Rectilinear chunks page: regular and rectilinear Zarr chunk grids

README.md

@@ -479,6 +479,20 @@ zarr-python (`test/fixtures/structure`, made by
 `lev`, then `lvl`, `t` (unfold), `ex` (stack), `pick` (x,y in the CRS),
 `tiles`, `pix`, `coast`, `grat`, `cam`.
 
+## Rectilinear chunks
+
+`rectilinear.html` compares a regular Zarr chunk grid with a rectilinear one
+(the `rectilinear` chunk grid of zarr-extensions, after ZEP0003): one list of
+chunk lengths per axis, cut across the whole array. Cases: the overhanging last
+chunk of a regular grid, days in months and years, years of files each chunked
+inside (a short last chunk per file, exact only if the file did not pad it),
+and mosaics of uneven, staggered and overlapping tiles (a grid is a partition,
+so overlap cannot be expressed). A read along time shows the chunks it touches
+and the values decoded against those wanted, for both grids. Paste a zarr.json
+or read one from a URL to draw its grid. `src/core/chunkgrid.js`, checked in
+`test/check-chunkgrid.mjs`. Hash keys: `case`, `grid` (`reg`, `rect`), `c`,
+`a`, `w`, `where` (`map`, `pixel`), `ex`, `cam`.
+
 ## Rasterize
 
 `rasterize.html` puts one polygon on one grid two ways, side by side. On the
@@ -842,6 +856,7 @@ h3.html, js/h3.js                      H3 hexagons on the icosahedron
 grids.html, js/grids-page.js           model grids page
 indexspace.html, js/indexspace.js      index space page
 structure.html, js/structure-page.js   tiles and overviews page
+rectilinear.html, js/rectilinear.js    rectilinear chunks: regular and rectilinear Zarr chunk grids, calendars, files, mosaics
 regular.html, js/regular-page.js       regular in what? storyline: geostationary, lon/lat arrays
 rasterize.html, js/rasterize-page.js   rasterize page
 affine.html, js/affine.js              Affine: the geotransform, world file, registering an image by two points
@@ -889,6 +904,7 @@ src/core/icosa.js                 icosahedron from 12 vertices, gnomonic face fr
 src/core/roms.js                  ROMS s-coordinate, synthetic grids and data, Zarr grid reader
 src/core/regular.js               which CRS makes a lon/lat array regular; example grids; geos scan angles
 src/core/structure.js             grid, tile and file structure of COG, Zarr, WMTS, ArcGIS, XYZ and specs
+src/core/chunkgrid.js             regular and rectilinear chunk grids: lookup, read cost, zarr.json chunk_grid, calendars, mosaics
 src/core/rasterize.js             centre-in scanline fill, exact coverage fractions, runs, tiles and bytes
 src/core/grids.js                 rotated pole, tripolar, cubed sphere and Yin-Yang grids
 src/core/homage-geo.js            Robinson, Winkel tripel, Van der Grinten, cea; Dymaxion icosahedron and net

aatgrid.html

@@ -28,7 +28,7 @@
   <aside id="panel">
     <header>
       <h1>playproj</h1>
-      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html" aria-current="page">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
+      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html" aria-current="page">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rectilinear.html">Rectilinear chunks</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
     </header>
 
     <section class="embed-keep">

affine.html

@@ -25,7 +25,7 @@
   <aside id="panel">
     <header>
       <h1>playproj</h1>
-      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html" aria-current="page">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
+      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rectilinear.html">Rectilinear chunks</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html" aria-current="page">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
     </header>
 
     <section>

bins.html

@@ -28,7 +28,7 @@
   <aside id="panel">
     <header>
       <h1>playproj</h1>
-      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html" aria-current="page">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
+      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html" aria-current="page">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rectilinear.html">Rectilinear chunks</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
     </header>
 
     <section class="embed-keep">

catastrophes.html

@@ -29,7 +29,7 @@
   <aside id="panel">
     <header>
       <h1>playproj</h1>
-      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html" aria-current="page">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
+      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rectilinear.html">Rectilinear chunks</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html" aria-current="page">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
     </header>
 
     <section class="embed-keep">

cells.html

@@ -28,7 +28,7 @@
   <aside id="panel">
     <header>
       <h1>playproj</h1>
-      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html" aria-current="page">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
+      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html" aria-current="page">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rectilinear.html">Rectilinear chunks</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
     </header>
 
     <section class="embed-keep">

cones.html

@@ -29,7 +29,7 @@
   <aside id="panel">
     <header>
       <h1>playproj</h1>
-      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html" aria-current="page">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
+      <nav class="pages"><span class="group"><a href="./">Perspective</a><a href="./cones.html" aria-current="page">Cones and cylinders</a></span><span class="group"><a href="./spilhaus.html">Spilhaus</a><a href="./globals.html">Globals and interrupteds</a><a href="./tissot.html">Distortion</a></span><span class="group"><a href="./ellipsoid.html">Ellipsoid</a><a href="./geoid.html">Geoid</a><a href="./ortho.html">Orthorectification</a></span><span class="group"><a href="./cells.html">s2 cells</a><a href="./h3.html">H3 hexagons</a><a href="./bins.html">L3 bins</a><a href="./grids.html">Model grids</a><a href="./indexspace.html">Index space</a><a href="./sentinel.html">MGRS and Sentinel-2</a><a href="./aatgrid.html">AAT grid</a><a href="./structure.html">Tiles and overviews</a><a href="./rectilinear.html">Rectilinear chunks</a><a href="./rasterize.html">Rasterize</a><a href="./affine.html">Affine</a><a href="./regular.html">Regular in what?</a><a href="./hull.html">Convex hull</a></span><span class="group"><a href="./catastrophes.html">Catastrophes</a><a href="./texture.html">Texture mapping</a><a href="./example.html">For example</a></span><span class="group"><a href="./homage.html">Homage</a><a href="./vicgrid.html">VicGrid</a></span><span class="group"><a href="./nuyina.html">Nuyina</a><a href="./rhumb.html">Rhumb lines</a></span></nav>
     </header>
 
     <section class="embed-keep">

css/app.css

@@ -288,3 +288,8 @@ table.gcps input { width: 72px; font: inherit; color: var(--text); background: #
 }
 /* ortho.html: the four images take the whole lower half on a phone */
 @media (max-width: 820px) { #map-label { display: none; } }
+/* rectilinear.html: the cuts along an axis, and the chunk_grid */
+canvas.axis { position: absolute; inset: 0; width: 100%; height: 100%; display: block; cursor: col-resize; touch-action: none; }
+.warn { color: var(--orange); }
+#url { display: block; width: 100%; margin-top: 4px; }
+#note3d:empty, #custom-note:empty { display: none; }