From 9eb96b9cb6af2643b21617e391d317c605cf7c7d Mon Sep 17 00:00:00 2001
From: scrawl <scrawl@baseoftrash.de>
Date: Mon, 15 Feb 2016 14:34:59 +0100
Subject: [PATCH] Parse the bullet version in FindBullet.cmake

---
 CMakeLists.txt                             | 3 +++
 cmake/FindBullet.cmake                     | 8 ++++++++
 components/resource/bulletshapemanager.hpp | 6 ------
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 520279e50..f5c468114 100644
--- a/CMakeLists.txt
+++ b/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
diff --git a/cmake/FindBullet.cmake b/cmake/FindBullet.cmake
index 6d5c517af..d70815dd5 100644
--- a/cmake/FindBullet.cmake
+++ b/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()
diff --git a/components/resource/bulletshapemanager.hpp b/components/resource/bulletshapemanager.hpp
index 3fe351f90..14b26962b 100644
--- a/components/resource/bulletshapemanager.hpp
+++ b/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;