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lib/main/google/olc/olc.h

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+#ifndef OLC_OPENLOCATIONCODE_H_
+#define OLC_OPENLOCATIONCODE_H_
+
+#include <stdlib.h>
+
+#define OLC_VERSION_MAJOR 1
+#define OLC_VERSION_MINOR 0
+#define OLC_VERSION_PATCH 0
+
+// OLC version number: 2.3.4 => 2003004
+// Useful for checking against a particular version or above:
+//
+// #if OLC_VERSION_NUM < OLC_MAKE_VERSION_NUM(1, 0, 2)
+// #error UNSUPPORTED OLC VERSION
+// #endif
+#define OLC_MAKE_VERSION_NUM(major, minor, patch) \
+  ((major * 1000 + minor) * 1000 + patch)
+
+// OLC version string: 2.3.4 => "2.3.4"
+#define OLC_MAKE_VERSION_STR_IMPL(major, minor, patch) \
+  (#major "." #minor "." #patch)
+#define OLC_MAKE_VERSION_STR(major, minor, patch) \
+  OLC_MAKE_VERSION_STR_IMPL(major, minor, patch)
+
+// Current version, as a number and a string
+#define OLC_VERSION_NUM \
+  OLC_MAKE_VERSION_NUM(OLC_VERSION_MAJOR, OLC_VERSION_MINOR, OLC_VERSION_PATCH)
+#define OLC_VERSION_STR \
+  OLC_MAKE_VERSION_STR(OLC_VERSION_MAJOR, OLC_VERSION_MINOR, OLC_VERSION_PATCH)
+
+// A pair of doubles representing latitude / longitude
+typedef struct OLC_LatLon {
+  double lat;
+  double lon;
+} OLC_LatLon;
+
+// An area defined by two corners (lo and hi) and a code length
+typedef struct OLC_CodeArea {
+  OLC_LatLon lo;
+  OLC_LatLon hi;
+  size_t len;
+} OLC_CodeArea;
+
+// Get the center coordinates for an area
+void OLC_GetCenter(const OLC_CodeArea* area, OLC_LatLon* center);
+
+// Get the effective length for a code
+size_t OLC_CodeLength(const char* code, size_t size);
+
+// Check for the three obviously-named conditions
+int OLC_IsValid(const char* code, size_t size);
+int OLC_IsShort(const char* code, size_t size);
+int OLC_IsFull(const char* code, size_t size);
+
+// Encode location with given code length (indicates precision) into an OLC
+// Return the string length of the code
+int OLC_Encode(const OLC_LatLon* location, size_t code_length, char* code);
+
+// Encode location with default code length into an OLC
+// Return the string length of the code
+int OLC_EncodeDefault(const OLC_LatLon* location, char* code);
+
+// Decode OLC into the original location
+int OLC_Decode(const char* code, size_t size, OLC_CodeArea* decoded);
+
+// Compute a (shorter) OLC for a given code and a reference location
+int OLC_Shorten(const char* code, size_t size, const OLC_LatLon* reference,
+                char* buf);
+
+// Given shorter OLC and reference location, compute original (full length) OLC
+int OLC_RecoverNearest(const char* short_code, size_t size,
+                       const OLC_LatLon* reference, char* code);
+
+#endif