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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 | 1× 1× 1× 6× 6× 3× 3× 3× 3× 6× 6× 1× 59× 59× 18× 27× 27× 18× 41× 41× 41× 41× 41× 41× 41× 254× 254× 254× 254× 254× 254× 254× 254× 1797× 1797× 1797× 1797× 713× 713× 254× 158× 158× 115× 158× 98× 41× 469× 240× 240× 41× 1× 2× 2× 3× 3× 3× 3× 2× 1× 1× 13× 4× 2× 2× 4× 9× 9× 9× 9× 9× 9× 9× 224× 224× 224× 191× 191× 191× 191× 9× 3× 3× 9× 1× 2544× 1× 126× 1× 125× 125× 125× 125× 125× 125× 125× 125× 125× 125× 125× 2× 2× 2× 123× 360× 360× 360× 360× 360× 8× 352× 352× 352× 352× 352× 10× 10× 10× 342× 342× 342× 342× 342× 342× 123× 123× 123× 1× 111× 111× 118× 118× 118× 118× 111× 1× 3× 3× 5× 5× 5× 5× 5× 3× | // Based on simplify-js https://github.com/mourner/simplify-js // Copyright (c) 2012, Vladimir Agafonkin // All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are met: // // 1. Redistributions of source code must retain the above copyright notice, // this list of conditions and the following disclaimer. // // 2. Redistributions in binary form must reproduce the above copyright // notice, this list of conditions and the following disclaimer in the // documentation and/or other materials provided with the distribution. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE // POSSIBILITY OF SUCH DAMAGE. goog.provide('ol.geom.flat.simplify'); goog.require('ol.math'); /** * @param {Array.<number>} flatCoordinates Flat coordinates. * @param {number} offset Offset. * @param {number} end End. * @param {number} stride Stride. * @param {number} squaredTolerance Squared tolerance. * @param {boolean} highQuality Highest quality. * @param {Array.<number>=} opt_simplifiedFlatCoordinates Simplified flat * coordinates. * @return {Array.<number>} Simplified line string. */ ol.geom.flat.simplify.lineString = function(flatCoordinates, offset, end, stride, squaredTolerance, highQuality, opt_simplifiedFlatCoordinates) { var simplifiedFlatCoordinates = opt_simplifiedFlatCoordinates !== undefined ? opt_simplifiedFlatCoordinates : []; if (!highQuality) { end = ol.geom.flat.simplify.radialDistance(flatCoordinates, offset, end, stride, squaredTolerance, simplifiedFlatCoordinates, 0); flatCoordinates = simplifiedFlatCoordinates; offset = 0; stride = 2; } simplifiedFlatCoordinates.length = ol.geom.flat.simplify.douglasPeucker( flatCoordinates, offset, end, stride, squaredTolerance, simplifiedFlatCoordinates, 0); return simplifiedFlatCoordinates; }; /** * @param {Array.<number>} flatCoordinates Flat coordinates. * @param {number} offset Offset. * @param {number} end End. * @param {number} stride Stride. * @param {number} squaredTolerance Squared tolerance. * @param {Array.<number>} simplifiedFlatCoordinates Simplified flat * coordinates. * @param {number} simplifiedOffset Simplified offset. * @return {number} Simplified offset. */ ol.geom.flat.simplify.douglasPeucker = function(flatCoordinates, offset, end, stride, squaredTolerance, simplifiedFlatCoordinates, simplifiedOffset) { var n = (end - offset) / stride; if (n < 3) { for (; offset < end; offset += stride) { simplifiedFlatCoordinates[simplifiedOffset++] = flatCoordinates[offset]; simplifiedFlatCoordinates[simplifiedOffset++] = flatCoordinates[offset + 1]; } return simplifiedOffset; } /** @type {Array.<number>} */ var markers = new Array(n); markers[0] = 1; markers[n - 1] = 1; /** @type {Array.<number>} */ var stack = [offset, end - stride]; var index = 0; var i; while (stack.length > 0) { var last = stack.pop(); var first = stack.pop(); var maxSquaredDistance = 0; var x1 = flatCoordinates[first]; var y1 = flatCoordinates[first + 1]; var x2 = flatCoordinates[last]; var y2 = flatCoordinates[last + 1]; for (i = first + stride; i < last; i += stride) { var x = flatCoordinates[i]; var y = flatCoordinates[i + 1]; var squaredDistance = ol.math.squaredSegmentDistance( x, y, x1, y1, x2, y2); if (squaredDistance > maxSquaredDistance) { index = i; maxSquaredDistance = squaredDistance; } } if (maxSquaredDistance > squaredTolerance) { markers[(index - offset) / stride] = 1; if (first + stride < index) { stack.push(first, index); } if (index + stride < last) { stack.push(index, last); } } } for (i = 0; i < n; ++i) { if (markers[i]) { simplifiedFlatCoordinates[simplifiedOffset++] = flatCoordinates[offset + i * stride]; simplifiedFlatCoordinates[simplifiedOffset++] = flatCoordinates[offset + i * stride + 1]; } } return simplifiedOffset; }; /** * @param {Array.<number>} flatCoordinates Flat coordinates. * @param {number} offset Offset. * @param {Array.<number>} ends Ends. * @param {number} stride Stride. * @param {number} squaredTolerance Squared tolerance. * @param {Array.<number>} simplifiedFlatCoordinates Simplified flat * coordinates. * @param {number} simplifiedOffset Simplified offset. * @param {Array.<number>} simplifiedEnds Simplified ends. * @return {number} Simplified offset. */ ol.geom.flat.simplify.douglasPeuckers = function(flatCoordinates, offset, ends, stride, squaredTolerance, simplifiedFlatCoordinates, simplifiedOffset, simplifiedEnds) { var i, ii; for (i = 0, ii = ends.length; i < ii; ++i) { var end = ends[i]; simplifiedOffset = ol.geom.flat.simplify.douglasPeucker( flatCoordinates, offset, end, stride, squaredTolerance, simplifiedFlatCoordinates, simplifiedOffset); simplifiedEnds.push(simplifiedOffset); offset = end; } return simplifiedOffset; }; /** * @param {Array.<number>} flatCoordinates Flat coordinates. * @param {number} offset Offset. * @param {Array.<Array.<number>>} endss Endss. * @param {number} stride Stride. * @param {number} squaredTolerance Squared tolerance. * @param {Array.<number>} simplifiedFlatCoordinates Simplified flat * coordinates. * @param {number} simplifiedOffset Simplified offset. * @param {Array.<Array.<number>>} simplifiedEndss Simplified endss. * @return {number} Simplified offset. */ ol.geom.flat.simplify.douglasPeuckerss = function( flatCoordinates, offset, endss, stride, squaredTolerance, simplifiedFlatCoordinates, simplifiedOffset, simplifiedEndss) { var i, ii; for (i = 0, ii = endss.length; i < ii; ++i) { var ends = endss[i]; var simplifiedEnds = []; simplifiedOffset = ol.geom.flat.simplify.douglasPeuckers( flatCoordinates, offset, ends, stride, squaredTolerance, simplifiedFlatCoordinates, simplifiedOffset, simplifiedEnds); simplifiedEndss.push(simplifiedEnds); offset = ends[ends.length - 1]; } return simplifiedOffset; }; /** * @param {Array.<number>} flatCoordinates Flat coordinates. * @param {number} offset Offset. * @param {number} end End. * @param {number} stride Stride. * @param {number} squaredTolerance Squared tolerance. * @param {Array.<number>} simplifiedFlatCoordinates Simplified flat * coordinates. * @param {number} simplifiedOffset Simplified offset. * @return {number} Simplified offset. */ ol.geom.flat.simplify.radialDistance = function(flatCoordinates, offset, end, stride, squaredTolerance, simplifiedFlatCoordinates, simplifiedOffset) { if (end <= offset + stride) { // zero or one point, no simplification possible, so copy and return for (; offset < end; offset += stride) { simplifiedFlatCoordinates[simplifiedOffset++] = flatCoordinates[offset]; simplifiedFlatCoordinates[simplifiedOffset++] = flatCoordinates[offset + 1]; } return simplifiedOffset; } var x1 = flatCoordinates[offset]; var y1 = flatCoordinates[offset + 1]; // copy first point simplifiedFlatCoordinates[simplifiedOffset++] = x1; simplifiedFlatCoordinates[simplifiedOffset++] = y1; var x2 = x1; var y2 = y1; for (offset += stride; offset < end; offset += stride) { x2 = flatCoordinates[offset]; y2 = flatCoordinates[offset + 1]; if (ol.math.squaredDistance(x1, y1, x2, y2) > squaredTolerance) { // copy point at offset simplifiedFlatCoordinates[simplifiedOffset++] = x2; simplifiedFlatCoordinates[simplifiedOffset++] = y2; x1 = x2; y1 = y2; } } if (x2 != x1 || y2 != y1) { // copy last point simplifiedFlatCoordinates[simplifiedOffset++] = x2; simplifiedFlatCoordinates[simplifiedOffset++] = y2; } return simplifiedOffset; }; /** * @param {number} value Value. * @param {number} tolerance Tolerance. * @return {number} Rounded value. */ ol.geom.flat.simplify.snap = function(value, tolerance) { return tolerance * Math.round(value / tolerance); }; /** * Simplifies a line string using an algorithm designed by Tim Schaub. * Coordinates are snapped to the nearest value in a virtual grid and * consecutive duplicate coordinates are discarded. This effectively preserves * topology as the simplification of any subsection of a line string is * independent of the rest of the line string. This means that, for examples, * the common edge between two polygons will be simplified to the same line * string independently in both polygons. This implementation uses a single * pass over the coordinates and eliminates intermediate collinear points. * @param {Array.<number>} flatCoordinates Flat coordinates. * @param {number} offset Offset. * @param {number} end End. * @param {number} stride Stride. * @param {number} tolerance Tolerance. * @param {Array.<number>} simplifiedFlatCoordinates Simplified flat * coordinates. * @param {number} simplifiedOffset Simplified offset. * @return {number} Simplified offset. */ ol.geom.flat.simplify.quantize = function(flatCoordinates, offset, end, stride, tolerance, simplifiedFlatCoordinates, simplifiedOffset) { // do nothing if the line is empty if (offset == end) { return simplifiedOffset; } // snap the first coordinate (P1) var x1 = ol.geom.flat.simplify.snap(flatCoordinates[offset], tolerance); var y1 = ol.geom.flat.simplify.snap(flatCoordinates[offset + 1], tolerance); offset += stride; // add the first coordinate to the output simplifiedFlatCoordinates[simplifiedOffset++] = x1; simplifiedFlatCoordinates[simplifiedOffset++] = y1; // find the next coordinate that does not snap to the same value as the first // coordinate (P2) var x2, y2; do { x2 = ol.geom.flat.simplify.snap(flatCoordinates[offset], tolerance); y2 = ol.geom.flat.simplify.snap(flatCoordinates[offset + 1], tolerance); offset += stride; if (offset == end) { // all coordinates snap to the same value, the line collapses to a point // push the last snapped value anyway to ensure that the output contains // at least two points // FIXME should we really return at least two points anyway? simplifiedFlatCoordinates[simplifiedOffset++] = x2; simplifiedFlatCoordinates[simplifiedOffset++] = y2; return simplifiedOffset; } } while (x2 == x1 && y2 == y1); while (offset < end) { var x3, y3; // snap the next coordinate (P3) x3 = ol.geom.flat.simplify.snap(flatCoordinates[offset], tolerance); y3 = ol.geom.flat.simplify.snap(flatCoordinates[offset + 1], tolerance); offset += stride; // skip P3 if it is equal to P2 if (x3 == x2 && y3 == y2) { continue; } // calculate the delta between P1 and P2 var dx1 = x2 - x1; var dy1 = y2 - y1; // calculate the delta between P3 and P1 var dx2 = x3 - x1; var dy2 = y3 - y1; // if P1, P2, and P3 are colinear and P3 is further from P1 than P2 is from // P1 in the same direction then P2 is on the straight line between P1 and // P3 if ((dx1 * dy2 == dy1 * dx2) && ((dx1 < 0 && dx2 < dx1) || dx1 == dx2 || (dx1 > 0 && dx2 > dx1)) && ((dy1 < 0 && dy2 < dy1) || dy1 == dy2 || (dy1 > 0 && dy2 > dy1))) { // discard P2 and set P2 = P3 x2 = x3; y2 = y3; continue; } // either P1, P2, and P3 are not colinear, or they are colinear but P3 is // between P3 and P1 or on the opposite half of the line to P2. add P2, // and continue with P1 = P2 and P2 = P3 simplifiedFlatCoordinates[simplifiedOffset++] = x2; simplifiedFlatCoordinates[simplifiedOffset++] = y2; x1 = x2; y1 = y2; x2 = x3; y2 = y3; } // add the last point (P2) simplifiedFlatCoordinates[simplifiedOffset++] = x2; simplifiedFlatCoordinates[simplifiedOffset++] = y2; return simplifiedOffset; }; /** * @param {Array.<number>} flatCoordinates Flat coordinates. * @param {number} offset Offset. * @param {Array.<number>} ends Ends. * @param {number} stride Stride. * @param {number} tolerance Tolerance. * @param {Array.<number>} simplifiedFlatCoordinates Simplified flat * coordinates. * @param {number} simplifiedOffset Simplified offset. * @param {Array.<number>} simplifiedEnds Simplified ends. * @return {number} Simplified offset. */ ol.geom.flat.simplify.quantizes = function( flatCoordinates, offset, ends, stride, tolerance, simplifiedFlatCoordinates, simplifiedOffset, simplifiedEnds) { var i, ii; for (i = 0, ii = ends.length; i < ii; ++i) { var end = ends[i]; simplifiedOffset = ol.geom.flat.simplify.quantize( flatCoordinates, offset, end, stride, tolerance, simplifiedFlatCoordinates, simplifiedOffset); simplifiedEnds.push(simplifiedOffset); offset = end; } return simplifiedOffset; }; /** * @param {Array.<number>} flatCoordinates Flat coordinates. * @param {number} offset Offset. * @param {Array.<Array.<number>>} endss Endss. * @param {number} stride Stride. * @param {number} tolerance Tolerance. * @param {Array.<number>} simplifiedFlatCoordinates Simplified flat * coordinates. * @param {number} simplifiedOffset Simplified offset. * @param {Array.<Array.<number>>} simplifiedEndss Simplified endss. * @return {number} Simplified offset. */ ol.geom.flat.simplify.quantizess = function( flatCoordinates, offset, endss, stride, tolerance, simplifiedFlatCoordinates, simplifiedOffset, simplifiedEndss) { var i, ii; for (i = 0, ii = endss.length; i < ii; ++i) { var ends = endss[i]; var simplifiedEnds = []; simplifiedOffset = ol.geom.flat.simplify.quantizes( flatCoordinates, offset, ends, stride, tolerance, simplifiedFlatCoordinates, simplifiedOffset, simplifiedEnds); simplifiedEndss.push(simplifiedEnds); offset = ends[ends.length - 1]; } return simplifiedOffset; }; |