[FEATURE] Vector tile layer - part 1

CMakeLists.txt

@@ -331,6 +331,11 @@ IF(WITH_CORE)
     MESSAGE (SEND_ERROR "sqlite3 dependency was not found!")
   ENDIF (NOT SQLITE3_FOUND)
 
+  FIND_PACKAGE(Protobuf REQUIRED)   # for decoding of vector tiles in MVT format
+  MESSAGE(STATUS "Found Protobuf: ${Protobuf_LIBRARIES}")
+  FIND_PACKAGE(ZLIB REQUIRED)       # for decompression of vector tiles in MBTiles file
+  MESSAGE(STATUS "Found zlib: ${ZLIB_LIBRARIES}")
+
   # optional
   IF (WITH_POSTGRESQL)
     FIND_PACKAGE(Postgres) # PostgreSQL provider

doc/CMakeLists.txt

@@ -99,6 +99,7 @@ IF(WITH_APIDOC)
       ${CMAKE_SOURCE_DIR}/src/core/scalebar
       ${CMAKE_SOURCE_DIR}/src/core/symbology
       ${CMAKE_SOURCE_DIR}/src/core/validity
+      ${CMAKE_SOURCE_DIR}/src/core/vectortile
       ${CMAKE_SOURCE_DIR}/src/gui
       ${CMAKE_SOURCE_DIR}/src/gui/auth
       ${CMAKE_SOURCE_DIR}/src/gui/attributetable

external/mapbox-vector-tile/README.md

@@ -0,0 +1,15 @@
+
+The .pb.cc and .pb.h are generated by 'protoc' tool and got copied here from https://github.com/TimSC/mbtiles-cpp
+
+
+Update pbf files
+----------------
+
+To update the protobuf files, get vector_tile.proto from https://github.com/mapbox/vector-tile-spec, remove the line "option optimize_for = LITE_RUNTIME;", then
+
+    mkdir vector_tile21
+
+    protoc vector_tile.proto --cpp_out vector_tile21
+
+protobuf lite is avoided because it doesn't contain SerializeToOstream functionality.
+