| | | 1 | | //======================================================================= |
| | | 2 | | // GridTraversal.cs |
| | | 3 | | //======================================================================= |
| | | 4 | | // MIT License, Copyright (c) 2024–present David Oravsky (mrdav30) |
| | | 5 | | // See LICENSE file in the project root for full license information. |
| | | 6 | | //======================================================================= |
| | | 7 | | |
| | | 8 | | using FixedMathSharp; |
| | | 9 | | using GridForge.Grids; |
| | | 10 | | using GridForge.Grids.Topology; |
| | | 11 | | using GridForge.Spatial; |
| | | 12 | | using SwiftCollections; |
| | | 13 | | using System.Runtime.CompilerServices; |
| | | 14 | | |
| | | 15 | | namespace GridForge.Utility; |
| | | 16 | | |
| | | 17 | | /// <summary> |
| | | 18 | | /// Selects which topology edge measurement a grid traversal should use for padding. |
| | | 19 | | /// </summary> |
| | | 20 | | public enum GridTraversalPaddingMode |
| | | 21 | | { |
| | | 22 | | /// <summary> |
| | | 23 | | /// Use the largest three-dimensional cell edge. |
| | | 24 | | /// </summary> |
| | | 25 | | MaxCellEdge, |
| | | 26 | | |
| | | 27 | | /// <summary> |
| | | 28 | | /// Use the largest X/Z-plane cell edge. |
| | | 29 | | /// </summary> |
| | | 30 | | PlanarMaxCellEdge |
| | | 31 | | } |
| | | 32 | | |
| | | 33 | | /// <summary> |
| | | 34 | | /// Tracks per-grid traversal padding while suppressing duplicate voxel visits. |
| | | 35 | | /// </summary> |
| | | 36 | | public struct GridTraversalState |
| | | 37 | | { |
| | | 38 | | private readonly GridWorld _world; |
| | | 39 | | private readonly GridTraversalPaddingMode _paddingMode; |
| | | 40 | | private ushort _currentGridIndex; |
| | | 41 | | private Fixed64 _cellEdge; |
| | | 42 | | private bool _hasCachedGrid; |
| | | 43 | | |
| | | 44 | | /// <summary> |
| | | 45 | | /// Initializes traversal state for one world and padding mode. |
| | | 46 | | /// </summary> |
| | | 47 | | public GridTraversalState(GridWorld world, GridTraversalPaddingMode paddingMode) |
| | | 48 | | { |
| | | 49 | | _world = world; |
| | | 50 | | _paddingMode = paddingMode; |
| | | 51 | | _currentGridIndex = 0; |
| | | 52 | | _cellEdge = Fixed64.Zero; |
| | | 53 | | _hasCachedGrid = false; |
| | | 54 | | } |
| | | 55 | | |
| | | 56 | | /// <summary> |
| | | 57 | | /// Visits a voxel only once and returns the selected cell-edge measurement for its grid. |
| | | 58 | | /// </summary> |
| | | 59 | | [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| | | 60 | | public bool TryVisitUnique(Voxel voxel, SwiftHashSet<int> visited, out Fixed64 cellEdge) |
| | | 61 | | { |
| | | 62 | | cellEdge = Fixed64.Zero; |
| | | 63 | | if (!visited.Add(voxel.SpawnToken)) |
| | | 64 | | return false; |
| | | 65 | | |
| | | 66 | | cellEdge = GetCellEdge(voxel); |
| | | 67 | | return true; |
| | | 68 | | } |
| | | 69 | | |
| | | 70 | | /// <summary> |
| | | 71 | | /// Gets the selected cell-edge measurement for a voxel's grid, caching repeated grid lookups. |
| | | 72 | | /// </summary> |
| | | 73 | | [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| | | 74 | | public Fixed64 GetCellEdge(Voxel voxel) |
| | | 75 | | { |
| | | 76 | | if (_hasCachedGrid && voxel.GridIndex == _currentGridIndex) |
| | | 77 | | return _cellEdge; |
| | | 78 | | |
| | | 79 | | _currentGridIndex = voxel.GridIndex; |
| | | 80 | | _hasCachedGrid = true; |
| | | 81 | | VoxelGrid grid = _world.ActiveGrids[_currentGridIndex]; |
| | | 82 | | _cellEdge = _paddingMode == GridTraversalPaddingMode.PlanarMaxCellEdge |
| | | 83 | | ? GridTopologyMetricUtility.GetPlanarMaxCellEdge(grid) |
| | | 84 | | : GridTopologyMetricUtility.GetMaxCellEdge(grid); |
| | | 85 | | return _cellEdge; |
| | | 86 | | } |
| | | 87 | | } |
| | | 88 | | |
| | | 89 | | /// <summary> |
| | | 90 | | /// Provides deterministic helpers for duplicate-safe voxel traversal. |
| | | 91 | | /// </summary> |
| | | 92 | | public static class GridTraversal |
| | | 93 | | { |
| | | 94 | | /// <summary> |
| | | 95 | | /// Gets a voxel partition once per voxel spawn token. |
| | | 96 | | /// </summary> |
| | | 97 | | [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| | | 98 | | public static bool TryGetUniquePartition<TPartition>( |
| | | 99 | | Voxel voxel, |
| | | 100 | | SwiftHashSet<int> visited, |
| | | 101 | | out TPartition? partition) |
| | | 102 | | where TPartition : class, IVoxelPartition |
| | | 103 | | { |
| | 2 | 104 | | partition = null; |
| | 2 | 105 | | return visited.Add(voxel.SpawnToken) |
| | 2 | 106 | | && voxel.TryGetPartition(out partition); |
| | | 107 | | } |
| | | 108 | | |
| | | 109 | | /// <summary> |
| | | 110 | | /// Tests whether a 3D world position lies inside bounds expanded by half of a cell edge. |
| | | 111 | | /// </summary> |
| | | 112 | | [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| | | 113 | | public static bool IsWorldPositionInPaddedBounds( |
| | | 114 | | Vector3d min, |
| | | 115 | | Vector3d max, |
| | | 116 | | Fixed64 cellEdge, |
| | | 117 | | Vector3d worldPosition) |
| | | 118 | | { |
| | 2 | 119 | | Fixed64 padding = cellEdge * Fixed64.Half; |
| | 2 | 120 | | return worldPosition.X >= min.X - padding |
| | 2 | 121 | | && worldPosition.X <= max.X + padding |
| | 2 | 122 | | && worldPosition.Y >= min.Y - padding |
| | 2 | 123 | | && worldPosition.Y <= max.Y + padding |
| | 2 | 124 | | && worldPosition.Z >= min.Z - padding |
| | 2 | 125 | | && worldPosition.Z <= max.Z + padding; |
| | | 126 | | } |
| | | 127 | | |
| | | 128 | | /// <summary> |
| | | 129 | | /// Tests whether a world position's X/Z projection lies inside bounds expanded by half of a cell edge. |
| | | 130 | | /// </summary> |
| | | 131 | | [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| | | 132 | | public static bool IsPlanarPositionInPaddedBounds( |
| | | 133 | | Vector2d min, |
| | | 134 | | Vector2d max, |
| | | 135 | | Fixed64 cellEdge, |
| | | 136 | | Vector3d worldPosition) |
| | | 137 | | { |
| | 2 | 138 | | Fixed64 padding = cellEdge * Fixed64.Half; |
| | 2 | 139 | | return worldPosition.X >= min.X - padding |
| | 2 | 140 | | && worldPosition.X <= max.X + padding |
| | 2 | 141 | | && worldPosition.Z >= min.Y - padding |
| | 2 | 142 | | && worldPosition.Z <= max.Y + padding; |
| | | 143 | | } |
| | | 144 | | } |