A bit more work on PK3.

-Expanded folder recognition for PK3s. Some resources are still not loaded from them yet.
-Took a glimpse at how maps are loaded, since the flat recognition is rooted somewhere there; did nothing yet about it though.
-Working towards "generalizing" how new resources are handled. Some var and functionality redundancy is still present.

src/r_things.c

@@ -368,6 +368,38 @@ static boolean R_AddSingleSpriteDef(const char *sprname, spritedef_t *spritedef,
 	return true;
 }
 
+// Auxiliary function for PK3 loading - Loads sprites from a specified range.
+void R_LoadSpritsRange(UINT16 wadnum, UINT16 first, UINT16 num)
+{
+	size_t i, addsprites = 0;
+	char wadname[MAX_WADPATH];
+	//
+	// scan through lumps, for each sprite, find all the sprite frames
+	//
+	for (i = 0; i < numsprites; i++)
+	{
+		spritename = sprnames[i];
+		if (spritename[4] && wadnum >= (UINT16)spritename[4])
+			continue;
+
+		if (R_AddSingleSpriteDef(spritename, &sprites[i], wadnum, first, first + num + 1))
+		{
+#ifdef HWRENDER
+			if (rendermode == render_opengl)
+				HWR_AddSpriteMD2(i);
+#endif
+			// if a new sprite was added (not just replaced)
+			addsprites++;
+#ifndef ZDEBUG
+			CONS_Debug(DBG_SETUP, "sprite %s set in pwad %d\n", spritename, wadnum);
+#endif
+		}
+	}
+
+	nameonly(strcpy(wadname, wadfiles[wadnum]->filename));
+	CONS_Printf(M_GetText("%s added %d frames in %s sprites\n"), wadname, num, sizeu1(addsprites));
+}
+
 //
 // Search for sprites replacements in a wad whose names are in namelist
 //