feat: Add antimeridian crossing support to RasterReprojector#269
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Detect when a tile's output positions span the ±180° meridian and normalize longitudes to a continuous range (e.g., [170, 190] instead of [170, -170]). This prevents mesh triangles from spanning 340° of longitude and ensures correct GPU-side interpolation for tiles near the date line.
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I'm curious as to how this works. In |
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@espg do you think you'd be able to add some visual screenshots/screencasts to your PRs to more visually explain the internals of the changes? |
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…hes to ±85.051° (#574) * docs(specs): add antimeridian crossing-tile (cut-in-two) design Design for rendering imagery crossing ±180° in Web Mercator (issues #171, #366). Splits a crossing tile at the antimeridian into west/east pieces so each reprojects as a normal non-crossing tile — avoiding the proj4-rewrap unwrap that prior attempts (#353/#374/#269) stumbled on. Generalizes the RasterReprojector to accept a delaunator-shaped initial-triangulation seed (subsuming #351 uvBounds / pole clamp), splits in _renderSubLayers into two single-mesh RasterLayers, and uses a two-box bounding volume composing with the merged world-copy traversal (#518). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * docs(specs): refine antimeridian spec — add test fixture, handle slanted cuts - Use the vendored geotiff-test-data antimeridian.tif fixture (42x42 EPSG:4326, crosses -180 at column 24) as the primary deterministic crossing test. - Handle slanted (rotated-geotransform) cuts, not just vertical: any straight cut yields convex pieces delaunator triangulates exactly; error only on curved/concave cuts. createInitialConditions is therefore part of the MVP crossing path. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * feat(raster-reproject): add createInitialConditions (delaunator-backed seed) Add the InitialTriangulation type and a tree-shakeable createInitialConditions helper that builds a Delaunay seed from a UV point set. delaunator is confined to its own module (initial-conditions.ts); delatin.ts does not import it and the package is sideEffects:false, so it tree-shakes out for consumers that don't use it. Foundation for antimeridian cut-in-two and the sub-domain capability in #351. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * refactor(raster-reproject): document delaunator seed pattern, don't ship a wrapper Per review: a one-line delaunator wrapper isn't worth a runtime dependency. Expose only the InitialTriangulation type and show the delaunator one-liner in its docstring. delaunator moves to devDependencies — used by tests to validate winding compatibility, not shipped to consumers. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * docs(specs): drop createInitialConditions wrapper from antimeridian design raster-reproject exposes only the InitialTriangulation type + documents the delaunator one-liner; delaunator is a dev/test dep (winding validation), not shipped. Runtime seed-building for crossing tiles is the deck.gl-raster builder's job (follow-up plan). Mark stage 1 done. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * feat(raster-reproject): seed RasterReprojector from an initial triangulation Generalize the constructor to accept an optional initialTriangulation seed (delaunator's data shape), defaulting to a hardcoded unit-square seed so behavior is unchanged and the package needs no runtime triangulation dep. Refinement only ever splits existing triangles, so a sub-domain seed confines the mesh to that region. Tests build seeds via delaunator (the documented pattern) to validate winding compatibility + sub-domain confinement. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * feat(raster-reproject): add rectangleSeed helper for sub-rectangle seeds Build an axis-aligned 2-triangle rectangle seed for a UV sub-rectangle (no delaunator, runtime-safe). UNIT_SQUARE_SEED is now rectangleSeed(0,0,1,1). Used to clamp a mesh to a UV band — e.g. the valid Web Mercator latitude band (#182 / #351) — and reused by the antimeridian vertical-cut case. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * feat(deck.gl-raster): add webMercatorClampSeed (clamp mesh to ±85.051°) Pure helper that returns a rectangleSeed clamping a north-up geographic tile's reprojection mesh to the Web Mercator latitude band, or undefined when no clamp is needed/possible (rotated/projected tiles, fully-polar tiles). Avoids the degenerate near-pole triangles from #182 / #351. Unit-tested with synthetic corner latitudes. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * feat(deck.gl-raster): clamp Web Mercator meshes to valid latitude band Wire the reprojector seed through the render path: RasterLayer gains an initialTriangulation prop (passed to RasterReprojector, regenerated on change); getTileMetadata computes a per-tile _webMercatorReprojectorSeed via webMercatorClampSeed; _renderSubLayers passes it in the Web Mercator branch only (globe shows the poles, full mesh). Fixes the degenerate near-pole triangles for EPSG:4326 imagery reaching ±90° (#182 / #351). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * refactor(deck.gl-raster): name clamp seed as initialTriangulation Rename webMercatorClampSeed → webMercatorInitialTriangulation and the tile metadata field _webMercatorReprojectorSeed → _webMercatorInitialTriangulation, for consistency with the InitialTriangulation type and the RasterLayer.initialTriangulation prop (drops the ad-hoc 'seed'/'ReprojectorSeed' terms). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * refactor(deck.gl-raster): rename clamp fn to createInitialWebMercatorTriangulation Verb-prefixed name for the builder (was webMercatorInitialTriangulation); the tile metadata field stays _webMercatorInitialTriangulation. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * refactor(raster-reproject): rename rectangleSeed -> triangulateRectangle Active verb name for the helper that triangulates a UV rectangle into an InitialTriangulation; internal UNIT_SQUARE_SEED -> UNIT_SQUARE_TRIANGULATION; test file renamed to match. Updates the deck.gl-raster clamp caller too. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * refactor: apply triangulateRectangle rename across source + caller Completes the rename (a657eb8 only moved the test file): rectangleSeed -> triangulateRectangle in delatin.ts + index export + the renamed test, and the deck.gl-raster web-mercator-clamp caller. UNIT_SQUARE_SEED -> UNIT_SQUARE_TRIANGULATION. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Ported from #266. Needed for default globe discussed on source-cooperative/source.coop#230.
Summary
RasterReprojector— when a tile's WGS84 longitudes span >180°, normalize them to a continuous range (e.g., [170, 190] instead of [170, -170]) so mesh triangles don't wrap the wrong way around the globeCloses #171
Test plan
pnpm testinraster-reproject)cog-basicexample — verify no regression in standard rendering