This file contains some documentation on the patterns in symbols/landcover.
Some of the patterns are created by hand, others are generated.
Most of the more complex patterns are generated with generate_pattern.py from a text file.
The first line of a pattern text file has the tile size.
Next the style of the symbols, such as color, opacity and stroke-width (provided as SVG attributes).
The third line should be the symbol shape (the instructions inside an SVG path). Make sure all path commands use relative positions.
Most of the rest is a list of x,y coordinates where to insert the symbol.
It is possible to concatenate multiple symbols with their list of coordinates to generate a pattern with multiple symbols.
Tiles of 8×8px.
Dots with a radius of 0.95px in a rectangular 8×8 grid (color: #f2efe9).
Tiles of 8×8px.
Square dots of 1px in a rectangular 8×8 grid (color: #759e6c).
Tiles of 32×32px.
Diagonal lines with a horizontal distance of 16px on top of a background of #ff5555 with 10% opacity.
Every line has a width of 2√2px (color: #ff5555 and 10% opacity).
Tiles of 32×32px.
Diagonal lines with a horizontal distance of 16px on top of a background of #ff5555 with 8% opacity.
Every line has a width of ½√2px (color: #ff5555 and 12% opacity).
Tiles of 32×32px.
Vertical lines with a distance of 16px on top of a background of #8e8e8e with 14% opacity.
Every line has a width of 3px (color: #8e8e8e and 32.9% opacity).
Tiles of 32×32px.
Horizontal lines with a width of 2px, repeated every 4px (color: #aad3df).
Tiles of 30×30.
Square dots of 1px in a triangular grid with a 6px distance (color: #0e5500 and 57.5% opacity).
Vertical spacing is ½√3=5.2; rounded down to 5px.
Final svg generated with generate_pattern.py from plant_nursery.txt.
Tiles of 256×256px.
Dots in a random pattern (color: #ffffff).
Positions generated with jsdotpattern.
The positions are rounded to two decimals, repeated across tile boundaries, and saved in salt_dots.txt.
The dots are offset by -0.05,-0.05px to align with a pre-existing svg.
Final svg generated with generate_pattern.py from salt_dots.txt.
Tiles of 128×128px.
Dots in a random pattern (color: #685d45 and 40% opacity).
Positions generated with jsdotpattern, rounded to two decimals and repeated across tile boundaries.
Most of the dots have a radius of 0.85px, but some have a radius of 0.8px or 1px.
Their distribution is based on the appearance of a pre-existing svg, with the positions saved in beach.txt.
Final svg generated with generate_pattern.py from beach.txt.
Tiles of 256×256px.
Dots and lines in a random pattern (color: #cbc9c6).
Positions generated with jsdotpattern, command sequence unknown.
Most of the dots have a radius of 1px, but some have a radius of 1.2px are a short line 0.8px wide.
Their distribution is based on the appearance of a pre-existing svg, with the positions saved in scree.txt.
Final svg generated with generate_pattern.py from scree.txt.
Tiles of 256×256px.
Based on scree.svg, color: #549ccd.
Tiles of 256×256px.
Based on scree.svg, color: #969696.
Tiles of 128×128px.
Dots in a random pattern (color: #a5d979).
Positions based on beach, size and shape of dots based on scree.
Final svg generated with generate_pattern.py from golf_rough.txt.
Tiles of 32x32px.
Two dog paw prints based on shop/pet.svg, scaled to 10x10px (color: #a6e0ab and 70% opacity).
Tiles of 32x32px.
A single symbol, repeated in a 32×32 grid. (color: #88b78e).
Tiles of 32x32px.
A single symbol, repeated in a 32×32 grid. (color: #88b78e).
Tiles of 32x32px.
A single symbol, repeated in a 32×32 grid. (color: #88b78e).
Tiles of 32x32px.
A single symbol, repeated in a 32×32 grid. (color: #88b78e).
A preview of the different forest symbols is available in forest.svg.
Note that the forest patterns don't have 40% opacity applied to the pattern, but at the Mapnik layer/attachment level.
This is to handle overlappings forest areas.
Tiles of 256×256px.
Random pattern of two symbols with a 30px distance (color: #6b8d5e).
Positions originally generated with jsdotpattern, command sequence not recorded.
Coordinates are recreated from a pre-existing svg, positions saved in leaftype_unknown.txt.
Final svg generated with generate_pattern.py from leaftype_unknown.txt.
Tiles of 256×256px.
Based on leaftype_unknown.svg, but with only one symbol (color: #6b8d5e).
Final svg generated with generate_pattern.py from leaftype_broadleaved.txt.
Tiles of 256×256px.
Based on leaftype_unknown.svg, but with only one symbol (color: #6b8d5e).
Final svg generated with generate_pattern.py from leaftype_leafless.txt.
Tiles of 256×256px.
Based on leaftype_unknown.svg, with two other symbols (color: #6b8d5e).
Final svg generated with generate_pattern.py from leaftype_mixed.txt.
Tiles of 256×256px.
Based on leaftype_unknown.svg, but with only one symbol (color: #6b8d5e).
Final svg generated with generate_pattern.py from leaftype_needleleaved.txt.
Tiles of 256×256px.
Symbols repeated in a triangular grid with a 45px distance (color: #e6e6e6).
Positions generated with jsdotpattern
The positions are rounded down and saved in quarry.txt.
Final svg generated with generate_pattern.py from quarry.txt.
Tiles of 128×128px.
Symbols repeated in a triangular grid with a 17px distance (color: #ffffff).
Positions generated with jsdotpattern
The positions are rounded down and saved in salt_pond.txt.
Final svg generated with generate_pattern.py from salt_pond.txt.
Tiles of 512×512px.
Random pattern of scrub symbols (color: #b0be93).
Positions generated with jsdotpattern.
The positions are rounded down, repeated across tile boundaries, and saved in scrub.txt.
Final svg generated with generate_pattern.py from scrub.txt.
Tiles of 32x32px.
Short vertical lines in a triangular pattern (color: #759e6c and 38% opacity).
Positions have been recreated after a pre-existing raster image.
Final svg generated with generate_pattern.py from vineyard.txt.
Tiles of 256×256px.
Random pattern of short horizontal lines (color: #4aa5fa).
Positions originally generated with jsdotpattern, command sequence not recorded.
Coordinates are recreated from a pre-existing svg, positions saved in wetland.txt.
Final svg generated with generate_pattern.py from wetland.txt.
All wetland tiles are 512×512px. The basis is wetland512.txt, which has the coordinates of wetland.txt repeated to cover the larger size.
The wetland patterns put different plant symbols on top of the blue wetland lines. The symbols have a ~2px casing around them, rounded to the nearest pixel boundary. If there is only 1 pixel left of the lines in the covered wetland pattern, that part of the line is be removed.
generate_pattern.py has some complexity to deal with this, but only in a very basic way. It is hard-coded for the wetland patterns, and every shape has the outline of its casing manually recorded in the text file.
A preview of the various shapes is available in wetland_casings.svg (created by adding a copy of the shape with stroke-width="4", and eyeballing the closest pixel boundary).
Tiles of 512x512px.
Random pattern of two grass symbols (color: #73b386), on top of the wetland512 pattern.
Positions originally generated with jsdotpattern, command sequence not recorded.
Coordinates are recreated from a pre-existing svg, positions saved in wetland_marsh.txt.
Final svg generated with generate_pattern.py from marsh.txt and wetland512.txt.
Tiles of 512x512px.
Based on marsh.txt, but with two reed symbols (color: #73b386).
Final svg generated with generate_pattern.py from reed.txt and wetland512.txt.
Tiles of 512x512px.
Based on marsh.txt, but with the two symbols of leaftype_unknown (color: #6b8d5e and 40% opacity).
Final svg generated with generate_pattern.py from swamp.txt and wetland512.txt.
Tiles of 512x512px.
Based on marsh.txt, but with only one symbol (color: #73b386).
Final svg generated with generate_pattern.py from bog.txt and wetland512.txt.
Tiles of 512x512px.
Based on marsh.txt, but with only one symbol (color: #709b6f).
Final svg generated with generate_pattern.py from mangrove.txt and wetland512.txt.
The wetland .txt files contain a casing: line. Example:
Casing: -5 -3|0 -3|4 -4|6 -5|7 -6|7 -5|6 -5|6 -5|6 -5|6 -5|6 -4|6
The first number is the number of pixels that the casing starts above the insertion point of the symbol.
Then for every lineof pixels there is a left|right pair describing the shape of the casing.
-3|4 means the casing starts at -3 from the insertion point: 3px to the left; and end at 4; 4px to the right.
Tiles of 256×256px. Random pattern of 12 complex shapes, each with 13 possible rotations. The positions are close enough for the shapes to overlap. Every shape has both a fill, and a casing of 0.6px around it to hide part of the underlying shapes.
Overlapping shapes, with a casing as outline in between, don't work with a pattern with opacity.
That is why rock.svg is the only pattern that needs to include both a foreground color (#cfcdca) and background color (#eee5dc).
One option to include casing is to repeat every shape twice: once with a stroke of 1.2px with the background color, and then one with only a fill on top of that. An alternative is to offset the path of the shape by 0.3px, and use that single shape with both a fill and a stroke of 0.6px. The alternative almost halves the complexity for the rasterizer, so now all shapes are offset in Inkscape.
A preview of the various original and offset shapes is available in rock_outlines.svg.
Pattern positions originally generated with jsdotpattern, command sequence not recorded.
rock.txt contains a list of coordinates, shapes and orientations extracted from a pre-existing svg.
rock.py is a script to convert the coordinates to SVG use elements, which are manually combined with the shapes from rock_outlines to create rock.svg.