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.

2 files changed, 23 insertions, 8 deletions

diff --git a/src/apps/gie.cpp b/src/apps/gie.cpp
index 6a67b55d..d9907776 100644
--- a/src/apps/gie.cpp
+++ b/src/apps/gie.cpp
@@ -1153,6 +1153,7 @@ static const struct errno_vs_err_const lookup[] = {
     {"pjd_err_inconsistent_unit"        ,  -59},
     {"pjd_err_mutually_exclusive_args"  ,  -60},
     {"pjd_err_generic_error"            ,  -61},
+    {"pjd_err_network_error"            ,  -62},
     {"pjd_err_dont_skip"                ,  5555},
     {"pjd_err_unknown"                  ,  9999},
     {"pjd_err_enomem"                   ,  ENOMEM},
diff --git a/src/apps/projinfo.cpp b/src/apps/projinfo.cpp
index bef47746..27ea278a 100644
--- a/src/apps/projinfo.cpp
+++ b/src/apps/projinfo.cpp
@@ -87,7 +87,8 @@ static void usage() {
         << "                [--spatial-test contains|intersects]" << std::endl
         << "                [--crs-extent-use none|both|intersection|smallest]"
         << std::endl
-        << "                [--grid-check none|discard_missing|sort] "
+        << "                [--grid-check "
+           "none|discard_missing|sort|known_available] "
            "[--show-superseded]"
         << std::endl
         << "                [--pivot-crs always|if_no_direct_transformation|"
@@ -554,7 +555,7 @@ static void outputObject(
     auto op = dynamic_cast<CoordinateOperation *>(obj.get());
     if (op && dbContext && getenv("PROJINFO_NO_GRID_CHECK") == nullptr) {
         try {
-            auto setGrids = op->gridsNeeded(dbContext);
+            auto setGrids = op->gridsNeeded(dbContext, false);
             bool firstWarning = true;
             for (const auto &grid : setGrids) {
                 if (!grid.available) {
@@ -570,6 +571,7 @@ static void outputObject(
                         if (!grid.url.empty()) {
                             std::cout << " at " << grid.url;
                         }
+                        std::cout << ", or on CDN";
                     } else if (!grid.url.empty()) {
                         std::cout << " Can be obtained at " << grid.url;
                     }
@@ -584,8 +586,9 @@ static void outputObject(
 
 // ---------------------------------------------------------------------------
 
-static void outputOperationSummary(const CoordinateOperationNNPtr &op,
-                                   const DatabaseContextPtr &dbContext) {
+static void outputOperationSummary(
+    const CoordinateOperationNNPtr &op, const DatabaseContextPtr &dbContext,
+    CoordinateOperationContext::GridAvailabilityUse gridAvailabilityUse) {
     auto ids = op->identifiers();
     if (!ids.empty()) {
         std::cout << *(ids[0]->codeSpace()) << ":" << ids[0]->code();
@@ -631,10 +634,16 @@ static void outputOperationSummary(const CoordinateOperationNNPtr &op,
 
     if (dbContext && getenv("PROJINFO_NO_GRID_CHECK") == nullptr) {
         try {
-            auto setGrids = op->gridsNeeded(dbContext);
+            auto setGrids = op->gridsNeeded(dbContext, false);
             for (const auto &grid : setGrids) {
                 if (!grid.available) {
                     std::cout << ", at least one grid missing";
+                    if (gridAvailabilityUse ==
+                            CoordinateOperationContext::GridAvailabilityUse::
+                                KNOWN_AVAILABLE &&
+                        !grid.packageName.empty()) {
+                        std::cout << " on the system, but available on CDN";
+                    }
                     break;
                 }
             }
@@ -731,7 +740,7 @@ static void outputOperations(
     }
     if (summary) {
         for (const auto &op : list) {
-            outputOperationSummary(op, dbContext);
+            outputOperationSummary(op, dbContext, gridAvailabilityUse);
         }
     } else {
         bool first = true;
@@ -744,7 +753,7 @@ static void outputOperations(
             std::cout << "-------------------------------------" << std::endl;
             std::cout << "Operation No. " << (i + 1) << ":" << std::endl
                       << std::endl;
-            outputOperationSummary(op, dbContext);
+            outputOperationSummary(op, dbContext, gridAvailabilityUse);
             std::cout << std::endl;
             outputObject(dbContext, op, allowUseIntermediateCRS, outputOpt);
         }
@@ -777,7 +786,9 @@ int main(int argc, char **argv) {
         CoordinateOperationContext::SourceTargetCRSExtentUse::SMALLEST;
     bool buildBoundCRSToWGS84 = false;
     CoordinateOperationContext::GridAvailabilityUse gridAvailabilityUse =
-        CoordinateOperationContext::GridAvailabilityUse::USE_FOR_SORTING;
+        pj_context_is_network_enabled(nullptr)
+            ? CoordinateOperationContext::GridAvailabilityUse::KNOWN_AVAILABLE
+            : CoordinateOperationContext::GridAvailabilityUse::USE_FOR_SORTING;
     CoordinateOperationContext::IntermediateCRSUse allowUseIntermediateCRS =
         CoordinateOperationContext::IntermediateCRSUse::
             IF_NO_DIRECT_TRANSFORMATION;
@@ -992,6 +1003,9 @@ int main(int argc, char **argv) {
             } else if (ci_equal(value, "sort")) {
                 gridAvailabilityUse = CoordinateOperationContext::
                     GridAvailabilityUse::USE_FOR_SORTING;
+            } else if (ci_equal(value, "known_available")) {
+                gridAvailabilityUse = CoordinateOperationContext::
+                    GridAvailabilityUse::KNOWN_AVAILABLE;
             } else {
                 std::cerr << "Unrecognized value for option --grid-check: "
                           << value << std::endl;