- Also known as RHS
-
- Posts: 983
- Joined: 31-January 05
- Gender:Male
- Location:United Kingdom
- Project:Sonic 2 Recreation
- Wiki edits:24
Hello, guys. I come forth with another two (maybe three) bug fixes! These bugs are present in Sonic 1 and Sonic 2, but has been fixed in Sonic 3 (and Knuckles).
There is a drowning bug. You know, you're underwater, timer starts, can't find air, you drown. But what happens if you get hurt as soon as you're about to drown? Well, this little video will demonstrate:
If you're hurt and you haven't landed yet, when you drown, Sonic will still be using the gravity from his falling back from hurt state. He will also be able to detect the floors and walls. Hence why in this video, I was able to move about after drowning. However, there is a timer present, and it will force you to the bottom of the screen and restart within seconds.
Also, in both Sonic 1 and 2, there is another bug, although, hard to pull off. If you drown around the 9:58 mark, then the timer hits 9:59 and you're still drowning, Sonic will all of a sudden zoom to the top of the screen then back down again, really fast, in his death animation. The Time over appears.
In Sonic 2, there is an extra bug. When you and Tails (sidekick) drowns (normally), when Sonic reaches to the bottom of the screen, if Tails hasn't yet, he will suddenly start flying and move closer to where you drowned, but will continue to fall downwards.
In Sonic 3 and Knuckles, all of these have been fixed. It doesn't matter if you're in the hurt state, Sonic will still fall normally and will ignore the floor. And unless Tails entered the water at the exact same time as you (like he does at the beginning of HCZ1), Tails will automatically start swimming to where you drowned but will not fall. If he did enter the water at the same time, he will drown with you, but won't have time to do that bug where he would start flying suddenly. Time over will still make an appearance if you drown near the 9:58 mark, but Sonic won't misbehave.
Today, I'm going to show you how to fix these bugs in Sonic 1 and Sonic 2, the way Sonic 3 and Knuckles did it. It's not that hard, I've done all the research for you.
I will show you Sonic 1 SVN, and for Sonic 2, both Xenowhirls 2007 and SVN disassembly.
Sonic 1 fix - SVN Disassembly
First, we need to make little edit to the drowning-routine. You need to open the "0A - Drowning Countdown.asm".
Go to "@reduceair:" and just after the "move.w #0,obInertia(a0)" command, insert this:
And just after "move.b #1,(f_nobgscroll).w", insert this:
So you have this:
Next, go to "@loc_13F86:" and change all this:
To this:
Right, that's the drowning-routine finished. Now, we need to make Sonic apply to this.
Now, open the main ASM file. Go to "Sonic_Index:" and add this line at the end of the table:
So you have:
Next, find "include "_incObj\Sonic Loops.asm"" and just below it, insert this:
Then, in the "_incObj" folder, make a new ASM file called "Sonic Drowns.asm" and insert this:
There, all done. When you drown, everything will be normal. If you got hurt then drown, everything will still be normal and you won't be able to hit the floor, nor will you fall fast. Also, as soon as Sonic drowns, the timer will stop immediately, rather than continuing to countdown. Because of this, there is no way you can get Time Over when drowning.
Sonic 2 fix - XenoWhirl's Disassembly
First, we need to make little edit to the drowning-routine. Go to "Obj0A_ReduceAir:" and just after the "move.w #0,inertia(a0)" command, insert this:
And just after "move.b #1,($FFFFEEDC).w", insert this:
So you have this:
Next, go to "loc_1D708:" and change all this:
To this:
Right, that's the drowning-routine finished. Now, we need to make the characters apply to this.
Sonic. Go to "Obj01_States:" and add this line at the end of the table:
So you have:
Next, go to "Sonic_Animate:" and just above it, insert this:
That's Sonic done. Tails is next. Go to "Obj02_States:" and again, insert this line at the end of the table:
So you have:
Next, go to "Tails_Animate:" and just above it, insert this:
There, all done. When you drown, everything will be normal. If you got hurt then drown, everything will still be normal and you won't be able to hit the floor, nor will you fall fast. If Tails is with you, he will fly out of the water as soon as you drown. Unless he entered the water at the exact same time as you; then he will drown with you, but won't have time to suddenly fly again.
Now, as soon as Sonic drowns, the timer will stop immediately, rather than continuing to countdown. Because of this, there is no way you can get Time Over when drowning.
Sonic 2 fix - SVN Disassembly
First, we need to make little edit to the drowning-routine. Go to "Obj0A_ReduceAir:" and just after the "move.w #0,inertia(a0)" command, insert this:
And just after "move.b #1,(Deform_lock).w", insert this:
So you have this:
Next, go to "loc_1D708:" and change all this:
To this:
Right, that's the drowning-routine finished. Now, we need to make the characters apply to this.
Sonic. Go to "Obj01_Index:" and add this line at the end of the table:
So you have:
Next, go to "Sonic_Animate:" and just above it, insert this:
That's Sonic done. Tails is next. Go to "Obj02_Index:" and again, insert this line at the end of the table:
So you have:
Next, go to "Tails_Animate:" and just above it, insert this:
There, all done. When you drown, everything will be normal. If you got hurt then drown, everything will still be normal and you won't be able to hit the floor, nor will you fall fast. If Tails is with you, he will fly out of the water as soon as you drown. Unless he entered the water at the exact same time as you; then he will drown with you, but won't have time to suddenly fly again.
Now, as soon as Sonic drowns, the timer will stop immediately, rather than continuing to countdown. Because of this, there is no way you can get Time Over when drowning.
There you have it! All fixed! Enjoy!
There is a drowning bug. You know, you're underwater, timer starts, can't find air, you drown. But what happens if you get hurt as soon as you're about to drown? Well, this little video will demonstrate:
If you're hurt and you haven't landed yet, when you drown, Sonic will still be using the gravity from his falling back from hurt state. He will also be able to detect the floors and walls. Hence why in this video, I was able to move about after drowning. However, there is a timer present, and it will force you to the bottom of the screen and restart within seconds.
Also, in both Sonic 1 and 2, there is another bug, although, hard to pull off. If you drown around the 9:58 mark, then the timer hits 9:59 and you're still drowning, Sonic will all of a sudden zoom to the top of the screen then back down again, really fast, in his death animation. The Time over appears.
In Sonic 2, there is an extra bug. When you and Tails (sidekick) drowns (normally), when Sonic reaches to the bottom of the screen, if Tails hasn't yet, he will suddenly start flying and move closer to where you drowned, but will continue to fall downwards.
In Sonic 3 and Knuckles, all of these have been fixed. It doesn't matter if you're in the hurt state, Sonic will still fall normally and will ignore the floor. And unless Tails entered the water at the exact same time as you (like he does at the beginning of HCZ1), Tails will automatically start swimming to where you drowned but will not fall. If he did enter the water at the same time, he will drown with you, but won't have time to do that bug where he would start flying suddenly. Time over will still make an appearance if you drown near the 9:58 mark, but Sonic won't misbehave.
Today, I'm going to show you how to fix these bugs in Sonic 1 and Sonic 2, the way Sonic 3 and Knuckles did it. It's not that hard, I've done all the research for you.
I will show you Sonic 1 SVN, and for Sonic 2, both Xenowhirls 2007 and SVN disassembly.
Sonic 1 fix - SVN Disassembly
First, we need to make little edit to the drowning-routine. You need to open the "0A - Drowning Countdown.asm".
Go to "@reduceair:" and just after the "move.w #0,obInertia(a0)" command, insert this:
move.b #$A,obRoutine(a0) ; Force the character to drown
And just after "move.b #1,(f_nobgscroll).w", insert this:
move.b #0,(f_timecount).w ; Stop the timer immediately
So you have this:
@reduceair: subq.w #1,(v_air).w ; subtract 1 from air remaining bcc.w @gotomakenum ; if air is above 0, branch ; Sonic drowns here bsr.w ResumeMusic move.b #$81,(f_lockmulti).w ; lock controls sfx sfx_Drown ; play drowning sound move.b #$A,$34(a0) move.w #1,$36(a0) move.w #$78,$2C(a0) move.l a0,-(sp) lea (v_player).w,a0 bsr.w Sonic_ResetOnFloor move.b #$17,obAnim(a0) ; use Sonic's drowning animation bset #1,obStatus(a0) bset #7,obGfx(a0) move.w #0,obVelY(a0) move.w #0,obVelX(a0) move.w #0,obInertia(a0) move.b #$A,obRoutine(a0) ; Force the character to drown move.b #1,(f_nobgscroll).w move.b #0,(f_timecount).w ; Stop the timer immediately movea.l (sp)+,a0 rts
Next, go to "@loc_13F86:" and change all this:
@loc_13F86: subq.w #1,$2C(a0) bne.s @loc_13F94 move.b #6,(v_player+obRoutine).w rts ; =========================================================================== @loc_13F94: move.l a0,-(sp) lea (v_player).w,a0 jsr SpeedToPos addi.w #$10,obVelY(a0) movea.l (sp)+,a0 bra.s @nochange
To this:
@loc_13F86: subq.w #1,$2C(a0) bne.s @nochange ; Make it jump straight to this location move.b #6,(v_player+obRoutine).w rts
Right, that's the drowning-routine finished. Now, we need to make Sonic apply to this.
Now, open the main ASM file. Go to "Sonic_Index:" and add this line at the end of the table:
dc.w Sonic_Drowned-Sonic_Index
So you have:
Sonic_Index: dc.w Sonic_Main-Sonic_Index dc.w Sonic_Control-Sonic_Index dc.w Sonic_Hurt-Sonic_Index dc.w Sonic_Death-Sonic_Index dc.w Sonic_ResetLevel-Sonic_Index dc.w Sonic_Drowned-Sonic_Index
Next, find "include "_incObj\Sonic Loops.asm"" and just below it, insert this:
include "_incObj\Sonic Drowns.asm"
Then, in the "_incObj" folder, make a new ASM file called "Sonic Drowns.asm" and insert this:
; --------------------------------------------------------------------------- ; Sonic when he's drowning ; --------------------------------------------------------------------------- ; ||||||||||||||| S U B R O U T I N E ||||||||||||||||||||||||||||||||||||||| Sonic_Drowned: bsr.w SpeedToPos ; Make Sonic able to move addi.w #$10,y_vel(a0) ; Apply gravity bsr.w Sonic_RecordPosition ; Record position bsr.s Sonic_Animate ; Animate Sonic bsr.w Sonic_LoadGfx ; Load Sonic's DPLCs bra.w DisplaySprite ; And finally, display Sonic
There, all done. When you drown, everything will be normal. If you got hurt then drown, everything will still be normal and you won't be able to hit the floor, nor will you fall fast. Also, as soon as Sonic drowns, the timer will stop immediately, rather than continuing to countdown. Because of this, there is no way you can get Time Over when drowning.
Sonic 2 fix - XenoWhirl's Disassembly
First, we need to make little edit to the drowning-routine. Go to "Obj0A_ReduceAir:" and just after the "move.w #0,inertia(a0)" command, insert this:
move.b #$C,routine(a0) ; Force the character to drown
And just after "move.b #1,($FFFFEEDC).w", insert this:
move.b #0,(Update_HUD_timer).w ; Stop the timer immediately
So you have this:
Obj0A_ReduceAir: subq.b #1,air_left(a2) ; subtract 1 from air remaining bcc.w BranchTo_Obj0A_MakeItem ; if air is above 0, branch move.b #$81,obj_control(a2) ; lock controls move.w #$32+$80,d0 jsr (PlaySound).l ; play drowning sound move.b #$A,objoff_34(a0) move.w #1,objoff_36(a0) move.w #$78,objoff_2C(a0) movea.l a2,a1 bsr.w ResumeMusic move.l a0,-(sp) movea.l a2,a0 bsr.w Sonic_ResetOnFloor_Part2 move.b #$17,anim(a0) ; use Sonic's drowning animation bset #1,status(a0) bset #7,art_tile(a0) move.w #0,y_vel(a0) move.w #0,x_vel(a0) move.w #0,inertia(a0) move.b #$C,routine(a0) ; Force the character to drown movea.l (sp)+,a0 ; load 0bj address ; restore a0 = obj0A cmpa.w #MainCharacter,a2 bne.s + ; if it isn't player 1, branch move.b #1,($FFFFEEDC).w move.b #0,(Update_HUD_timer).w ; Stop the timer immediately + rts
Next, go to "loc_1D708:" and change all this:
loc_1D708: subq.w #1,objoff_2C(a0) bne.s + move.b #6,routine(a2) rts ; --------------------------------------------------------------------------- + move.l a0,-(sp) movea.l a2,a0 jsr ObjectMove addi.w #$10,y_vel(a0) movea.l (sp)+,a0 ; load 0bj address bra.s loc_1D72C
To this:
loc_1D708: subq.w #1,objoff_2C(a0) bne.s loc_1D72C ; Make it jump straight to this location move.b #6,routine(a2) rts
Right, that's the drowning-routine finished. Now, we need to make the characters apply to this.
Sonic. Go to "Obj01_States:" and add this line at the end of the table:
dc.w Obj01_Drowned - Obj01_States ;$C
So you have:
Obj01_States: dc.w Obj01_Init - Obj01_States ; 0 dc.w Obj01_Control - Obj01_States ; 2 dc.w Obj01_Hurt - Obj01_States ; 4 dc.w Obj01_Dead - Obj01_States ; 6 dc.w Obj01_Gone - Obj01_States ; 8 dc.w Obj01_Respawning - Obj01_States ;$A dc.w Obj01_Drowned - Obj01_States ;$C
Next, go to "Sonic_Animate:" and just above it, insert this:
; --------------------------------------------------------------------------- ; Sonic when he's drowning ; --------------------------------------------------------------------------- Obj01_Drowned: bsr.w ObjectMove ; Make Sonic able to move addi.w #$10,y_vel(a0) ; Apply gravity bsr.w Sonic_RecordPos ; Record position bsr.w Sonic_Animate ; Animate Sonic bsr.w LoadSonicDynPLC ; Load Sonic's DPLCs bra.w DisplaySprite ; And finally, display Sonic
That's Sonic done. Tails is next. Go to "Obj02_States:" and again, insert this line at the end of the table:
dc.w Obj02_Drowned - Obj02_States ;$C
So you have:
Obj02_States: dc.w Obj02_Init - Obj02_States ; 0 dc.w Obj02_Control - Obj02_States ; 2 dc.w Obj02_Hurt - Obj02_States ; 4 dc.w Obj02_Dead - Obj02_States ; 6 dc.w Obj02_Gone - Obj02_States ; 8 dc.w Obj02_Respawning - Obj02_States ;$A dc.w Obj02_Drowned - Obj02_States ;$C
Next, go to "Tails_Animate:" and just above it, insert this:
; --------------------------------------------------------------------------- ; Tails when he's drowning ; --------------------------------------------------------------------------- Obj02_Drowned: bsr.w ObjectMove ; Make Tails able to move addi.w #$10,y_vel(a0) ; Apply gravity bsr.w Tails_RecordPos ; Record position bsr.s Tails_Animate ; Animate Tails bsr.w LoadTailsDynPLC ; Load Tails's DPLCs bra.w DisplaySprite ; And finally, display Tails
There, all done. When you drown, everything will be normal. If you got hurt then drown, everything will still be normal and you won't be able to hit the floor, nor will you fall fast. If Tails is with you, he will fly out of the water as soon as you drown. Unless he entered the water at the exact same time as you; then he will drown with you, but won't have time to suddenly fly again.
Now, as soon as Sonic drowns, the timer will stop immediately, rather than continuing to countdown. Because of this, there is no way you can get Time Over when drowning.
Sonic 2 fix - SVN Disassembly
First, we need to make little edit to the drowning-routine. Go to "Obj0A_ReduceAir:" and just after the "move.w #0,inertia(a0)" command, insert this:
move.b #$C,routine(a0) ; Force the character to drown
And just after "move.b #1,(Deform_lock).w", insert this:
move.b #0,(Update_HUD_timer).w ; Stop the timer immediately
So you have this:
Obj0A_ReduceAir: subq.b #1,air_left(a2) ; subtract 1 from air remaining bcc.w BranchTo_Obj0A_MakeItem ; if air is above 0, branch move.b #$81,obj_control(a2) ; lock controls move.w #SndID_Drown,d0 jsr (PlaySound).l ; play drowning sound move.b #$A,objoff_34(a0) move.w #1,objoff_36(a0) move.w #$78,objoff_2C(a0) movea.l a2,a1 bsr.w ResumeMusic move.l a0,-(sp) movea.l a2,a0 bsr.w Sonic_ResetOnFloor_Part2 move.b #$17,anim(a0) ; use Sonic's drowning animation bset #1,status(a0) bset #high_priority_bit,art_tile(a0) move.w #0,y_vel(a0) move.w #0,x_vel(a0) move.w #0,inertia(a0) move.b #$C,routine(a0) ; Force the character to drown movea.l (sp)+,a0 ; load 0bj address ; restore a0 = obj0A cmpa.w #MainCharacter,a2 bne.s + ; if it isn't player 1, branch move.b #1,(Deform_lock).w move.b #0,(Update_HUD_timer).w ; Stop the timer immediately + rts
Next, go to "loc_1D708:" and change all this:
loc_1D708: subq.w #1,objoff_2C(a0) bne.s + move.b #6,routine(a2) rts ; --------------------------------------------------------------------------- + move.l a0,-(sp) movea.l a2,a0 jsr (ObjectMove).l addi.w #$10,y_vel(a0) movea.l (sp)+,a0 ; load 0bj address bra.s loc_1D72C
To this:
loc_1D708: subq.w #1,objoff_2C(a0) bne.s loc_1D72C ; Make it jump straight to this location move.b #6,routine(a2) rts
Right, that's the drowning-routine finished. Now, we need to make the characters apply to this.
Sonic. Go to "Obj01_Index:" and add this line at the end of the table:
offsetTableEntry.w Obj01_Drowned ; $C
So you have:
Obj01_Index: offsetTable offsetTableEntry.w Obj01_Init ; 0 offsetTableEntry.w Obj01_Control ; 2 offsetTableEntry.w Obj01_Hurt ; 4 offsetTableEntry.w Obj01_Dead ; 6 offsetTableEntry.w Obj01_Gone ; 8 offsetTableEntry.w Obj01_Respawning ; $A offsetTableEntry.w Obj01_Drowned ; $C
Next, go to "Sonic_Animate:" and just above it, insert this:
; --------------------------------------------------------------------------- ; Sonic when he's drowning ; --------------------------------------------------------------------------- Obj01_Drowned: bsr.w ObjectMove ; Make Sonic able to move addi.w #$10,y_vel(a0) ; Apply gravity bsr.w Sonic_RecordPos ; Record position bsr.w Sonic_Animate ; Animate Sonic bsr.w LoadSonicDynPLC ; Load Sonic's DPLCs bra.w DisplaySprite ; And finally, display Sonic
That's Sonic done. Tails is next. Go to "Obj02_Index:" and again, insert this line at the end of the table:
offsetTableEntry.w Obj02_Drowned ; $C
So you have:
Obj02_Index: offsetTable offsetTableEntry.w Obj02_Init ; 0 offsetTableEntry.w Obj02_Control ; 2 offsetTableEntry.w Obj02_Hurt ; 4 offsetTableEntry.w Obj02_Dead ; 6 offsetTableEntry.w Obj02_Gone ; 8 offsetTableEntry.w Obj02_Respawning ; $A offsetTableEntry.w Obj02_Drowned ; $C
Next, go to "Tails_Animate:" and just above it, insert this:
; --------------------------------------------------------------------------- ; Tails when he's drowning ; --------------------------------------------------------------------------- Obj02_Drowned: bsr.w ObjectMove ; Make Tails able to move addi.w #$10,y_vel(a0) ; Apply gravity bsr.w Tails_RecordPos ; Record position bsr.s Tails_Animate ; Animate Tails bsr.w LoadTailsDynPLC ; Load Tails's DPLCs bra.w DisplaySprite ; And finally, display Tails
There, all done. When you drown, everything will be normal. If you got hurt then drown, everything will still be normal and you won't be able to hit the floor, nor will you fall fast. If Tails is with you, he will fly out of the water as soon as you drown. Unless he entered the water at the exact same time as you; then he will drown with you, but won't have time to suddenly fly again.
Now, as soon as Sonic drowns, the timer will stop immediately, rather than continuing to countdown. Because of this, there is no way you can get Time Over when drowning.
There you have it! All fixed! Enjoy!
