Merge pull request #11 from threeal/update-cpm

Update CPM Script

.cmake-format

@@ -0,0 +1,3 @@
+{
+	"line_width": 120
+}

cmake/CPM.cmake

@@ -1,12 +1,19 @@
-set(CPM_DOWNLOAD_LOCATION "${CMAKE_BINARY_DIR}/cmake/CPM.cmake")
-set(CPM_VERSION 0.36.0)
+set(CPM_DOWNLOAD_VERSION 0.36.0)
 
-if(NOT EXISTS ${CPM_DOWNLOAD_LOCATION})
-  message(STATUS "Downloading CPM.cmake")
-  file(
-    DOWNLOAD
-    https://github.com/TheLartians/CPM.cmake/releases/download/v${CPM_VERSION}/CPM.cmake
-    ${CPM_DOWNLOAD_LOCATION})
+if(CPM_SOURCE_CACHE)
+  set(CPM_DOWNLOAD_LOCATION "${CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+elseif(DEFINED ENV{CPM_SOURCE_CACHE})
+  set(CPM_DOWNLOAD_LOCATION "$ENV{CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+else()
+  set(CPM_DOWNLOAD_LOCATION "${CMAKE_BINARY_DIR}/cmake/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+endif()
+
+# Expand relative path. This is important if the provided path contains a tilde (~)
+get_filename_component(CPM_DOWNLOAD_LOCATION ${CPM_DOWNLOAD_LOCATION} ABSOLUTE)
+if(NOT (EXISTS ${CPM_DOWNLOAD_LOCATION}))
+  message(STATUS "Downloading CPM.cmake to ${CPM_DOWNLOAD_LOCATION}")
+  file(DOWNLOAD https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
+       ${CPM_DOWNLOAD_LOCATION})
 endif()
 
 include(${CPM_DOWNLOAD_LOCATION})