WinRT: build fixes and additional WinRT-related integrations with SDL 2.0.0

include/SDL_config_windowsrt.h

@@ -83,6 +83,7 @@ typedef unsigned int uintptr_t;
 #define HAVE_STRING_H 1
 #define HAVE_CTYPE_H 1
 #define HAVE_MATH_H 1
+#define HAVE_FLOAT_H 1
 #define HAVE_SIGNAL_H 1
 
 /* C library functions */
@@ -123,7 +124,7 @@ typedef unsigned int uintptr_t;
 #define HAVE_ATAN 1
 #define HAVE_ATAN2 1
 #define HAVE_CEIL 1
-//#define HAVE_COPYSIGN 1   // TODO, WinRT: consider using _copysign instead
+#define HAVE__COPYSIGN 1
 #define HAVE_COS 1
 #define HAVE_COSF 1
 #define HAVE_FABS 1
@@ -131,6 +132,7 @@ typedef unsigned int uintptr_t;
 #define HAVE_LOG 1
 #define HAVE_POW 1
 //#define HAVE_SCALBN 1
+#define HAVE__SCALB 1
 #define HAVE_SIN 1
 #define HAVE_SINF 1
 #define HAVE_SQRT 1

include/SDL_platform.h

@@ -120,10 +120,27 @@
 #undef __SOLARIS__
 #define __SOLARIS__ 1
 #endif
-#if defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__)
-#undef __WIN32__
-#define __WIN32__   1
-#endif
+
+#if defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__)
+/* Try to find out what version of Windows we are compiling for */
+#if defined(_MSC_VER) && (_MSC_VER >= 1700)	/* _MSC_VER==1700 for MSVC 2012 */
+#include <winapifamily.h>
+#endif
+/* Default to classic, Win32 / Desktop compilation either if:
+     1. the version of Windows is explicity set to a 'Desktop' (non-Metro) app
+     2. the version of Windows cannot be determined via winapifamily.h
+   If neither is true, see if we're compiling for WinRT.
+ */
+#if ! defined(WINAPI_FAMILY_PARTITION) || WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
+#undef __WIN32__
+#define __WIN32__   1
+/* See if we're compiling for WinRT: */
+#elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)
+#undef __WINRT__
+#define __WINRT__ 1
+#endif /* ! defined(WINAPI_FAMILY_PARTITION) */
+#endif /* defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__) */
+
 #if defined(__PSP__)
 #undef __PSP__
 #define __PSP__ 1

include/SDL_stdinc.h

@@ -80,6 +80,9 @@
 # endif
 # include <math.h>
 #endif
+#ifdef HAVE_FLOAT_H
+# include <float.h>
+#endif
 #if defined(HAVE_ICONV) && defined(HAVE_ICONV_H)
 # include <iconv.h>
 #endif