Fix placement of label anchors in the tile buffer

The anchor point that `--convert-polygons-to-label-points` computes was stored
in `serial_feature` as a single `unsigned long long`, the Morton index of two
*unsigned 32-bit* coordinates. That representation cost two things:

* `SHIFT_LEFT` can legitimately put an anchor outside the [0, 2^32) plane --
  that is exactly what happens for a feature reaching into a tile's buffer --
  but `encode_index` only takes 32-bit unsigned values, so the anchor was
  masked with `& ((1LL << 32) - 1)` on the way in. An anchor just west or
  north of the plane wrapped around to the far edge of the world rather than
  staying where it was. This is most visible in the buffer of the z0 tile,
  whose own bounds are the whole plane, so every buffer anchor is out of range.

* Zero was overloaded as "no anchor," but zero is also the index of the
  legitimate world coordinate (0, 0).

Store the anchor as a pair of signed `long long` coordinates with an explicit
`has_label_point` flag instead. The serialized form grows from one varint to
two, both zigzag-encoded so negative coordinates round-trip; this is the
internal geometry temp file, not tile output, so nothing external depends on
the layout. `write_tile` now checks the flag rather than relying on the
sentinel, and drops the feature when there is no anchor instead of quietly
tiling one at (0, 0).

`checkerboard_anchors` gains the tile buffer as a parameter and short-circuits:
if the real anchor lies within the tile plus its buffer, emit it directly
rather than searching the repeating checkerboard for a substitute. Computing
`ty2` is what makes that test possible -- it had been commented out because
only `tx2` was needed for the label spacing.

The one place this changes test output is
tests/ne_110m_admin_0_countries/out/-z2_--convert-polygons-to-label-points.json,
where Antarctica's anchors move. That fixture is regenerated here.

CHANGELOG and version follow this repo's conventions: an entry under a new
2.81.1 heading, patch rather than minor since this only fixes behavior.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NcSXLjtokxioaBCCwGTEv1

CHANGELOG.md

@@ -1,3 +1,15 @@
+# 2.81.1
+
+* Fix the placement of `--convert-polygons-to-label-points` anchors, most
+  visibly in the buffer of the z0 tile. The anchor was stored as a packed
+  index of two unsigned 32-bit coordinates, so an anchor in the tile buffer
+  outside the [0, 2^32) plane was wrapped to the opposite edge of the world
+  instead of kept where it was, and an anchor at exactly (0, 0) was
+  indistinguishable from having no anchor at all. Store the anchor as a pair
+  of signed coordinates with a separate presence flag, and place it directly
+  when it falls within the tile plus its buffer rather than searching the
+  repeating checkerboard for a substitute.
+
 # 2.81.0
 
 * Add `--drop-by-attribute-as-needed=`*attribute* to drop the features with

geometry.cpp

@@ -944,23 +944,33 @@ drawvec polygon_to_anchor(const drawvec &geom) {
 	return drawvec();
 }
 
-drawvec checkerboard_anchors(drawvec const &geom, int tx, int ty, int z, unsigned long long label_point) {
+drawvec checkerboard_anchors(drawvec const &geom, int tx, int ty, int z, long long wx, long long wy, int buffer) {
 	drawvec out;
 
-	// anchor point in world coordinates
-	unsigned wx, wy;
-	decode_index(label_point, &wx, &wy);
-
 	// upper left of tile in world coordinates
 	long long tx1 = 0, ty1 = 0;
 	// lower right of tile in world coordinates;
-	long long tx2 = 1LL << 32;  // , ty2 = 1LL << 32;
+	long long tx2 = 1LL << 32, ty2 = 1LL << 32;
 	if (z != 0) {
 		tx1 = (long long) tx << (32 - z);
 		ty1 = (long long) ty << (32 - z);
 
 		tx2 = (long long) (tx + 1) << (32 - z);
-		// ty2 = (long long) (ty + 1) << (32 - z);
+		ty2 = (long long) (ty + 1) << (32 - z);
+	}
+
+	long long tx1_buffer = tx1 - (1LL << (32 - z)) * buffer / 256;
+	long long ty1_buffer = ty1 - (1LL << (32 - z)) * buffer / 256;
+	long long tx2_buffer = tx2 + (1LL << (32 - z)) * buffer / 256;
+	long long ty2_buffer = ty2 + (1LL << (32 - z)) * buffer / 256;
+
+	// if the central label point is within this tile, always prefer that.
+	// none of the label repetition code below matters much any more,
+	// now that we truncate the tile pyramid once we have all the features
+	if (wx >= tx1_buffer && wx <= tx2_buffer && wy >= ty1_buffer && wy <= ty2_buffer) {
+		// offset to tile origin
+		out.push_back(draw(VT_MOVETO, wx - tx1, wy - ty1));
+		return out;
 	}
 
 	// upper left of feature in world coordinates

geometry.hpp

@@ -89,7 +89,7 @@ void check_polygon(drawvec &geom);
 double get_area(const drawvec &geom, size_t i, size_t j);
 double get_mp_area(drawvec &geom);
 drawvec polygon_to_anchor(const drawvec &geom);
-drawvec checkerboard_anchors(drawvec const &geom, int tx, int ty, int z, unsigned long long label_point);
+drawvec checkerboard_anchors(drawvec const &geom, int tx, int ty, int z, long long wx, long long wy, int buffer);
 
 drawvec simple_clip_poly(drawvec &geom, int z, int buffer, drawvec &shared_nodes, bool prevent_simplify_shared_nodes);
 drawvec simple_clip_poly(drawvec &geom, long long x1, long long y1, long long x2, long long y2, bool prevent_simplify_shared_nodes);

serial.cpp

@@ -186,7 +186,7 @@ std::string serialize_feature(serial_feature *sf, long long wx, long long wy) {
 
 	long long layer = 0;
 	layer |= sf->layer << FLAG_LAYER;
-	layer |= (sf->label_point != 0) << FLAG_LABEL_POINT;
+	layer |= (sf->has_label_point) << FLAG_LABEL_POINT;
 	layer |= (sf->index != 0) << FLAG_INDEX;
 	layer |= (sf->extent != 0) << FLAG_EXTENT;
 	layer |= sf->has_id << FLAG_ID;
@@ -213,8 +213,9 @@ std::string serialize_feature(serial_feature *sf, long long wx, long long wy) {
 		serialize_ulong_long(s, sf->index);
 		serialize_ulong_long(s, sf->gap);
 	}
-	if (sf->label_point != 0) {
+	if (sf->has_label_point) {
-		serialize_ulong_long(s, sf->label_point);
+		serialize_long_long(s, sf->label_point_x);
+		serialize_long_long(s, sf->label_point_y);
 	}
 	if (sf->extent != 0) {
 		serialize_long_long(s, sf->extent);
@@ -261,7 +262,9 @@ serial_feature deserialize_feature(std::string const &geoms, unsigned z, unsigne
 
 	sf.index = 0;
 	sf.gap = 0;
-	sf.label_point = 0;
+	sf.label_point_x = 0;
+	sf.label_point_y = 0;
+	sf.has_label_point = false;
 	sf.extent = 0;
 
 	sf.geometry = decode_geometry(&cp, z, tx, ty, sf.bbox, initial_x[sf.segment], initial_y[sf.segment]);
@@ -271,7 +274,9 @@ serial_feature deserialize_feature(std::string const &geoms, unsigned z, unsigne
 		deserialize_ulong_long(&cp, &sf.gap);
 	}
 	if (sf.layer & (1 << FLAG_LABEL_POINT)) {
-		deserialize_ulong_long(&cp, &sf.label_point);
+		sf.has_label_point = true;
+		deserialize_long_long(&cp, &sf.label_point_x);
+		deserialize_long_long(&cp, &sf.label_point_y);
 	}
 	if (sf.layer & (1 << FLAG_EXTENT)) {
 		deserialize_long_long(&cp, &sf.extent);
@@ -734,9 +739,9 @@ int serialize_feature(struct serialization_state *sst, serial_feature &sf, std::
 	if (sf.t == VT_POLYGON && additional[A_GENERATE_POLYGON_LABEL_POINTS]) {
 		drawvec dv = polygon_to_anchor(scaled_geometry);
 		if (dv.size() > 0) {
-			dv[0].x = SHIFT_LEFT(dv[0].x) & ((1LL << 32) - 1);
+			sf.label_point_x = SHIFT_LEFT(dv[0].x);
-			dv[0].y = SHIFT_LEFT(dv[0].y) & ((1LL << 32) - 1);
+			sf.label_point_y = SHIFT_LEFT(dv[0].y);
-			sf.label_point = encode_index(dv[0].x, dv[0].y);
+			sf.has_label_point = true;
 		}
 	}
 

serial.hpp

@@ -119,9 +119,15 @@ struct serial_feature {
 	drawvec geometry = drawvec();
 	unsigned long long index = 0;
 	unsigned long long gap = 0;  // filled in during z0. square of planar distance
-	unsigned long long label_point = 0;
 	long long extent = 0;
 
+	// The anchor point for a polygon label, in world coordinates,
+	// which can legitimately be outside the [0, 2^32) plane, so a
+	// separate flag rather than a sentinel value marks its absence.
+	bool has_label_point = false;
+	long long label_point_x = 0;
+	long long label_point_y = 0;
+
 	// These fields are not directly serialized, but are used
 	// to create the keys and values references into the string pool
 	// during initial serialization

tests/ne_110m_admin_0_countries/out/-z2_--convert-polygons-to-label-points.json

@@ -366,7 +366,7 @@
 ,
 { "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 2, "sovereignt": "Australia", "sov_a3": "AU1", "adm0_dif": 1, "level": 2, "type": "Country", "admin": "Australia", "adm0_a3": "AUS", "geou_dif": 0, "geounit": "Australia", "gu_a3": "AUS", "su_dif": 0, "subunit": "Australia", "su_a3": "AUS", "brk_diff": 0, "name": "Australia", "name_long": "Australia", "brk_a3": "AUS", "brk_name": "Australia", "abbrev": "Auz.", "postal": "AU", "formal_en": "Commonwealth of Australia", "name_sort": "Australia", "mapcolor7": 1, "mapcolor8": 2, "mapcolor9": 2, "mapcolor13": 7, "pop_est": 21262641, "gdp_md_est": 800200, "pop_year": -99, "lastcensus": 2006, "gdp_year": -99, "economy": "2. Developed region: nonG7", "income_grp": "1. High income: OECD", "wikipedia": -99, "iso_a2": "AU", "iso_a3": "AUS", "iso_n3": "036", "un_a3": "036", "wb_a2": "AU", "wb_a3": "AUS", "woe_id": -99, "adm0_a3_is": "AUS", "adm0_a3_us": "AUS", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Oceania", "region_un": "Oceania", "subregion": "Australia and New Zealand", "region_wb": "East Asia & Pacific", "name_len": 9, "long_len": 9, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "Point", "coordinates": [ 134.472656, -26.037042 ] } }
 ,
-{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "MultiPoint", "coordinates": [ [ -103.095703, -83.932990 ], [ 4.921875, -74.519889 ], [ 112.851562, -83.932990 ] ] } }
+{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 4.921875, -81.710526 ], [ 112.851562, -68.911005 ] ] } }
 ] }
 ] }
 ,
@@ -390,7 +390,7 @@
 ,
 { "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 5, "sovereignt": "United Kingdom", "sov_a3": "GB1", "adm0_dif": 1, "level": 2, "type": "Dependency", "admin": "Falkland Islands", "adm0_a3": "FLK", "geou_dif": 0, "geounit": "Falkland Islands", "gu_a3": "FLK", "su_dif": 0, "subunit": "Falkland Islands", "su_a3": "FLK", "brk_diff": 1, "name": "Falkland Is.", "name_long": "Falkland Islands", "brk_a3": "B12", "brk_name": "Falkland Is.", "abbrev": "Flk. Is.", "postal": "FK", "formal_en": "Falkland Islands", "note_adm0": "U.K.", "note_brk": "Admin. by U.K.; Claimed by Argentina", "name_sort": "Falkland Islands", "name_alt": "Islas Malvinas", "mapcolor7": 6, "mapcolor8": 6, "mapcolor9": 6, "mapcolor13": 3, "pop_est": 3140, "gdp_md_est": 105.1, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "2. Developed region: nonG7", "income_grp": "1. High income: OECD", "wikipedia": -99, "iso_a2": "FK", "iso_a3": "FLK", "iso_n3": "238", "un_a3": "238", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "FLK", "adm0_a3_us": "FLK", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "South America", "region_un": "Americas", "subregion": "South America", "region_wb": "Latin America & Caribbean", "name_len": 12, "long_len": 16, "abbrev_len": 8, "tiny": -99, "homepart": -99 }, "geometry": { "type": "Point", "coordinates": [ -59.414062, -51.699800 ] } }
 ,
-{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "MultiPoint", "coordinates": [ [ -103.139648, -83.937633 ], [ -49.130859, -80.305330 ] ] } }
+{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "MultiPoint", "coordinates": [ [ -103.139648, -81.704187 ], [ -49.130859, -84.818373 ] ] } }
 ] }
 ] }
 ,
@@ -550,7 +550,7 @@
 ,
 { "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 2, "sovereignt": "Australia", "sov_a3": "AU1", "adm0_dif": 1, "level": 2, "type": "Country", "admin": "Australia", "adm0_a3": "AUS", "geou_dif": 0, "geounit": "Australia", "gu_a3": "AUS", "su_dif": 0, "subunit": "Australia", "su_a3": "AUS", "brk_diff": 0, "name": "Australia", "name_long": "Australia", "brk_a3": "AUS", "brk_name": "Australia", "abbrev": "Auz.", "postal": "AU", "formal_en": "Commonwealth of Australia", "name_sort": "Australia", "mapcolor7": 1, "mapcolor8": 2, "mapcolor9": 2, "mapcolor13": 7, "pop_est": 21262641, "gdp_md_est": 800200, "pop_year": -99, "lastcensus": 2006, "gdp_year": -99, "economy": "2. Developed region: nonG7", "income_grp": "1. High income: OECD", "wikipedia": -99, "iso_a2": "AU", "iso_a3": "AUS", "iso_n3": "036", "un_a3": "036", "wb_a2": "AU", "wb_a3": "AUS", "woe_id": -99, "adm0_a3_is": "AUS", "adm0_a3_us": "AUS", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Oceania", "region_un": "Oceania", "subregion": "Australia and New Zealand", "region_wb": "East Asia & Pacific", "name_len": 9, "long_len": 9, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "Point", "coordinates": [ 134.472656, -25.997550 ] } }
 ,
-{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 4.877930, -74.519889 ], [ 58.886719, -80.305330 ], [ 112.895508, -74.519889 ] ] } }
+{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 4.877930, -81.704187 ], [ 58.886719, -76.750473 ], [ 112.895508, -68.926811 ], [ 166.860352, -84.818373 ] ] } }
 ] }
 ] }
 ,
@@ -778,7 +778,7 @@
 ,
 { "type": "FeatureCollection", "properties": { "zoom": 2, "x": 0, "y": 3 }, "features": [
 { "type": "FeatureCollection", "properties": { "layer": "in", "version": 2, "extent": 4096 }, "features": [
-{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "Point", "coordinates": [ -119.179688, -81.127169 ] } }
+{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "Point", "coordinates": [ -119.179688, -79.038437 ] } }
 ] }
 ] }
 ,
@@ -800,7 +800,7 @@
 ,
 { "type": "FeatureCollection", "properties": { "zoom": 2, "x": 1, "y": 3 }, "features": [
 { "type": "FeatureCollection", "properties": { "layer": "in", "version": 2, "extent": 4096 }, "features": [
-{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "Point", "coordinates": [ -57.150879, -84.830266 ] } }
+{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "Point", "coordinates": [ -57.150879, -83.606375 ] } }
 ] }
 ] }
 ,
@@ -914,7 +914,7 @@
 ,
 { "type": "FeatureCollection", "properties": { "zoom": 2, "x": 2, "y": 3 }, "features": [
 { "type": "FeatureCollection", "properties": { "layer": "in", "version": 2, "extent": 4096 }, "features": [
-{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 4.877930, -81.127169 ], [ 66.906738, -74.816180 ] ] } }
+{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 4.877930, -79.038437 ], [ 66.906738, -71.272595 ] ] } }
 ] }
 ] }
 ,
@@ -1146,7 +1146,7 @@
 ,
 { "type": "FeatureCollection", "properties": { "zoom": 2, "x": 3, "y": 3 }, "features": [
 { "type": "FeatureCollection", "properties": { "layer": "in", "version": 2, "extent": 4096 }, "features": [
-{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "Point", "coordinates": [ 128.935547, -81.127169 ] } }
+{ "type": "Feature", "properties": { "scalerank": 1, "featurecla": "Admin-0 country", "labelrank": 4, "sovereignt": "Antarctica", "sov_a3": "ATA", "adm0_dif": 0, "level": 2, "type": "Indeterminate", "admin": "Antarctica", "adm0_a3": "ATA", "geou_dif": 0, "geounit": "Antarctica", "gu_a3": "ATA", "su_dif": 0, "subunit": "Antarctica", "su_a3": "ATA", "brk_diff": 0, "name": "Antarctica", "name_long": "Antarctica", "brk_a3": "ATA", "brk_name": "Antarctica", "abbrev": "Ant.", "postal": "AQ", "note_brk": "Multiple claims held in abeyance", "name_sort": "Antarctica", "mapcolor7": 4, "mapcolor8": 5, "mapcolor9": 1, "mapcolor13": -99, "pop_est": 3802, "gdp_md_est": 760.4, "pop_year": -99, "lastcensus": -99, "gdp_year": -99, "economy": "6. Developing region", "income_grp": "2. High income: nonOECD", "wikipedia": -99, "iso_a2": "AQ", "iso_a3": "ATA", "iso_n3": "010", "un_a3": "-099", "wb_a2": "-99", "wb_a3": "-99", "woe_id": -99, "adm0_a3_is": "ATA", "adm0_a3_us": "ATA", "adm0_a3_un": -99, "adm0_a3_wb": -99, "continent": "Antarctica", "region_un": "Antarctica", "subregion": "Antarctica", "region_wb": "Antarctica", "name_len": 10, "long_len": 10, "abbrev_len": 4, "tiny": -99, "homepart": 1 }, "geometry": { "type": "Point", "coordinates": [ 128.935547, -79.038437 ] } }
 ] }
 ] }
 ,

tile.cpp

@@ -1910,7 +1910,11 @@ long long write_tile(decompressor *geoms, std::atomic<long long> *geompos_in, ch
 				if (ngeom.size() == 0) {
 					continue;
 				}
-				sf.geometry = checkerboard_anchors(ngeom, tx, ty, z, sf.label_point);
+				if (sf.has_label_point) {
+					sf.geometry = checkerboard_anchors(ngeom, tx, ty, z, sf.label_point_x, sf.label_point_y, buffer);
+				} else {
+					sf.geometry.clear();
+				}
 				if (sf.geometry.size() == 0) {
 					continue;
 				}

version.hpp

@@ -1,6 +1,6 @@
 #ifndef VERSION_HPP
 #define VERSION_HPP
 
-#define VERSION "v2.81.0"
+#define VERSION "v2.81.1"
 
 #endif