Adjust cmake file paths to match make install for distribution

cmake/glm/glmConfig.cmake

@@ -0,0 +1,22 @@
+cmake_minimum_required(VERSION 3.2 FATAL_ERROR)
+cmake_policy(VERSION 3.2)
+
+set(GLM_VERSION 0.9.9)
+
+get_filename_component(_IMPORT_PREFIX "${CMAKE_CURRENT_LIST_FILE}" PATH)
+get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
+get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
+if (_IMPORT_PREFIX STREQUAL "/")
+  set(_IMPORT_PREFIX "")
+endif()
+
+# Set the old GLM_INCLUDE_DIRS variable for backwards compatibility
+set(GLM_INCLUDE_DIRS ${_IMPORT_PREFIX})
+
+add_library(glm::glm INTERFACE IMPORTED)
+set_target_properties(glm::glm PROPERTIES
+    INTERFACE_INCLUDE_DIRECTORIES ${GLM_INCLUDE_DIRS})
+
+mark_as_advanced(glm_DIR)
+set(_IMPORT_PREFIX)
+

glmConfig.cmake

@@ -1,13 +0,0 @@
-cmake_minimum_required(VERSION 3.2 FATAL_ERROR)
-cmake_policy(VERSION 3.2)
-
-set(GLM_VERSION 0.9.9)
-# Set the old GLM_INCLUDE_DIRS variable for backwards compatibility
-set(GLM_INCLUDE_DIRS ${CMAKE_CURRENT_LIST_DIR})
-
-add_library(glm::glm INTERFACE IMPORTED)
-set_target_properties(glm::glm PROPERTIES
-    INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_LIST_DIR})
-
-mark_as_advanced(glm_DIR)
-