FlatGeobuf MultiPolygon parsing [#2]

flatgeobuf.cpp

@@ -36,13 +36,12 @@ uint64_t PackedRTreeSize(const uint64_t numItems, const uint16_t nodeSize)
     return numNodes * sizeof(NodeItem);
 }
 
-drawvec readGeometry(const FlatGeobuf::Geometry *geometry, FlatGeobuf::GeometryType geometry_type) {
+drawvec readPolygon(const FlatGeobuf::Geometry *geometry) {
-	// if it is a GeometryCollection, parse Parts, ignore XY
 	auto xy = geometry->xy();
 	auto ends = geometry->ends();
 	size_t current_end = 0;
-
 	drawvec dv;
+
 	for (unsigned int i = 0; i < xy->size(); i+=2) {
 		long long x, y;
 		projection->project(xy->Get(i), xy->Get(i+1), 32, &x, &y);
@@ -53,10 +52,30 @@ drawvec readGeometry(const FlatGeobuf::Geometry *geometry, FlatGeobuf::GeometryT
 			dv.push_back(draw(VT_LINETO, x, y));
 		}
 	}
-
 	return dv;
 }
 
+drawvec readGeometry(const FlatGeobuf::Geometry *geometry, FlatGeobuf::GeometryType h_geometry_type) {
+
+	if (h_geometry_type == FlatGeobuf::GeometryType::Polygon) {
+		return readPolygon(geometry);
+	} else if (h_geometry_type == FlatGeobuf::GeometryType::MultiPolygon) { 
+	// if it is a GeometryCollection, parse Parts, ignore XY
+		drawvec dv;
+		for (size_t part = 0; part < geometry->parts()->size(); part++) {
+			drawvec dv2 = readPolygon(geometry->parts()->Get(part));
+			for (size_t k = 0; k < dv2.size(); k++) {
+				dv.push_back(dv2[k]);
+			}
+			dv.push_back(draw(VT_CLOSEPATH, 0, 0));
+		}
+		return dv;
+	} else {
+		fprintf(stderr, "flatgeobuf has unsupported geometry type %u\n", (unsigned int)h_geometry_type);
+		exit(EXIT_FAILURE);
+	}
+}
+
 void parse_flatgeobuf(std::vector<struct serialization_state> *sst, const char *src, int layer, std::string layername) {
 	auto header_size = flatbuffers::GetPrefixedSize((const uint8_t *)src + 8);
 	auto header = FlatGeobuf::GetSizePrefixedHeader(src + 8);
@@ -86,7 +105,7 @@ void parse_flatgeobuf(std::vector<struct serialization_state> *sst, const char *
 		case FlatGeobuf::GeometryType::GeometryCollection :
 			break;
 		default:
-			fprintf(stderr, "flatgeobuf has unsupported geometry type\n");
+			fprintf(stderr, "flatgeobuf has unsupported geometry type %u\n", (unsigned int)h_geometry_type);
 			exit(EXIT_FAILURE);
 	}
 
@@ -125,18 +144,24 @@ void parse_flatgeobuf(std::vector<struct serialization_state> *sst, const char *
 			FlatGeobuf::ColumnType col_type = h_column_types[col_idx];
 
 			serial_val sv;
-			if (col_type == FlatGeobuf::ColumnType::Long) {
+			if (col_type == FlatGeobuf::ColumnType::Int) {
+				sv.type = mvt_double; // this is quirky
+				int32_t int_val;
+				memcpy(&int_val, feature->properties()->data() + p_pos + 2, sizeof(int_val));
+				sv.s = to_string(int_val);
+				p_pos += 2 + sizeof(int_val);
+			} else if (col_type == FlatGeobuf::ColumnType::Long) {
 				sv.type = mvt_double; // this is quirky
 				uint64_t long_val;
 				memcpy(&long_val, feature->properties()->data() + p_pos + 2, sizeof(long_val));
 				sv.s = to_string(long_val);
-				p_pos += 2 + 8;
+				p_pos += 2 + sizeof(long_val);
 			} else if (col_type == FlatGeobuf::ColumnType::Double) {
 				sv.type = mvt_double;
 				double double_val;
 				memcpy(&double_val, feature->properties()->data() + p_pos + 2, sizeof(double_val));
 				sv.s = milo::dtoa_milo(double_val);
-				p_pos += 2 + 8;
+				p_pos += 2 + sizeof(double_val);
 			} else if (col_type == FlatGeobuf::ColumnType::String) {
 				sv.type = mvt_string;
 				uint32_t str_len;
@@ -145,7 +170,7 @@ void parse_flatgeobuf(std::vector<struct serialization_state> *sst, const char *
 				sv.s = s;
 				p_pos += 2 + 4 + str_len;
 			} else {
-				fprintf(stderr, "flatgeobuf has unsupported column type\n");
+				fprintf(stderr, "flatgeobuf has unsupported column type %u\n", (unsigned int)col_type);
 				exit(EXIT_FAILURE);
 			}
 			full_keys.push_back(h_column_names[col_idx]);