lib/main/google/olc/olc.h

   1 #ifndef OLC_OPENLOCATIONCODE_H_
   2 #define OLC_OPENLOCATIONCODE_H_
   3
   4 #include <stdlib.h>
   5
   6 #define OLC_VERSION_MAJOR 1
   7 #define OLC_VERSION_MINOR 0
   8 #define OLC_VERSION_PATCH 0
   9
  10 // OLC version number: 2.3.4 => 2003004
  11 // Useful for checking against a particular version or above:
  12 //
  13 // #if OLC_VERSION_NUM < OLC_MAKE_VERSION_NUM(1, 0, 2)
  14 // #error UNSUPPORTED OLC VERSION
  15 // #endif
  16 #define OLC_MAKE_VERSION_NUM(major, minor, patch) \
  17   ((major * 1000 + minor) * 1000 + patch)
  18
  19 // OLC version string: 2.3.4 => "2.3.4"
  20 #define OLC_MAKE_VERSION_STR_IMPL(major, minor, patch) \
  21   (#major "." #minor "." #patch)
  22 #define OLC_MAKE_VERSION_STR(major, minor, patch) \
  23   OLC_MAKE_VERSION_STR_IMPL(major, minor, patch)
  24
  25 // Current version, as a number and a string
  26 #define OLC_VERSION_NUM \
  27   OLC_MAKE_VERSION_NUM(OLC_VERSION_MAJOR, OLC_VERSION_MINOR, OLC_VERSION_PATCH)
  28 #define OLC_VERSION_STR \
  29   OLC_MAKE_VERSION_STR(OLC_VERSION_MAJOR, OLC_VERSION_MINOR, OLC_VERSION_PATCH)
  30
  31 // A pair of doubles representing latitude / longitude
  32 typedef struct OLC_LatLon {
  33   double lat;
  34   double lon;
  35 } OLC_LatLon;
  36
  37 // An area defined by two corners (lo and hi) and a code length
  38 typedef struct OLC_CodeArea {
  39   OLC_LatLon lo;
  40   OLC_LatLon hi;
  41   size_t len;
  42 } OLC_CodeArea;
  43
  44 // Get the center coordinates for an area
  45 void OLC_GetCenter(const OLC_CodeArea* area, OLC_LatLon* center);
  46
  47 // Get the effective length for a code
  48 size_t OLC_CodeLength(const char* code, size_t size);
  49
  50 // Check for the three obviously-named conditions
  51 int OLC_IsValid(const char* code, size_t size);
  52 int OLC_IsShort(const char* code, size_t size);
  53 int OLC_IsFull(const char* code, size_t size);
  54
  55 // Encode location with given code length (indicates precision) into an OLC
  56 // Return the string length of the code
  57 int OLC_Encode(const OLC_LatLon* location, size_t code_length, char* code,
  58                int maxlen);
  59
  60 // Encode location with default code length into an OLC
  61 // Return the string length of the code
  62 int OLC_EncodeDefault(const OLC_LatLon* location, char* code, int maxlen);
  63
  64 // Decode OLC into the original location
  65 int OLC_Decode(const char* code, size_t size, OLC_CodeArea* decoded);
  66
  67 // Compute a (shorter) OLC for a given code and a reference location
  68 int OLC_Shorten(const char* code, size_t size, const OLC_LatLon* reference,
  69                 char* buf, int maxlen);
  70
  71 // Given shorter OLC and reference location, compute original (full length) OLC
  72 int OLC_RecoverNearest(const char* short_code, size_t size,
  73                        const OLC_LatLon* reference, char* code, int maxlen);
  74
  75 #endif