Use object pool to speed up octree construction

This commit is contained in:
Marc Gilleron 2019-04-23 00:47:52 +01:00
parent bfbe382a7d
commit cead529f11
3 changed files with 126 additions and 63 deletions

35
dmc/object_pool.h Normal file
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@ -0,0 +1,35 @@
#ifndef OBJECT_POOL_H
#define OBJECT_POOL_H
#include "core/os/memory.h"
#include <vector>
template <class T>
class ObjectPool {
public:
T *create() {
if (_objects.empty()) {
return memnew(T);
} else {
T *obj = _objects.back();
_objects.pop_back();
return obj;
}
}
void recycle(T *obj) {
obj->init();
_objects.push_back(obj);
}
~ObjectPool() {
for (auto it = _objects.begin(); it != _objects.end(); ++it) {
memdelete(*it);
}
}
private:
std::vector<T *> _objects;
};
#endif // OBJECT_POOL_H

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@ -16,49 +16,7 @@ const float SURFACE_ISO_LEVEL = 0.0;
const float NEAR_SURFACE_FACTOR = 2.0; const float NEAR_SURFACE_FACTOR = 2.0;
const float SQRT3 = 1.7320508075688772; const float SQRT3 = 1.7320508075688772;
// Octree used only for dual grid construction // Helper to modify padded voxel data
struct OctreeNode {
Vector3i origin;
int size; // Nodes are cubic
HermiteValue center_value;
OctreeNode *children[8];
OctreeNode() {
for (int i = 0; i < 8; ++i) {
children[i] = nullptr;
}
}
~OctreeNode() {
for (int i = 0; i < 8; ++i) {
if (children[i]) {
memdelete(children[i]);
}
}
}
inline bool has_children() const {
return children[0] != nullptr;
}
};
void split(OctreeNode *node) {
CRASH_COND(node->has_children());
CRASH_COND(node->size == 1);
for (int i = 0; i < 8; ++i) {
OctreeNode *child = memnew(OctreeNode);
const int *v = OctreeUtility::g_octant_position[i];
child->size = node->size / 2;
child->origin = node->origin + Vector3i(v[0], v[1], v[2]) * child->size;
node->children[i] = child;
}
}
struct VoxelAccess { struct VoxelAccess {
const VoxelBuffer &buffer; const VoxelBuffer &buffer;
@ -190,28 +148,63 @@ inline Vector3 get_center(const OctreeNode *node) {
return node->origin.to_vec3() + 0.5 * Vector3(node->size, node->size, node->size); return node->origin.to_vec3() + 0.5 * Vector3(node->size, node->size, node->size);
} }
void generate_octree_top_down(OctreeNode *node, const VoxelAccess &voxels, float geometric_error) { class OctreeBuilderTopDown {
public:
OctreeBuilderTopDown(const VoxelAccess &voxels, float geometry_error, OctreeNodePool &pool) :
_voxels(voxels),
_geometry_error(geometry_error),
_pool(pool) {
}
if (can_split(node->origin, node->size, voxels, geometric_error)) { OctreeNode *build(Vector3i origin, int size) {
OctreeNode *root = _pool.create();
root->origin = origin;
root->size = size;
build(root);
return root;
}
split(node); private:
void build(OctreeNode *node) {
if (can_split(node->origin, node->size, _voxels, _geometry_error)) {
split(node);
for (int i = 0; i < 8; ++i) {
build(node->children[i]);
}
} else {
node->center_value = _voxels.get_interpolated_hermite_value(get_center(node));
}
}
void split(OctreeNode *node) {
CRASH_COND(node->has_children());
CRASH_COND(node->size == 1);
for (int i = 0; i < 8; ++i) { for (int i = 0; i < 8; ++i) {
generate_octree_top_down(node->children[i], voxels, geometric_error);
OctreeNode *child = _pool.create();
const int *v = OctreeUtility::g_octant_position[i];
child->size = node->size / 2;
child->origin = node->origin + Vector3i(v[0], v[1], v[2]) * child->size;
node->children[i] = child;
} }
} else {
node->center_value = voxels.get_interpolated_hermite_value(get_center(node));
} }
}
private:
const VoxelAccess &_voxels;
const float _geometry_error;
OctreeNodePool &_pool;
};
// Builds the octree bottom-up, to ensure that no detail can be missed by a top-down approach. // Builds the octree bottom-up, to ensure that no detail can be missed by a top-down approach.
class OctreeBuilderBottomUp { class OctreeBuilderBottomUp {
public: public:
OctreeBuilderBottomUp(const VoxelAccess &voxels, float geometry_error) : OctreeBuilderBottomUp(const VoxelAccess &voxels, float geometry_error, OctreeNodePool &pool) :
_voxels(voxels), _voxels(voxels),
_geometry_error(geometry_error) { _geometry_error(geometry_error),
_pool(pool) {
} }
OctreeNode *build(Vector3i node_origin, int node_size) const { OctreeNode *build(Vector3i node_origin, int node_size) const {
@ -235,7 +228,7 @@ public:
// No nodes, test if the 8 octants are worth existing (this could be leaves) // No nodes, test if the 8 octants are worth existing (this could be leaves)
if (can_split(node_origin, node_size, _voxels, _geometry_error)) { if (can_split(node_origin, node_size, _voxels, _geometry_error)) {
node = memnew(OctreeNode); node = _pool.create();
node->origin = node_origin; node->origin = node_origin;
node->size = node_size; node->size = node_size;
@ -252,7 +245,7 @@ public:
// Some child nodes were deemed worthy of existence, // Some child nodes were deemed worthy of existence,
// create their siblings at the same detail level // create their siblings at the same detail level
node = memnew(OctreeNode); node = _pool.create();
node->origin = node_origin; node->origin = node_origin;
node->size = node_size; node->size = node_size;
@ -271,7 +264,7 @@ public:
private: private:
inline OctreeNode *create_child(Vector3i parent_origin, int parent_size, int i) const { inline OctreeNode *create_child(Vector3i parent_origin, int parent_size, int i) const {
const int *dir = OctreeUtility::g_octant_position[i]; const int *dir = OctreeUtility::g_octant_position[i];
OctreeNode *child = memnew(OctreeNode); OctreeNode *child = _pool.create();
child->size = parent_size / 2; child->size = parent_size / 2;
child->origin = parent_origin + child->size * Vector3i(dir[0], dir[1], dir[2]); child->origin = parent_origin + child->size * Vector3i(dir[0], dir[1], dir[2]);
child->center_value = _voxels.get_interpolated_hermite_value(get_center(child)); child->center_value = _voxels.get_interpolated_hermite_value(get_center(child));
@ -281,6 +274,7 @@ private:
private: private:
const VoxelAccess &_voxels; const VoxelAccess &_voxels;
const float _geometry_error; const float _geometry_error;
OctreeNodePool &_pool;
}; };
template <typename Action_T> template <typename Action_T>
@ -1285,13 +1279,11 @@ Ref<ArrayMesh> VoxelMesherDMC::build_mesh(const VoxelBuffer &voxels, real_t geom
// because all voxels are queried. // because all voxels are queried.
// //
#ifdef BUILD_OCTREE_BOTTOM_UP #ifdef BUILD_OCTREE_BOTTOM_UP
dmc::OctreeBuilderBottomUp octree_builder(voxels_access, geometric_error); dmc::OctreeBuilderBottomUp octree_builder(voxels_access, geometric_error, _octree_node_pool);
dmc::OctreeNode *root = octree_builder.build(Vector3i(), chunk_size); dmc::OctreeNode *root = octree_builder.build(Vector3i(), chunk_size);
#else #else
dmc::OctreeNode *root = memnew(dmc::OctreeNode); dmc::OctreeBuilderTopDown octree_builder(voxels_access, geometric_error, _octree_node_pool);
root->origin = Vector3i(); dmc::OctreeNode *root = octree_builder.build(Vector3i(), chunk_size);
root->size = chunk_size;
dmc::generate_octree_top_down(root, voxels_access, geometric_error);
#endif #endif
// TODO OctreeNode pool to stop allocating. Or, flat octree? // TODO OctreeNode pool to stop allocating. Or, flat octree?
@ -1331,7 +1323,7 @@ Ref<ArrayMesh> VoxelMesherDMC::build_mesh(const VoxelBuffer &voxels, real_t geom
_dual_grid.cells.clear(); _dual_grid.cells.clear();
} }
memdelete(root); root->recycle(_octree_node_pool);
} }
// TODO Marching squares skirts // TODO Marching squares skirts

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@ -4,10 +4,45 @@
#include "../voxel_buffer.h" #include "../voxel_buffer.h"
#include "hermite_value.h" #include "hermite_value.h"
#include "mesh_builder.h" #include "mesh_builder.h"
#include "object_pool.h"
#include "scene/resources/mesh.h" #include "scene/resources/mesh.h"
namespace dmc { namespace dmc {
struct OctreeNode;
typedef ObjectPool<OctreeNode> OctreeNodePool;
// Octree used only for dual grid construction
struct OctreeNode {
Vector3i origin;
int size; // Nodes are cubic
HermiteValue center_value;
OctreeNode *children[8];
OctreeNode() {
init();
}
inline void init() {
for (int i = 0; i < 8; ++i) {
children[i] = nullptr;
}
}
void recycle(OctreeNodePool &pool) {
for (int i = 0; i < 8; ++i) {
if (children[i]) {
pool.recycle(children[i]);
}
}
}
inline bool has_children() const {
return children[0] != nullptr;
}
};
struct DualCell { struct DualCell {
Vector3 corners[8]; Vector3 corners[8];
HermiteValue values[8]; HermiteValue values[8];
@ -49,6 +84,7 @@ protected:
private: private:
dmc::MeshBuilder _mesh_builder; dmc::MeshBuilder _mesh_builder;
dmc::DualGrid _dual_grid; dmc::DualGrid _dual_grid;
dmc::OctreeNodePool _octree_node_pool;
struct Stats { struct Stats {
real_t octree_build_time; real_t octree_build_time;