Intermediate C++ Game Programming Tutorial 21
Smart pointers. I know pointers, I have the smartest pointers. In this video we learn about
std::unique_ptr<>, which is by far the most frequently-used and important smart pointer.
std::shared_ptr<> can go suck on an egg.
- How to pass (and not to pass) smart pointers
- Custom deleters
Video Timestamp Index
The addition of smart pointers to
Surface has allowed us to reduce the amount of code we need to write for
Surface, making it simpler and correct by default. But we still need to write logic for those pesky copy operations... What if we used a container like
std::vector! Then all that copying bullshit will be taken care of for us.
This is what we do in the bonus video. The only problem is, although adding
std::vector will not make our release build any slower (the compiler optimizes out all of the extra abstraction for us), it does make the debug build slow. Usually, we don't worry about performance under debug, but for stuff like
PutPixel, since we're calling it potentially millions of times per second, if our debug build is too slow it will become unusable for development and testing.
So the second goal of this bonus video is to optimize the debug build so that
PutPixel-related operation run very fast, regardless of the fact that we are using
std::vector to manage the array of pixels. The end result is that we can achieve rendering speeds which are over 100x faster than without the optimized debug configuration.
Although Chili uses
Surface, which allows us to
= default the move members and leave the destructor undeclared, the astute student will realize that
Surface should actually be setting the
height of the donor surface to
0 when pilfering, so we actually still need to declare move members in this case. This is done in the Bonus Video where we perfect
Also note one major mistake: when we convert
MemeFighter to use
std::unique_ptr for owning its
Weapon, we remove the destructor (because we no longer need to manually
delete the heap
Weapon object). However, we still need to mark the destructor as
virtual so that the proper derived destructor gets called in polymorphic situations. The correct course should have been to change the destructor to
virtual ~MemeFighter() = default; (a commit has been pushed after the fact that fixes this issue).