Parse the bullet version in FindBullet.cmake

CMakeLists.txt

@@ -304,6 +304,9 @@ find_package(Boost REQUIRED COMPONENTS ${BOOST_COMPONENTS})
 find_package(SDL2 REQUIRED)
 find_package(OpenAL REQUIRED)
 find_package(Bullet REQUIRED)
+if (NOT BULLET_FOUND OR BULLET_VERSION VERSION_LESS 283)
+    message(FATAL_ERROR "OpenMW requires Bullet version 2.83 or later")
+endif()
 
 include_directories("."
     SYSTEM

cmake/FindBullet.cmake

@@ -14,11 +14,14 @@
 #
 
 # Copyright (c) 2009, Philip Lowman <philip at yhbt.com>
+# Modified for OpenMW to parse BT_BULLET_VERSION.
 #
 # Redistribution AND use is allowed according to the terms of the New
 # BSD license.
 # For details see the accompanying COPYING-CMAKE-SCRIPTS file.
 
+include(PreprocessorUtils)
+
 set(BULLET_ROOT $ENV{BULLET_ROOT})
 
 macro(_FIND_BULLET_LIBRARY _var)
@@ -75,4 +78,9 @@ if(BULLET_FOUND)
    #_BULLET_APPEND_LIBRARIES(BULLET_LIBRARIES BULLET_DYNAMICS_LIBRARY)
    _BULLET_APPEND_LIBRARIES(BULLET_LIBRARIES BULLET_COLLISION_LIBRARY)
    _BULLET_APPEND_LIBRARIES(BULLET_LIBRARIES BULLET_MATH_LIBRARY)
+
+    find_file(BULLET_BTSCALAR_FILE NAMES btScalar.h PATHS "${BULLET_INCLUDE_DIR}/LinearMath")
+    file(READ ${BULLET_BTSCALAR_FILE} BULLET_BTSCALAR_CONTENT)
+    get_preprocessor_entry(BULLET_BTSCALAR_CONTENT BT_BULLET_VERSION BULLET_VERSION)
+    message(STATUS "Bullet version: ${BULLET_VERSION}")
 endif()

components/resource/bulletshapemanager.hpp

@@ -6,15 +6,9 @@
 
 #include <osg/ref_ptr>
 
-#include <LinearMath/btScalar.h>
-
 #include "bulletshape.hpp"
 #include "resourcemanager.hpp"
 
-#if BT_BULLET_VERSION < 283
-#error "OpenMW requires Bullet version 2.83 or later"
-#endif
-
 namespace Resource
 {
     class SceneManager;