Add missing sdl_ctx.h

gfx/context/sdl_ctx.h

@@ -0,0 +1,32 @@
+/*  RetroArch - A frontend for libretro.
+ *  Copyright (C) 2010-2012 - Hans-Kristian Arntzen
+ * 
+ *  RetroArch is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with RetroArch.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _SDL_CTX_H
+#define _SDL_CTX_H
+
+#if SDL_VERSION_ATLEAST(1, 3, 0)
+#define SDL_MODERN 1
+#else
+#define SDL_MODERN 0
+#endif
+
+// Not legal to cast (void*) to fn-pointer. Need workaround to be compliant.
+#define SDL_SYM_WRAP(sym, symbol) { \
+   rarch_assert(sizeof(void*) == sizeof(void (*)(void))); \
+   void *sym__ = SDL_GL_GetProcAddress(symbol); \
+   memcpy(&(sym), &sym__, sizeof(void*)); \
+}
+
+#endif