aboutsummaryrefslogtreecommitdiff
path: root/src/gridinfo.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/gridinfo.cpp')
-rw-r--r--src/gridinfo.cpp991
1 files changed, 991 insertions, 0 deletions
diff --git a/src/gridinfo.cpp b/src/gridinfo.cpp
new file mode 100644
index 00000000..046abfcc
--- /dev/null
+++ b/src/gridinfo.cpp
@@ -0,0 +1,991 @@
+/******************************************************************************
+ * Project: PROJ.4
+ * Purpose: Functions for handling individual PJ_GRIDINFO's. Includes
+ * loaders for all formats but CTABLE (in nad_init.c).
+ * Author: Frank Warmerdam, warmerdam@pobox.com
+ *
+ ******************************************************************************
+ * Copyright (c) 2000, 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 <errno.h>
+#include <math.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "proj_internal.h"
+#include "projects.h"
+
+/************************************************************************/
+/* swap_words() */
+/* */
+/* Convert the byte order of the given word(s) in place. */
+/************************************************************************/
+
+static const int byte_order_test = 1;
+#define IS_LSB (1 == ((const unsigned char *) (&byte_order_test))[0])
+
+static void swap_words( unsigned char *data, int word_size, int word_count )
+
+{
+ int word;
+
+ for( word = 0; word < word_count; word++ )
+ {
+ int i;
+
+ for( i = 0; i < word_size/2; i++ )
+ {
+ unsigned char t;
+
+ t = data[i];
+ data[i] = data[word_size-i-1];
+ data[word_size-i-1] = t;
+ }
+
+ data += word_size;
+ }
+}
+
+/************************************************************************/
+/* to_double() */
+/* */
+/* Returns a double from the pointed data. */
+/************************************************************************/
+
+static double to_double( unsigned char* data )
+{
+ double d;
+ memcpy(&d, data, sizeof(d));
+ return d;
+}
+
+/************************************************************************/
+/* pj_gridinfo_free() */
+/************************************************************************/
+
+void pj_gridinfo_free( projCtx ctx, PJ_GRIDINFO *gi )
+
+{
+ if( gi == nullptr )
+ return;
+
+ if( gi->child != nullptr )
+ {
+ PJ_GRIDINFO *child, *next;
+
+ for( child = gi->child; child != nullptr; child=next)
+ {
+ next=child->next;
+ pj_gridinfo_free( ctx, child );
+ }
+ }
+
+ if( gi->ct != nullptr )
+ nad_free( gi->ct );
+
+ free( gi->gridname );
+ if( gi->filename != nullptr )
+ free( gi->filename );
+
+ pj_dalloc( gi );
+}
+
+/************************************************************************/
+/* pj_gridinfo_load() */
+/* */
+/* This function is intended to implement delayed loading of */
+/* the data contents of a grid file. The header and related */
+/* stuff are loaded by pj_gridinfo_init(). */
+/************************************************************************/
+
+int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
+
+{
+ struct CTABLE ct_tmp;
+
+ if( gi == nullptr || gi->ct == nullptr )
+ return 0;
+
+ pj_acquire_lock();
+ if( gi->ct->cvs != nullptr )
+ {
+ pj_release_lock();
+ return 1;
+ }
+
+ memcpy(&ct_tmp, gi->ct, sizeof(struct CTABLE));
+
+/* -------------------------------------------------------------------- */
+/* Original platform specific CTable format. */
+/* -------------------------------------------------------------------- */
+ if( strcmp(gi->format,"ctable") == 0 )
+ {
+ PAFile fid;
+ int result;
+
+ fid = pj_open_lib( ctx, gi->filename, "rb" );
+
+ if( fid == nullptr )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ pj_release_lock();
+ return 0;
+ }
+
+ result = nad_ctable_load( ctx, &ct_tmp, fid );
+
+ pj_ctx_fclose( ctx, fid );
+
+ gi->ct->cvs = ct_tmp.cvs;
+ pj_release_lock();
+
+ return result;
+ }
+
+/* -------------------------------------------------------------------- */
+/* CTable2 format. */
+/* -------------------------------------------------------------------- */
+ else if( strcmp(gi->format,"ctable2") == 0 )
+ {
+ PAFile fid;
+ int result;
+
+ fid = pj_open_lib( ctx, gi->filename, "rb" );
+
+ if( fid == nullptr )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ pj_release_lock();
+ return 0;
+ }
+
+ result = nad_ctable2_load( ctx, &ct_tmp, fid );
+
+ pj_ctx_fclose( ctx, fid );
+
+ gi->ct->cvs = ct_tmp.cvs;
+
+ pj_release_lock();
+ return result;
+ }
+
+/* -------------------------------------------------------------------- */
+/* NTv1 format. */
+/* We process one line at a time. Note that the array storage */
+/* direction (e-w) is different in the NTv1 file and what */
+/* the CTABLE is supposed to have. The phi/lam are also */
+/* reversed, and we have to be aware of byte swapping. */
+/* -------------------------------------------------------------------- */
+ else if( strcmp(gi->format,"ntv1") == 0 )
+ {
+ double *row_buf;
+ int row;
+ PAFile fid;
+
+ fid = pj_open_lib( ctx, gi->filename, "rb" );
+
+ if( fid == nullptr )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ pj_release_lock();
+ return 0;
+ }
+
+ pj_ctx_fseek( ctx, fid, gi->grid_offset, SEEK_SET );
+
+ row_buf = (double *) pj_malloc(gi->ct->lim.lam * sizeof(double) * 2);
+ ct_tmp.cvs = (FLP *) pj_malloc(gi->ct->lim.lam*gi->ct->lim.phi*sizeof(FLP));
+ if( row_buf == nullptr || ct_tmp.cvs == nullptr )
+ {
+ pj_dalloc( row_buf );
+ pj_dalloc( ct_tmp.cvs );
+ pj_ctx_set_errno( ctx, ENOMEM );
+ pj_release_lock();
+ return 0;
+ }
+
+ for( row = 0; row < gi->ct->lim.phi; row++ )
+ {
+ int i;
+ FLP *cvs;
+ double *diff_seconds;
+
+ if( pj_ctx_fread( ctx, row_buf,
+ sizeof(double), gi->ct->lim.lam * 2, fid )
+ != (size_t)( 2 * gi->ct->lim.lam ) )
+ {
+ pj_dalloc( row_buf );
+ pj_dalloc( ct_tmp.cvs );
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ pj_release_lock();
+ return 0;
+ }
+
+ if( IS_LSB )
+ swap_words( (unsigned char *) row_buf, 8, gi->ct->lim.lam*2 );
+
+ /* convert seconds to radians */
+ diff_seconds = row_buf;
+
+ for( i = 0; i < gi->ct->lim.lam; i++ )
+ {
+ cvs = ct_tmp.cvs + (row) * gi->ct->lim.lam
+ + (gi->ct->lim.lam - i - 1);
+
+ cvs->phi = (float) (*(diff_seconds++) * ((M_PI/180.0) / 3600.0));
+ cvs->lam = (float) (*(diff_seconds++) * ((M_PI/180.0) / 3600.0));
+ }
+ }
+
+ pj_dalloc( row_buf );
+
+ pj_ctx_fclose( ctx, fid );
+
+ gi->ct->cvs = ct_tmp.cvs;
+ pj_release_lock();
+
+ return 1;
+ }
+
+/* -------------------------------------------------------------------- */
+/* NTv2 format. */
+/* We process one line at a time. Note that the array storage */
+/* direction (e-w) is different in the NTv2 file and what */
+/* the CTABLE is supposed to have. The phi/lam are also */
+/* reversed, and we have to be aware of byte swapping. */
+/* -------------------------------------------------------------------- */
+ else if( strcmp(gi->format,"ntv2") == 0 )
+ {
+ float *row_buf;
+ int row;
+ PAFile fid;
+
+ pj_log( ctx, PJ_LOG_DEBUG_MINOR,
+ "NTv2 - loading grid %s", gi->ct->id );
+
+ fid = pj_open_lib( ctx, gi->filename, "rb" );
+
+ if( fid == nullptr )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ pj_release_lock();
+ return 0;
+ }
+
+ pj_ctx_fseek( ctx, fid, gi->grid_offset, SEEK_SET );
+
+ row_buf = (float *) pj_malloc(gi->ct->lim.lam * sizeof(float) * 4);
+ ct_tmp.cvs = (FLP *) pj_malloc(gi->ct->lim.lam*gi->ct->lim.phi*sizeof(FLP));
+ if( row_buf == nullptr || ct_tmp.cvs == nullptr )
+ {
+ pj_dalloc( row_buf );
+ pj_dalloc( ct_tmp.cvs );
+ pj_ctx_set_errno( ctx, ENOMEM );
+ pj_release_lock();
+ return 0;
+ }
+
+ for( row = 0; row < gi->ct->lim.phi; row++ )
+ {
+ int i;
+ FLP *cvs;
+ float *diff_seconds;
+
+ if( pj_ctx_fread( ctx, row_buf, sizeof(float),
+ gi->ct->lim.lam*4, fid )
+ != (size_t)( 4 * gi->ct->lim.lam ) )
+ {
+ pj_dalloc( row_buf );
+ pj_dalloc( ct_tmp.cvs );
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ pj_release_lock();
+ return 0;
+ }
+
+ if( gi->must_swap )
+ swap_words( (unsigned char *) row_buf, 4,
+ gi->ct->lim.lam*4 );
+
+ /* convert seconds to radians */
+ diff_seconds = row_buf;
+
+ for( i = 0; i < gi->ct->lim.lam; i++ )
+ {
+ cvs = ct_tmp.cvs + (row) * gi->ct->lim.lam
+ + (gi->ct->lim.lam - i - 1);
+
+ cvs->phi = (float) (*(diff_seconds++) * ((M_PI/180.0) / 3600.0));
+ cvs->lam = (float) (*(diff_seconds++) * ((M_PI/180.0) / 3600.0));
+ diff_seconds += 2; /* skip accuracy values */
+ }
+ }
+
+ pj_dalloc( row_buf );
+
+ pj_ctx_fclose( ctx, fid );
+
+ gi->ct->cvs = ct_tmp.cvs;
+
+ pj_release_lock();
+ return 1;
+ }
+
+/* -------------------------------------------------------------------- */
+/* GTX format. */
+/* -------------------------------------------------------------------- */
+ else if( strcmp(gi->format,"gtx") == 0 )
+ {
+ int words = gi->ct->lim.lam * gi->ct->lim.phi;
+ PAFile fid;
+
+ fid = pj_open_lib( ctx, gi->filename, "rb" );
+
+ if( fid == nullptr )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ pj_release_lock();
+ return 0;
+ }
+
+ pj_ctx_fseek( ctx, fid, gi->grid_offset, SEEK_SET );
+
+ ct_tmp.cvs = (FLP *) pj_malloc(words*sizeof(float));
+ if( ct_tmp.cvs == nullptr )
+ {
+ pj_ctx_set_errno( ctx, ENOMEM );
+ pj_release_lock();
+ return 0;
+ }
+
+ if( pj_ctx_fread( ctx, ct_tmp.cvs, sizeof(float), words, fid )
+ != (size_t)words )
+ {
+ pj_dalloc( ct_tmp.cvs );
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ pj_release_lock();
+ return 0;
+ }
+
+ if( IS_LSB )
+ swap_words( (unsigned char *) ct_tmp.cvs, 4, words );
+
+ pj_ctx_fclose( ctx, fid );
+ gi->ct->cvs = ct_tmp.cvs;
+ pj_release_lock();
+ return 1;
+ }
+
+ else
+ {
+ pj_release_lock();
+ return 0;
+ }
+}
+
+/************************************************************************/
+/* gridinfo_parent() */
+/* */
+/* Seek a parent grid file by name from a grid list */
+/************************************************************************/
+
+static PJ_GRIDINFO* gridinfo_parent( PJ_GRIDINFO *gilist,
+ const char *name, int length )
+{
+ while( gilist )
+ {
+ if( strncmp(gilist->ct->id,name,length) == 0 ) return gilist;
+ if( gilist->child )
+ {
+ PJ_GRIDINFO *parent=gridinfo_parent( gilist->child, name, length );
+ if( parent ) return parent;
+ }
+ gilist=gilist->next;
+ }
+ return gilist;
+}
+
+/************************************************************************/
+/* pj_gridinfo_init_ntv2() */
+/* */
+/* Load a ntv2 (.gsb) file. */
+/************************************************************************/
+
+static int pj_gridinfo_init_ntv2( projCtx ctx, PAFile fid, PJ_GRIDINFO *gilist )
+{
+ unsigned char header[11*16];
+ int num_subfiles, subfile;
+ int must_swap;
+
+ /* cppcheck-suppress sizeofCalculation */
+ STATIC_ASSERT( sizeof(pj_int32) == 4 );
+ /* cppcheck-suppress sizeofCalculation */
+ STATIC_ASSERT( sizeof(double) == 8 );
+
+/* -------------------------------------------------------------------- */
+/* Read the overview header. */
+/* -------------------------------------------------------------------- */
+ if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ return 0;
+ }
+
+ if( header[8] == 11 )
+ must_swap = !IS_LSB;
+ else
+ must_swap = IS_LSB;
+
+/* -------------------------------------------------------------------- */
+/* Byte swap interesting fields if needed. */
+/* -------------------------------------------------------------------- */
+ if( must_swap )
+ {
+ swap_words( header+8, 4, 1 );
+ swap_words( header+8+16, 4, 1 );
+ swap_words( header+8+32, 4, 1 );
+ swap_words( header+8+7*16, 8, 1 );
+ swap_words( header+8+8*16, 8, 1 );
+ swap_words( header+8+9*16, 8, 1 );
+ swap_words( header+8+10*16, 8, 1 );
+ }
+
+/* -------------------------------------------------------------------- */
+/* Get the subfile count out ... all we really use for now. */
+/* -------------------------------------------------------------------- */
+ memcpy( &num_subfiles, header+8+32, 4 );
+
+/* ==================================================================== */
+/* Step through the subfiles, creating a PJ_GRIDINFO for each. */
+/* ==================================================================== */
+ for( subfile = 0; subfile < num_subfiles; subfile++ )
+ {
+ struct CTABLE *ct;
+ LP ur;
+ int gs_count;
+ PJ_GRIDINFO *gi;
+
+/* -------------------------------------------------------------------- */
+/* Read header. */
+/* -------------------------------------------------------------------- */
+ if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ return 0;
+ }
+
+ if( strncmp((const char *) header,"SUB_NAME",8) != 0 )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ return 0;
+ }
+
+/* -------------------------------------------------------------------- */
+/* Byte swap interesting fields if needed. */
+/* -------------------------------------------------------------------- */
+ if( must_swap )
+ {
+ swap_words( header+8+16*4, 8, 1 );
+ swap_words( header+8+16*5, 8, 1 );
+ swap_words( header+8+16*6, 8, 1 );
+ swap_words( header+8+16*7, 8, 1 );
+ swap_words( header+8+16*8, 8, 1 );
+ swap_words( header+8+16*9, 8, 1 );
+ swap_words( header+8+16*10, 4, 1 );
+ }
+
+/* -------------------------------------------------------------------- */
+/* Initialize a corresponding "ct" structure. */
+/* -------------------------------------------------------------------- */
+ ct = (struct CTABLE *) pj_malloc(sizeof(struct CTABLE));
+ if (!ct) {
+ pj_ctx_set_errno(ctx, ENOMEM);
+ return 0;
+ }
+ strncpy( ct->id, (const char *) header + 8, 8 );
+ ct->id[8] = '\0';
+
+ ct->ll.lam = - to_double(header+7*16+8); /* W_LONG */
+ ct->ll.phi = to_double(header+4*16+8); /* S_LAT */
+
+ ur.lam = - to_double(header+6*16+8); /* E_LONG */
+ ur.phi = to_double(header+5*16+8); /* N_LAT */
+
+ ct->del.lam = to_double(header+9*16+8);
+ ct->del.phi = to_double(header+8*16+8);
+
+ ct->lim.lam = (pj_int32) (fabs(ur.lam-ct->ll.lam)/ct->del.lam + 0.5) + 1;
+ ct->lim.phi = (pj_int32) (fabs(ur.phi-ct->ll.phi)/ct->del.phi + 0.5) + 1;
+
+ pj_log( ctx, PJ_LOG_DEBUG_MINOR,
+ "NTv2 %s %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)",
+ ct->id,
+ ct->lim.lam, ct->lim.phi,
+ ct->ll.lam/3600.0, ct->ll.phi/3600.0,
+ ur.lam/3600.0, ur.phi/3600.0 );
+
+ ct->ll.lam *= DEG_TO_RAD/3600.0;
+ ct->ll.phi *= DEG_TO_RAD/3600.0;
+ ct->del.lam *= DEG_TO_RAD/3600.0;
+ ct->del.phi *= DEG_TO_RAD/3600.0;
+
+ memcpy( &gs_count, header + 8 + 16*10, 4 );
+ if( gs_count != ct->lim.lam * ct->lim.phi )
+ {
+ pj_log( ctx, PJ_LOG_ERROR,
+ "GS_COUNT(%d) does not match expected cells (%dx%d=%d)",
+ gs_count, ct->lim.lam, ct->lim.phi,
+ ct->lim.lam * ct->lim.phi );
+ pj_dalloc(ct);
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ return 0;
+ }
+
+ ct->cvs = nullptr;
+
+/* -------------------------------------------------------------------- */
+/* Create a new gridinfo for this if we aren't processing the */
+/* 1st subfile, and initialize our grid info. */
+/* -------------------------------------------------------------------- */
+ if( subfile == 0 )
+ gi = gilist;
+ else
+ {
+ gi = (PJ_GRIDINFO *) pj_calloc(1, sizeof(PJ_GRIDINFO));
+ if (!gi) {
+ pj_dalloc(ct);
+ pj_gridinfo_free(ctx, gilist);
+ pj_ctx_set_errno(ctx, ENOMEM);
+ return 0;
+ }
+
+ gi->gridname = pj_strdup( gilist->gridname );
+ gi->filename = pj_strdup( gilist->filename );
+ if (!gi->gridname || !gi->filename) {
+ pj_gridinfo_free(ctx, gi);
+ pj_dalloc(ct);
+ pj_gridinfo_free(ctx, gilist);
+ pj_ctx_set_errno(ctx, ENOMEM);
+ return 0;
+ }
+ gi->next = nullptr;
+ }
+
+ gi->must_swap = must_swap;
+ gi->ct = ct;
+ gi->format = "ntv2";
+ gi->grid_offset = pj_ctx_ftell( ctx, fid );
+
+/* -------------------------------------------------------------------- */
+/* Attach to the correct list or sublist. */
+/* -------------------------------------------------------------------- */
+ if( strncmp((const char *)header+24,"NONE",4) == 0 )
+ {
+ if( gi != gilist )
+ {
+ PJ_GRIDINFO *lnk;
+
+ for( lnk = gilist; lnk->next != nullptr; lnk = lnk->next ) {}
+ lnk->next = gi;
+ }
+ }
+
+ else
+ {
+ PJ_GRIDINFO *lnk;
+ PJ_GRIDINFO *gp = gridinfo_parent(gilist,
+ (const char*)header+24,8);
+
+ if( gp == nullptr )
+ {
+ pj_log( ctx, PJ_LOG_ERROR,
+ "pj_gridinfo_init_ntv2(): "
+ "failed to find parent %8.8s for %s.",
+ (const char *) header+24, gi->ct->id );
+
+ for( lnk = gilist; lnk->next != nullptr; lnk = lnk->next ) {}
+ lnk->next = gi;
+ }
+ else
+ {
+ if( gp->child == nullptr )
+ {
+ gp->child = gi;
+ }
+ else
+ {
+ for( lnk = gp->child; lnk->next != nullptr; lnk = lnk->next ) {}
+ lnk->next = gi;
+ }
+ }
+ }
+
+/* -------------------------------------------------------------------- */
+/* Seek past the data. */
+/* -------------------------------------------------------------------- */
+ pj_ctx_fseek( ctx, fid, gs_count * 16, SEEK_CUR );
+ }
+
+ return 1;
+}
+
+/************************************************************************/
+/* pj_gridinfo_init_ntv1() */
+/* */
+/* Load an NTv1 style Canadian grid shift file. */
+/************************************************************************/
+
+static int pj_gridinfo_init_ntv1( projCtx ctx, PAFile fid, PJ_GRIDINFO *gi )
+
+{
+ unsigned char header[192]; /* 12 records of 16 bytes */
+ struct CTABLE *ct;
+ LP ur;
+
+ /* cppcheck-suppress sizeofCalculation */
+ STATIC_ASSERT( sizeof(pj_int32) == 4 );
+ /* cppcheck-suppress sizeofCalculation */
+ STATIC_ASSERT( sizeof(double) == 8 );
+
+/* -------------------------------------------------------------------- */
+/* Read the header. */
+/* -------------------------------------------------------------------- */
+ if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ return 0;
+ }
+
+/* -------------------------------------------------------------------- */
+/* Regularize fields of interest. */
+/* -------------------------------------------------------------------- */
+ if( IS_LSB )
+ {
+ swap_words( header+8, 4, 1 );
+ swap_words( header+24, 8, 1 );
+ swap_words( header+40, 8, 1 );
+ swap_words( header+56, 8, 1 );
+ swap_words( header+72, 8, 1 );
+ swap_words( header+88, 8, 1 );
+ swap_words( header+104, 8, 1 );
+ }
+
+ if( *((int *) (header+8)) != 12 )
+ {
+ pj_log( ctx, PJ_LOG_ERROR,
+ "NTv1 grid shift file has wrong record count, corrupt?" );
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ return 0;
+ }
+
+/* -------------------------------------------------------------------- */
+/* Fill in CTABLE structure. */
+/* -------------------------------------------------------------------- */
+ ct = (struct CTABLE *) pj_malloc(sizeof(struct CTABLE));
+ if (!ct) {
+ pj_ctx_set_errno(ctx, ENOMEM);
+ return 0;
+ }
+ strcpy( ct->id, "NTv1 Grid Shift File" );
+
+ ct->ll.lam = - to_double(header+72);
+ ct->ll.phi = to_double(header+24);
+ ur.lam = - to_double(header+56);
+ ur.phi = to_double(header+40);
+ ct->del.lam = to_double(header+104);
+ ct->del.phi = to_double(header+88);
+ ct->lim.lam = (pj_int32) (fabs(ur.lam-ct->ll.lam)/ct->del.lam + 0.5) + 1;
+ ct->lim.phi = (pj_int32) (fabs(ur.phi-ct->ll.phi)/ct->del.phi + 0.5) + 1;
+
+ pj_log( ctx, PJ_LOG_DEBUG_MINOR,
+ "NTv1 %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)",
+ ct->lim.lam, ct->lim.phi,
+ ct->ll.lam, ct->ll.phi, ur.lam, ur.phi );
+
+ ct->ll.lam *= DEG_TO_RAD;
+ ct->ll.phi *= DEG_TO_RAD;
+ ct->del.lam *= DEG_TO_RAD;
+ ct->del.phi *= DEG_TO_RAD;
+ ct->cvs = nullptr;
+
+ gi->ct = ct;
+ gi->grid_offset = (long) sizeof(header);
+ gi->format = "ntv1";
+
+ return 1;
+}
+
+/************************************************************************/
+/* pj_gridinfo_init_gtx() */
+/* */
+/* Load a NOAA .gtx vertical datum shift file. */
+/************************************************************************/
+
+static int pj_gridinfo_init_gtx( projCtx ctx, PAFile fid, PJ_GRIDINFO *gi )
+
+{
+ unsigned char header[40];
+ struct CTABLE *ct;
+ double xorigin,yorigin,xstep,ystep;
+ int rows, columns;
+
+ /* cppcheck-suppress sizeofCalculation */
+ STATIC_ASSERT( sizeof(pj_int32) == 4 );
+ /* cppcheck-suppress sizeofCalculation */
+ STATIC_ASSERT( sizeof(double) == 8 );
+
+/* -------------------------------------------------------------------- */
+/* Read the header. */
+/* -------------------------------------------------------------------- */
+ if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
+ {
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ return 0;
+ }
+
+/* -------------------------------------------------------------------- */
+/* Regularize fields of interest and extract. */
+/* -------------------------------------------------------------------- */
+ if( IS_LSB )
+ {
+ swap_words( header+0, 8, 4 );
+ swap_words( header+32, 4, 2 );
+ }
+
+ memcpy( &yorigin, header+0, 8 );
+ memcpy( &xorigin, header+8, 8 );
+ memcpy( &ystep, header+16, 8 );
+ memcpy( &xstep, header+24, 8 );
+
+ memcpy( &rows, header+32, 4 );
+ memcpy( &columns, header+36, 4 );
+
+ if( xorigin < -360 || xorigin > 360
+ || yorigin < -90 || yorigin > 90 )
+ {
+ pj_log( ctx, PJ_LOG_ERROR,
+ "gtx file header has invalid extents, corrupt?");
+ pj_ctx_set_errno( ctx, PJD_ERR_FAILED_TO_LOAD_GRID );
+ return 0;
+ }
+
+/* -------------------------------------------------------------------- */
+/* Fill in CTABLE structure. */
+/* -------------------------------------------------------------------- */
+ ct = (struct CTABLE *) pj_malloc(sizeof(struct CTABLE));
+ if (!ct) {
+ pj_ctx_set_errno(ctx, ENOMEM);
+ return 0;
+ }
+ strcpy( ct->id, "GTX Vertical Grid Shift File" );
+
+ ct->ll.lam = xorigin;
+ ct->ll.phi = yorigin;
+ ct->del.lam = xstep;
+ ct->del.phi = ystep;
+ ct->lim.lam = columns;
+ ct->lim.phi = rows;
+
+ /* some GTX files come in 0-360 and we shift them back into the
+ expected -180 to 180 range if possible. This does not solve
+ problems with grids spanning the dateline. */
+ if( ct->ll.lam >= 180.0 )
+ ct->ll.lam -= 360.0;
+
+ if( ct->ll.lam >= 0.0 && ct->ll.lam + ct->del.lam * ct->lim.lam > 180.0 )
+ {
+ pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+ "This GTX spans the dateline! This will cause problems." );
+ }
+
+ pj_log( ctx, PJ_LOG_DEBUG_MINOR,
+ "GTX %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)",
+ ct->lim.lam, ct->lim.phi,
+ ct->ll.lam, ct->ll.phi,
+ ct->ll.lam + (columns-1)*xstep, ct->ll.phi + (rows-1)*ystep);
+
+ ct->ll.lam *= DEG_TO_RAD;
+ ct->ll.phi *= DEG_TO_RAD;
+ ct->del.lam *= DEG_TO_RAD;
+ ct->del.phi *= DEG_TO_RAD;
+ ct->cvs = nullptr;
+
+ gi->ct = ct;
+ gi->grid_offset = 40;
+ gi->format = "gtx";
+
+ return 1;
+}
+
+/************************************************************************/
+/* pj_gridinfo_init() */
+/* */
+/* Open and parse header details from a datum gridshift file */
+/* returning a list of PJ_GRIDINFOs for the grids in that */
+/* file. This superceeds use of nad_init() for modern */
+/* applications. */
+/************************************************************************/
+
+PJ_GRIDINFO *pj_gridinfo_init( projCtx ctx, const char *gridname )
+
+{
+ char fname[MAX_PATH_FILENAME+1];
+ PJ_GRIDINFO *gilist;
+ PAFile fp;
+ char header[160];
+ size_t header_size = 0;
+
+ errno = pj_errno = 0;
+ ctx->last_errno = 0;
+
+/* -------------------------------------------------------------------- */
+/* Initialize a GRIDINFO with stub info we would use if it */
+/* cannot be loaded. */
+/* -------------------------------------------------------------------- */
+ gilist = (PJ_GRIDINFO *) pj_calloc(1, sizeof(PJ_GRIDINFO));
+ if (!gilist) {
+ pj_ctx_set_errno(ctx, ENOMEM);
+ return nullptr;
+ }
+
+ gilist->gridname = pj_strdup( gridname );
+ if (!gilist->gridname) {
+ pj_dalloc(gilist);
+ pj_ctx_set_errno(ctx, ENOMEM);
+ return nullptr;
+ }
+ gilist->filename = nullptr;
+ gilist->format = "missing";
+ gilist->grid_offset = 0;
+ gilist->ct = nullptr;
+ gilist->next = nullptr;
+
+/* -------------------------------------------------------------------- */
+/* Open the file using the usual search rules. */
+/* -------------------------------------------------------------------- */
+ strcpy(fname, gridname);
+ if (!(fp = pj_open_lib(ctx, fname, "rb"))) {
+ ctx->last_errno = 0; /* don't treat as a persistent error */
+ return gilist;
+ }
+
+ gilist->filename = pj_strdup(fname);
+ if (!gilist->filename) {
+ pj_dalloc(gilist->gridname);
+ pj_dalloc(gilist);
+ pj_ctx_set_errno(ctx, ENOMEM);
+ return nullptr;
+ }
+
+/* -------------------------------------------------------------------- */
+/* Load a header, to determine the file type. */
+/* -------------------------------------------------------------------- */
+ if( (header_size = pj_ctx_fread( ctx, header, 1,
+ sizeof(header), fp ) ) != sizeof(header) )
+ {
+ /* some files may be smaller that sizeof(header), eg 160, so */
+ ctx->last_errno = 0; /* don't treat as a persistent error */
+ pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+ "pj_gridinfo_init: short header read of %d bytes",
+ (int)header_size );
+ }
+
+ pj_ctx_fseek( ctx, fp, SEEK_SET, 0 );
+
+/* -------------------------------------------------------------------- */
+/* Determine file type. */
+/* -------------------------------------------------------------------- */
+ if( header_size >= 144 + 16
+ && strncmp(header + 0, "HEADER", 6) == 0
+ && strncmp(header + 96, "W GRID", 6) == 0
+ && strncmp(header + 144, "TO NAD83 ", 16) == 0 )
+ {
+ pj_gridinfo_init_ntv1( ctx, fp, gilist );
+ }
+
+ else if( header_size >= 48 + 7
+ && strncmp(header + 0, "NUM_OREC", 8) == 0
+ && strncmp(header + 48, "GS_TYPE", 7) == 0 )
+ {
+ pj_gridinfo_init_ntv2( ctx, fp, gilist );
+ }
+
+ else if( strlen(gridname) > 4
+ && (strcmp(gridname+strlen(gridname)-3,"gtx") == 0
+ || strcmp(gridname+strlen(gridname)-3,"GTX") == 0) )
+ {
+ pj_gridinfo_init_gtx( ctx, fp, gilist );
+ }
+
+ else if( header_size >= 9 && strncmp(header + 0,"CTABLE V2",9) == 0 )
+ {
+ struct CTABLE *ct = nad_ctable2_init( ctx, fp );
+
+ gilist->format = "ctable2";
+ gilist->ct = ct;
+
+ if (ct == nullptr)
+ {
+ pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+ "CTABLE V2 ct is NULL.");
+ }
+ else
+ {
+ pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+ "Ctable2 %s %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)",
+ ct->id,
+ ct->lim.lam, ct->lim.phi,
+ ct->ll.lam * RAD_TO_DEG, ct->ll.phi * RAD_TO_DEG,
+ (ct->ll.lam + (ct->lim.lam-1)*ct->del.lam) * RAD_TO_DEG,
+ (ct->ll.phi + (ct->lim.phi-1)*ct->del.phi) * RAD_TO_DEG );
+ }
+ }
+
+ else
+ {
+ struct CTABLE *ct = nad_ctable_init( ctx, fp );
+ if (ct == nullptr)
+ {
+ pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+ "CTABLE ct is NULL.");
+ } else
+ {
+ gilist->format = "ctable";
+ gilist->ct = ct;
+
+ pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+ "Ctable %s %dx%d: LL=(%.9g,%.9g) UR=(%.9g,%.9g)",
+ ct->id,
+ ct->lim.lam, ct->lim.phi,
+ ct->ll.lam * RAD_TO_DEG, ct->ll.phi * RAD_TO_DEG,
+ (ct->ll.lam + (ct->lim.lam-1)*ct->del.lam) * RAD_TO_DEG,
+ (ct->ll.phi + (ct->lim.phi-1)*ct->del.phi) * RAD_TO_DEG );
+ }
+ }
+
+ pj_ctx_fclose(ctx, fp);
+
+ return gilist;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-15 18:33:47 +0000