SDL2 resource destructors fix

This is from ninenines#12

Author: brainstormi

c_src/sdl_gl.c

@@ -14,10 +14,16 @@
 
 #include "esdl2.h"
 
+
+NIF_CAST_HANDLER(thread_destroy_GLContext)
+{
+	SDL_GL_DeleteContext(NIF_RES_GET(GLContext, args[0]));
+        enif_release_resource(NIF_RES_DEP(GLContext, args[0]));
+}
+
 void dtor_GLContext(ErlNifEnv* env, void* obj)
 {
-	SDL_GL_DeleteContext(NIF_RES_GET(GLContext, obj));
-	enif_release_resource(NIF_RES_DEP(GLContext, obj));
+	nif_thread_cast(env,thread_destroy_GLContext,1,obj);
 }
 
 // gl_create_context

c_src/sdl_renderer.c

@@ -14,10 +14,14 @@
 
 #include "esdl2.h"
 
+NIF_CAST_HANDLER(thread_destroy_renderer)
+{
+ 	SDL_DestroyRenderer(NIF_RES_GET(Renderer, args[0]));
+        enif_release_resource(NIF_RES_DEP(Renderer, args[0]));
+}
 void dtor_Renderer(ErlNifEnv* env, void* obj)
 {
-	SDL_DestroyRenderer(NIF_RES_GET(Renderer, obj));
-	enif_release_resource(NIF_RES_DEP(Renderer, obj));
+	nif_thread_cast(env,thread_destroy_renderer,1,obj);
 }
 
 #define RENDERER_FLAGS(F) \

c_src/sdl_surface.c

@@ -15,9 +15,13 @@
 #include "esdl2.h"
 #include "SDL_image.h"
 
+NIF_CAST_HANDLER(thread_destroy_surface)
+{
+	SDL_FreeSurface(NIF_RES_GET(Surface, args[0]));
+}
 void dtor_Surface(ErlNifEnv* env, void* obj)
 {
-	SDL_FreeSurface(NIF_RES_GET(Surface, obj));
+	nif_thread_cast(env,thread_destroy_surface,1,obj);
 }
 
 // img_load

c_src/sdl_texture.c

@@ -17,9 +17,13 @@
 NIF_ATOM_TO_ENUM_FUNCTION_DECL(atom_to_blend_mode, SDL_BlendMode)
 NIF_ENUM_TO_ATOM_FUNCTION_DECL(blend_mode_to_atom, SDL_BlendMode)
 
+NIF_CAST_HANDLER(thread_destroy_texture)
+{
+	SDL_DestroyTexture(NIF_RES_GET(Texture, args[0]));
+}
 void dtor_Texture(ErlNifEnv* env, void* obj)
 {
-	SDL_DestroyTexture(NIF_RES_GET(Texture, obj));
+	nif_thread_cast(env,thread_destroy_texture,1,obj);
 }
 
 // create_texture_from_surface

c_src/sdl_window.c

@@ -16,9 +16,13 @@
 
 NIF_ATOM_TO_ENUM_FUNCTION_DECL(atom_to_bool, SDL_bool)
 
+NIF_CAST_HANDLER(thread_destroy_window)
+{
+	SDL_DestroyWindow(NIF_RES_GET(Window, args[0]));
+}
 void dtor_Window(ErlNifEnv* env, void* obj)
 {
-	SDL_DestroyWindow(NIF_RES_GET(Window, obj));
+	nif_thread_cast(env,thread_destroy_window,1,obj);
 }
 
 #define WINDOW_FLAGS(F) \