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Function: resolveSecondaryTiles()

resolveSecondaryTiles(primaryLevel, primaryCol, primaryRow, secondaryLevel, secondaryZ): SecondaryTileResolution

Defined in: packages/deck.gl-raster/src/multi-raster-tileset/secondary-tile-resolver.ts:138

Resolve which secondary tiles cover a primary tile's extent, and compute the UV transform to map from primary UV space into the stitched secondary texture.

The UV transform [offsetX, offsetY, scaleX, scaleY] is intended for use in a shader as sampledUV = uv * scale + offset, where uv is the primary tile's local UV coordinate in [0,1]^2.

The Y axis follows a top-left convention: origin is at the top-left corner, Y increases downward in texture/UV space. CRS coordinates may increase upward (north), so offsetY is computed as (stitchedMaxY - primaryMaxY) / stitchedCrsHeight to account for the flip.

Parameters

primaryLevel

TilesetLevel

The TilesetLevel describing the primary tileset.

primaryCol

number

Column index of the primary tile.

primaryRow

number

Row index of the primary tile.

secondaryLevel

TilesetLevel

The TilesetLevel describing the secondary tileset.

secondaryZ

number

The zoom level index of secondaryLevel within its TilesetDescriptor.levels array. Stored in the returned SecondaryTileResolution.z so the consumer knows which COG overview to fetch.

Returns

SecondaryTileResolution

A SecondaryTileResolution with tile indices, UV transform, stitched dimensions, and the min col/row of the covered range.