diff options
Diffstat (limited to 'src/pj_apply_vgridshift.cpp')
| -rw-r--r-- | src/pj_apply_vgridshift.cpp | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/src/pj_apply_vgridshift.cpp b/src/pj_apply_vgridshift.cpp new file mode 100644 index 00000000..c1344951 --- /dev/null +++ b/src/pj_apply_vgridshift.cpp @@ -0,0 +1,331 @@ +/****************************************************************************** + * Project: PROJ.4 + * Purpose: Apply vertical datum shifts based on grid shift files, normally + * geoid grids mapping WGS84 to NAVD88 or something similar. + * Author: Frank Warmerdam, warmerdam@pobox.com + * + ****************************************************************************** + * Copyright (c) 2010, Frank Warmerdam <warmerdam@pobox.com> + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + *****************************************************************************/ + +#define PJ_LIB__ + +#include <stdio.h> +#include <string.h> + +#include "proj_math.h" +#include "proj_internal.h" +#include "projects.h" + +static int is_nodata(float value) +{ + /* nodata? */ + /* GTX official nodata value if -88.88880f, but some grids also */ + /* use other big values for nodata (e.g naptrans2008.gtx has */ + /* nodata values like -2147479936), so test them too */ + return value > 1000 || value < -1000 || value == -88.88880f; +} + +static double read_vgrid_value( PJ *defn, LP input, int *gridlist_count_p, PJ_GRIDINFO **tables, struct CTABLE *ct) { + int itable = 0; + double value = HUGE_VAL; + double grid_x, grid_y; + long grid_ix, grid_iy; + long grid_ix2, grid_iy2; + float *cvs; + /* do not deal with NaN coordinates */ + /* cppcheck-suppress duplicateExpression */ + if( isnan(input.phi) || isnan(input.lam) ) + itable = *gridlist_count_p; + + /* keep trying till we find a table that works */ + for ( ; itable < *gridlist_count_p; itable++ ) + { + PJ_GRIDINFO *gi = tables[itable]; + + ct = gi->ct; + + /* skip tables that don't match our point at all. */ + if( ct->ll.phi > input.phi || ct->ll.lam > input.lam + || ct->ll.phi + (ct->lim.phi-1) * ct->del.phi < input.phi + || ct->ll.lam + (ct->lim.lam-1) * ct->del.lam < input.lam ) + continue; + + /* If we have child nodes, check to see if any of them apply. */ + while( gi->child != NULL ) + { + PJ_GRIDINFO *child; + + for( child = gi->child; child != NULL; child = child->next ) + { + struct CTABLE *ct1 = child->ct; + + if( ct1->ll.phi > input.phi || ct1->ll.lam > input.lam + || ct1->ll.phi+(ct1->lim.phi-1)*ct1->del.phi < input.phi + || ct1->ll.lam+(ct1->lim.lam-1)*ct1->del.lam < input.lam) + continue; + + break; + } + + /* we didn't find a more refined child node to use, so go with current grid */ + if( child == NULL ) + { + break; + } + + /* Otherwise let's try for childrens children .. */ + gi = child; + ct = child->ct; + } + + /* load the grid shift info if we don't have it. */ + if( ct->cvs == NULL && !pj_gridinfo_load( pj_get_ctx(defn), gi ) ) + { + pj_ctx_set_errno( defn->ctx, PJD_ERR_FAILED_TO_LOAD_GRID ); + return PJD_ERR_FAILED_TO_LOAD_GRID; + } + + + /* Interpolation a location within the grid */ + grid_x = (input.lam - ct->ll.lam) / ct->del.lam; + grid_y = (input.phi - ct->ll.phi) / ct->del.phi; + grid_ix = lround(floor(grid_x)); + grid_iy = lround(floor(grid_y)); + grid_x -= grid_ix; + grid_y -= grid_iy; + + grid_ix2 = grid_ix + 1; + if( grid_ix2 >= ct->lim.lam ) + grid_ix2 = ct->lim.lam - 1; + grid_iy2 = grid_iy + 1; + if( grid_iy2 >= ct->lim.phi ) + grid_iy2 = ct->lim.phi - 1; + + cvs = (float *) ct->cvs; + { + float value_a = cvs[grid_ix + grid_iy * ct->lim.lam]; + float value_b = cvs[grid_ix2 + grid_iy * ct->lim.lam]; + float value_c = cvs[grid_ix + grid_iy2 * ct->lim.lam]; + float value_d = cvs[grid_ix2 + grid_iy2 * ct->lim.lam]; + double total_weight = 0.0; + int n_weights = 0; + value = 0.0f; + if( !is_nodata(value_a) ) + { + double weight = (1.0-grid_x) * (1.0-grid_y); + value += value_a * weight; + total_weight += weight; + n_weights ++; + } + if( !is_nodata(value_b) ) + { + double weight = (grid_x) * (1.0-grid_y); + value += value_b * weight; + total_weight += weight; + n_weights ++; + } + if( !is_nodata(value_c) ) + { + double weight = (1.0-grid_x) * (grid_y); + value += value_c * weight; + total_weight += weight; + n_weights ++; + } + if( !is_nodata(value_d) ) + { + double weight = (grid_x) * (grid_y); + value += value_d * weight; + total_weight += weight; + n_weights ++; + } + if( n_weights == 0 ) + value = HUGE_VAL; + else if( n_weights != 4 ) + value /= total_weight; + } + + } + + return value; +} + +/************************************************************************/ +/* pj_apply_vgridshift() */ +/* */ +/* This implementation takes uses the gridlist from a coordinate */ +/* system definition. If the gridlist has not yet been */ +/* populated in the coordinate system definition we set it up */ +/* now. */ +/************************************************************************/ +int pj_apply_vgridshift( PJ *defn, const char *listname, + PJ_GRIDINFO ***gridlist_p, + int *gridlist_count_p, + int inverse, + long point_count, int point_offset, + double *x, double *y, double *z ) + +{ + int i; + static int debug_count = 0; + PJ_GRIDINFO **tables; + struct CTABLE ct; + + if( *gridlist_p == NULL ) + { + *gridlist_p = + pj_gridlist_from_nadgrids( pj_get_ctx(defn), + pj_param(defn->ctx,defn->params,listname).s, + gridlist_count_p ); + + if( *gridlist_p == NULL || *gridlist_count_p == 0 ) + return defn->ctx->last_errno; + } + + if( *gridlist_count_p == 0 ) + { + pj_ctx_set_errno( defn->ctx, PJD_ERR_FAILED_TO_LOAD_GRID); + return PJD_ERR_FAILED_TO_LOAD_GRID; + } + + tables = *gridlist_p; + defn->ctx->last_errno = 0; + + for( i = 0; i < point_count; i++ ) + { + double value; + long io = i * point_offset; + LP input; + + input.phi = y[io]; + input.lam = x[io]; + + value = read_vgrid_value(defn, input, gridlist_count_p, tables, &ct); + + if( inverse ) + z[io] -= value; + else + z[io] += value; + if( value != HUGE_VAL ) + { + if( debug_count++ < 20 ) { + proj_log_trace(defn, "pj_apply_gridshift(): used %s", ct.id); + break; + } + } + + if( value == HUGE_VAL ) + { + int itable; + char gridlist[3000]; + + proj_log_debug(defn, + "pj_apply_vgridshift(): failed to find a grid shift table for\n" + " location (%.7fdW,%.7fdN)", + x[io] * RAD_TO_DEG, + y[io] * RAD_TO_DEG ); + + gridlist[0] = '\0'; + for( itable = 0; itable < *gridlist_count_p; itable++ ) + { + PJ_GRIDINFO *gi = tables[itable]; + if( strlen(gridlist) + strlen(gi->gridname) > sizeof(gridlist)-100 ) + { + strcat( gridlist, "..." ); + break; + } + + if( itable == 0 ) + sprintf( gridlist, " tried: %s", gi->gridname ); + else + sprintf( gridlist+strlen(gridlist), ",%s", gi->gridname ); + } + + proj_log_debug(defn, "%s", gridlist); + pj_ctx_set_errno( defn->ctx, PJD_ERR_GRID_AREA ); + + return PJD_ERR_GRID_AREA; + } + } + + return 0; +} + +/**********************************************/ +int proj_vgrid_init(PJ* P, const char *grids) { +/********************************************** + + Initizalize and populate gridlist. + + Takes a PJ-object and the plus-parameter + name that is used in the proj-string to + specify the grids to load, e.g. "+grids". + The + should be left out here. + + Returns the number of loaded grids. + +***********************************************/ + + /* prepend "s" to the "grids" string to allow usage with pj_param */ + char *sgrids = (char *) pj_malloc( (strlen(grids)+1+1) *sizeof(char) ); + sprintf(sgrids, "%s%s", "s", grids); + + if (P->vgridlist_geoid == NULL) { + P->vgridlist_geoid = pj_gridlist_from_nadgrids( + P->ctx, + pj_param(P->ctx, P->params, sgrids).s, + &(P->vgridlist_geoid_count) + ); + + if( P->vgridlist_geoid == NULL || P->vgridlist_geoid_count == 0 ) { + pj_dealloc(sgrids); + return 0; + } + } + + if (P->vgridlist_geoid_count == 0) { + proj_errno_set(P, PJD_ERR_FAILED_TO_LOAD_GRID); + } + + pj_dealloc(sgrids); + return P->vgridlist_geoid_count; +} + +/***********************************************/ +double proj_vgrid_value(PJ *P, LP lp){ +/*********************************************** + + Read grid value at position lp in grids loaded + with proj_grid_init. + + Returns the grid value of the given coordinate. + +************************************************/ + + struct CTABLE used_grid; + double value; + memset(&used_grid, 0, sizeof(struct CTABLE)); + + value = read_vgrid_value(P, lp, &(P->vgridlist_geoid_count), P->vgridlist_geoid, &used_grid); + proj_log_trace(P, "proj_vgrid_value: (%f, %f) = %f", lp.lam*RAD_TO_DEG, lp.phi*RAD_TO_DEG, value); + + return value; +} |