Class: RGeo::CoordSys::CRSToCRS

Inherits:
Object
  • Object
show all
Defined in:
lib/rgeo/coord_sys/crs_to_crs.rb,
ext/proj4_c_impl/main.c

Overview

This is a Ruby wrapper around a proj crs_to_crs A crs_to_crs transformation object is a pipeline between two known coordinate reference systems. proj.org/development/reference/functions.html#c.proj_create_crs_to_crs

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

._create(from, to) ⇒ Object 



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# File 'ext/proj4_c_impl/main.c', line 388

static VALUE cmethod_crs_to_crs_create(VALUE klass, VALUE from, VALUE to)
{
  VALUE result;
  RGeo_Proj4Data *from_data;
  RGeo_Proj4Data *to_data;
  result = Qnil;
  PJ *from_pj;
  PJ *to_pj;
  PJ *gis_pj;
  PJ *crs_to_crs;
  RGeo_CRSToCRSData* data;

  TypedData_Get_Struct(from, RGeo_Proj4Data, &rgeo_proj4_data_type, from_data);
  TypedData_Get_Struct(to, RGeo_Proj4Data, &rgeo_proj4_data_type, to_data);
  from_pj = from_data->pj;
  to_pj = to_data->pj;
  crs_to_crs = proj_create_crs_to_crs_from_pj(PJ_DEFAULT_CTX, from_pj, to_pj, 0, NULL);

  // necessary to use proj_normalize_for_visualization so that we
  // do not have to worry about the order of coordinates in every
  // coord system
  gis_pj = proj_normalize_for_visualization(PJ_DEFAULT_CTX, crs_to_crs);
  if(gis_pj){
    proj_destroy(crs_to_crs);
    crs_to_crs = gis_pj;
  }
  data = ALLOC(RGeo_CRSToCRSData);
  if (data){
    data->crs_to_crs = crs_to_crs;
    result = TypedData_Wrap_Struct(klass, &rgeo_crs_to_crs_data_type, data);
  }
  return result;
}

.create(from, to) ⇒ Object 



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# File 'lib/rgeo/coord_sys/crs_to_crs.rb', line 16

def create(from, to)
  _create(from, to)
end

Instance Method Details

#_transform_coords(x, y, z) ⇒ Object 



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# File 'ext/proj4_c_impl/main.c', line 423

static VALUE method_crs_to_crs_transform(VALUE self, VALUE x, VALUE y, VALUE z)
{
  VALUE result;
  RGeo_CRSToCRSData *crs_to_crs_data;
  PJ *crs_to_crs_pj;
  double xval, yval, zval;
  PJ_COORD input;
  PJ_COORD output;

  result = Qnil;
  TypedData_Get_Struct(self, RGeo_CRSToCRSData, &rgeo_crs_to_crs_data_type, crs_to_crs_data);
  crs_to_crs_pj = crs_to_crs_data->crs_to_crs;
  if(crs_to_crs_pj){
    xval = rb_num2dbl(x);
    yval = rb_num2dbl(y);
    zval = NIL_P(z) ? 0.0 : rb_num2dbl(z);

    input = proj_coord(xval, yval, zval, HUGE_VAL);
    output = proj_trans(crs_to_crs_pj, PJ_FWD, input);

    result = rb_ary_new2(NIL_P(z) ? 2 : 3);
    rb_ary_push(result, DBL2NUM(output.xyz.x));
    rb_ary_push(result, DBL2NUM(output.xyz.y));
    if(!NIL_P(z)){
      rb_ary_push(result, DBL2NUM(output.xyz.z));
    }
  }
  return result;
}

#transform_coords(x, y, z) ⇒ Object

transform the coordinates from the initial CRS to the destination CRS



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# File 'lib/rgeo/coord_sys/crs_to_crs.rb', line 11

def transform_coords(x, y, z)
  _transform_coords(x, y, z)
end