Put nodes in a broadphase to reduce tree updates

include/bounce/softbody/softbody.h

@@ -22,7 +22,7 @@
 #include <bounce/common/math/transform.h>
 #include <bounce/common/memory/stack_allocator.h>
 
-#include <bounce/collision/trees/dynamic_tree.h>
+#include <bounce/collision/broad_phase.h>
 
 class b3World;
 
@@ -189,8 +189,11 @@ private:
 	// Soft body triangles
 	b3SoftBodyTriangle* m_triangles;
 
-	// Node tree
-	b3DynamicTree m_nodeTree;
+	// Broadphase
+	b3BroadPhase m_broadPhase;
+
+	// Time-step
+	float32 m_dt;
 
 	// Attached world
 	b3World* m_world;

include/bounce/softbody/softbody_node.h

@@ -163,8 +163,8 @@ private:
 	// Node and body contact
 	b3NodeBodyContact m_bodyContact;
 
-	// Tree identifier
-	u32 m_treeId;
+	// Broadphase proxy
+	u32 m_broadPhaseId;
 
 	// Soft body
 	b3SoftBody* m_body;

src/bounce/softbody/softbody.cpp

@@ -463,6 +463,7 @@ b3SoftBody::b3SoftBody(const b3SoftBodyDef& def)
 	m_c_max = def.c_max;
 	m_gravity.SetZero();
 	m_world = nullptr;
+	m_dt = 0.0f;
 
 	const b3SoftBodyMesh* m = m_mesh;
 
@@ -489,7 +490,7 @@ b3SoftBody::b3SoftBody(const b3SoftBodyDef& def)
 		b3AABB3 aabb;
 		aabb.Set(n->m_position, 0.0f);
 
-		n->m_treeId = m_nodeTree.InsertNode(aabb, n);
+		n->m_broadPhaseId = m_broadPhase.CreateProxy(aabb, n);
 	}
 
 	// Compute mass
@@ -778,7 +779,7 @@ void b3SoftBody::UpdateContacts()
 			continue;
 		}
 
-		b3AABB3 aabb = m_nodeTree.GetAABB(n->m_treeId);
+		b3AABB3 aabb = m_broadPhase.GetAABB(n->m_broadPhaseId);
 
 		b3SoftBodyUpdateContactsQueryListener listener;
 		listener.sphere.vertex = n->m_position;
@@ -839,6 +840,8 @@ void b3SoftBody::Step(float32 dt, u32 velocityIterations, u32 positionIterations
 {
 	B3_PROFILE("Soft Body Step");
 
+	m_dt = dt;
+
 	// Update contacts
 	UpdateContacts();
 

src/bounce/softbody/softbody_node.cpp

@@ -39,5 +39,7 @@ void b3SoftBodyNode::Synchronize()
 	b3AABB3 aabb;
 	aabb.Set(m_position, m_radius);
 
-	m_body->m_nodeTree.UpdateNode(m_treeId, aabb);
+	b3Vec3 displacement = m_body->m_dt * m_velocity;
+
+	m_body->m_broadPhase.MoveProxy(m_broadPhaseId, aabb, displacement);
 }