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, 17 insertions, 3 deletions

diff --git a/src/iso19111/c_api.cpp b/src/iso19111/c_api.cpp
index 9f73f8e9..4c98af3d 100644
--- a/src/iso19111/c_api.cpp
+++ b/src/iso19111/c_api.cpp
@@ -177,7 +177,11 @@ static PJ *pj_obj_create(PJ_CONTEXT *ctx, const IdentifiedObjectNNPtr &objIn) {
             auto formatter = PROJStringFormatter::create(
                 PROJStringFormatter::Convention::PROJ_5, dbContext);
             auto projString = coordop->exportToPROJString(formatter.get());
+            if (pj_context_is_network_enabled(ctx)) {
+                ctx->defer_grid_opening = true;
+            }
             auto pj = pj_create_internal(ctx, projString.c_str());
+            ctx->defer_grid_opening = false;
             if (pj) {
                 pj->iso_obj = objIn;
                 if (ctx->cpp_context) {
@@ -766,7 +770,7 @@ int PROJ_DLL proj_grid_get_info_from_database(
         bool open_license;
         bool available;
         if (!db_context->lookForGridInfo(
-                grid_name, ctx->cpp_context->lastGridFullName_,
+                grid_name, false, ctx->cpp_context->lastGridFullName_,
                 ctx->cpp_context->lastGridPackageName_,
                 ctx->cpp_context->lastGridUrl_, direct_download, open_license,
                 available)) {
@@ -6615,7 +6619,10 @@ int proj_coordoperation_is_instantiable(PJ_CONTEXT *ctx,
     }
     auto dbContext = getDBcontextNoException(ctx, __FUNCTION__);
     try {
-        auto ret = op->isPROJInstantiable(dbContext) ? 1 : 0;
+        auto ret = op->isPROJInstantiable(dbContext,
+                                          pj_context_is_network_enabled(ctx))
+                       ? 1
+                       : 0;
         if (ctx->cpp_context) {
             ctx->cpp_context->autoCloseDbIfNeeded();
         }
@@ -6927,7 +6934,8 @@ int proj_coordoperation_get_grid_used_count(PJ_CONTEXT *ctx,
     try {
         if (!coordoperation->gridsNeededAsked) {
             coordoperation->gridsNeededAsked = true;
-            const auto gridsNeeded = co->gridsNeeded(dbContext);
+            const auto gridsNeeded =
+                co->gridsNeeded(dbContext, pj_context_is_network_enabled(ctx));
             for (const auto &gridDesc : gridsNeeded) {
                 coordoperation->gridsNeeded.emplace_back(gridDesc);
             }
@@ -7264,6 +7272,12 @@ void PROJ_DLL proj_operation_factory_context_set_grid_availability_use(
                 CoordinateOperationContext::GridAvailabilityUse::
                     IGNORE_GRID_AVAILABILITY);
             break;
+
+        case PROJ_GRID_AVAILABILITY_KNOWN_AVAILABLE:
+            factory_ctx->operationContext->setGridAvailabilityUse(
+                CoordinateOperationContext::GridAvailabilityUse::
+                    KNOWN_AVAILABLE);
+            break;
         }
     } catch (const std::exception &e) {
         proj_log_error(ctx, __FUNCTION__, e.what());