Abstraction of tile decoding

protobuf.hh

@@ -2,3 +2,61 @@ bool is_compressed(std::string const &data);
 int decompress(std::string const &input, std::string &output);
 int compress(std::string const &input, std::string &output);
 int dezig(unsigned n);
+
+enum pb_geometry_type {
+	pb_point = 1, pb_linestring = 2, pb_polygon = 3
+};
+
+enum pb_operation {
+	pb_moveto = 1, pb_lineto = 2, pb_closepath = 7
+};
+
+enum pb_value_type {
+	pb_string, pb_float, pb_double, pb_int, pb_uint, pb_sint, pb_bool
+};
+
+struct pb_value {
+	pb_value_type type;
+	std::string string_value;
+	union {
+		float float_value;
+		double double_value;
+		long long int_value;
+		unsigned long long uint_value;
+		long long sint_value;
+		bool bool_value;
+	} numeric_value;
+};
+
+struct pb_geometry {
+	int /* pb_operation */ op;
+	long long x;
+	long long y;
+
+	pb_geometry(int op, long long x, long long y) {
+		this->op = op;
+		this->x = x;
+		this->y = y;
+	}
+};
+
+struct pb_feature {
+	std::vector<unsigned> tags;
+	int /* pb_geometry_type */ type;
+	std::vector<pb_geometry> geometry;
+};
+
+struct pb_layer {
+	int version;
+	std::string name;
+	std::vector<pb_feature> features;
+	std::vector<std::string> keys;
+	std::vector<pb_value> values;
+	int extent;
+};
+
+struct pb_tile {
+	std::vector<pb_layer> layers;
+};
+
+bool pb_decode(std::string &message, pb_tile &out);