Cycles: Introduce scene host_update function

The longer-term goal is to separate host-only scene update
from device update: make it possible to make kernel features
depend on actual scene state and flags.

This change makes it so shaders are compiled before kernel
load, making checks like "has_volume" available at the
kernel features calculation state.

No functional changes are expected at this point.

Differential Revision: https://developer.blender.org/D12795

1 files changed, 47 insertions, 28 deletions

diff --git a/intern/cycles/render/osl.cpp b/intern/cycles/render/osl.cpp
index 5a43b641872..b6c743ac295 100644
--- a/intern/cycles/render/osl.cpp
+++ b/intern/cycles/render/osl.cpp
@@ -91,24 +91,20 @@ void OSLShaderManager::reset(Scene * /*scene*/)
   shading_system_init();
 }
 
-void OSLShaderManager::device_update_specific(Device *device,
-                                              DeviceScene *dscene,
-                                              Scene *scene,
-                                              Progress &progress)
+void OSLShaderManager::host_update_specific(Device *device, Scene *scene, Progress &progress)
 {
-  if (!need_update())
+  if (!need_update()) {
     return;
+  }
 
   scoped_callback_timer timer([scene](double time) {
     if (scene->update_stats) {
-      scene->update_stats->osl.times.add_entry({"device_update", time});
+      scene->update_stats->osl.times.add_entry({"host_update", time});
     }
   });
 
   VLOG(1) << "Total " << scene->shaders.size() << " shaders.";
 
-  device_free(device, dscene, scene);
-
   /* set texture system */
   scene->image_manager->set_osl_texture_system((void *)ts);
 
@@ -116,13 +112,14 @@ void OSLShaderManager::device_update_specific(Device *device,
   OSLGlobals *og = (OSLGlobals *)device->get_cpu_osl_memory();
   Shader *background_shader = scene->background->get_shader(scene);
 
-  foreach (Shader *shader, scene->shaders) {
+  for (Shader *shader : scene->shaders) {
     assert(shader->graph);
 
-    if (progress.get_cancel())
+    if (progress.get_cancel()) {
       return;
+    }
 
-    /* we can only compile one shader at the time as the OSL ShadingSytem
+    /* we can only compile one shader at the time as the OSL ShadingSystem
      * has a single state, but we put the lock here so different renders can
      * compile shaders alternating */
     thread_scoped_lock lock(ss_mutex);
@@ -131,30 +128,15 @@ void OSLShaderManager::device_update_specific(Device *device,
     compiler.background = (shader == background_shader);
     compiler.compile(og, shader);
 
-    if (shader->get_use_mis() && shader->has_surface_emission)
+    if (shader->get_use_mis() && shader->has_surface_emission) {
       scene->light_manager->tag_update(scene, LightManager::SHADER_COMPILED);
+    }
   }
 
-  /* setup shader engine */
-  og->ss = ss;
-  og->ts = ts;
-  og->services = services;
-
-  int background_id = scene->shader_manager->get_shader_id(background_shader);
-  og->background_state = og->surface_state[background_id & SHADER_MASK];
-  og->use = true;
-
-  foreach (Shader *shader, scene->shaders)
-    shader->clear_modified();
-
-  update_flags = UPDATE_NONE;
-
   /* add special builtin texture types */
   services->textures.insert(ustring("@ao"), new OSLTextureHandle(OSLTextureHandle::AO));
   services->textures.insert(ustring("@bevel"), new OSLTextureHandle(OSLTextureHandle::BEVEL));
 
-  device_update_common(device, dscene, scene, progress);
-
   {
     /* Perform greedyjit optimization.
      *
@@ -172,6 +154,43 @@ void OSLShaderManager::device_update_specific(Device *device,
   }
 }
 
+void OSLShaderManager::device_update_specific(Device *device,
+                                              DeviceScene *dscene,
+                                              Scene *scene,
+                                              Progress &progress)
+{
+  if (!need_update())
+    return;
+
+  scoped_callback_timer timer([scene](double time) {
+    if (scene->update_stats) {
+      scene->update_stats->osl.times.add_entry({"device_update", time});
+    }
+  });
+
+  device_free(device, dscene, scene);
+
+  OSLGlobals *og = (OSLGlobals *)device->get_cpu_osl_memory();
+  Shader *background_shader = scene->background->get_shader(scene);
+
+  /* Setup shader engine. */
+  og->ss = ss;
+  og->ts = ts;
+  og->services = services;
+
+  const int background_id = scene->shader_manager->get_shader_id(background_shader);
+  og->background_state = og->surface_state[background_id & SHADER_MASK];
+  og->use = true;
+
+  foreach (Shader *shader, scene->shaders) {
+    shader->clear_modified();
+  }
+
+  update_flags = UPDATE_NONE;
+
+  device_update_common(device, dscene, scene, progress);
+}
+
 void OSLShaderManager::device_free(Device *device, DeviceScene *dscene, Scene *scene)
 {
   OSLGlobals *og = (OSLGlobals *)device->get_cpu_osl_memory();