Add SDL renderer, demo webm
diff --git a/screen.h b/screen.h
index e504617..4128005 100644
--- a/screen.h
+++ b/screen.h
@@ -2,6 +2,8 @@
 
 #include <stdint.h>
 
+#ifndef SCREEN_ONLY_SDL
+
 #undef NK_IMPLEMENTATION
 #define NK_INCLUDE_FIXED_TYPES
 #define NK_INCLUDE_STANDARD_IO
@@ -12,5 +14,20 @@
 #define NK_INCLUDE_DEFAULT_FONT
 #include "nuklear/nuklear.h"
 
-// draw the CPU screen
 void screen(struct nk_context *ctx, uint8_t *mem, uint8_t size);
+
+#endif
+
+#include <SDL2/SDL.h>
+
+
+typedef struct
+{
+	SDL_Window *win;
+	SDL_Renderer *r;
+	uint8_t size;
+} sdl_screen_t;
+
+// draw the CPU screen
+sdl_screen_t new_sdl_screen(uint8_t size);
+void sdl_screen(sdl_screen_t *scr, uint8_t *mem);