Depsgraph: New dependency graph integration commit

This commit integrates the work done so far on the new dependency graph system,
where goal was to replace legacy depsgraph with the new one, supporting loads of
neat features like:

- More granular dependency relation nature, which solves issues with fake cycles
  in the dependencies.

- Move towards all-animatable, by better integration of drivers into the system.

- Lay down some basis for upcoming copy-on-write, overrides and so on.

The new system is living side-by-side with the previous one and disabled by
default, so nothing will become suddenly broken. The way to enable new depsgraph
is to pass `--new-depsgraph` command line argument.

It's a bit early to consider the system production-ready, there are some TODOs
and issues were discovered during the merge period, they'll be addressed ASAP.
But it's important to merge, because it's the only way to attract artists to
really start testing this system.

There are number of assorted documents related on the design of the new system:

* http://wiki.blender.org/index.php/User:Aligorith/GSoC2013_Depsgraph#Design_Documents
* http://wiki.blender.org/index.php/User:Nazg-gul/DependencyGraph

There are also some user-related information online:

* http://code.blender.org/2015/02/blender-dependency-graph-branch-for-users/
* http://code.blender.org/2015/03/more-dependency-graph-tricks/

Kudos to everyone who was involved into the project:

- Joshua "Aligorith" Leung -- design specification, initial code
- Lukas "lukas_t" Toenne -- integrating code into blender, with further fixes
- Sergey "Sergey" "Sharybin" -- some mocking around, trying to wrap up the
  project and so
- Bassam "slikdigit" Kurdali -- stressing the new system, reporting all the
  issues and recording/writing documentation.
- Everyone else who i forgot to mention here :)

1 files changed, 197 insertions, 0 deletions

diff --git a/source/blender/depsgraph/intern/depsnode_component.h b/source/blender/depsgraph/intern/depsnode_component.h
new file mode 100644
index 00000000000..06a18b60abb
--- /dev/null
+++ b/source/blender/depsgraph/intern/depsnode_component.h
@@ -0,0 +1,197 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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) 2013 Blender Foundation.
+ * All rights reserved.
+ *
+ * Original Author: Joshua Leung
+ * Contributor(s): None Yet
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#ifndef __DEPSNODE_COMPONENT_H__
+#define __DEPSNODE_COMPONENT_H__
+
+#include "depsnode.h"
+
+#include "depsgraph_util_hash.h"
+#include "depsgraph_util_map.h"
+#include "depsgraph_util_set.h"
+
+struct ID;
+struct bPoseChannel;
+
+struct Depsgraph;
+struct DepsgraphCopyContext;
+struct EvaluationContext;
+struct OperationDepsNode;
+struct BoneComponentDepsNode;
+
+
+/* ID Component - Base type for all components */
+struct ComponentDepsNode : public DepsNode {
+	/* Key used to look up operations within a component */
+	struct OperationIDKey
+	{
+		eDepsOperation_Code opcode;
+		string name;
+
+
+		OperationIDKey() :
+			opcode(DEG_OPCODE_OPERATION), name("")
+		{}
+		OperationIDKey(eDepsOperation_Code opcode) :
+			opcode(opcode), name("")
+		{}
+		OperationIDKey(eDepsOperation_Code opcode, const string &name) :
+		   opcode(opcode), name(name)
+		{}
+
+		string identifier() const
+		{
+			char codebuf[5];
+			sprintf(codebuf, "%d", opcode);
+
+			return string("OperationIDKey(") + codebuf + ", " + name + ")";
+		}
+
+		bool operator==(const OperationIDKey &other) const
+		{
+			return (opcode == other.opcode) && (name == other.name);
+		}
+	};
+
+	/* XXX can't specialize std::hash for this purpose, because ComponentKey is a nested type ...
+	 * http://stackoverflow.com/a/951245
+	 */
+	struct operation_key_hash {
+		bool operator() (const OperationIDKey &key) const
+		{
+			return hash_combine(hash<int>()(key.opcode), hash<string>()(key.name));
+		}
+	};
+
+	/* Typedef for container of operations */
+	typedef unordered_map<OperationIDKey, OperationDepsNode *, operation_key_hash> OperationMap;
+
+
+	ComponentDepsNode();
+	~ComponentDepsNode();
+
+	void init(const ID *id, const string &subdata);
+	void copy(DepsgraphCopyContext *dcc, const ComponentDepsNode *src);
+
+	string identifier() const;
+
+	/* Find an existing operation, will throw an assert() if it does not exist. */
+	OperationDepsNode *find_operation(OperationIDKey key) const;
+	OperationDepsNode *find_operation(eDepsOperation_Code opcode, const string &name) const;
+
+	/* Check operation exists and return it. */
+	OperationDepsNode *has_operation(OperationIDKey key) const;
+	OperationDepsNode *has_operation(eDepsOperation_Code opcode, const string &name) const;
+
+	/**
+	 * Create a new node for representing an operation and add this to graph
+	 * \warning If an existing node is found, it will be modified. This helps when node may
+	 * have been partially created earlier (e.g. parent ref before parent item is added)
+	 *
+	 * \param type: Operation node type (corresponding to context/component that it operates in)
+	 * \param optype: Role that operation plays within component (i.e. where in eval process)
+	 * \param op: The operation to perform
+	 * \param name: Identifier for operation - used to find/locate it again
+	 */
+	OperationDepsNode *add_operation(eDepsOperation_Type optype, DepsEvalOperationCb op, eDepsOperation_Code opcode, const string &name);
+
+	void remove_operation(eDepsOperation_Code opcode, const string &name);
+	void clear_operations();
+
+	void tag_update(Depsgraph *graph);
+
+	/* Evaluation Context Management .................. */
+
+	/* Initialize component's evaluation context used for the specified purpose */
+	virtual bool eval_context_init(EvaluationContext * /*eval_ctx*/) { return false; }
+	/* Free data in component's evaluation context which is used for the specified purpose
+	 * NOTE: this does not free the actual context in question
+	 */
+	virtual void eval_context_free(EvaluationContext * /*eval_ctx*/) {}
+
+	OperationDepsNode *get_entry_operation();
+	OperationDepsNode *get_exit_operation();
+
+	IDDepsNode *owner;
+
+	OperationMap operations;    /* inner nodes for this component */
+	OperationDepsNode *entry_operation;
+	OperationDepsNode *exit_operation;
+
+	// XXX: a poll() callback to check if component's first node can be started?
+};
+
+/* ---------------------------------------- */
+
+struct ParametersComponentDepsNode : public ComponentDepsNode {
+	DEG_DEPSNODE_DECLARE;
+};
+
+struct AnimationComponentDepsNode : public ComponentDepsNode {
+	DEG_DEPSNODE_DECLARE;
+};
+
+struct TransformComponentDepsNode : public ComponentDepsNode {
+	DEG_DEPSNODE_DECLARE;
+};
+
+struct ProxyComponentDepsNode : public ComponentDepsNode {
+	DEG_DEPSNODE_DECLARE;
+};
+
+struct GeometryComponentDepsNode : public ComponentDepsNode {
+	DEG_DEPSNODE_DECLARE;
+};
+
+struct SequencerComponentDepsNode : public ComponentDepsNode {
+	DEG_DEPSNODE_DECLARE;
+};
+
+struct PoseComponentDepsNode : public ComponentDepsNode {
+	DEG_DEPSNODE_DECLARE;
+};
+
+/* Bone Component */
+struct BoneComponentDepsNode : public ComponentDepsNode {
+	void init(const ID *id, const string &subdata);
+
+	struct bPoseChannel *pchan;     /* the bone that this component represents */
+
+	DEG_DEPSNODE_DECLARE;
+};
+
+struct ParticlesComponentDepsNode : public ComponentDepsNode {
+	DEG_DEPSNODE_DECLARE;
+};
+
+struct ShadingComponentDepsNode : public ComponentDepsNode {
+	DEG_DEPSNODE_DECLARE;
+};
+
+
+void DEG_register_component_depsnodes();
+
+#endif  /* __DEPSNODE_COMPONENT_H__ */