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#include "api-client.h"
#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
// Max number of base64 bytes to encode a geo point.
#define MAPSWITHME_MAX_POINT_BYTES 10
#define MAPSWITHME_MAX_COORD_BITS (MAPSWITHME_MAX_POINT_BYTES * 3)
char MapsWithMe_Base64Char(int x)
{
assert(x >= 0 && x < 64);
return "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"[x];
}
// Map latitude: [-90, 90] -> [0, maxValue]
int MapsWithMe_LatToInt(double lat, int maxValue)
{
// M = maxValue, L = maxValue-1
// lat: -90 90
// x: 0 1 2 L M
// |--+--|--+--|--...--|--+--|
// 000111111222222...LLLLLMMMM
double const x = (lat + 90.0) / 180.0 * maxValue;
return (x < 0 ? 0 : (x > maxValue ? maxValue : (int)(x + 0.5)));
}
// Make lon in [-180, 180)
double MapsWithMe_LonIn180180(double lon)
{
if (lon >= 0)
return fmod(lon + 180.0, 360.0) - 180.0;
else
{
// Handle the case of l = -180
double const l = fmod(lon - 180.0, 360.0) + 180.0;
return l < 180.0 ? l : l - 360.0;
}
}
// Map longitude: [-180, 180) -> [0, maxValue]
int MapsWithMe_LonToInt(double lon, int maxValue)
{
double const x = (MapsWithMe_LonIn180180(lon) + 180.0) / 360.0 * (maxValue + 1.0) + 0.5;
return (x <= 0 || x >= maxValue + 1) ? 0 : (int)x;
}
void MapsWithMe_LatLonToString(double lat, double lon, char * s, int nBytes)
{
if (nBytes > MAPSWITHME_MAX_POINT_BYTES)
nBytes = MAPSWITHME_MAX_POINT_BYTES;
int const latI = MapsWithMe_LatToInt(lat, (1 << MAPSWITHME_MAX_COORD_BITS) - 1);
int const lonI = MapsWithMe_LonToInt(lon, (1 << MAPSWITHME_MAX_COORD_BITS) - 1);
for (int i = 0, shift = MAPSWITHME_MAX_COORD_BITS - 3; i < nBytes; ++i, shift -= 3)
{
int const latBits = latI >> shift & 7;
int const lonBits = lonI >> shift & 7;
int const nextByte =
(latBits >> 2 & 1) << 5 |
(lonBits >> 2 & 1) << 4 |
(latBits >> 1 & 1) << 3 |
(lonBits >> 1 & 1) << 2 |
(latBits & 1) << 1 |
(lonBits & 1);
s[i] = MapsWithMe_Base64Char(nextByte);
}
}
// Replaces ' ' with '_' and vice versa.
void MapsWithMe_TransformName(char * s)
{
for (; *s != 0; ++s)
{
if (*s == ' ')
*s = '_';
else if (*s == '_')
*s = ' ';
}
}
// URL Encoding.
// URL restricted / unsafe / unwise characters are %-encoded.
// See rfc3986, rfc1738, rfc2396.
int MapsWithMe_UrlEncodeString(char const * s, int size, char ** res)
{
*res = malloc(size * 3 + 1);
char * out = *res;
for (int i = 0; i < size; ++i)
{
unsigned char c = (unsigned char)(s[i]);
switch (c)
{
case 0x00: case 0x01: case 0x02: case 0x03: case 0x04: case 0x05: case 0x06: case 0x07:
case 0x08: case 0x09: case 0x0A: case 0x0B: case 0x0C: case 0x0D: case 0x0E: case 0x0F:
case 0x10: case 0x11: case 0x12: case 0x13: case 0x14: case 0x15: case 0x16: case 0x17:
case 0x18: case 0x19: case 0x1A: case 0x1B: case 0x1C: case 0x1D: case 0x1E: case 0x1F:
case 0x7F:
case ' ':
case '<':
case '>':
case '#':
case '%':
case '"':
case '!':
case '*':
case '\'':
case '(':
case ')':
case ';':
case ':':
case '@':
case '&':
case '=':
case '+':
case '$':
case ',':
case '/':
case '?':
case '[':
case ']':
case '{':
case '}':
case '|':
case '^':
case '`':
*(out++) = '%';
*(out++) = "0123456789ABCDEF"[c >> 4];
*(out++) = "0123456789ABCDEF"[c & 15];
break;
default:
*(out++) = s[i];
}
}
*(out++) = 0;
return out - *res - 1;
}
void MapsWithMe_AppendString(char * buf, int bufSize, int * bytesAppended, char const * s, int size)
{
int const bytesAvailable = bufSize - *bytesAppended;
if (bytesAvailable > 0)
memcpy(buf + *bytesAppended, s, size < bytesAvailable ? size : bytesAvailable);
*bytesAppended += size;
}
int MapsWithMe_GenShortShowMapUrl(double lat, double lon, double zoom, char const * name, char * buf, int bufSize)
{
// @TODO: Implement MapsWithMe_GenShortShowMapUrl().
// URL format:
//
// +------------------ 1 byte: zoom level
// |+-------+--------- 9 bytes: lat,lon
// || | +--+---- Variable number of bytes: point name
// || | | |
// ge0://ZCoordba64/Name
int fullUrlSize = 0;
char urlPrefix[] = "ge0://ZCoord6789";
int const zoomI = (zoom <= 4 ? 0 : (zoom >= 19.75 ? 63 : (int) ((zoom - 4) * 4)));
urlPrefix[6] = MapsWithMe_Base64Char(zoomI);
MapsWithMe_LatLonToString(lat, lon, urlPrefix + 7, 9);
MapsWithMe_AppendString(buf, bufSize, &fullUrlSize, urlPrefix, 16);
if (name != 0 && name[0] != 0)
{
MapsWithMe_AppendString(buf, bufSize, &fullUrlSize, "/", 1);
char * newName = strdup(name);
MapsWithMe_TransformName(newName);
char * encName;
int const encNameSize = MapsWithMe_UrlEncodeString(newName, strlen(newName), &encName);
MapsWithMe_AppendString(buf, bufSize, &fullUrlSize, encName, encNameSize);
free(encName);
free(newName);
}
return fullUrlSize;
}
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