Merge RFC4 (#1865)

This commit is the result of the squashing of rfc4_dev branch in a single
commit. It implements mostly RFC 4 related work.

* Grid handling:
  - remove obsolete and presumably unfinished implementation of grid catalog functionality
  - all grid functionality is in grids.cpp/.hpp
  - vertical and horizontal grid shift: rework to no longer load whole grid into memory
  - remove hgrids and vgrids member from PJ structure, and store them in hgridshift/vgridshift/deformation structures
  - build systems: add optional libtiff dependency. Must be explicitly disabled if not desired
  - add support for horizontal and vertical grids in GeoTIFF, if libtiff is available
  - add GenericShiftGridSet and GenericShiftGrid classes, relying on TIFF grids, that can be used for generic purpose grid-based adjustment
  - add a +proj=xyzgridshift method to perform geocentric translation by grid. Used for French NTF to RGF93 transformation using gr3df97a.tif grid
  - deformation: add support for +grids= for GeoTIFF grids
  - horizontal grid shift: fix failures on points slightly outside a subgrid (fixes #209)

* File management:
  - add a filemanager.cpp/.hpp to deal with file related work
  - test for legacy proj_api.h fileapi
  - proj.h: add proj_context_set_fileapi() and proj_context_set_sqlite3_vfs_name() (fixes #866)
  - add capability to read resource files from the user writable directory

* Network access:
  - build systems: add optional curl dependency
  - add a curl-based default implementation for network related functionality
  - proj.h: add C API to control network functionality, and optionaly provide network callbacks
  - add data/proj.ini with default settings
  - add a SQLite3 local cache of downloaded chunks
  - add proj_is_download_needed() and proj_download_file()

* Use Win32 Unicode APIs and expect all strings to be UTF-8 (fixes #1765)
  For backward compatibility, if PROJ_LIB content is found to be not UTF-8 or
  pointing to a non existing directory, then an attempt at interpretating it
  in the ANSI page encoding is done.
  proj_context_set_search_paths() now assumes strings to be in UTF-8, and
  functions returning paths will also return values in UTF-8.

1 files changed, 141 insertions, 4 deletions

diff --git a/src/transform.cpp b/src/transform.cpp
index 781c0061..ea3d9ae2 100644
--- a/src/transform.cpp
+++ b/src/transform.cpp
@@ -34,6 +34,9 @@
 #include "proj.h"
 #include "proj_internal.h"
 #include "geocent.h"
+#include "grids.hpp"
+
+using namespace NS_PROJ;
 
 static int adjust_axis( projCtx ctx, const char *axis, int denormalize_flag,
                            long point_count, int point_offset,
@@ -447,6 +450,78 @@ static int height_unit (PJ *P, PJ_DIRECTION dir, long n, int dist, double *z) {
 }
 
 
+/************************************************************************/
+/*                        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.                                                            */
+/************************************************************************/
+static int pj_apply_vgridshift( PJ *defn,
+                         int inverse,
+                         long point_count, int point_offset,
+                         double *x, double *y, double *z )
+
+{
+    if( defn->vgrids_legacy == nullptr )
+    {
+        defn->vgrids_legacy = new ListOfVGrids;
+        auto vgrids = pj_vgrid_init(defn, "geoidgrids");
+        if( vgrids.empty() )
+            return 0;
+        *static_cast<ListOfVGrids*>(defn->vgrids_legacy) = std::move(vgrids);
+    }
+    if( static_cast<ListOfVGrids*>(defn->vgrids_legacy)->empty() )
+    {
+        return 0;
+    }
+
+    for( int i = 0; i < point_count; i++ )
+    {
+        double value;
+        long io = i * point_offset;
+        PJ_LP   input;
+
+        input.phi = y[io];
+        input.lam = x[io];
+
+        value = pj_vgrid_value(defn, *static_cast<ListOfVGrids*>(defn->vgrids_legacy), input, 1.0);
+
+        if( inverse )
+            z[io] -= value;
+        else
+            z[io] += value;
+
+        if( value == HUGE_VAL )
+        {
+            std::string gridlist;
+
+            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 );
+
+            for( const auto& gridset: *static_cast<ListOfVGrids*>(defn->vgrids_legacy) )
+            {
+                if( gridlist.empty() )
+                    gridlist += "   tried: ";
+                else
+                    gridlist += ',';
+                gridlist += gridset->name();
+            }
+
+            proj_log_debug(defn, "%s", gridlist.c_str());
+            pj_ctx_set_errno( defn->ctx, PJD_ERR_GRID_AREA );
+
+            return PJD_ERR_GRID_AREA;
+        }
+    }
+
+    return 0;
+}
+
 
 /* -------------------------------------------------------------------- */
 /*           Transform to ellipsoidal heights if needed                 */
@@ -457,10 +532,7 @@ static int geometric_to_orthometric (PJ *P, PJ_DIRECTION dir, long n, int dist,
         return 0;
     if (z==nullptr)
         return PJD_ERR_GEOCENTRIC;
-    err = pj_apply_vgridshift (P, "sgeoidgrids",
-              &(P->vgridlist_geoid),
-              &(P->vgridlist_geoid_count),
-              dir==PJ_FWD ? 1 : 0, n, dist, x, y, z );
+    err = pj_apply_vgridshift (P, dir==PJ_FWD ? 1 : 0, n, dist, x, y, z );
     if (err)
         return pj_ctx_get_errno(P->ctx);
     return 0;
@@ -822,6 +894,66 @@ int pj_geocentric_from_wgs84( PJ *defn,
     return 0;
 }
 
+
+/************************************************************************/
+/*                        pj_apply_gridshift_2()                        */
+/*                                                                      */
+/*      This implementation 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.                                                            */
+/************************************************************************/
+static
+int pj_apply_gridshift_2( PJ *defn, int inverse,
+                          long point_count, int point_offset,
+                          double *x, double *y, double * /*z*/ )
+
+{
+    if( defn->hgrids_legacy == nullptr )
+    {
+        defn->hgrids_legacy = new ListOfHGrids;
+        auto hgrids = pj_hgrid_init(defn, "nadgrids");
+        if( hgrids.empty() )
+            return 0;
+        *static_cast<ListOfHGrids*>(defn->hgrids_legacy) = std::move(hgrids);
+    }
+    if( static_cast<ListOfHGrids*>(defn->hgrids_legacy)->empty() )
+    {
+        return 0;
+    }
+
+    for( long i = 0; i < point_count; i++ )
+    {
+        PJ_LP   input;
+
+        long io = i * point_offset;
+        input.phi = y[io];
+        input.lam = x[io];
+
+        auto output = pj_hgrid_apply(defn->ctx, *static_cast<ListOfHGrids*>(defn->hgrids_legacy), input, inverse ? PJ_INV : PJ_FWD);
+
+        if ( output.lam != HUGE_VAL )
+        {
+            y[io] = output.phi;
+            x[io] = output.lam;
+        }
+        else
+        {
+            if( defn->ctx->debug_level >= PJ_LOG_DEBUG_MAJOR )
+            {
+                pj_log( defn->ctx, PJ_LOG_DEBUG_MAJOR,
+                    "pj_apply_gridshift(): failed to find a grid shift table for\n"
+                    "                      location (%.7fdW,%.7fdN)",
+                    x[io] * RAD_TO_DEG,
+                    y[io] * RAD_TO_DEG );
+            }
+        }
+    }
+
+    return 0;
+}
+
+
 /************************************************************************/
 /*                         pj_datum_transform()                         */
 /*                                                                      */
@@ -1062,3 +1194,8 @@ static int adjust_axis( projCtx ctx,
 
     return 0;
 }
+// ---------------------------------------------------------------------------
+
+void pj_deallocate_grids()
+{
+}