one more try

Toolchain-mingw32.cmake

@@ -4,14 +4,37 @@ set(CMAKE_SYSTEM_NAME Windows)
 #remove the runtime dependency for libgcc_s_sjlj-1.dll
 set (CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -static-libgcc")
 
+# Which compilers to use for C and C++, and location of target
+# environment.
+if(EXISTS /usr/i586-mingw32msvc)
+# First look in standard location as used by Debian/Ubuntu/etc.
+set(CMAKE_C_COMPILER i586-mingw32msvc-gcc)
+set(CMAKE_CXX_COMPILER i586-mingw32msvc-g++)
+set(CMAKE_RC_COMPILER i586-mingw32msvc-windres)
+set(CMAKE_FIND_ROOT_PATH /usr/i586-mingw32msvc)
+elseif(EXISTS /usr/i686-w64-mingw32)
+# First look in standard location as used by Debian/Ubuntu/etc.
+set(CMAKE_C_COMPILER i686-w64-mingw32-gcc)
+set(CMAKE_CXX_COMPILER i686-w64-mingw32-g++)
+set(CMAKE_RC_COMPILER i686-w64-mingw32-windres)
+set(CMAKE_AR:FILEPATH /usr/bin/i686-w64-mingw32-ar)
+elseif(EXISTS /opt/mingw)
 # You can get a MinGW environment using the script at <http://mxe.cc>.
 # It downloads and builds MinGW and most of the dependencies for you.
 # You can use the toolchain file generated by MXE called `mxe-conf.cmake'
 # or you can use this file by adjusting the above and following paths.
-set(CMAKE_C_COMPILER i686-pc-mingw32-gcc)
+set(CMAKE_C_COMPILER /opt/mingw/usr/bin/i686-pc-mingw32-gcc)
-set(CMAKE_CXX_COMPILER i686-pc-mingw32-g++)
+set(CMAKE_CXX_COMPILER /opt/mingw/usr/bin/i686-pc-mingw32-g++)
-set(CMAKE_RC_COMPILER i686-pc-mingw32-windres)
+set(CMAKE_RC_COMPILER /opt/mingw/usr/bin/i686-pc-mingw32-windres)
-set(CMAKE_FIND_ROOT_PATH i686-pc-mingw32)
+set(CMAKE_FIND_ROOT_PATH /opt/mingw/usr/i686-pc-mingw32)
+else()
+# Else fill in local path which the user will likely adjust.
+# This is the location assumed by <http://www.libsdl.org/extras/win32/cross/>
+set(CMAKE_C_COMPILER /usr/local/cross-tools/bin/i386-mingw32-gcc)
+set(CMAKE_CXX_COMPILER /usr/local/cross-tools/bin/i386-mingw32-g++)
+set(CMAKE_RC_COMPILER /usr/local/cross-tools/bin/i386-mingw32-windres)
+set(CMAKE_FIND_ROOT_PATH /usr/local/cross-tools)
+endif() 
 
 # Adjust the default behaviour of the FIND_XXX() commands:
 # search headers and libraries in the target environment, search