SDL_rtf: Use CMAKE_CURRENT_*_DIR instead of CMAKE_*_DIR (db0e4)

SDL Commits
1 
From db0e4676d6f9f6a271747ae21f997c3743cd53e1 Mon Sep 17 00:00:00 2001
From: Anonymous Maarten <[EMAIL REDACTED]>
Date: Thu, 5 Oct 2023 19:10:17 +0200
Subject: [PATCH] Use CMAKE_CURRENT_*_DIR instead of CMAKE_*_DIR

---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 025eb50..4a68119 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,7 +11,7 @@ set(SDL_REQUIRED_VERSION 2.0.0)
 include(PrivateSdlFunctions)
 sdl_calculate_derived_version_variables()
 
-if(CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR)
+if(CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_CURRENT_BINARY_DIR)
     message(FATAL_ERROR "Prevented in-tree built. Please create a build directory outside of the SDL_rtf source code and call cmake from there")
 endif()