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Cleanup from adding line simplification in overzoom

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This commit is contained in:
Erica Fischer
2024-07-30 15:53:51 -07:00
parent 6a6ec0c038
commit eb723111f9
3 changed files with 3 additions and 98 deletions
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geometry.cpp
+1 -97
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@@ -1,7 +1,6 @@
#include <iostream>
#include <fstream>
#include <string>
#include <stack>
#include <vector>
#include <map>
#include <algorithm>
@@ -206,101 +205,6 @@ bool point_within_tile(long long x, long long y, int z) {
return x >= 0 && y >= 0 && x < area && y < area;
}
// https://github.com/Project-OSRM/osrm-backend/blob/733d1384a40f/Algorithms/DouglasePeucker.cpp
static void douglas_peucker(drawvec &geom, int start, int n, double e, size_t kept, size_t retain) {
std::stack<int> recursion_stack;
if (!geom[start + 0].necessary || !geom[start + n - 1].necessary) {
fprintf(stderr, "endpoints not marked necessary\n");
exit(EXIT_IMPOSSIBLE);
}
int prev = 0;
for (int here = 1; here < n; here++) {
if (geom[start + here].necessary) {
recursion_stack.push(prev);
recursion_stack.push(here);
prev = here;
if (prevent[P_SIMPLIFY_SHARED_NODES]) {
if (retain > 0) {
retain--;
}
}
}
}
// These segments are put on the stack from start to end,
// independent of winding, so note that anything that uses
// "retain" to force it to keep at least N points will
// keep a different set of points when wound one way than
// when wound the other way.
while (!recursion_stack.empty()) {
// pop next element
int second = recursion_stack.top();
recursion_stack.pop();
int first = recursion_stack.top();
recursion_stack.pop();
double max_distance = -1;
int farthest_element_index;
// find index idx of element with max_distance
int i;
if (geom[start + first] < geom[start + second]) {
farthest_element_index = first;
for (i = first + 1; i < second; i++) {
double temp_dist = distance_from_line(geom[start + i].x, geom[start + i].y, geom[start + first].x, geom[start + first].y, geom[start + second].x, geom[start + second].y);
double distance = std::fabs(temp_dist);
if ((distance > e || kept < retain) && (distance > max_distance || (distance == max_distance && geom[start + i] < geom[start + farthest_element_index]))) {
farthest_element_index = i;
max_distance = distance;
}
}
} else {
farthest_element_index = second;
for (i = second - 1; i > first; i--) {
double temp_dist = distance_from_line(geom[start + i].x, geom[start + i].y, geom[start + second].x, geom[start + second].y, geom[start + first].x, geom[start + first].y);
double distance = std::fabs(temp_dist);
if ((distance > e || kept < retain) && (distance > max_distance || (distance == max_distance && geom[start + i] < geom[start + farthest_element_index]))) {
farthest_element_index = i;
max_distance = distance;
}
}
}
if (max_distance >= 0) {
// mark idx as necessary
geom[start + farthest_element_index].necessary = 1;
kept++;
if (geom[start + first] < geom[start + second]) {
if (1 < farthest_element_index - first) {
recursion_stack.push(first);
recursion_stack.push(farthest_element_index);
}
if (1 < second - farthest_element_index) {
recursion_stack.push(farthest_element_index);
recursion_stack.push(second);
}
} else {
if (1 < second - farthest_element_index) {
recursion_stack.push(farthest_element_index);
recursion_stack.push(second);
}
if (1 < farthest_element_index - first) {
recursion_stack.push(first);
recursion_stack.push(farthest_element_index);
}
}
}
}
}
// If any line segment crosses a tile boundary, add a node there
// that cannot be simplified away, to prevent the edge of any
// feature from jumping abruptly at the tile boundary.
@@ -410,7 +314,7 @@ drawvec simplify_lines(drawvec &geom, int z, int tx, int ty, int detail, bool ma
if (additional[A_VISVALINGAM]) {
visvalingam(geom, i, j, scale, retain);
} else {
douglas_peucker(geom, i, j - i, res * simplification, 2, retain);
douglas_peucker(geom, i, j - i, res * simplification, 2, retain, prevent[P_SIMPLIFY_SHARED_NODES]);
}
}
i = j - 1;