Migrating from tactile¶

isotile keeps the tiling type numbers (IH1 to IH93, 81 of them), the parameter format and the geometry of tactile: vertices, aspects, translation vectors, edge transforms and the tile order of the scanline fill agree with tactile for all types. What changes is the interface: results are NumPy arrays instead of lists of points and generators, and tiles are returned as one TileSet.

The code blocks marked py use tactile and are not run; the python blocks use isotile and run with the pages.

Create a tiling and set parameters¶

import tactile

tiling = tactile.IsohedralTiling(7)
tiling.parameters = [0.5, 0.2]  # must be a Python list
print(tiling.num_parameters, tiling.vertices)  # list of Point

from isotile import IsohedralTiling

tiling = IsohedralTiling(7)
tiling.parameters = [0.5, 0.2]  # any array-like, stored as float64
print(tiling.type.n_params, tiling.vertices.shape)  # (6, 2) array

The parameters setter checks the length and that the prototile is a simple polygon, and keeps the previous state when it raises InvalidPrototileError (a ValueError). with_parameters returns a changed copy and leaves the tiling unchanged. tactile does not check the prototile; use check_prototile to test a parameter set without constructing a tiling.

Geometry of the prototile¶

tactile	isotile
`tactile.tiling_types` (list)	`tiling_types()` (tuple of the 81 numbers)
`tiling.num_parameters`, `num_vertices`, `num_aspects`, `num_edge_shapes`	`tiling.type.n_params`, `n_vertices`, `n_aspects`, `n_edge_shapes`
`tiling.vertices` (list of `Point`)	`tiling.vertices`, an `(n_vertices, 2)` array
`tiling.aspects` (list of 6-lists)	`tiling.aspects`, an `(n_aspects, 2, 3)` array of affine matrices
`tiling.t1`, `tiling.t2`	`tiling.translation_u`, `tiling.translation_v`
`tiling.edges`, `tiling.reversals`	`tiling.edge_transforms` `(n_vertices, 2, 3)`, `tiling.edge_reversed`
`tiling.shapes`, `tiling.parts` (generators of `Shape`)	`tiling.edges` (tuple of `EdgeInfo`), `tiling.edge_shape_ids`, `tiling.edge_shapes`
`tiling.edge_shapes` (`EdgeShape` enum)	`tiling.edge_shapes` (strings `"I"`, `"J"`, `"U"`, `"S"`)

An affine matrix is (2, 3): the linear part and the translation. tactile stores it as [a, b, tx, c, d, ty].

Fill a rectangle¶

for shape in tiling.fill_region_bounds(0, 0, 10, 6):
    t, t1, t2, aspect = shape.T, shape.t1, shape.t2, shape.aspect
    color = tiling.get_color(t1, t2, aspect)

tiles = tiling.fill((0, 0, 10, 6))  # the same tiles in the same order, without repeats
print(len(tiles), tiles.cell[0], tiles.aspect[0], tiles.transforms.shape, tiles.colors()[:3])

The tile i has the lattice cell tiles.cell[i] (tactile's t1, t2), the index tiles.aspect[i] and the affine transform tiles.transforms[i] of the prototile onto the tile. tiles.vertices() gives the corners of all tiles and tiles.colors() the colors of get_color. tactile's fill can return the same tile twice for some regions; fill returns each tile once. fill and tactile's fill_region_bounds use the native coordinates of the type; to place tiles in a region of your coordinates use fill_region (a tile count or a tile size) or set a frame.

What tactile does not have¶

Tile selection that covers a region (cover, fill_region) and tiles from lattice cells (tiles).
Adjacency of tiles from a lattice table: tiles.adjacency("edge"), neighbors, neighbor_lists.
A frame (scale, rotation, position), named constructors for squares, hexagons, triangles and quadrilaterals, and presets (list_presets).
Edge curves with symmetry constraints and an exact validity test, serialization (save, load, to_dict) and GeoJSON export (TileSet.to_geojson).
find_types and TilingType.info to select and describe types.

Not carried over¶

The 12 types of tactile's numbering without an implementation (IH numbers missing from tiling_types()) are not provided, as in tactile. The tactile package itself is only needed to rebuild src/isotile/data/types.npz and to run the equivalence tests.