diegoripley/tippecanoe
1
0
Fork 0
mirror of https://github.com/felt/tippecanoe.git synced 2026-10-02 16:35:40 +02:00
Code Issues Packages Projects Releases Wiki Activity

Add maximum pseudocluster size option for low-zoom points (#119)

Browse Source 
* Trying to improve cluster positions

* Fix centroid calculation

* Just move points to cluster centroids; add point gap threshold

* Add maximum-point-gap option

* Fix formatting

* Rename options for clarity; add tests; update changelog

* Add missing break to switch

* Revert unneeded constructor cleanup that broke a test somehow

* Clean up comments

* Remove unused --move-points-to-cluster-centroids

* Mention tile-join change in changelog
This commit is contained in:
Erica Fischer
2023-07-17 15:33:07 -07:00
committed by GitHub
parent 1c3bd5352c
commit 4318e964e3
8 changed files with 2640 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files
main.cpp
+39 -6
View File
@@ -90,6 +90,7 @@ size_t limit_tile_feature_count = 0;
size_t limit_tile_feature_count_at_maxzoom = 0;
unsigned int drop_denser = 0;
std::map<std::string, serial_val> set_attributes;
unsigned long long preserve_point_density_threshold = 0;
std::vector<order_field> order_by;
bool order_reverse;
@@ -277,7 +278,7 @@ struct drop_state {
double gap;
unsigned long long previndex;
double interval;
double seq;
double seq; // floating point because interval is
};
struct drop_densest {
@@ -292,8 +293,6 @@ struct drop_densest {
int calc_feature_minzoom(struct index *ix, struct drop_state *ds, int maxzoom, double gamma) {
int feature_minzoom = 0;
unsigned xx, yy;
decode_index(ix->ix, &xx, &yy);
if (gamma >= 0 && (ix->t == VT_POINT ||
(additional[A_LINE_DROP] && ix->t == VT_LINE) ||
@@ -301,12 +300,43 @@ int calc_feature_minzoom(struct index *ix, struct drop_state *ds, int maxzoom, d
for (ssize_t i = maxzoom; i >= 0; i--) {
ds[i].seq++;
}
ssize_t chosen = maxzoom + 1;
for (ssize_t i = maxzoom; i >= 0; i--) {
if (ds[i].seq >= 0) {
ds[i].seq -= ds[i].interval;
} else {
if (ds[i].seq < 0) {
feature_minzoom = i + 1;
// The feature we are pushing out
// appears in zooms i + 1 through maxzoom,
// so track where that was so we can make sure
// not to cluster something else that is *too*
// far away into it.
for (ssize_t j = i + 1; j <= maxzoom; j++) {
ds[j].previndex = ix->ix;
}
chosen = i + 1;
break;
} else {
ds[i].seq -= ds[i].interval;
}
}
// If this feature has been chosen only for a high zoom level,
// check whether at a low zoom level it is nevertheless too far
// from the last feature chosen for that low zoom, in which case
// we will go ahead and push it out.
if (preserve_point_density_threshold > 0) {
for (ssize_t i = 0; i < chosen && i < maxzoom; i++) {
if (ix->ix - ds[i].previndex > ((1LL << (32 - i)) / preserve_point_density_threshold) * ((1LL << (32 - i)) / preserve_point_density_threshold)) {
feature_minzoom = i;
for (ssize_t j = i; j <= maxzoom; j++) {
ds[j].previndex = ix->ix;
}
break;
}
}
}
@@ -2898,6 +2928,7 @@ int main(int argc, char **argv) {
{"drop-polygons", no_argument, &additional[A_POLYGON_DROP], 1},
{"cluster-distance", required_argument, 0, 'K'},
{"cluster-maxzoom", required_argument, 0, 'k'},
{"preserve-point-density-threshold", required_argument, 0, '~'},
{"Dropping or merging a fraction of features to keep under tile size limits", 0, 0, 0},
{"drop-densest-as-needed", no_argument, &additional[A_DROP_DENSEST_AS_NEEDED], 1},
@@ -3105,6 +3136,8 @@ int main(int argc, char **argv) {
fprintf(stderr, "%s: --drop-denser can be at most 100\n", argv[0]);
exit(EXIT_ARGS);
}
} else if (strcmp(opt, "preserve-point-density-threshold") == 0) {
preserve_point_density_threshold = atoll_require(optarg, "Preserve point density threshold");
} else {
fprintf(stderr, "%s: Unrecognized option --%s\n", argv[0], opt);
exit(EXIT_ARGS);