Cycles: Replace use_qbvh boolean flag with an enum-based property

This was we can introduce other types of BVH, for example, wider ones, without
causing too much mess around boolean flags.

Thoughs:

- Ideally device info should probably return bitflag of what BVH types it
  supports.

  It is possible to implement based on simple logic in device/ and mesh.cpp,
  rest of the changes will stay the same.

- Not happy with workarounds in util_debug and duplicated enum in kernel.
  Maybe enbum should be stores in kernel, but then it's kind of weird to include
  kernel types from utils. Soudns some cyclkic dependency.

Reviewers: brecht, maxim_d33

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D3011

1 files changed, 9 insertions, 5 deletions

diff --git a/intern/cycles/render/mesh.cpp b/intern/cycles/render/mesh.cpp
index 5d5a416e293..4bf5b60a737 100644
--- a/intern/cycles/render/mesh.cpp
+++ b/intern/cycles/render/mesh.cpp
@@ -1058,7 +1058,9 @@ void Mesh::compute_bvh(Device *device,
 
 			BVHParams bparams;
 			bparams.use_spatial_split = params->use_bvh_spatial_split;
-			bparams.use_qbvh = params->use_qbvh && device->info.has_qbvh;
+			bparams.bvh_layout = BVHParams::best_bvh_layout(
+			        params->bvh_layout,
+			        device->info.bvh_layout_mask);
 			bparams.use_unaligned_nodes = dscene->data.bvh.have_curves &&
 			                              params->use_bvh_unaligned_nodes;
 			bparams.num_motion_triangle_steps = params->num_bvh_time_steps;
@@ -1817,15 +1819,17 @@ void MeshManager::device_update_bvh(Device *device, DeviceScene *dscene, Scene *
 
 	BVHParams bparams;
 	bparams.top_level = true;
-	bparams.use_qbvh = scene->params.use_qbvh && device->info.has_qbvh;
+	bparams.bvh_layout = BVHParams::best_bvh_layout(
+	        scene->params.bvh_layout,
+	        device->info.bvh_layout_mask);
 	bparams.use_spatial_split = scene->params.use_bvh_spatial_split;
 	bparams.use_unaligned_nodes = dscene->data.bvh.have_curves &&
 	                              scene->params.use_bvh_unaligned_nodes;
 	bparams.num_motion_triangle_steps = scene->params.num_bvh_time_steps;
 	bparams.num_motion_curve_steps = scene->params.num_bvh_time_steps;
 
-	VLOG(1) << (bparams.use_qbvh ? "Using QBVH optimization structure"
-	                             : "Using regular BVH optimization structure");
+	VLOG(1) << "Using " << bvh_layout_name(bparams.bvh_layout)
+	        << " layout.";
 
 	BVH *bvh = BVH::create(bparams, scene->objects);
 	bvh->build(progress);
@@ -1882,7 +1886,7 @@ void MeshManager::device_update_bvh(Device *device, DeviceScene *dscene, Scene *
 	}
 
 	dscene->data.bvh.root = pack.root_index;
-	dscene->data.bvh.use_qbvh = bparams.use_qbvh;
+	dscene->data.bvh.bvh_layout = bparams.bvh_layout;
 	dscene->data.bvh.use_bvh_steps = (scene->params.num_bvh_time_steps != 0);
 
 	delete bvh;