/usr/lib/python2.7/dist-packages/TileStache/Sandwich.py is in tilestache 1.49.8-3.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 | """ Layered, composite rendering for TileStache.
The Sandwich Provider supplies a Photoshop-like rendering pipeline, making it
possible to use the output of other configured tile layers as layers or masks
to create a combined output. Sandwich is modeled on Lars Ahlzen's TopOSM.
The external "Blit" library is required by Sandwich, and can be installed
via Pip, easy_install, or directly from Github:
https://github.com/migurski/Blit
The "stack" configuration parameter describes a layer or stack of layers that
can be combined to create output. A simple stack that merely outputs a single
color orange tile looks like this:
{"color" "#ff9900"}
Other layers in the current TileStache configuration can be reference by name,
as in this example stack that simply echoes another layer:
{"src": "layer-name"}
Bitmap images can also be referenced by local filename or URL, and will be
tiled seamlessly, assuming 256x256 parent tiles:
{"src": "image.png"}
{"src": "http://example.com/image.png"}
Layers can be limited to appear at certain zoom levels, given either as a range
or as a single number:
{"src": "layer-name", "zoom": "12"}
{"src": "layer-name", "zoom": "12-18"}
Layers can also be used as masks, as in this example that uses one layer
to mask another layer:
{"mask": "layer-name", "src": "other-layer"}
Many combinations of "src", "mask", and "color" can be used together, but it's
an error to provide all three.
Layers can be combined through the use of opacity and blend modes. Opacity is
specified as a value from 0.0-1.0, and blend mode is specified as a string.
This example layer is blended using the "hard light" mode at 50% opacity:
{"src": "hillshading", "mode": "hard light", "opacity": 0.5}
Currently-supported blend modes include "screen", "add", "multiply", "subtract",
"linear light", and "hard light".
Layers can also be affected by adjustments. Adjustments are specified as an
array of names and parameters. This example layer has been slightly darkened
using the "curves" adjustment, moving the input value of 181 (light gray)
to 50% gray while leaving black and white alone:
{"src": "hillshading", "adjustments": [ ["curves", [0, 181, 255]] ]}
Available adjustments:
"threshold" - Blit.adjustments.threshold()
"curves" - Blit.adjustments.curves()
"curves2" - Blit.adjustments.curves2()
See detailed information about adjustments in Blit documentation:
https://github.com/migurski/Blit#readme
Finally, the stacking feature allows layers to combined in more complex ways.
This example stack combines a background color and foreground layer:
[
{"color": "#ff9900"},
{"src": "layer-name"}
]
A complete example configuration might look like this:
{
"cache":
{
"name": "Test"
},
"layers":
{
"base":
{
"provider": {"name": "mapnik", "mapfile": "mapnik-base.xml"}
},
"halos":
{
"provider": {"name": "mapnik", "mapfile": "mapnik-halos.xml"},
"metatile": {"buffer": 128}
},
"outlines":
{
"provider": {"name": "mapnik", "mapfile": "mapnik-outlines.xml"},
"metatile": {"buffer": 16}
},
"streets":
{
"provider": {"name": "mapnik", "mapfile": "mapnik-streets.xml"},
"metatile": {"buffer": 128}
},
"sandwiches":
{
"provider":
{
"name": "Sandwich",
"stack":
[
{"src": "base"},
{"src": "outlines", "mask": "halos"},
{"src": "streets"}
]
}
}
}
}
"""
from re import search
from StringIO import StringIO
from itertools import product
from urlparse import urljoin
from urllib import urlopen
from . import Core
import Image
import Blit
blend_modes = {
'screen': Blit.blends.screen,
'add': Blit.blends.add,
'multiply': Blit.blends.multiply,
'subtract': Blit.blends.subtract,
'linear light': Blit.blends.linear_light,
'hard light': Blit.blends.hard_light
}
adjustment_names = {
'threshold': Blit.adjustments.threshold,
'curves': Blit.adjustments.curves,
'curves2': Blit.adjustments.curves2
}
class Provider:
""" Sandwich Provider.
Stack argument is a list of layer dictionaries described in module docs.
"""
def __init__(self, layer, stack):
self.layer = layer
self.config = layer.config
self.stack = stack
@staticmethod
def prepareKeywordArgs(config_dict):
""" Convert configured parameters to keyword args for __init__().
"""
return {'stack': config_dict['stack']}
def renderTile(self, width, height, srs, coord):
rendered = self.draw_stack(coord, dict())
if rendered.size() == (width, height):
return rendered.image()
else:
return rendered.image().resize((width, height))
def draw_stack(self, coord, tiles):
""" Render this image stack.
Given a coordinate, return an output image with the results of all the
layers in this stack pasted on in turn.
Final argument is a dictionary used to temporarily cache results
of layers retrieved from layer_bitmap(), to speed things up in case
of repeatedly-used identical images.
"""
# start with an empty base
rendered = Blit.Color(0, 0, 0, 0)
for layer in self.stack:
if 'zoom' in layer and not in_zoom(coord, layer['zoom']):
continue
#
# Prepare pixels from elsewhere.
#
source_name, mask_name, color_name = [layer.get(k, None) for k in ('src', 'mask', 'color')]
if source_name and color_name and mask_name:
raise Core.KnownUnknown("You can't specify src, color and mask together in a Sandwich Layer: %s, %s, %s" % (repr(source_name), repr(color_name), repr(mask_name)))
if source_name and source_name not in tiles:
if source_name in self.config.layers:
tiles[source_name] = layer_bitmap(self.config.layers[source_name], coord)
else:
tiles[source_name] = local_bitmap(source_name, self.config, coord, self.layer.dim)
if mask_name and mask_name not in tiles:
tiles[mask_name] = layer_bitmap(self.config.layers[mask_name], coord)
#
# Build up the foreground layer.
#
if source_name and color_name:
# color first, then layer
foreground = make_color(color_name).blend(tiles[source_name])
elif source_name:
foreground = tiles[source_name]
elif color_name:
foreground = make_color(color_name)
elif mask_name:
raise Core.KnownUnknown("You have to provide more than just a mask to Sandwich Layer: %s" % repr(mask_name))
else:
raise Core.KnownUnknown("You have to provide at least some combination of src, color and mask to Sandwich Layer")
#
# Do the final composition with adjustments and blend modes.
#
for (name, args) in layer.get('adjustments', []):
adjustfunc = adjustment_names.get(name)(*args)
foreground = foreground.adjust(adjustfunc)
opacity = float(layer.get('opacity', 1.0))
blendfunc = blend_modes.get(layer.get('mode', None), None)
if mask_name:
rendered = rendered.blend(foreground, tiles[mask_name], opacity, blendfunc)
else:
rendered = rendered.blend(foreground, None, opacity, blendfunc)
return rendered
def local_bitmap(source, config, coord, dim):
""" Return Blit.Bitmap representation of a raw image.
"""
address = urljoin(config.dirpath, source)
bytes = urlopen(address).read()
image = Image.open(StringIO(bytes)).convert('RGBA')
coord = coord.zoomBy(8)
w, h, col, row = image.size[0], image.size[1], int(coord.column), int(coord.row)
x = w * (col / w) - col
y = h * (row / h) - row
output = Image.new('RGBA', (dim, dim))
for (x, y) in product(range(x, dim, w), range(y, dim, h)):
# crop the top-left if needed
xmin = 0 if x > 0 else -x
ymin = 0 if y > 0 else -y
# don't paste up and to the left
x = x if x >= 0 else 0
y = y if y >= 0 else 0
output.paste(image.crop((xmin, ymin, w, h)), (x, y))
return Blit.Bitmap(output)
def layer_bitmap(layer, coord):
""" Return Blit.Bitmap representation of tile from a given layer.
Uses TileStache.getTile(), so caches are read and written as normal.
"""
from . import getTile
mime, body = getTile(layer, coord, 'png')
image = Image.open(StringIO(body)).convert('RGBA')
return Blit.Bitmap(image)
def in_zoom(coord, range):
""" Return True if the coordinate zoom is within the textual range.
Range might look like "1-10" or just "5".
"""
zooms = search("^(\d+)-(\d+)$|^(\d+)$", range)
if not zooms:
raise Core.KnownUnknown("Bad zoom range in a Sandwich Layer: %s" % repr(range))
min_zoom, max_zoom, at_zoom = zooms.groups()
if min_zoom is not None and max_zoom is not None:
min_zoom, max_zoom = int(min_zoom), int(max_zoom)
elif at_zoom is not None:
min_zoom, max_zoom = int(at_zoom), int(at_zoom)
else:
min_zoom, max_zoom = 0, float('inf')
return min_zoom <= coord.zoom and coord.zoom <= max_zoom
def make_color(color):
""" Convert colors expressed as HTML-style RGB(A) strings to Blit.Color.
Examples:
white: "#ffffff", "#fff", "#ffff", "#ffffffff"
black: "#000000", "#000", "#000f", "#000000ff"
null: "#0000", "#00000000"
orange: "#f90", "#ff9900", "#ff9900ff"
transparent orange: "#f908", "#ff990088"
"""
if type(color) not in (str, unicode):
raise Core.KnownUnknown('Color must be a string: %s' % repr(color))
if color[0] != '#':
raise Core.KnownUnknown('Color must start with hash: "%s"' % color)
if len(color) not in (4, 5, 7, 9):
raise Core.KnownUnknown('Color must have three, four, six or eight hex chars: "%s"' % color)
if len(color) == 4:
color = ''.join([color[i] for i in (0, 1, 1, 2, 2, 3, 3)])
elif len(color) == 5:
color = ''.join([color[i] for i in (0, 1, 1, 2, 2, 3, 3, 4, 4)])
try:
r = int(color[1:3], 16)
g = int(color[3:5], 16)
b = int(color[5:7], 16)
a = len(color) == 7 and 0xFF or int(color[7:9], 16)
except ValueError:
raise Core.KnownUnknown('Color must be made up of valid hex chars: "%s"' % color)
return Blit.Color(r, g, b, a)
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