PJ_GRID_INFO proj_grid_info(const char *gridname) {
/******************************************************************************
Information about a named datum grid.
Returns PJ_GRID_INFO struct.
******************************************************************************/
PJ_GRID_INFO grinfo;
/*PJ_CONTEXT *ctx = proj_context_create(); */
PJ_CONTEXT *ctx = pj_get_default_ctx();
PJ_GRIDINFO *gridinfo = pj_gridinfo_init(ctx, gridname);
memset(&grinfo, 0, sizeof(PJ_GRID_INFO));
/* in case the grid wasn't found */
if (gridinfo->filename == NULL) {
pj_gridinfo_free(ctx, gridinfo);
strcpy(grinfo.format, "missing");
return grinfo;
}
/* The string copies below are automatically null-terminated due to */
/* the memset above, so strncpy is safe */
/* name of grid */
strncpy (grinfo.gridname, gridname, sizeof(grinfo.gridname) - 1);
/* full path of grid */
pj_find_file(ctx, gridname, grinfo.filename, sizeof(grinfo.filename) - 1);
/* grid format */
strncpy (grinfo.format, gridinfo->format, sizeof(grinfo.format) - 1);
/* grid size */
grinfo.n_lon = gridinfo->ct->lim.lam;
grinfo.n_lat = gridinfo->ct->lim.phi;
/* cell size */
grinfo.cs_lon = gridinfo->ct->del.lam;
grinfo.cs_lat = gridinfo->ct->del.phi;
/* bounds of grid */
grinfo.lowerleft = gridinfo->ct->ll;
grinfo.upperright.lam = grinfo.lowerleft.lam + grinfo.n_lon*grinfo.cs_lon;
grinfo.upperright.phi = grinfo.lowerleft.phi + grinfo.n_lat*grinfo.cs_lat;
pj_gridinfo_free(ctx, gridinfo);
return grinfo;
}
void pj_gridinfo_free( projCtx ctx, PJ_GRIDINFO *gi )
{
if( gi == NULL )
return;
if( gi->child != NULL )
{
PJ_GRIDINFO *child, *next;
for( child = gi->child; child != NULL; child=next)
{
next=child->next;
pj_gridinfo_free( ctx, child );
}
}
if( gi->ct != NULL )
nad_free( gi->ct );
free( gi->gridname );
if( gi->filename != NULL )
free( gi->filename );
pj_dalloc( gi );
}
void pj_deallocate_grids()
{
while( grid_list != NULL )
{
PJ_GRIDINFO *item = grid_list;
grid_list = grid_list->next;
item->next = NULL;
pj_gridinfo_free( item );
}
if( last_nadgrids != NULL )
{
pj_dalloc( last_nadgrids );
last_nadgrids = NULL;
pj_dalloc( last_nadgrids_list );
last_nadgrids_list = NULL;
last_nadgrids_count = 0;
last_nadgrids_max = 0;
}
}
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 = NULL;
/* -------------------------------------------------------------------- */
/* 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 = NULL;
}
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 != NULL; lnk = lnk->next ) {}
lnk->next = gi;
}
}
else
{
PJ_GRIDINFO *lnk;
PJ_GRIDINFO *gp = gridinfo_parent(gilist,
(const char*)header+24,8);
if( gp == NULL )
{
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 != NULL; lnk = lnk->next ) {}
lnk->next = gi;
}
else
{
if( gp->child == NULL )
{
gp->child = gi;
}
else
{
for( lnk = gp->child; lnk->next != NULL; lnk = lnk->next ) {}
lnk->next = gi;
}
}
}
/* -------------------------------------------------------------------- */
/* Seek past the data. */
/* -------------------------------------------------------------------- */
pj_ctx_fseek( ctx, fid, gs_count * 16, SEEK_CUR );
}
return 1;
}
