Added a way to get a framebuffer interface for a window, and also a way to create a software renderer for an arbitrary surface.

The software renderer has been re-routed to use the framebuffer interface, which makes it possible to have software rendering available even on simple ports.

src/render/software/SDL_renderer_sw_c.h

@@ -0,0 +1,25 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2010 Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library 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
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+
+extern SDL_Renderer * SW_CreateRendererForSurface(SDL_Surface * surface);
+
+/* vi: set ts=4 sw=4 expandtab: */