Question

(Note: I’m coding in Pascal)

In the creator of a class TQuest, I initialize some objects with a pSDL_Surface given as a parameter as follows :

quests.Add( CPopuQuest.create('Get money ! ','Get more than $10,000', IMG_LOAD(MONEY_ICON), 1000, 10) );
(The interesting part is IMG_LOAD(MONEY_ICON) with MONEY_ICON the path to an image.

When I end my program, I get an error at the destructor of this CPopuQuest object in this line:

if badge<>nil then SDL_FreeSurface(badge)

(badge is the attribute where the pSDL_Surface instantiated by IMG_LOAD(MONEY_ICON) is copied)

It works most of the time, but from time a time I still get an error when closing the program … If anyone can help 🙂 (as you can see I’m quite confused with how IMG_LOAD works, what it returns, and how memory is allocated when its called).

Answer 1

Anything that IMG_Load returns will be safe to pass to SDL_FreeSurface, even if it returns a null pointer. (Thus, you don’t need to check badge <> nil before calling SDL_FreeSurface(badge).)

If your program crashes when you call SDL_FreeSurface, then it’s due to other problems in your program. That function is the correct way to free anything that IMG_Load loads. Everything shown in this question is right.