/**
* h3ToCenterChild produces the center child index for a given H3 index at
* the specified resolution
*
* @param h H3Index to find center child of
* @param childRes The resolution to switch to
*
* @return H3Index of the center child, or 0 if you actually asked for a parent
*/
public static H3Index h3ToCenterChild(H3Index h, int childRes)
{
int parentRes = H3_GET_RESOLUTION(h);
if (!_isValidChildRes(parentRes, childRes))
{
return(H3_INVALID_INDEX);
}
else if (childRes == parentRes)
{
return(h);
}
H3Index child = H3_SET_RESOLUTION(ref h, childRes);
for (int i = parentRes + 1; i <= childRes; i++)
{
H3_SET_INDEX_DIGIT(ref child, i, 0);
}
return(child);
}
/**
* h3ToParent produces the parent index for a given H3 index
*
* @param h H3Index to find parent of
* @param parentRes The resolution to switch to (parent, grandparent, etc)
*
* @return H3Index of the parent, or 0 if you actually asked for a child
*/
public static H3Index h3ToParent(H3Index h, int parentRes)
{
int childRes = H3_GET_RESOLUTION(h);
if (parentRes > childRes)
{
return(H3_INVALID_INDEX);
}
else if (parentRes == childRes)
{
return(h);
}
else if (parentRes < 0 || parentRes > Constants.MAX_H3_RES)
{
return(H3_INVALID_INDEX);
}
H3Index parentH = H3_SET_RESOLUTION(ref h, parentRes);
for (int i = parentRes + 1; i <= childRes; i++)
{
H3_SET_INDEX_DIGIT(ref parentH, i, (Direction)H3_DIGIT_MASK);
}
return(parentH);
}
/**
* Gets the highest bit of the H3 index.
*/
public static int H3_GET_HIGH_BIT(H3Index h3)
{
return((int)((((h3) & H3_HIGH_BIT_MASK) >> H3_MAX_OFFSET)));
}
/**
* Converts an H3 index into a string representation.
* @param h The H3 index to convert.
* @param str The string representation of the H3 index.
* @param sz Size of the buffer `str`
*/
public static string h3ToString(H3Index h)
{
return(h.value.ToString("x"));
}
/**
* Returns whether or not an H3 index is a valid cell (hexagon or pentagon).
* @param h The H3 index to validate.
* @return 1 if the H3 index if valid, and 0 if it is not.
*/
public static bool h3IsValid(H3Index h)
{
if (H3_GET_HIGH_BIT(h) != 0)
{
return(false);
}
if (H3_GET_MODE(h) != Constants.H3_HEXAGON_MODE)
{
return(false);
}
if (H3_GET_RESERVED_BITS(h) != 0)
{
return(false);
}
int baseCell = H3_GET_BASE_CELL(h);
if (baseCell < 0 || baseCell >= Constants.NUM_BASE_CELLS)
{
return(false);
}
int res = H3_GET_RESOLUTION(h);
if (res < 0 || res > Constants.MAX_H3_RES)
{
return(false);
}
bool foundFirstNonZeroDigit = false;
for (int r = 1; r <= res; r++)
{
Direction digit = H3_GET_INDEX_DIGIT(h, r);
if (!foundFirstNonZeroDigit && digit != Direction.CENTER_DIGIT)
{
foundFirstNonZeroDigit = true;
if (BaseCellData._isBaseCellPentagon(baseCell) && digit == Direction.K_AXES_DIGIT)
{
return(false);
}
}
if (digit < Direction.CENTER_DIGIT || digit >= Direction.NUM_DIGITS)
{
return(false);
}
}
for (int r = res + 1; r <= Constants.MAX_H3_RES; r++)
{
Direction digit = H3_GET_INDEX_DIGIT(h, r);
if (digit != Direction.INVALID_DIGIT)
{
return(false);
}
}
return(true);
}
/**
* Gets the integer base cell of h3.
*/
public static int H3_GET_BASE_CELL(H3Index h3)
{
return((int)((((h3) & H3_BC_MASK) >> H3_BC_OFFSET)));
}
/**
* Returns the H3 base cell "number" of an H3 cell (hexagon or pentagon).
*
* Note: Technically works on H3 edges, but will return base cell of the
* origin cell.
*
* @param h The H3 cell.
* @return The base cell "number" of the H3 cell argument.
*/
public static int h3GetBaseCell(H3Index h)
{
return(H3_GET_BASE_CELL(h));
}
/**
* Gets a value in the reserved space. Should always be zero for valid indexes.
*/
public static int H3_GET_RESERVED_BITS(H3Index h3)
{
return((int)((((h3) & H3_RESERVED_MASK) >> H3_RESERVED_OFFSET)));
}
/**
* Sets the resolution res digit of h3 to the integer digit (0-7)
*/
public static void H3_SET_INDEX_DIGIT(ref H3Index h3, int res, Direction digit)
{
h3 = (((h3) & ~((H3_DIGIT_MASK << ((Constants.MAX_H3_RES - (res)) * H3_PER_DIGIT_OFFSET)))) |
(((ulong)(digit)) << ((Constants.MAX_H3_RES - (res)) * H3_PER_DIGIT_OFFSET)));
}
/**
* Gets the resolution res integer digit (0-7) of h3.
*/
public static Direction H3_GET_INDEX_DIGIT(H3Index h3, int res)
{
return((Direction)((((h3) >> ((Constants.MAX_H3_RES - (res)) * H3_PER_DIGIT_OFFSET)) & H3_DIGIT_MASK)));
}
/**
* Sets a value in the reserved space. Setting to non-zero may produce invalid
* indexes.
*/
public static void H3_SET_RESERVED_BITS(ref H3Index h3, int v)
{
h3 = (((h3) & H3_RESERVED_MASK_NEGATIVE) | (((ulong)(v)) << H3_RESERVED_OFFSET));
}
/**
* Sets the integer resolution of h3.
*/
public static H3Index H3_SET_RESOLUTION(ref H3Index h3, int res)
{
h3 = (((h3) & H3_RES_MASK_NEGATIVE) | (((ulong)(res)) << H3_RES_OFFSET));
return(h3);
}
/**
* Gets the integer resolution of h3.
*/
public static int H3_GET_RESOLUTION(H3Index h3)
{
return((int)((((h3) & H3_RES_MASK) >> H3_RES_OFFSET)));
}
/**
* Sets the integer base cell of h3 to bc.
*/
public static void H3_SET_BASE_CELL(ref H3Index h3, int bc)
{
h3 = (((h3) & H3_BC_MASK_NEGATIVE) | (((ulong)(bc)) << H3_BC_OFFSET));
}
/**
* Sets the highest bit of the h3 to v.
*/
public static void H3_SET_HIGH_BIT(ref H3Index h3, int v)
{
h3 = (((h3) & H3_HIGH_BIT_MASK_NEGATIVE) | (((ulong)(v)) << H3_MAX_OFFSET));
}
/**
* Returns the H3 resolution of an H3 index.
* @param h The H3 index.
* @return The resolution of the H3 index argument.
*/
public static int h3GetResolution(H3Index h)
{
return(H3_GET_RESOLUTION(h));
}
/**
* Gets the integer mode of h3.
*/
public static int H3_GET_MODE(H3Index h3)
{
return((int)((((h3) & H3_MODE_MASK) >> H3_MODE_OFFSET)));
}
/**
* Sets the integer mode of h3 to v.
*/
public static void H3_SET_MODE(ref H3Index h3, int v)
{
h3 = (((h3) & H3_MODE_MASK_NEGATIVE) | (((ulong)(v)) << H3_MODE_OFFSET));
}