Cycles: Ensure order of shader nodes in the dependnecies set

The issue was than nodes dependencies were stored as set<ShaderNode*> which
is actually a so called "strict weak ordered", meaning order of nodes in
the set is strictly defined, but based on the ShaderNode pointer. This means
that between different render invokations order of original nodes could be
different due to different pointers allocated for ShaderNode.

This commit makes it so dependencies and maps used for ShaderNodes are based
on the node->id which has much more predictable order. It's still possible
to trick the system by doing some crazy edits during viewport rendfer and
cause difference between viewport and final render stacks.

Reviewers: brecht

Reviewed By: brecht

Subscribers: LazyDodo

Differential Revision: https://developer.blender.org/D1630

1 files changed, 14 insertions, 13 deletions

diff --git a/intern/cycles/render/svm.h b/intern/cycles/render/svm.h
index e48fe5e32ed..02855f22fb3 100644
--- a/intern/cycles/render/svm.h
+++ b/intern/cycles/render/svm.h
@@ -112,35 +112,36 @@ protected:
 	struct StackBackup {
 		Stack stack;
 		vector<int> offsets;
-		set<ShaderNode*> done;
+		ShaderNodeSet done;
 	};
 
-	void stack_backup(StackBackup& backup, set<ShaderNode*>& done);
-	void stack_restore(StackBackup& backup, set<ShaderNode*>& done);
+	void stack_backup(StackBackup& backup, ShaderNodeSet& done);
+	void stack_restore(StackBackup& backup, ShaderNodeSet& done);
 
 	void stack_clear_temporary(ShaderNode *node);
 	int stack_size(ShaderSocketType type);
-	void stack_clear_users(ShaderNode *node, set<ShaderNode*>& done);
+	void stack_clear_users(ShaderNode *node, ShaderNodeSet& done);
 
 	bool node_skip_input(ShaderNode *node, ShaderInput *input);
 
 	/* single closure */
-	void find_dependencies(set<ShaderNode*>& dependencies,
-	                       const set<ShaderNode*>& done,
+	void find_dependencies(ShaderNodeSet& dependencies,
+	                       const ShaderNodeSet& done,
 	                       ShaderInput *input,
 	                       ShaderNode *skip_node = NULL);
-	void generate_node(ShaderNode *node, set<ShaderNode*>& done);
-	void generate_closure_node(ShaderNode *node, set<ShaderNode*>& done);
+	void generate_node(ShaderNode *node, ShaderNodeSet& done);
+	void generate_closure_node(ShaderNode *node, ShaderNodeSet& done);
 	void generated_shared_closure_nodes(ShaderNode *root_node, ShaderNode *node,
-	                                    set<ShaderNode*>& done,
-		set<ShaderNode*>& closure_done, const set<ShaderNode*>& shared);
-	void generate_svm_nodes(const set<ShaderNode*>& nodes, set<ShaderNode*>& done);
+	                                    ShaderNodeSet& done,
+	                                    ShaderNodeSet& closure_done,
+	                                    const ShaderNodeSet& shared);
+	void generate_svm_nodes(const ShaderNodeSet& nodes, ShaderNodeSet& done);
 
 	/* multi closure */
 	void generate_multi_closure(ShaderNode *root_node,
 	                            ShaderNode *node,
-	                            set<ShaderNode*>& done,
-	                            set<ShaderNode*>& closure_done);
+	                            ShaderNodeSet& done,
+	                            ShaderNodeSet& closure_done);
 
 	/* compile */
 	void compile_type(Shader *shader, ShaderGraph *graph, ShaderType type);