Cleanup: converted Depsgraph Building Pipeline to object-oriented code

This will make it easier & cleaner to make custom-built depsgraph (for
example for exporting invisible objects to USD or Alembic, see T75936).

No functional changes.

Reviewed by: sergey

Differential Revision: https://developer.blender.org/D8423

1 files changed, 132 insertions, 0 deletions

diff --git a/source/blender/depsgraph/intern/builder/pipeline.cc b/source/blender/depsgraph/intern/builder/pipeline.cc
new file mode 100644
index 00000000000..d6893ba11d8
--- /dev/null
+++ b/source/blender/depsgraph/intern/builder/pipeline.cc
@@ -0,0 +1,132 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+#include "pipeline.h"
+
+#include "PIL_time.h"
+
+#include "BKE_global.h"
+
+#include "DNA_scene_types.h"
+
+#include "deg_builder_cycle.h"
+#include "deg_builder_nodes.h"
+#include "deg_builder_relations.h"
+#include "deg_builder_transitive.h"
+
+namespace blender {
+namespace deg {
+
+AbstractBuilderPipeline::AbstractBuilderPipeline(::Depsgraph *graph,
+                                                 Main *bmain,
+                                                 Scene *scene,
+                                                 ViewLayer *view_layer)
+    : deg_graph_(reinterpret_cast<Depsgraph *>(graph)),
+      bmain_(bmain),
+      scene_(scene),
+      view_layer_(view_layer),
+      builder_cache_()
+{
+}
+
+AbstractBuilderPipeline::~AbstractBuilderPipeline()
+{
+}
+
+void AbstractBuilderPipeline::build()
+{
+  double start_time = 0.0;
+  if (G.debug & (G_DEBUG_DEPSGRAPH_BUILD | G_DEBUG_DEPSGRAPH_TIME)) {
+    start_time = PIL_check_seconds_timer();
+  }
+
+  build_step_sanity_check();
+  build_step_nodes();
+  build_step_relations();
+  build_step_finalize();
+
+  if (G.debug & (G_DEBUG_DEPSGRAPH_BUILD | G_DEBUG_DEPSGRAPH_TIME)) {
+    printf("Depsgraph built in %f seconds.\n", PIL_check_seconds_timer() - start_time);
+  }
+}
+
+void AbstractBuilderPipeline::build_step_sanity_check()
+{
+  BLI_assert(BLI_findindex(&scene_->view_layers, view_layer_) != -1);
+  BLI_assert(deg_graph_->scene == scene_);
+  BLI_assert(deg_graph_->view_layer == view_layer_);
+}
+
+void AbstractBuilderPipeline::build_step_nodes()
+{
+  /* Generate all the nodes in the graph first */
+  unique_ptr<DepsgraphNodeBuilder> node_builder = construct_node_builder();
+  node_builder->begin_build();
+  build_nodes(*node_builder);
+  node_builder->end_build();
+}
+
+void AbstractBuilderPipeline::build_step_relations()
+{
+  /* Hook up relationships between operations - to determine evaluation order. */
+  unique_ptr<DepsgraphRelationBuilder> relation_builder = construct_relation_builder();
+  relation_builder->begin_build();
+  build_relations(*relation_builder);
+  relation_builder->build_copy_on_write_relations();
+  relation_builder->build_driver_relations();
+}
+
+void AbstractBuilderPipeline::build_step_finalize()
+{
+  /* Detect and solve cycles. */
+  deg_graph_detect_cycles(deg_graph_);
+  /* Simplify the graph by removing redundant relations (to optimize
+   * traversal later). */
+  /* TODO: it would be useful to have an option to disable this in cases where
+   *       it is causing trouble. */
+  if (G.debug_value == 799) {
+    deg_graph_transitive_reduction(deg_graph_);
+  }
+  /* Store pointers to commonly used valuated datablocks. */
+  deg_graph_->scene_cow = (Scene *)deg_graph_->get_cow_id(&deg_graph_->scene->id);
+  /* Flush visibility layer and re-schedule nodes for update. */
+  deg_graph_build_finalize(bmain_, deg_graph_);
+  DEG_graph_on_visible_update(bmain_, reinterpret_cast<::Depsgraph *>(deg_graph_), false);
+#if 0
+  if (!DEG_debug_consistency_check(deg_graph_)) {
+    printf("Consistency validation failed, ABORTING!\n");
+    abort();
+  }
+#endif
+  /* Relations are up to date. */
+  deg_graph_->need_update = false;
+}
+
+unique_ptr<DepsgraphNodeBuilder> AbstractBuilderPipeline::construct_node_builder()
+{
+  return std::make_unique<DepsgraphNodeBuilder>(bmain_, deg_graph_, &builder_cache_);
+}
+
+unique_ptr<DepsgraphRelationBuilder> AbstractBuilderPipeline::construct_relation_builder()
+{
+  return std::make_unique<DepsgraphRelationBuilder>(bmain_, deg_graph_, &builder_cache_);
+}
+
+}  // namespace deg
+}  // namespace blender