# Serial Query functions

These functions are prefixed by `geomodelgrids_squery`.

## Preprocessor macros

- **GEOMODELGRIDS_NODATA_VALUE** Value assigned to points with no data.
- **GEOMODELGRIDS_SQUASH_NONE** Disable squashing.
- **GEOMODELGRIDS_SQUASH_TOP_SURFACE** Squash relative to the top surface of the model.
- **GEOMODELGRIDS_SQUASH_TOPOGRAPHY_BATHYMETRY** Squash relative to the topography/bathymetry surface.

## Functions

### void* geomodelgrids_squery_create()

Create C++ query object.

- **returns** Pointer to C++ query object (`NULL` on failure).


### geomodelgrids_squery_destroy(void** handle)

Destroy C++ query object.


### void* geomodelgrids_squery_getErrorHandler()

Get the error handler.

- **handle**[in] Pointer to C++ query object.
- **returns** Pointer to C++ error handler.


### int geomodelgrids_squery_initialize(void* handle, const char* const modelFilenames\[\], const int modelFilenamesSize, const char* const valueNames\[\], const int valueNamesSize, const char* const inputCRSString)

Setup for querying.

- **handle**[in] Pointer to C++ query object.
- **modelFilenames**[in] Array of model filenames (in query order).
- **modelFilenamesSize**[in] Size of model filenames array.
- **valueNames**[in] Array of names of values to return in query.
- **valueNamesSize**[in] Size of names of values array.
- **inputCRSString**[in] Coordinate reference system (CRS) as string (PROJ, EPSG, WKT) for input points.
- **returns** GeomodelgridsStatusEnum for error status.


### int geomodelgrids_squery_setSquashMinElev(const double value)

Set minimum elevation (m) above which vertical coordinate is given as -depth.

This option is used to adjust (squash) topography to sea level above `value`. Below `value` the original geometry of the model is maintained. For example, this maintains the original geometry of deeper structure.

- **handle**[in] Pointer to C++ query object.
- **value**[in] Minimum elevation (m) for squashing topography.
- **returns** GeomodelgridsStatusEnum for error status.


### int geomodelgrids_squery_setSquashing(const int value)

Set squashing type.

- **handle**[in] Pointer to C++ query object.
- **value**[in] Valid values are `GEOMODELGRIDS_SQUASH_NONE`, `GEOMODELGRIDS_SQUASH_TOP_SURFACE`, and `GEOMODELGRIDS_SQUASH_TOPOGRAPHY_BATHYMETRY`.
- **returns** GeomodelgridsStatusEnum for error status.


### double geomodelgrids_squery_queryTopElevation(const double x, const double y)

Query model for elevation of the top surface of the model at a point.

- **handle**[in] Pointer to C++ query object.
- **x**[in] X coordinate of of point in (in input CRS).
- **y**[in] Y coordinate of of point in (in input CRS).
- **return value** Elevation (meters) of surface at point.


### double geomodelgrids_squery_queryTopoBathyElevation(const double x, const double y)

Query model for elevation of the topography/bathymetry surface at a point.

- **handle**[in] Pointer to C++ query object.
- **x**[in] X coordinate of of point in (in input CRS).
- **y**[in] Y coordinate of of point in (in input CRS).
- **return value** Elevation (meters) of surface at point.


### int geomodelgrids_squery_query(const double* values, const double x, const double y, const double z)

Query model for values at a point.

- **handle**[in] Pointer to C++ query object.
- **values**[out] Array of values (must be preallocated).
- **x**[in] X coordinate of of point in (in input CRS).
- **y**[in] Y coordinate of of point in (in input CRS).
- **z**[in] Z coordinate of of point in (in input CRS).
- **returns** GeomodelgridsStatusEnum for error status.


### geomodelgrids_squery_finalize()

Cleanup after querying.

- **handle**[in] Pointer to C++ query object.