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

2 files changed, 19 insertions, 11 deletions

diff --git a/intern/cycles/util/util_debug.cpp b/intern/cycles/util/util_debug.cpp
index eb078d69252..9a66a372822 100644
--- a/intern/cycles/util/util_debug.cpp
+++ b/intern/cycles/util/util_debug.cpp
@@ -18,6 +18,8 @@
 
 #include <stdlib.h>
 
+#include "bvh/bvh_params.h"
+
 #include "util/util_logging.h"
 #include "util/util_string.h"
 
@@ -29,7 +31,7 @@ DebugFlags::CPU::CPU()
     sse41(true),
     sse3(true),
     sse2(true),
-    qbvh(true),
+    bvh_layout(BVH_LAYOUT_DEFAULT),
     split_kernel(false)
 {
 	reset();
@@ -55,7 +57,7 @@ void DebugFlags::CPU::reset()
 #undef STRINGIFY
 #undef CHECK_CPU_FLAGS
 
-	qbvh = true;
+	bvh_layout = BVH_LAYOUT_DEFAULT;
 	split_kernel = false;
 }
 
@@ -139,13 +141,13 @@ std::ostream& operator <<(std::ostream &os,
                           DebugFlagsConstRef debug_flags)
 {
 	os << "CPU flags:\n"
-	   << "  AVX2   : " << string_from_bool(debug_flags.cpu.avx2)  << "\n"
-	   << "  AVX    : " << string_from_bool(debug_flags.cpu.avx)   << "\n"
-	   << "  SSE4.1 : " << string_from_bool(debug_flags.cpu.sse41) << "\n"
-	   << "  SSE3   : " << string_from_bool(debug_flags.cpu.sse3)  << "\n"
-	   << "  SSE2   : " << string_from_bool(debug_flags.cpu.sse2)  << "\n"
-	   << "  QBVH   : " << string_from_bool(debug_flags.cpu.qbvh)  << "\n"
-	   << "  Split  : " << string_from_bool(debug_flags.cpu.split_kernel) << "\n";
+	   << "  AVX2       : " << string_from_bool(debug_flags.cpu.avx2) << "\n"
+	   << "  AVX        : " << string_from_bool(debug_flags.cpu.avx) << "\n"
+	   << "  SSE4.1     : " << string_from_bool(debug_flags.cpu.sse41) << "\n"
+	   << "  SSE3       : " << string_from_bool(debug_flags.cpu.sse3) << "\n"
+	   << "  SSE2       : " << string_from_bool(debug_flags.cpu.sse2) << "\n"
+	   << "  BVH layout : " << bvh_layout_name(debug_flags.cpu.bvh_layout) << "\n"
+	   << "  Split      : " << string_from_bool(debug_flags.cpu.split_kernel) << "\n";
 
 	os << "CUDA flags:\n"
 	   << " Adaptive Compile: " << string_from_bool(debug_flags.cuda.adaptive_compile) << "\n";
diff --git a/intern/cycles/util/util_debug.h b/intern/cycles/util/util_debug.h
index ec38cd373ba..f17f8a560ee 100644
--- a/intern/cycles/util/util_debug.h
+++ b/intern/cycles/util/util_debug.h
@@ -20,6 +20,8 @@
 #include <cassert>
 #include <iostream>
 
+#include "bvh/bvh_params.h"
+
 CCL_NAMESPACE_BEGIN
 
 /* Global storage for all sort of flags used to fine-tune behavior of particular
@@ -54,8 +56,12 @@ public:
 		bool has_sse3()  { return has_sse2()  && sse3; }
 		bool has_sse2()  { return sse2; }
 
-		/* Whether QBVH usage is allowed or not. */
-		bool qbvh;
+		/* Requested BVH size.
+		 *
+		 * Rendering will use widest possible BVH which is below or equal
+		 * this one.
+		 */
+		BVHLayout bvh_layout;
 
 		/* Whether split kernel is used */
 		bool split_kernel;