ExternalVendorCode/tippecanoe
1
0
Fork 0
mirror of https://github.com/mapbox/tippecanoe.git synced 2025-02-02 01:08:14 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Merge remote-tracking branch 'origin/master' into multilayer

Browse Source
This commit is contained in:
Eric Fischer 2015-03-25 13:54:29 -07:00
commit a076c5619d
3 changed files with 29 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
README.md
View File

@ -58,7 +58,7 @@ Options
* -f: Delete the mbtiles file if it already exists instead of giving an error
* -r <i>rate</i>: Rate at which dots are dropped at lower zoom levels (default 2.5)
* -b <i>pixels</i>: Buffer size where features are duplicated from adjacent tiles (default 5)
* -g <i>gamma</i>: Rate at which especially dense dots are dropped (default 1, for no effect). A gamma of 2 reduces the number of dots less than a pixel apart to the square root of their original number.
* -g <i>gamma</i>: Rate at which especially dense dots are dropped (default 0, for no effect). A gamma of 2 reduces the number of dots less than a pixel apart to the square root of their original number.
Example
-------

2
geojson.c
View File

@ -942,7 +942,7 @@ int main(int argc, char **argv) {
int minzoom = 0;
int force = 0;
double droprate = 2.5;
double gamma = 1;
double gamma = 0;
int buffer = 5;
const char *tmpdir = "/tmp";

52
tile.cc
View File

@ -508,11 +508,11 @@ long long write_tile(char **geoms, char *metabase, unsigned *file_bbox, int z, u
continue;
}
if (t == VT_POINT && z < feature_minzoom && gamma == 0) {
if (t == VT_POINT && z < feature_minzoom && gamma < 0) {
continue;
}
if (t == VT_POINT && gamma != 0) {
if (t == VT_POINT && gamma >= 0) {
seq++;
if (seq >= 0) {
seq -= interval;
@ -520,32 +520,34 @@ long long write_tile(char **geoms, char *metabase, unsigned *file_bbox, int z, u
continue;
}
unsigned long long index = encode(bbox[0] / 2 + bbox[2] / 2, bbox[1] / 2 + bbox[3] / 2);
if (gap > 0) {
if (index == previndex) {
continue; // Exact duplicate: can't fulfil the gap requirement
if (gamma > 0) {
unsigned long long index = encode(bbox[0] / 2 + bbox[2] / 2, bbox[1] / 2 + bbox[3] / 2);
if (gap > 0) {
if (index == previndex) {
continue; // Exact duplicate: can't fulfil the gap requirement
}
if (exp(log((index - previndex) / scale) * gamma) >= gap) {
// Dot is further from the previous than the nth root of the gap,
// so produce it, and choose a new gap at the next point.
gap = 0;
} else {
continue;
}
} else {
gap = (index - previndex) / scale;
if (gap == 0) {
continue; // Exact duplicate: skip
} else if (gap < 1) {
continue; // Narrow dot spacing: need to stretch out
} else {
gap = 0; // Wider spacing than minimum: so pass through unchanged
}
}
if (exp(log((index - previndex) / scale) * gamma) >= gap) {
// Dot is further from the previous than the nth root of the gap,
// so produce it, and choose a new gap at the next point.
gap = 0;
} else {
continue;
}
} else {
gap = (index - previndex) / scale;
if (gap == 0) {
continue; // Exact duplicate: skip
} else if (gap < 1) {
continue; // Narrow dot spacing: need to stretch out
} else {
gap = 0; // Wider spacing than minimum: so pass through unchanged
}
previndex = index;
}
previndex = index;
}
bool reduced = false;