(svn r16336) -Codechange: make the SpriteGroup pool more like the 'normal' pools

src/newgrf_spritegroup.h

@@ -11,6 +11,7 @@
 #include "gfx_type.h"
 #include "engine_type.h"
 #include "tile_type.h"
+#include "oldpool.h"
 
 #include "newgrf_cargo.h"
 #include "newgrf_callbacks.h"
@@ -182,8 +183,18 @@ enum SpriteGroupType {
 	SGT_INDUSTRY_PRODUCTION,
 };
 
+typedef uint32 SpriteGroupID;
+DECLARE_OLD_POOL(SpriteGroup, SpriteGroup, 9, 250)
+
 /* Common wrapper for all the different sprite group types */
-struct SpriteGroup {
+struct SpriteGroup : PoolItem<SpriteGroup, SpriteGroupID, &_SpriteGroup_pool> {
+	SpriteGroup(SpriteGroupType type = SGT_INVALID) :
+		type(type)
+	{
+	}
+
+	~SpriteGroup();
+
 	SpriteGroupType type;
 
 	union {
@@ -195,13 +206,11 @@ struct SpriteGroup {
 		TileLayoutSpriteGroup layout;
 		IndustryProductionSpriteGroup indprod;
 	} g;
+
+	inline bool IsValid() const { return this->type != SGT_INVALID; }
 };
 
 
-SpriteGroup *AllocateSpriteGroup();
-void InitializeSpriteGroupPool();
-
-
 struct ResolverObject {
 	CallbackID callback;
 	uint32 callback_param1;