Track Music SpeedUp on Final Lap [Melg, MrBean, CLF78]

Code:

First ASM: Check if the conditions (lap, timer, flag) are met and then executes the speedup

#inject(0x8070B2b8)\n\n (PAL)

#inject(0x80704914)\n\n (NTSC-U)

#inject(0x8070a924)\n\n (NTSC-J)

#inject(0x806f9660)\n\n (NTSC-K)



.set region, 'P'

.if (region == 'P' || region == 'p') # RMCP



.set RACEINFO, 0x809BD730

.set RACEDATA, 0x809bd728

.set SOUNDDATA, 0x809C2898

.set SubtractTimers, 0x807ee860



.elseif (region == 'E' || region == 'e') # RMCE

.set RACEDATA, 0x809B8F68

.set SubtractTimers, 0x808423FC



.elseif (region == 'J' || region == 'j') # RMCJ

.set RACEDATA, 0x809BC788

.set SubtractTimers, 0x807EDECC



.elseif (region == 'K' || region == 'k') # RMCk

.set RACEDATA, 0x809abd68

.set SubtractTimers, 0x807DCC20



.else # Invalid Region

.abort

.endif



#r3 = RaceInfoPlayer[LocalPlayer0], r5 = RACEINFO, r29 = PlayerHolder->PlayerArray[LocalPlayer0 ID]->PlayerPointers->Field 0x1C, r31 = MaxLap of LocalPlayer0



#cr1 = CR bit used later in the function to swap (or not) to the _F version of the brstm



cmpwi cr1, r31, 1    #Check if currentLap>1 (if it's first lap then no laps have been stored in RaceInfo)

beq- cr1, end



lis r4, RACEDATA@ha

lwz r4, RACEDATA@l (r4)

lbz r4, 0xb8d (r4) #LapCount

cmplw cr1, r4, r31 #If MaxLap = LapCount, we are on final lap

bne+ cr1, end



lwz r4, 0x14 (r5)  #RaceInfo->TimerManager

addi r4, r4, 0x4   #Align with the minutes



lwz r3, 0x3C (r3)  #RaceInfoPlayer[Me]->lapFinishTimes Array

subi r5, r31, 2    #First position of that array gets stored on the transition from lap 1 to 2 (ie MaxLap = 2=

mulli r5, r5, 0xC  #Each array element is 0xC long



add r5, r3, r5     #Get the correct array element depending on the lap



subi r3, sp, 10    #Buffer for the function



lis r12, SubtractTimers@h      #Calculates the time elapsed since the player last crossed the line

ori r12, r12, SubtractTimers@l

mtctr r12

bctrl



subi r3, sp, 10

lhz r4, 0x4 (r3)  #Minutes elapsed

cmpwi cr1, r4, 0  #End if 1m or more

bgt- cr1, end



lbz r4, 0x6 (r3)  #Seconds elapsed

cmpwi cr1, r4, 5  #Only execute the speedup for the first 5s

bgt+ cr1, end







lwz r3, 0x5C (r29) #0x809C2898 -> Field 0x5BC which gets stored when PlayerHolder gets constructed on loading.

lwz r3, 0x34 (r3) 

lwz r3, 0x4 (r3)



lbz r4, -0x72 (r3) #SpeedupFlag, initially byte 0x3E of the BRSTM

cmpwi cr1, r4, 1   #If it's 1, skip the speedup

beq- cr1, end

lwz r4, -0xB4 (r3)

addi r4, r4, 0x68D #Additive speedup

stw r4, -0xB4 (r3)



end:

lbz r0, 0xDB (r29) #Default



------------------------------------------------------------------------------------

Followed a few instructions later by beq- cr1, 0x2c (the 04 in the code). The game has already checked that we are on a lap transition. If the branch is taken, then normal behaviour will occur.

Code:

Second ASM: in the same function as the first ASM. 



#inject(0x8070b2e4)\n\n (PAL)

#inject(0x80704940)\n\n (NTSC-U)

#inject(0x8070A950)\n\n (NTSC-J)

#inject(0x806F968C)\n\n (NTSC-K)



#Changes the BRSAR sound ID arg that the game will use for the lap jingle. Before this ASM, there is a "compare current lap with lap count", hence the bne+

li r4, 0xda  #If on final lap, play the normal lap jingle

bne+ end

li r4, 0x74  #Else, play the normal lap jingle

end:

Code:

Third ASM: Keeps the volume part from MrBean's initial code, and now also load and store byte 0x3E

#inject(0x800a5350)\n\n (PAL)

#inject(0x800a52B0)\n\n (NTSC-U)

#inject(0x800a5270)\n\n (NTSC-J)

#inject(0x800a53B0)\n\n (NTSC-K)



#The game has already checked that it has correctly loaded the BRSTM Header.



#r29 points to the BRSTM header

lwz r3, 0x74(sp)            #Pointer to a structure where a bunch of music related settings are stored, including volume and speed

lbz r0, 0x3F(r29)           #Get the volume byte



cmpwi r0, 0                 #If the byte hasn't been changed, return

beq+ end



stw r0, 0x44(r29)           #Store values in the stack, free space as BRSTM headers are only 0x40 bytes

li r0, 0x7F

stw r0, 0x48(r29)



psq_l f1, 0x44(r29), 0, 4  #Reload floats using paired singles

ps_merge11 f2, f1, f1      #Move f1 ps1 to f2

fdivs f1, f1, f2

stfs f1, -0x5C(r3)





end:

lwz r3, 0(r30)             #Original instruction default

lbz r0, 0x3E (r29)

stb r0, -0x72 (r3)

lwz r3, 0 (r30)       #Default