diegoripley/tippecanoe
1
0
Fork 0
mirror of https://github.com/felt/tippecanoe.git synced 2026-10-03 00:45:41 +02:00
Code Issues Packages Projects Releases Wiki Activity

Don't always keep the first feature in a tile, after all

Browse Source
This commit is contained in:
Erica Fischer
2024-02-14 16:04:10 -08:00
parent 44879aab9b
commit fcecdf9afb
2 changed files with 33 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files
main.cpp
+20 -22
View File
@@ -298,31 +298,26 @@ struct drop_densest {
}
};
int calc_feature_minzoom(struct index *ix, struct drop_state *ds, int maxzoom, double gamma) {
int feature_minzoom = 0;
int calc_feature_minzoom(struct index *ix, struct drop_state *ds, size_t maxzoom, double gamma) {
size_t feature_minzoom = 0;
if (gamma >= 0 && (ix->t == VT_POINT ||
(additional[A_LINE_DROP] && ix->t == VT_LINE) ||
(additional[A_POLYGON_DROP] && ix->t == VT_POLYGON))) {
for (ssize_t i = maxzoom; i >= 0; i--) {
feature_minzoom = maxzoom;
// Advance the counter for all zooms
for (size_t i = 0; i <= maxzoom; i++) {
ds[i].seq++;
}
for (ssize_t i = maxzoom; i >= 0; i--) {
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;
}
// Find the zoom at which it is time for a feature
for (size_t i = 0; i <= maxzoom; i++) {
if (ds[i].seq >= ds[i].interval) {
feature_minzoom = i;
break;
} else {
ds[i].seq -= ds[i].interval;
}
}
@@ -332,19 +327,22 @@ int calc_feature_minzoom(struct index *ix, struct drop_state *ds, int maxzoom, d
// we will go ahead and push it out.
if (preserve_point_density_threshold > 0) {
for (ssize_t i = 0; i < feature_minzoom && i < maxzoom; i++) {
for (size_t i = 0; i < feature_minzoom && 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;
}
}
}
// Set the counter back in all zooms that this feature will appear in,
// and remember its index for the next maximum-distance-exceeded decision
for (size_t i = feature_minzoom; i <= maxzoom; i++) {
ds[i].seq -= ds[i].interval;
ds[i].previndex = ix->ix;
}
// XXX manage_gap
}