Movie: simplify silly loop

[Tilka]

NFC

[mitaclaw]

A more literal interpretation of this loop would be std::count_if, though std::all_of could also be a good rework. Initializing an array to compare against seems inefficient.

[Pokechu22]

Looks like a previous version of this loop was added in ca650d4, where it looked like this:

dolphin/Source/Core/Core/Src/Movie.cpp

Lines 1162 to 1169 in ca650d4

	for (int i=0; i<16; i++)
	{
	if (tmpHeader.md5[i] != 0)
	continue;
	if (i == 15)
	return;
	}
	Core::DisplayMessage("Checking md5 of game file against recorded game...", 2000);

but that returns if the last byte in the md5 is 0, rather than all bytes. (If it used break instead of continue I think it would work?)

That was changed to the current loop with two variables in 1917f83:

dolphin/Source/Core/Core/Src/Movie.cpp

Lines 1144 to 1152 in 1917f83

	for (int i=0, n=0; i<16; i++)
	{
	if (tmpHeader.md5[i] != 0)
	continue;
	n++;
	if (n == 16)
	return;
	}
	Core::DisplayMessage("Verifying checksum...", 2000);

It's worth noting that std::array was only used here in 75d056b; before it was a C-style array.

A comment like this might be helpful:

  // Very old DTM files don't include an md5, in which case that previously-reserved area is all zeros.
  // Skip the MD5 check in that case.

[JosJuice]

A more literal interpretation of this loop would be std::count_if, though std::all_of could also be a good rework. Initializing an array to compare against seems inefficient.

It depends on how the compiler optimizes it. If we're lucky, the compiler might be able to skip putting the std::array on the stack, putting it in two registers instead. We'd need to see the emitted assembly to know for sure. Personally, since this runs super rarely, I don't care too much either way.

[Tilka]

Added a comment.