Sonic gems collection sound effect update#
Sonic gems collection sound effect code#

It breaks because it overwrites a0, which was also used for the object slot pointer. There's another version that does that and exits the object, and this broken one is meant to set it and then return back to the object. The first sets a 'bookmark' that the object manager will jump to in future calls for that object.Title screen has 3 unused object functions that are broken.Even if there are some functions that should also be shared from one common file, they aren't, and this explains some of the weird minute differences between level files. While levels did use some commonly shared code, they did copy and paste other files for more specific things like scrolling, object lists, data, etc. The Gems Collection of the game has leftover symbol data that can give a glimpse into how files were structured.This explains why the Taxman version appears to take longer to do a time warp sometimes, even though it really isn't.

Sonic gems collection sound effect update#

The 'I'm outta here' and time warp timers are updated every V-BLANK, so even if the game is lagging, they update at a steady 50/60 Hz.They all point to the same function, but the command ID is used for another table for loading in the appropriate data. Each level gets their own Sub CPU command for loading it.A set for normal playback, and another for the sound test. Each music track gets their own Sub CPU command entry for playing it.The second channel's registers are set to corrupt data and actually does sound, but its volume is set to 0, so nothing is actually played back from it. It's possible that stereo audio was planned, but scrapped.

Sonic gems collection sound effect code#

Speaking of FMV PCM streaming, there's code for setting up a second channel.

Their setup turned out to be unnecessary anyways, but they probably didn't know that, since PCM playback address wrapping back to the start of wave RAM when going past the end isn't officially documented.

FMV PCM streaming code has an issue where it'll not write the last 8 bytes in a packet, due to the very last PCM bank having a loop flag set, and them lazily not wanting to overwrite it, resulting in playback quality degradation.

R11A uses direct addresses for player variables in LevelSizeLoad, and also takes out some leftover Sonic 1 code, while the other level files I've seen pass the player slot into a6 and retain said leftover Sonic 1 code.

Level demo files are built from a slightly older version of the level codebase.

Level 16x16 blocks are compressed in Nemesis, which is usually only meant for graphics compression, not metadata compression. Files for the Sub CPU code for the ending FMVs have the wrong filenames (GOODEND.BIN is for the bad ending, BADEND.BIN is for the good ending.Y'know what? I think I can make a thread out of this.