node_pool.mdx

Overview

The node_pool module defines a templated node_t structure and the node_pool class, which together represent a memory-efficient structure for storing and processing hierarchical spatial data such as Sparse Voxel DAGs (SVDAGs). This system is used extensively in voxel rendering, compression, and geometry processing.

node_t<T>

Description

A generic node structure that holds eight children (octree format). This templated class provides value accessors, equality comparison, null node creation, and type-safe utilities.

Definition

template <typename T>
struct node_t {
    std::array<T, 8> children = {0};
    ...
};

Key Methods

  • has_value(): Returns true if any of the children are non-zero.
  • operator bool(): Implicit cast to bool based on has_value().
  • operator== / operator!=: Compares child node values.
  • value(): Access to the internal array (const/non-const).
  • value(size_t index): Access a single child (bounds-checked).
  • static null(): Returns a default node with all-zero children.

murmur_hasher32_t

Description

A custom 32-bit and 64-bit compatible MurmurHash-style hasher for spans of uint32_t. Used to deduplicate node_t<int> efficiently.

Key Methods

  • operator()(std::span<const uint32_t>)
  • operator()(std::span<const uint32_t, 2>)

This ensures compatibility with both general node hashing and a more compact 2-word representation.

Specialization

template<>
struct std::hash<oasis::node_t<int>> {
    size_t operator()(const node_t<int>& v) const;
};

node_pool Class

Purpose

Manages a vector of voxel nodes and provides methods for serialization, deduplication, and manipulation of voxel DAG structures.

Definition

class node_pool {
  std::vector<node_t<int>> m_nodes;
  ...
};

Friend Classes

  • node_pool_editor
  • node_pool_builder
  • node_pool_traversal

Public Interface

Constructor

node_pool();

Destructor

~node_pool();

Methods

void shift_indexes(int size)

Adjusts node indices by an offset (useful when merging multiple pools).

void compress()

Deduplicates nodes to reduce memory and optimize access.

void deserialize(const std::string filename)

Loads node data from a binary file into the pool.

std::vector<node_t<int>>& get_nodes()

Returns a reference to the entire node list.

node_t<int>& get_node(int index)

Access a specific node by index.

size_t size() const

Returns the total number of nodes in the pool.