/* Copyright (c) 2013, Project OSRM, Dennis Luxen, others All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 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. */ #include #include "DouglasPeucker.h" #include "../DataStructures/SegmentInformation.h" #include "../Util/SimpleLogger.h" #include #include #include DouglasPeucker::DouglasPeucker() : douglas_peucker_thresholds({262144., // z0 131072., // z1 65536., // z2 32768., // z3 16384., // z4 8192., // z5 4096., // z6 2048., // z7 960., // z8 480., // z9 240., // z10 90., // z11 50., // z12 25., // z13 15., // z14 5., // z15 .65, // z16 .5, // z17 .35 // z18 }) { } void DouglasPeucker::Run(std::vector &input_geometry, const unsigned zoom_level) { input_geometry.front().necessary = true; input_geometry.back().necessary = true; BOOST_ASSERT_MSG(!input_geometry.empty(), "geometry invalid"); if (input_geometry.size() < 2) { return; } SimpleLogger().Write() << "input_geometry.size()=" << input_geometry.size(); { BOOST_ASSERT_MSG(zoom_level < 19, "unsupported zoom level"); unsigned left_border = 0; unsigned right_border = 1; // Sweep over array and identify those ranges that need to be checked do { if (!input_geometry[left_border].necessary) { SimpleLogger().Write() << "broken interval [" << left_border << "," << right_border << "]"; } BOOST_ASSERT_MSG(input_geometry[left_border].necessary, "left border must be necessary"); BOOST_ASSERT_MSG(input_geometry.back().necessary, "right border must be necessary"); if (input_geometry[right_border].necessary) { recursion_stack.emplace(left_border, right_border); left_border = right_border; } ++right_border; } while (right_border < input_geometry.size()); } while (!recursion_stack.empty()) { // pop next element const GeometryRange pair = recursion_stack.top(); recursion_stack.pop(); BOOST_ASSERT_MSG(input_geometry[pair.first].necessary, "left border mus be necessary"); BOOST_ASSERT_MSG(input_geometry[pair.second].necessary, "right border must be necessary"); BOOST_ASSERT_MSG(pair.second < input_geometry.size(), "right border outside of geometry"); BOOST_ASSERT_MSG(pair.first < pair.second, "left border on the wrong side"); double max_distance = std::numeric_limits::min(); unsigned farthest_element_index = pair.second; // find index idx of element with max_distance for (unsigned i = pair.first + 1; i < pair.second; ++i) { const double temp_dist = FixedPointCoordinate::ComputePerpendicularDistance( input_geometry[i].location, input_geometry[pair.first].location, input_geometry[pair.second].location); const double distance = std::abs(temp_dist); if (distance > douglas_peucker_thresholds[zoom_level] && distance > max_distance) { farthest_element_index = i; max_distance = distance; } } if (max_distance > douglas_peucker_thresholds[zoom_level]) { // mark idx as necessary input_geometry[farthest_element_index].necessary = true; if (1 < (farthest_element_index - pair.first)) { recursion_stack.emplace(pair.first, farthest_element_index); } if (1 < (pair.second - farthest_element_index)) { recursion_stack.emplace(farthest_element_index, pair.second); } } } }