prim_type(), scene_delegate, p_id);
+  scene_delegate->GetRenderIndex().InsertSprim(p_type, scene_delegate, p_id);
 }
 
 void LightData::remove()
 {
   CLOG_INFO(LOG_BSD, 2, "%s", id->name);
-  scene_delegate->GetRenderIndex().RemoveSprim(prim_type(), p_id);
+  scene_delegate->GetRenderIndex().RemoveSprim(p_type, p_id);
 }
 
 void LightData::update()
@@ -171,7 +169,7 @@ void LightData::update()
   CLOG_INFO(LOG_BSD, 2, "%s", id->name);
 
   Light *light = (Light *)((Object *)id)->data;
-  if (light->type != p_type || light->area_shape != p_shape) {
+  if (prim_type(light) != p_type) {
     remove();
     init();
     insert();
diff --git a/source/blender/render/hydra/scene_delegate/light.h b/source/blender/render/hydra/scene_delegate/light.h
index 59733a5d31ca..f351450c084b 100644
--- a/source/blender/render/hydra/scene_delegate/light.h
+++ b/source/blender/render/hydra/scene_delegate/light.h
@@ -7,6 +7,8 @@
 #include <pxr/usd/sdf/assetPath.h>
 #include <pxr/usd/sdf/path.h>
 
+#include "BKE_light.h"
+
 #include "object.h"
 
 namespace blender::render::hydra {
@@ -24,9 +26,8 @@ class LightData : public ObjectData {
 
  private:
   std::map<pxr::TfToken, pxr::VtValue> data;
-  short p_type;
-  short p_shape;
-  pxr::TfToken prim_type();
+  pxr::TfToken p_type;
+  pxr::TfToken prim_type(Light *light);
 };
 
 }  // namespace blender::render::hydra
-- 
2.30.2


From 44cce409743e3317c97f3a1e332fdde07459e0d9 Mon Sep 17 00:00:00 2001
From: Bogdan Nagirniak <bnagirniak@luxoft.com>
Date: Mon, 10 Apr 2023 12:58:15 +0300
Subject: [PATCH 8/9] Code simplification and renamings

---
 source/blender/render/hydra/preview_engine.cc | 63 ++++++++++---------
 source/blender/render/hydra/preview_engine.h  | 18 +++---
 source/blender/render/hydra/python.cc         | 10 +--
 3 files changed, 46 insertions(+), 45 deletions(-)

diff --git a/source/blender/render/hydra/preview_engine.cc b/source/blender/render/hydra/preview_engine.cc
index 041075a72c4a..34bbe04b8f4f 100644
--- a/source/blender/render/hydra/preview_engine.cc
+++ b/source/blender/render/hydra/preview_engine.cc
@@ -9,32 +9,47 @@
 
 namespace blender::render::hydra {
 
-std::unique_ptr<PreviewEngine> PreviewEngine::preview_engine;
+const double LIFETIME = 180.0;
 
-void PreviewEngine::free()
+std::unique_ptr<PreviewEngine> PreviewEngine::instance;
+
+void PreviewEngine::schedule_free()
 {
-  if (preview_engine) {
-    BLI_timer_register((uintptr_t)preview_engine.get(),
-                       preview_engine->delete_preview_engine,
-                       &preview_engine,
-                       nullptr,
-                       preview_engine->preview_engine_lifetime,
-                       true);
-  }
+  instance->render_delegate->Stop();
+
+  /* Register timer for schedule free PreviewEngine instance */
+  BLI_timer_register((uintptr_t)instance.get(),
+                      free_instance,
+                      nullptr,
+                      nullptr,
+                      LIFETIME,
+                      true);
 }
 
-std::unique_ptr<PreviewEngine> *PreviewEngine::get(RenderEngine *bl_engine,
-                                                   char *render_delegate_id)
+PreviewEngine *PreviewEngine::get_instance(RenderEngine *bl_engine, const std::string &render_delegate_id)
 {
-  if (!preview_engine) {
-    preview_engine = std::make_unique<PreviewEngine>(bl_engine, render_delegate_id);
+  if (!instance) {
+    instance = std::make_unique<PreviewEngine>(bl_engine, render_delegate_id);
   }
-  if (BLI_timer_is_registered((uintptr_t)preview_engine.get())) {
-    BLI_timer_unregister((uintptr_t)preview_engine.get());
+  if (BLI_timer_is_registered((uintptr_t)instance.get())) {
+    /* Unregister timer while PreviewEngine is working */
+    BLI_timer_unregister((uintptr_t)instance.get());
   }
-  preview_engine->update_bl_engine(bl_engine);
+  instance->update_bl_engine(bl_engine);
 
-  return &preview_engine;
+  return instance.get();
+}
+
+double PreviewEngine::free_instance(uintptr_t uuid, void *user_data)
+{
+  if (!instance->render_task_delegate->is_converged()) {
+    /* Restart timer if render isn't completed */
+    return LIFETIME;
+  }
+
+  CLOG_INFO(LOG_EN, 2, "");
+  instance = nullptr;
+  return -1;
 }
 
 void PreviewEngine::sync(Depsgraph *depsgraph,
@@ -107,18 +122,6 @@ void PreviewEngine::update_bl_engine(RenderEngine *bl_engine)
   this->bl_engine = bl_engine;
 }
 
-double PreviewEngine::delete_preview_engine(uintptr_t uuid, void *user_data)
-{
-  std::unique_ptr<PreviewEngine> *preview_engine = static_cast<std::unique_ptr<PreviewEngine>*>(user_data);
-  if (preview_engine && preview_engine->get()->render_task_delegate->is_converged()) {
-    CLOG_INFO(LOG_EN, uuid, "Delete preview engine");
-    preview_engine->reset();
-    return -1;
-  }
-
-  return preview_engine_lifetime;
-}
-
 void PreviewEngine::update_render_result(const std::string &layer_name,
                                          int width,
                                          int height,
diff --git a/source/blender/render/hydra/preview_engine.h b/source/blender/render/hydra/preview_engine.h
index 006d2012f6c2..6d17fddc90ca 100644
--- a/source/blender/render/hydra/preview_engine.h
+++ b/source/blender/render/hydra/preview_engine.h
@@ -8,17 +8,21 @@
 namespace blender::render::hydra {
 
 class PreviewEngine : public FinalEngine {
+ private:
+  /* Singleton class instance */
+  static std::unique_ptr<PreviewEngine> instance;
+  static double free_instance(uintptr_t uuid, void *user_data);
+
  public:
+  static PreviewEngine *get_instance(RenderEngine *bl_engine, const std::string &render_delegate_id);
+  static void schedule_free();
+
   using FinalEngine::FinalEngine;
-  static void free();
-  static std::unique_ptr<PreviewEngine> *get(RenderEngine *bl_engine = nullptr,
-                                             char *render_delegate_id = nullptr);
   void sync(Depsgraph *depsgraph,
             bContext *context,
             pxr::HdRenderSettingsMap &render_settings) override;
   void render(Depsgraph *depsgraph) override;
   void update_bl_engine(RenderEngine *bl_engine);
-  static double delete_preview_engine(uintptr_t uuid, void *user_data);
 
  protected:
   void update_render_result(const std::string &layer_name,
@@ -26,12 +30,6 @@ class PreviewEngine : public FinalEngine {
                             int height,
                             std::vector<float> &pixels);
 
- public:
-  static inline double preview_engine_lifetime = 180.0;
-
- protected:
-  static std::unique_ptr<PreviewEngine> preview_engine;
-  pxr::HdRenderSettingsMap render_settings;
 };
 
 }  // namespace blender::render::hydra
diff --git a/source/blender/render/hydra/python.cc b/source/blender/render/hydra/python.cc
index cefba258ac69..b97a31b15555 100644
--- a/source/blender/render/hydra/python.cc
+++ b/source/blender/render/hydra/python.cc
@@ -114,7 +114,7 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
     engine = new ViewportEngine(bl_engine, render_delegate_id);
   }
   else if (STREQ(engine_type, "PREVIEW")) {
-    engine = PreviewEngine::get(bl_engine, render_delegate_id)->get();
+    engine = PreviewEngine::get_instance(bl_engine, render_delegate_id);
   }
   else {
     if (bl_engine->type->flag & RE_USE_GPU_CONTEXT) {
@@ -140,11 +140,11 @@ static PyObject *engine_free_func(PyObject * /*self*/, PyObject *args)
   Engine *engine = (Engine *)PyLong_AsVoidPtr(pyengine);
   PreviewEngine *preview_engine = dynamic_cast<PreviewEngine *>(engine);
   if (preview_engine) {
-    preview_engine->free();
-    Py_RETURN_NONE;
+    PreviewEngine::schedule_free();
+  }
+  else {
+    delete engine;
   }
-
-  delete engine;
 
   CLOG_INFO(LOG_EN, 2, "Engine %016llx", engine);
   Py_RETURN_NONE;
-- 
2.30.2


From f73befb068965a7efa7e642ba8903aa90633bcc5 Mon Sep 17 00:00:00 2001
From: Bogdan Nagirniak <bnagirniak@luxoft.com>
Date: Mon, 10 Apr 2023 13:42:25 +0300
Subject: [PATCH 9/9] Code improvement, added TODO.

---
 source/blender/render/hydra/preview_engine.cc | 5 +++--
 source/blender/render/hydra/preview_engine.h  | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/source/blender/render/hydra/preview_engine.cc b/source/blender/render/hydra/preview_engine.cc
index 34bbe04b8f4f..ffb9891952e2 100644
--- a/source/blender/render/hydra/preview_engine.cc
+++ b/source/blender/render/hydra/preview_engine.cc
@@ -35,7 +35,7 @@ PreviewEngine *PreviewEngine::get_instance(RenderEngine *bl_engine, const std::s
     /* Unregister timer while PreviewEngine is working */
     BLI_timer_unregister((uintptr_t)instance.get());
   }
-  instance->update_bl_engine(bl_engine);
+  instance->update(bl_engine, render_delegate_id);
 
   return instance.get();
 }
@@ -117,9 +117,10 @@ void PreviewEngine::render(Depsgraph *depsgraph)
   update_render_result(layer_name, res[0], res[1], pixels);
 }
 
-void PreviewEngine::update_bl_engine(RenderEngine *bl_engine)
+void PreviewEngine::update(RenderEngine *bl_engine, const std::string &render_delegate_id)
 {
   this->bl_engine = bl_engine;
+  /* TODO: recreate render_delegate when render_delegate_id is changed */
 }
 
 void PreviewEngine::update_render_result(const std::string &layer_name,
diff --git a/source/blender/render/hydra/preview_engine.h b/source/blender/render/hydra/preview_engine.h
index 6d17fddc90ca..97ee9da93a3e 100644
--- a/source/blender/render/hydra/preview_engine.h
+++ b/source/blender/render/hydra/preview_engine.h
@@ -22,9 +22,9 @@ class PreviewEngine : public FinalEngine {
             bContext *context,
             pxr::HdRenderSettingsMap &render_settings) override;
   void render(Depsgraph *depsgraph) override;
-  void update_bl_engine(RenderEngine *bl_engine);
 
- protected:
+ private:
+  void update(RenderEngine *bl_engine, const std::string &render_delegate_id);
   void update_render_result(const std::string &layer_name,
                             int width,
                             int height,
-- 
2.30.2