Cycles: Wrap spatial split storage into own structure

This has following advantages:

- Localizes all the run-time storage into a single structure,
  which could easily be extended further.

- Storage could be created per-thread, so once builder is
  threaded we wouldn't have any conflicts between threads.

- Global nature of the storage avoids memory re-allocation
  on the runtime, keeping builder as fast as possible.

Currently it's just API changes, which don't affect user at all.

1 files changed, 23 insertions, 6 deletions

diff --git a/intern/cycles/bvh/bvh_split.h b/intern/cycles/bvh/bvh_split.h
index 1e46bb66203..cc61899c9b5 100644
--- a/intern/cycles/bvh/bvh_split.h
+++ b/intern/cycles/bvh/bvh_split.h
@@ -37,9 +37,18 @@ public:
 	BoundBox right_bounds;
 
 	BVHObjectSplit() {}
-	BVHObjectSplit(BVHBuild *builder, const BVHRange& range, float nodeSAH);
+	BVHObjectSplit(BVHBuild *builder,
+	               BVHSpatialStorage *storage,
+	               const BVHRange& range,
+	               float nodeSAH);
 
-	void split(BVHBuild *builder, BVHRange& left, BVHRange& right, const BVHRange& range);
+	void split(BVHBuild *builder,
+	           BVHRange& left,
+	           BVHRange& right,
+	           const BVHRange& range);
+
+protected:
+	BVHSpatialStorage *storage_;
 };
 
 /* Spatial Split */
@@ -52,7 +61,10 @@ public:
 	float pos;
 
 	BVHSpatialSplit() : sah(FLT_MAX), dim(0), pos(0.0f) {}
-	BVHSpatialSplit(BVHBuild *builder, const BVHRange& range, float nodeSAH);
+	BVHSpatialSplit(BVHBuild *builder,
+	                BVHSpatialStorage *storage,
+	                const BVHRange& range,
+	                float nodeSAH);
 
 	void split(BVHBuild *builder, BVHRange& left, BVHRange& right, const BVHRange& range);
 	void split_reference(BVHBuild *builder,
@@ -63,6 +75,8 @@ public:
 	                     float pos);
 
 protected:
+	BVHSpatialStorage *storage_;
+
 	/* Lower-level functions which calculates boundaries of left and right nodes
 	 * needed for spatial split.
 	 *
@@ -123,7 +137,10 @@ public:
 
 	bool no_split;
 
-	__forceinline BVHMixedSplit(BVHBuild *builder, const BVHRange& range, int level)
+	__forceinline BVHMixedSplit(BVHBuild *builder,
+	                            BVHSpatialStorage *storage,
+	                            const BVHRange& range,
+	                            int level)
 	{
 		/* find split candidates. */
 		float area = range.bounds().safe_area();
@@ -131,14 +148,14 @@ public:
 		leafSAH = area * builder->params.primitive_cost(range.size());
 		nodeSAH = area * builder->params.node_cost(2);
 
-		object = BVHObjectSplit(builder, range, nodeSAH);
+		object = BVHObjectSplit(builder, storage, range, nodeSAH);
 
 		if(builder->params.use_spatial_split && level < BVHParams::MAX_SPATIAL_DEPTH) {
 			BoundBox overlap = object.left_bounds;
 			overlap.intersect(object.right_bounds);
 
 			if(overlap.safe_area() >= builder->spatial_min_overlap)
-				spatial = BVHSpatialSplit(builder, range, nodeSAH);
+				spatial = BVHSpatialSplit(builder, storage, range, nodeSAH);
 		}
 
 		/* leaf SAH is the lowest => create leaf. */