GridTracer and Coverage

GridTracer and Coverage

GridTracer is the utility layer that translates world-space shapes into grid-space coverage.

Several higher-level systems depend on the same answer:

"Which cells does this world-space region touch in this world?"

The Core Outputs

GridTracer exposes world-scoped entry points such as:

• TraceLine(GridWorld world, Vector3d start, Vector3d end, ...)
• TraceLine(GridWorld world, Vector2d start, Vector2d end, ...)
• GetCoveredVoxels(GridWorld world, Vector3d boundsMin, Vector3d boundsMax, ...)
• GetCoveredScanCells(GridWorld world, Vector3d boundsMin, Vector3d boundsMax, ...)

The Common Coverage Pipeline

world-space input
  -> snap to voxel-aligned bounds or points
  -> find candidate grids through GridWorld
  -> enumerate covered voxels or scan cells
  -> group or yield results

Why Coverage Is Grouped By Grid

Coverage often crosses more than one grid. Returning grouped results preserves that reality.

GridVoxelSet keeps:

• the VoxelGrid that owns the covered cells
• the list of covered voxels for that grid

How Blockers Use Coverage

Blocker and BoundsBlocker delegate region-to-voxel logic to the tracer.

blocker bounds
  -> GridTracer.GetCoveredVoxels(world, ...)
  -> per-grid covered voxel sets
  -> obstacle mutation on each covered voxel

Result Lifetime And Pooling

This is one of the most important practical details:

• GridVoxelSet.Voxels is backed by pooled storage
• the tracer releases those pooled lists after yielding each grouped result

Callers should treat grouped voxel lists as transient and consume them immediately inside the enumeration.