Bounding box of tile-relative mvt geometry

Makefile

@@ -74,7 +74,7 @@ tile-join: tile-join.o projection.o mbtiles.o mvt.o memfile.o dirtiles.o jsonpul
 tippecanoe-json-tool: jsontool.o jsonpull/jsonpull.o csv.o text.o geojson-loop.o
 	$(CXX) $(PG) $(LIBS) $(FINAL_FLAGS) $(CXXFLAGS) -o $@ $^ $(LDFLAGS) -lm -lz -lsqlite3 -lpthread
 
-unit: unit.o text.o sort.o mvt.o
+unit: unit.o text.o sort.o mvt.o projection.o
 	$(CXX) $(PG) $(LIBS) $(FINAL_FLAGS) $(CXXFLAGS) -o $@ $^ $(LDFLAGS) -lm -lz -lsqlite3 -lpthread
 
 tippecanoe-overzoom: overzoom.o mvt.o clip.o evaluator.o jsonpull/jsonpull.o text.o attribute.o read_json.o projection.o

clip.cpp

@@ -1184,20 +1184,17 @@ struct index_event {
 	}
 };
 
-void get_quadkey_bounds(std::vector<mvt_geometry> const &geom,
-			unsigned long long *start, unsigned long long *end,
-			int z, int x, int y, int extent) {
-}
-
-mvt_tile assign_to_bins(mvt_tile const &features, std::vector<mvt_layer> const &bins, int z, int x, int y, int extent) {
+mvt_tile assign_to_bins(mvt_tile const &features, std::vector<mvt_layer> const &bins, int z, int x, int y, int detail) {
 	std::vector<index_event> events;
 
 	// Index bins
 	for (size_t i = 0; i < bins.size(); i++) {
 		for (size_t j = 0; j < bins[i].features.size(); j++) {
+			long long xmin, ymin, xmax, ymax;
 			unsigned long long start, end;
 
-			get_quadkey_bounds(bins[i].features[j].geometry, &start, &end, z, x, y, extent);
+			get_bbox(bins[i].features[j].geometry, &xmin, &ymin, &xmax, &ymax, z, x, y, detail);
+			// get_quadkey_bounds(xmin, xmax, ymin, ymax, &start, &end, z, x, y, detail);
 			events.emplace_back(start, index_event::ENTER, i, j);
 			events.emplace_back(end, index_event::EXIT, i, j);
 		}
@@ -1206,9 +1203,11 @@ mvt_tile assign_to_bins(mvt_tile const &features, std::vector<mvt_layer> const &
 	// Index points
 	for (size_t i = 0; i < features.layers.size(); i++) {
 		for (size_t j = 0; j < features.layers[i].features.size(); j++) {
+			long long xmin, ymin, xmax, ymax;
 			unsigned long long start, end;
 
-			get_quadkey_bounds(bins[i].features[j].geometry, &start, &end, z, x, y, extent);
+			get_bbox(bins[i].features[j].geometry, &xmin, &ymin, &xmax, &ymax, z, x, y, detail);
+			// get_quadkey_bounds(xmin, xmax, ymin, ymax, &start, &end, z, x, y, detail);
 			events.emplace_back(start, index_event::CHECK, i, j);
 		}
 	}
@@ -1448,7 +1447,7 @@ std::string overzoom(std::vector<source_tile> const &tiles, int nz, int nx, int
 	}
 
 	if (bins.size() > 0) {
-		outtile = assign_to_bins(outtile, bins, nz, nx, ny, 1 << detail);
+		outtile = assign_to_bins(outtile, bins, nz, nx, ny, detail);
 	}
 
 	for (ssize_t i = outtile.layers.size() - 1; i >= 0; i--) {

mvt.cpp

@@ -835,3 +835,34 @@ long long mvt_value_to_long_long(mvt_value const &v) {
 		exit(EXIT_IMPOSSIBLE);
 	}
 }
+
+void get_bbox(std::vector<mvt_geometry> const &geom,
+	      long long *xmin, long long *ymin, long long *xmax, long long *ymax,
+	      int z, int tx, int ty, int detail) {
+	*xmin = LLONG_MAX;
+	*ymin = LLONG_MAX;
+	*xmax = 0;
+	*ymax = 0;
+
+	for (auto const &g : geom) {
+		if (g.op == mvt_moveto || g.op == mvt_lineto) {
+			long long x = g.x;
+			long long y = g.y;
+
+			// to world scale
+			x = x * (1LL << (32 - z - detail));
+			y = y * (1LL << (32 - z - detail));
+
+			// to world origin
+			if (z > 0) {
+				x += (1LL << (32 - z)) * tx;
+				y += (1LL << (32 - z)) * ty;
+			}
+
+			*xmin = std::min(*xmin, x);
+			*ymin = std::min(*ymin, y);
+			*xmax = std::max(*xmax, x);
+			*ymax = std::max(*ymax, y);
+		}
+	}
+}

mvt.hpp

@@ -199,4 +199,8 @@ bool is_unsigned_integer(const char *s, unsigned long long *v);
 
 struct serial_val;
 serial_val mvt_value_to_serial_val(mvt_value const &v);
+
+void get_bbox(std::vector<mvt_geometry> const &geom,
+	      long long *xmin, long long *ymin, long long *xmax, long long *ymax,
+	      int z, int tx, int ty, int detail);
 #endif

unit.cpp

@@ -3,6 +3,8 @@
 #include "text.hpp"
 #include "sort.hpp"
 #include "tile-cache.hpp"
+#include "mvt.hpp"
+#include "projection.hpp"
 #include <unistd.h>
 #include <limits.h>
 
@@ -124,3 +126,22 @@ TEST_CASE("Bit reversal", "bit reversal") {
 	REQUIRE(bit_reverse(0x1234567812489BCF) == 0xF3D912481E6A2C48);
 	REQUIRE(bit_reverse(0xF3D912481E6A2C48) == 0x1234567812489BCF);
 }
+
+TEST_CASE("mvt_geometry bbox") {
+	std::vector<mvt_geometry> geom;
+
+	geom.emplace_back(mvt_moveto, 128, 128);
+	geom.emplace_back(mvt_lineto, 256, 256);
+
+	long long xmin, ymin, xmax, ymax;
+	get_bbox(geom, &xmin, &ymin, &xmax, &ymax, 11, 327, 791, 9);
+
+	double lon, lat;
+	tile2lonlat(xmin, ymin, 32, &lon, &lat);
+	REQUIRE(std::to_string(lon) == "-122.475586");
+	REQUIRE(std::to_string(lat) == "37.822802");
+
+	tile2lonlat(xmax, ymax, 32, &lon, &lat);
+	REQUIRE(std::to_string(lon) == "-122.431641");
+	REQUIRE(std::to_string(lat) == "37.788081");
+}