Cycles: merging features from tomato branch.

=== BVH build time optimizations ===

* BVH building was multithreaded. Not all building is multithreaded, packing
  and the initial bounding/splitting is still single threaded, but recursive
  splitting is, which was the main bottleneck.

* Object splitting now uses binning rather than sorting of all elements, using
  code from the Embree raytracer from Intel.
  http://software.intel.com/en-us/articles/embree-photo-realistic-ray-tracing-kernels/

* Other small changes to avoid allocations, pack memory more tightly, avoid
  some unnecessary operations, ...

These optimizations do not work yet when Spatial Splits are enabled, for that
more work is needed. There's also other optimizations still needed, in
particular for the case of many low poly objects, the packing step and node
memory allocation.

BVH raytracing time should remain about the same, but BVH build time should be
significantly reduced, test here show speedup of about 5x to 10x on a dual core
and 5x to 25x on an 8-core machine, depending on the scene.

=== Threads ===

Centralized task scheduler for multithreading, which is basically the
CPU device threading code wrapped into something reusable.

Basic idea is that there is a single TaskScheduler that keeps a pool of threads,
one for each core. Other places in the code can then create a TaskPool that they
can drop Tasks in to be executed by the scheduler, and wait for them to complete
or cancel them early.

=== Normal ====

Added a Normal output to the texture coordinate node. This currently
gives the object space normal, which is the same under object animation.

In the future this might become a "generated" normal so it's also stable for
deforming objects, but for now it's already useful for non-deforming objects.

=== Render Layers ===

Per render layer Samples control, leaving it to 0 will use the common scene
setting.

Environment pass will now render environment even if film is set to transparent.

Exclude Layers" added. Scene layers (all object that influence the render,
directly or indirectly) are shared between all render layers. However sometimes
it's useful to leave out some object influence for a particular render layer.
That's what this option allows you to do.

=== Filter Glossy ===

When using a value higher than 0.0, this will blur glossy reflections after
blurry bounces, to reduce noise at the cost of accuracy. 1.0 is a good
starting value to tweak.

Some light paths have a low probability of being found while contributing much
light to the pixel. As a result these light paths will be found in some pixels
and not in others, causing fireflies. An example of such a difficult path might
be a small light that is causing a small specular highlight on a sharp glossy
material, which we are seeing through a rough glossy material. With path tracing
it is difficult to find the specular highlight, but if we increase the roughness
on the material the highlight gets bigger and softer, and so easier to find.

Often this blurring will be hardly noticeable, because we are seeing it through
a blurry material anyway, but there are also cases where this will lead to a
loss of detail in lighting.

1 files changed, 88 insertions, 3 deletions

diff --git a/intern/cycles/bvh/bvh_params.h b/intern/cycles/bvh/bvh_params.h
index 38093438500..0cf5e905fea 100644
--- a/intern/cycles/bvh/bvh_params.h
+++ b/intern/cycles/bvh/bvh_params.h
@@ -18,6 +18,8 @@
 #ifndef __BVH_PARAMS_H__
 #define __BVH_PARAMS_H__
 
+#include "util_boundbox.h"
+
 CCL_NAMESPACE_BEGIN
 
 /* BVH Parameters */
@@ -73,14 +75,97 @@ public:
 	}
 
 	/* SAH costs */
-	float cost(int num_nodes, int num_tris) const
+	__forceinline float cost(int num_nodes, int num_tris) const
 	{ return node_cost(num_nodes) + triangle_cost(num_tris); }
 
-	float triangle_cost(int n) const
+	__forceinline float triangle_cost(int n) const
 	{ return n*sah_triangle_cost; }
 
-	float node_cost(int n) const
+	__forceinline float node_cost(int n) const
 	{ return n*sah_node_cost; }
+
+	__forceinline bool small_enough_for_leaf(int size, int level)
+	{ return (size <= min_leaf_size || level >= MAX_DEPTH); }
+};
+
+/* BVH Reference
+ *
+ * Reference to a primitive. Primitive index and object are sneakily packed
+ * into BoundBox to reduce memory usage and align nicely */
+
+class BVHReference
+{
+public:
+	__forceinline BVHReference() {}
+
+	__forceinline BVHReference(const BoundBox& bounds_, int prim_index, int prim_object)
+	: rbounds(bounds_)
+	{
+		rbounds.min.w = __int_as_float(prim_index);
+		rbounds.max.w = __int_as_float(prim_object);
+	}
+
+	__forceinline const BoundBox& bounds() const { return rbounds; }
+	__forceinline int prim_index() const { return __float_as_int(rbounds.min.w); }
+	__forceinline int prim_object() const { return __float_as_int(rbounds.max.w); }
+
+protected:
+	BoundBox rbounds;
+};
+
+/* BVH Range
+ *
+ * Build range used during construction, to indicate the bounds and place in
+ * the reference array of a subset of pirmitives Again uses trickery to pack
+ * integers into BoundBox for alignment purposes. */
+
+class BVHRange
+{
+public:
+	__forceinline BVHRange()
+	{
+		rbounds.min.w = __int_as_float(0);
+		rbounds.max.w = __int_as_float(0);
+	}
+
+	__forceinline BVHRange(const BoundBox& bounds_, int start_, int size_)
+	: rbounds(bounds_)
+	{
+		rbounds.min.w = __int_as_float(start_);
+		rbounds.max.w = __int_as_float(size_);
+	}
+
+	__forceinline BVHRange(const BoundBox& bounds_, const BoundBox& cbounds_, int start_, int size_)
+	: rbounds(bounds_), cbounds(cbounds_)
+	{
+		rbounds.min.w = __int_as_float(start_);
+		rbounds.max.w = __int_as_float(size_);
+	}
+
+	__forceinline void set_start(int start_) { rbounds.min.w = __int_as_float(start_); }
+
+	__forceinline const BoundBox& bounds() const { return rbounds; }
+	__forceinline const BoundBox& cent_bounds() const { return cbounds; }
+	__forceinline int start() const { return __float_as_int(rbounds.min.w); }
+	__forceinline int size() const { return __float_as_int(rbounds.max.w); }
+	__forceinline int end() const { return start() + size(); }
+
+protected:
+	BoundBox rbounds;
+	BoundBox cbounds;
+};
+
+/* BVH Spatial Bin */
+
+struct BVHSpatialBin
+{
+	BoundBox bounds;
+	int enter;
+	int exit;
+
+	__forceinline BVHSpatialBin()
+	{
+	}
 };
 
 CCL_NAMESPACE_END