Made it possible to disable the rendering subsystem with configure --disable-render

src/render/software/SDL_drawline.c

@@ -21,6 +21,8 @@
 */
 #include "SDL_config.h"
 
+#if !SDL_RENDER_DISABLED
+
 #include "SDL_draw.h"
 #include "SDL_drawline.h"
 #include "SDL_drawpoint.h"
@@ -208,4 +210,6 @@ SDL_DrawLines(SDL_Surface * dst, const SDL_Point * points, int count,
     return 0;
 }
 
+#endif /* !SDL_RENDER_DISABLED */
+
 /* vi: set ts=4 sw=4 expandtab: */