[nanort] Add new port (#7778)

ports/nanort/CONTROL

@@ -0,0 +1,4 @@
+Source: nanort
+Version: 2019-08-20
+Description: Single header only modern ray tracing kernel
+Homepage: https://github.com/lighttransport/nanort

ports/nanort/portfile.cmake

@@ -0,0 +1,47 @@
+# Single header only library
+
+include(vcpkg_common_functions)
+
+function(shorten_ref REF SHORTENED_REF)
+    set(REF_MAX_LENGTH 10)
+    string(LENGTH ${REF} REF_LENGTH)
+    math(EXPR FROM_REF ${REF_LENGTH}-${REF_MAX_LENGTH})
+    if(FROM_REF LESS 0)
+        set(FROM_REF 0)
+    endif()
+    string(SUBSTRING ${REF} ${FROM_REF} ${REF_LENGTH} SUB_REF)
+    set(${SHORTENED_REF} ${SUB_REF} PARENT_SCOPE)
+endfunction()
+
+set(SOURCE_VERSION c85fe7a10be5baf8242c81288718c244f25d0183)
+shorten_ref(${SOURCE_VERSION} SHORTED_VERSION)
+set(SOURCE_PATH ${CURRENT_BUILDTREES_DIR}/src/lighttransport-nanort-${SHORTED_VERSION})
+
+file(MAKE_DIRECTORY ${SOURCE_PATH})
+
+# See ports/nlohmann-json/portfile.cmake
+function(download_src SUBPATH SHA512)
+    vcpkg_download_distfile(
+        FILE
+        URLS "https://raw.githubusercontent.com/lighttransport/nanort/master/${SUBPATH}"
+        FILENAME "lighttransport-nanort-${SHORTED_VERSION}/${SUBPATH}"
+        SHA512 ${SHA512}
+    )
+    get_filename_component(SUBPATH_DIR "${SOURCE_PATH}/${SUBPATH}" DIRECTORY)
+    file(COPY ${FILE} DESTINATION ${SUBPATH_DIR})
+endfunction()
+
+download_src(
+    nanort.h
+    3e1f6f5fa295ebc472e37daf106c3871873f0bea4e3175cd4042b5649f581a90bfb9f2db989fa1994c82a2de78e40ecbcafd188b68bf10b5983a41b48e53dcbc
+)
+
+download_src(
+    LICENSE
+    454b304dcfae816d7a569ccbe29cc9c4bd68aa7ac41467bfa33b39aaf5be4620df5aeb6989319aaa04f305c053c068559b39c7a38c0bee1d4f194b2bc1aac240
+)
+
+file(COPY ${SOURCE_PATH}/nanort.h DESTINATION ${CURRENT_PACKAGES_DIR}/include)
+
+# Handle copyright
+configure_file(${SOURCE_PATH}/LICENSE ${CURRENT_PACKAGES_DIR}/share/${PORT}/copyright COPYONLY)