Revert ":construction: Replace vcpkg with conan"

This reverts commit 104cdb6.

Conflicts:
	CMakeLists.txt
	conanfile.py

CMakeLists.txt

@@ -19,6 +19,38 @@ cmake_minimum_required(VERSION 3.14)
 SET(CMAKE_NINJA_FORCE_RESPONSE_FILE 1 CACHE INTERNAL "")
 
 include(SelectLibraryConfigurations)
+# Passing of variables to vcpkg
+#
+# vcpkg runs cmake scripts in an isolated environment, see this for details:
+# https://github.com/Microsoft/vcpkg/issues/3712
+#
+# Here's how this works and how we work around this issue:
+#
+# 1. This file (CMakeLists.txt) runs first and is authoritative. It is the one
+#    that reads the environment, sets variables and sets a default value.
+# 2. It writes the contents of the variables to
+#    $CMAKE_CURRENT_BINARY_DIR/_env/$VARNAME
+# 3. hifi_vcpkg.py takes the _env directory, and copies it to the vcpkg dir.
+#    This solves the issue of CMakeLists.txt not knowing where the vcpkg dir is.
+# 4. cmake/ports/*/portfile.cmake does know where the vcpkg dir is, and can
+#    read the _env that was copied there to obtain the variable's name.
+#
+# To ensure no old data could be accidentally read, the _env directories are
+# deleted on each execution and fully recreated.
+
+# Ensure nothing is kept from any previous run
+file(REMOVE_RECURSE "${CMAKE_CURRENT_BINARY_DIR}/_env")
+file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/_env")
+
+# Base URL for externally downloaded files
+set(EXTERNAL_BUILD_ASSETS "https://build-deps.overte.org")
+
+if( DEFINED ENV{EXTERNAL_BUILD_ASSETS} )
+    set(EXTERNAL_BUILD_ASSETS "$ENV{EXTERNAL_BUILD_ASSETS}")
+endif()
+
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/_env/EXTERNAL_BUILD_ASSETS.txt" "${EXTERNAL_BUILD_ASSETS}")
+MESSAGE(STATUS "EXTERNAL_BUILD_ASSETS: ${EXTERNAL_BUILD_ASSETS}")
 
 # read USE_GLES enviroment variable and sets it as GLES option
 # TODO still gets overwritten by "use GLES on linux aarch64"
@@ -35,15 +67,25 @@ if (CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_SYSTEM_PROCESSOR STREQUAL "aarc
     set(GLES_OPTION ON)
 endif()
 
+# Will affect VCPKG dependencies
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/_env/USE_GLES.txt" "${GLES_OPTION}")
+MESSAGE(STATUS "GLES_OPTION: ${GLES_OPTION}")
+
+include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/macros/TargetPython.cmake")
+target_python()
+
+if (WIN32 AND NOT HIFI_ANDROID AND NOT (CMAKE_GENERATOR STREQUAL "Ninja"))
+    # Force x64 toolset
+    set(CMAKE_GENERATOR_TOOLSET "host=x64" CACHE STRING "64-bit toolset" FORCE)
+endif()
+
 # set our OS X deployment target
 # (needs to be set before first project() call and before prebuild.py)
 # Will affect VCPKG dependencies
 if (APPLE)
   set(ENV{MACOSX_DEPLOYMENT_TARGET} 10.11)
 endif()
 
-set(EXTERNAL_BUILD_ASSETS "https://build-deps.overte.org")
-
 set(RELEASE_TYPE "$ENV{RELEASE_TYPE}")
 if ((NOT "${RELEASE_TYPE}" STREQUAL "PRODUCTION") AND (NOT "${RELEASE_TYPE}" STREQUAL "PR"))
     set(RELEASE_TYPE "DEV")
@@ -67,6 +109,8 @@ if( NOT WIN32 )
     set(OVERTE_OPTIMIZE_FLAGS "")
 
     if(OVERTE_OPTIMIZE)
+
+        file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/_env/OVERTE_OPTIMIZE.txt" "${OVERTE_OPTIMIZE}")
         if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
             message("Clang compiler detected, adding -O3 -fPIC -g flags")
             set(OVERTE_OPTIMIZE_FLAGS "-O3 -fPIC -g")
@@ -92,6 +136,7 @@ if( NOT WIN32 )
     endif()
 
     if(DEFINED OVERTE_CPU_ARCHITECTURE)
+        file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/_env/OVERTE_CPU_ARCHITECTURE.txt" "${OVERTE_CPU_ARCHITECTURE}")
         set(OVERTE_OPTIMIZE_FLAGS "${OVERTE_OPTIMIZE_FLAGS} ${OVERTE_CPU_ARCHITECTURE}")
         message("Adding CPU architecture flags: ${OVERTE_CPU_ARCHITECTURE}")
         MESSAGE(STATUS "OVERTE_CPU_ARCHITECTURE: ${OVERTE_CPU_ARCHITECTURE}")
@@ -156,9 +201,53 @@ if(OVERTE_WARNINGS_AS_ERRORS)
 endif()
 
 
+if (HIFI_ANDROID)
+    execute_process(
+        COMMAND ${HIFI_PYTHON_EXEC} ${CMAKE_CURRENT_SOURCE_DIR}/prebuild.py --release-type ${RELEASE_TYPE} --android ${HIFI_ANDROID_APP} --build-root ${CMAKE_BINARY_DIR}
+        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} RESULTS_VARIABLE PREBUILD_RET
+    )
+else()
+    set(VCPKG_BUILD_TYPE_PARAM "")
+    if (VCPKG_BUILD_TYPE)
+      set(VCPKG_BUILD_TYPE_PARAM --vcpkg-build-type ${VCPKG_BUILD_TYPE})
+    endif()
+    execute_process(
+        COMMAND ${HIFI_PYTHON_EXEC} ${CMAKE_CURRENT_SOURCE_DIR}/prebuild.py --release-type ${RELEASE_TYPE} --build-root ${CMAKE_BINARY_DIR} ${VCPKG_BUILD_TYPE_PARAM}
+        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} RESULTS_VARIABLE PREBUILD_RET
+    )
+endif()
+
+if (PREBUILD_RET GREATER 0)
+  message(FATAL_ERROR "prebuild.py failed with error ${PREBUILD_RET}")
+endif()
+if(NOT EXISTS "${CMAKE_BINARY_DIR}/vcpkg.cmake")
+    message(FATAL_ERROR "vcpkg configuration missing.")
+endif()
+include("${CMAKE_BINARY_DIR}/vcpkg.cmake")
+
+if (HIFI_ANDROID)
+  set(QT_CMAKE_PREFIX_PATH "$ENV{HIFI_ANDROID_PRECOMPILED}/qt/lib/cmake")
+else()
+  if ("$ENV{OVERTE_USE_SYSTEM_QT}" STREQUAL "")
+     if(NOT EXISTS "${CMAKE_BINARY_DIR}/qt.cmake")
+        message(FATAL_ERROR "qt configuration missing.")
+    endif()
+    include("${CMAKE_BINARY_DIR}/qt.cmake")
+    message(STATUS "${CMAKE_BINARY_DIR}/qt.cmake included!")
+  else()
+    message(STATUS "System Qt in use, not including qt.cmake!")
+  endif()
+endif()
+
+option(VCPKG_APPLOCAL_DEPS OFF)
+
 project(overte)
 include("cmake/init.cmake")
 include("cmake/compiler.cmake")
+option(VCPKG_APPLOCAL_DEPS OFF)
+
+add_paths_to_fixup_libs(${VCPKG_INSTALL_ROOT}/bin)
+add_paths_to_fixup_libs(${VCPKG_INSTALL_ROOT}/debug/bin)
 
 if (NOT DEFINED CLIENT_ONLY)
   set(CLIENT_ONLY 0)
@@ -335,6 +424,12 @@ endif()
 
 set_packaging_parameters()
 
+# Locate the required Qt build on the filesystem
+setup_qt()
+
+if ("$ENV{OVERTE_USE_SYSTEM_QT}" STREQUAL "")
+  list(APPEND CMAKE_PREFIX_PATH "${QT_CMAKE_PREFIX_PATH}")
+endif()
 
 find_package( Threads )