Use external Catch2 if available in cmake build (#600)

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.0)
+cmake_minimum_required(VERSION 3.1)
 
 project(RecastNavigation)
 

RecastDemo/premake5.lua

@@ -213,7 +213,7 @@ project "Tests"
 		"../Recast/Source",
 		"../Tests/Recast",
 		"../Tests",
-		"../Tests/Contrib/Catch"
+		"../Tests/Contrib"
 	}
 	files { 
 		"../Tests/*.h",
@@ -223,7 +223,7 @@ project "Tests"
 		"../Tests/Recast/*.cpp",
 		"../Tests/Detour/*.h",
 		"../Tests/Detour/*.cpp",
-		"../Tests/Contrib/Catch/*.cpp"
+		"../Tests/Contrib/catch2/*.cpp"
 	}
 
 	-- project dependencies

Tests/CMakeLists.txt

@@ -1,9 +1,7 @@
-file(GLOB TESTS_SOURCES *.cpp Detour/*.cpp Recast/*.cpp Contrib/Catch/*.cpp)
+file(GLOB TESTS_SOURCES Detour/*.cpp Recast/*.cpp)
 
 include_directories(../Detour/Include)
 include_directories(../Recast/Include)
-include_directories(./Contrib/Catch)
-include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 
 add_executable(Tests ${TESTS_SOURCES})
 
@@ -11,4 +9,13 @@ set_property(TARGET Tests PROPERTY CXX_STANDARD 17)
 
 add_dependencies(Tests Recast Detour)
 target_link_libraries(Tests Recast Detour)
+
+find_package(Catch2 QUIET)
+if (Catch2_FOUND)
+	target_link_libraries(Tests Catch2::Catch2WithMain)
+else()
+	include_directories(./Contrib)
+	target_sources(Tests PRIVATE Contrib/catch2/catch_amalgamated.cpp)
+endif()
+
 add_test(Tests Tests)

Tests/Contrib/catch2/catch_amalgamated.cpp

@@ -12,7 +12,7 @@
 //  You probably shouldn't edit it directly.
 //  ----------------------------------------------------------
 
-#include "catch_amalgamated.hpp"
+#include "catch_all.hpp"
 
 
 #ifndef CATCH_WINDOWS_H_PROXY_HPP_INCLUDED

Tests/Detour/Tests_Detour.cpp

@@ -1,4 +1,4 @@
-#include "catch_amalgamated.hpp"
+#include "catch2/catch_all.hpp"
 
 #include "DetourCommon.h"
 

Tests/Recast/Tests_Recast.cpp

@@ -1,7 +1,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "catch_amalgamated.hpp"
+#include "catch2/catch_all.hpp"
 
 #include "Recast.h"
 #include "RecastAlloc.h"

Tests/main.cpp

@@ -1,2 +0,0 @@
-#define CATCH_CONFIG_MAIN
-#include "catch_amalgamated.hpp"