guile-sdl surface-pixels patch

surface-pixels.patch

--- src/sdlsurface.c	2013-05-24 18:03:03.156043808 -0400
+++ src/sdlsurface.c	2013-06-06 21:19:03.591137715 -0400
@@ -170,6 +170,33 @@
 #undef FUNC_NAME
 }

+PRIMPROC
+ (surface_pixels, "surface-pixels", 1, 0, 0,
+  (SCM surface),
+  doc: /***********
+ Return the pixel data of @var{surface} as a new SRFI 4 u8vector.
+ If there are problems, return @code{#f}.  */)
+ {
+ #define FUNC_NAME s_surface_pixels
+   SDL_Surface *src;
+   size_t len;
+   void *pixels;
+
+   ASSERT_SURFACE (surface, 1);
+   src = UNPACK_SURFACE (surface);
+   len = src->w * src->h * src->format->BytesPerPixel;
+   if (! (pixels = malloc (len)))
+     RETURN_FALSE;
+   if (! memcpy (pixels, src->pixels, len))
+     {
+       /* Should never get here, since ‘memcpy’ returns ‘pixels’,
+          but who knows?  */
+       free (pixels);
+       RETURN_FALSE;
+     }
+   return scm_take_u8vector (pixels, len);
+ #undef FUNC_NAME
+ }

 /* utilities */