mirror of https://github.com/bsnes-emu/bsnes.git
d621136d69
byuu says:
Changelog:
- higan/emulator: added new Random class with three entropy settings:
none, low, and high
- md/vdp: corrected Vcounter readout in interlace mode [MoD]
- sfc: updated core to use the new Random class; defaults to high
entropy
No entropy essentially returns 0, unless the random.bias(n) function is
called, in which case, it returns n. In this case, n is meant to be the
"logical/ideal" default value that maximizes compatibility with games.
Low entropy is a very simple entropy modeled after RAM initialization
striping patterns (eg 32 0x00s, followed by 32 0xFFs, repeating
throughout.) It doesn't "glitch" like real hardware does on rare
occasions (parts of the pattern being broken from time to time.) It also
only really returns 0 or ~0. So the entropy is indeed extremely low, and
not very useful at all for detecting bugs. Over time, we can try to
improve this, of course.
High entropy is PCG. This replaces the older, lower-entropy and more
predictable, LFSR. PCG should be more than enough for emulator
randomness, while still being quite fast.
Unfortunately, the bad news ... both no entropy and low entropy fix the
Konami logo popping sound in Prince of Persia, but all three entropy
settings still cause the distortion in-game, especially evident at the
title screen. So ... this may be a more serious bug than first
suspected.
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| .. | ||
| background.cpp | ||
| dma.cpp | ||
| io.cpp | ||
| memory.cpp | ||
| render.cpp | ||
| serialization.cpp | ||
| sprite.cpp | ||
| vdp.cpp | ||
| vdp.hpp | ||