Cycles: code refactoring to deduplicate the various BVH traversal variations.

Now there is a single BVH traversal code with #ifdefs for various features.
At runtime it will then select the appropriate variation to use depending if
instancing, hair or motion blur is in use.

This makes scenes without hair render a bit faster, especially after the
minimum width feature was added. It's not the most beautiful code, but we can't
use c++ templates and there were already 4 copies, adding 4 more to handle the
hair case separately would be too much.

1 files changed, 17 insertions, 3 deletions

diff --git a/intern/cycles/render/object.cpp b/intern/cycles/render/object.cpp
index 17008b7a7f3..1a2780995e3 100644
--- a/intern/cycles/render/object.cpp
+++ b/intern/cycles/render/object.cpp
@@ -156,6 +156,7 @@ void ObjectManager::device_update_transforms(Device *device, DeviceScene *dscene
 	map<Mesh*, float> surface_area_map;
 	Scene::MotionType need_motion = scene->need_motion(device->info.advanced_shading);
 	bool have_motion = false;
+	bool have_curves = false;
 
 	objects = dscene->objects.resize(OBJECT_SIZE*scene->objects.size());
 	if(need_motion == Scene::MOTION_PASS)
@@ -176,7 +177,7 @@ void ObjectManager::device_update_transforms(Device *device, DeviceScene *dscene
 		float surface_area = 0.0f;
 		float pass_id = ob->pass_id;
 		float random_number = (float)ob->random_id * (1.0f/(float)0xFFFFFFFF);
-		
+
 		if(transform_uniform_scale(tfm, uniform_scale)) {
 			map<Mesh*, float>::iterator it = surface_area_map.find(mesh);
 
@@ -282,6 +283,10 @@ void ObjectManager::device_update_transforms(Device *device, DeviceScene *dscene
 			flag |= SD_HOLDOUT_MASK;
 		object_flag[i] = flag;
 
+		/* have curves */
+		if(mesh->curves.size())
+			have_curves = true;
+
 		i++;
 
 		if(progress.get_cancel()) return;
@@ -292,6 +297,8 @@ void ObjectManager::device_update_transforms(Device *device, DeviceScene *dscene
 		device->tex_alloc("__objects_vector", dscene->objects_vector);
 
 	dscene->data.bvh.have_motion = have_motion;
+	dscene->data.bvh.have_curves = have_curves;
+	dscene->data.bvh.have_instancing = true;
 }
 
 void ObjectManager::device_update(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
@@ -319,7 +326,7 @@ void ObjectManager::device_update(Device *device, DeviceScene *dscene, Scene *sc
 	/* todo: do before to support getting object level coords? */
 	if(scene->params.bvh_type == SceneParams::BVH_STATIC) {
 		progress.set_status("Updating Objects", "Applying Static Transformations");
-		apply_static_transforms(scene, object_flag, progress);
+		apply_static_transforms(dscene, scene, object_flag, progress);
 	}
 
 	/* allocate object flag */
@@ -338,7 +345,7 @@ void ObjectManager::device_free(Device *device, DeviceScene *dscene)
 	dscene->object_flag.clear();
 }
 
-void ObjectManager::apply_static_transforms(Scene *scene, uint *object_flag, Progress& progress)
+void ObjectManager::apply_static_transforms(DeviceScene *dscene, Scene *scene, uint *object_flag, Progress& progress)
 {
 	/* todo: normals and displacement should be done before applying transform! */
 	/* todo: create objects/meshes in right order! */
@@ -352,6 +359,7 @@ void ObjectManager::apply_static_transforms(Scene *scene, uint *object_flag, Pro
 	bool motion_blur = false;
 #endif
 	int i = 0;
+	bool have_instancing = false;
 
 	foreach(Object *object, scene->objects) {
 		map<Mesh*, int>::iterator it = mesh_users.find(object->mesh);
@@ -377,10 +385,16 @@ void ObjectManager::apply_static_transforms(Scene *scene, uint *object_flag, Pro
 
 				object_flag[i] |= SD_TRANSFORM_APPLIED;
 			}
+			else
+				have_instancing = true;
 		}
+		else
+			have_instancing = true;
 
 		i++;
 	}
+
+	dscene->data.bvh.have_instancing = have_instancing;
 }
 
 void ObjectManager::tag_update(Scene *scene)