- Master of MS Paint.
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- Posts: 144
- Joined: 01-July 10
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- Location:Tomball, TEXAS
- Project:Sonic 2 beta 3 hoax, SONIC X ABRIDGED BITCH!!!
- Wiki edits:46
08
Have you ever been working on a hack in Sonic 1 and realized you don't have enough VRAM to load more art? I know I have, and the idea of not having enough room is quite annoying. Well no more, because with this tutorial,you nice folks will now have 31 free 8x8 blocks of VRAM.
As a side note, this tutorial is written specifically with the 2005 disassembly in mind. I'm assuming that this tutorial is simple enough to port to the HG disassembly, but as I have little time to actually do it myself, or mental enough to try to waddle my way around the damn thing, port to your own risk. Also, this code should work in all of the Sonic 128 disassemblies as well, in fact this code was written is said disassembly.
Enjoy
Step One: Adding the DMA Queue
If you haven't added this piece of code and it's fixes into your disassembly, go ahead and add it. You may have it already if you've added in the Spin Dash from this tutorial. If that is the case, go down to Step two.
Look for "PalCycle_SS" and add this piece of code right before it. This will speed things up for later.
Once you've finished, go to "loc_CD4", "loc_DAE", "loc_EEE", and loc_FAE"
Replace this piece of code.
With this.
Next, go to "Level_ClrVars3". After this piece of code
Add this
Next, go to "loc_47D4". After
Add
The last fix will be fixing the Sonic Object.
Go to "LoadSonicDynPLC". Replace this.
With this.
At this point, your ROM should be safe to build, so go ahead and build. Go play a level and see if Sonic appears on screen. If so, that means you did good and you deserve a cookie.
Step Two: Separating the Shield and Invincibility objects
This step is probably the most difficult step, but once it is outta the way, it'll make things easier.
First, go to Object 38, you should see this.
Delete the whole object. In it's place put this in.
This object is now just the shield object. Now, let's go add in the invincibility object.
Find Obj4A, you should see this.
Replace the whole object with this.
This completes the object replacement portion of the tutorial, let's move on. If you tried to build at this point, you'll notice it won't as there is a few errors. This next step will remedy that.
Step Three: Adding and fixing the Art
This step is the second most easiest step of this tutorial. First, you need to download these two files and save them into the "artunc" folder.
Uncompressed Invicibility Stars Art
Uncompressed Shield Art
(btw, click on the names, they are hyperlinks straight to the art downloads.)
Now, assuming you've already placed the art into the correct folder, go ahead and replace that with this.
Now your objects will load the art. But before you go off and build, go open your "Pattern Load Cues.asm" file. You'll need to fix just one portion of the cues.
Go to "PLC_Main2", and you should see this.
Replace it with this.
This should fix all the art issues. Now, for those wondering why I'm making you load uncompressed art as opposed to Nemesis compressed art, a simple explanation shall be given.
1. The DMA queue can not load Nemesis compressed art.
2. Even if it could, you still need to remove the art from the PLC. The reason is that now your art between Invincibility and Shield now shares the same VRAM location, and will simply overwrite each other when the one of the objects is in use.
Now, there is one last step to finish, and that is....
Step Four: Object loading from the Monitors
For those who have noticed, the shield and Invincibility objects are now separate objects. As such, the way that the monitor loads said objects must also be updated. Luckily for us, since only the Invincibility object is the only one that changed, this last step will be the easiest step of all.
Go to "Obj2E_ChkInvinc". Replace this.
With this
Once you have finished, save and build. If you've done everything correctly, your ROM will build.
Special Thanks to Shockwave for double checking and testing this code.
A thanks to shobiz, who already had the first part already done in a different tutorial. Nevertheless, saved me a bunch of time.
As a side note, this tutorial is written specifically with the 2005 disassembly in mind. I'm assuming that this tutorial is simple enough to port to the HG disassembly, but as I have little time to actually do it myself, or mental enough to try to waddle my way around the damn thing, port to your own risk. Also, this code should work in all of the Sonic 128 disassemblies as well, in fact this code was written is said disassembly.
Enjoy
Step One: Adding the DMA Queue
If you haven't added this piece of code and it's fixes into your disassembly, go ahead and add it. You may have it already if you've added in the Spin Dash from this tutorial. If that is the case, go down to Step two.
Look for "PalCycle_SS" and add this piece of code right before it. This will speed things up for later.
; --------------------------------------------------------------------------- ; Subroutine for queueing VDP commands (seems to only queue transfers to VRAM), ; to be issued the next time ProcessDMAQueue is called. ; Can be called a maximum of 18 times before the buffer needs to be cleared ; by issuing the commands (this subroutine DOES check for overflow) ; --------------------------------------------------------------------------- ; In case you wish to use this queue system outside of the spin dash, this is the ; registers in which it expects data in: ; d1.l: Address to data (In 68k address space) ; d2.w: Destination in VRAM ; d3.w: Length of data ; --------------------------------------------------------------------------- ; ||||||||||||||| S U B R O U T I N E ||||||||||||||||||||||||||||||||||||||| ; sub_144E: DMA_68KtoVRAM: QueueCopyToVRAM: QueueVDPCommand: Add_To_DMA_Queue: QueueDMATransfer: movea.l ($FFFFC8FC).w,a1 cmpa.w #$C8FC,a1 beq.s QueueDMATransfer_Done ; return if there's no more room in the buffer ; piece together some VDP commands and store them for later... move.w #$9300,d0 ; command to specify DMA transfer length & $00FF move.b d3,d0 move.w d0,(a1)+ ; store command move.w #$9400,d0 ; command to specify DMA transfer length & $FF00 lsr.w #8,d3 move.b d3,d0 move.w d0,(a1)+ ; store command move.w #$9500,d0 ; command to specify source address & $0001FE lsr.l #1,d1 move.b d1,d0 move.w d0,(a1)+ ; store command move.w #$9600,d0 ; command to specify source address & $01FE00 lsr.l #8,d1 move.b d1,d0 move.w d0,(a1)+ ; store command move.w #$9700,d0 ; command to specify source address & $FE0000 lsr.l #8,d1 move.b d1,d0 move.w d0,(a1)+ ; store command andi.l #$FFFF,d2 ; command to specify destination address and begin DMA lsl.l #2,d2 lsr.w #2,d2 swap d2 ori.l #$40000080,d2 ; set bits to specify VRAM transfer move.l d2,(a1)+ ; store command move.l a1,($FFFFC8FC).w ; set the next free slot address cmpa.w #$C8FC,a1 beq.s QueueDMATransfer_Done ; return if there's no more room in the buffer move.w #0,(a1) ; put a stop token at the end of the used part of the buffer ; return_14AA: QueueDMATransfer_Done: rts ; End of function QueueDMATransfer ; --------------------------------------------------------------------------- ; Subroutine for issuing all VDP commands that were queued ; (by earlier calls to QueueDMATransfer) ; Resets the queue when it's done ; --------------------------------------------------------------------------- ; ||||||||||||||| S U B R O U T I N E ||||||||||||||||||||||||||||||||||||||| ; sub_14AC: CopyToVRAM: IssueVDPCommands: Process_DMA: Process_DMA_Queue: ProcessDMAQueue: lea ($C00004).l,a5 lea ($FFFFC800).w,a1 ; loc_14B6: ProcessDMAQueue_Loop: move.w (a1)+,d0 beq.s ProcessDMAQueue_Done ; branch if we reached a stop token ; issue a set of VDP commands... move.w d0,(a5) ; transfer length move.w (a1)+,(a5) ; transfer length move.w (a1)+,(a5) ; source address move.w (a1)+,(a5) ; source address move.w (a1)+,(a5) ; source address move.w (a1)+,(a5) ; destination move.w (a1)+,(a5) ; destination cmpa.w #$C8FC,a1 bne.s ProcessDMAQueue_Loop ; loop if we haven't reached the end of the buffer ; loc_14CE: ProcessDMAQueue_Done: move.w #0,($FFFFC800).w move.l #$FFFFC800,($FFFFC8FC).w rts ; End of function ProcessDMAQueue
Once you've finished, go to "loc_CD4", "loc_DAE", "loc_EEE", and loc_FAE"
Replace this piece of code.
tst.b ($FFFFF767).w beq.s loc_D50 lea ($C00004).l,a5 move.l #$94019370,(a5) move.l #$96E49500,(a5) move.w #$977F,(a5) move.w #$7000,(a5) move.w #$83,($FFFFF640).w move.w ($FFFFF640).w,(a5) move.b #0,($FFFFF767).w
With this.
jsr (ProcessDMAQueue).l
Next, go to "Level_ClrVars3". After this piece of code
move.w #$8ADF,($FFFFF624).w move.w ($FFFFF624).w,(a6)
Add this
clr.w ($FFFFC800).w move.l #$FFFFC800,($FFFFC8FC).w
Next, go to "loc_47D4". After
jsr Hud_Base
Add
clr.w ($FFFFC800).w
move.l #$FFFFC800,($FFFFC8FC).w
The last fix will be fixing the Sonic Object.
Go to "LoadSonicDynPLC". Replace this.
​ moveq #0,d0 move.b $1A(a0),d0 ; load frame number cmp.b ($FFFFF766).w,d0 beq.s locret_13C96 move.b d0,($FFFFF766).w lea (SonicDynPLC).l,a2 add.w d0,d0 adda.w (a2,d0.w),a2 moveq #0,d1 move.b (a2)+,d1 ; read "number of entries" value subq.b #1,d1 bmi.s locret_13C96 lea ($FFFFC800).w,a3 move.b #1,($FFFFF767).w SPLC_ReadEntry: moveq #0,d2 move.b (a2)+,d2 move.w d2,d0 lsr.b #4,d0 lsl.w #8,d2 move.b (a2)+,d2 lsl.w #5,d2 lea (Art_Sonic).l,a1 adda.l d2,a1 SPLC_LoadTile: movem.l (a1)+,d2-d6/a4-a6 movem.l d2-d6/a4-a6,(a3) lea $20(a3),a3 ; next tile dbf d0,SPLC_LoadTile ; repeat for number of tiles dbf d1,SPLC_ReadEntry ; repeat for number of entries locret_13C96: rts
With this.
moveq #0,d0 move.b $1A(a0),d0 ; load frame number cmp.b ($FFFFF766).w,d0 beq.s locret_13C96 move.b d0,($FFFFF766).w lea (SonicDynPLC).l,a2 add.w d0,d0 adda.w (a2,d0.w),a2 moveq #0,d5 move.b (a2)+,d5 subq.w #1,d5 bmi.s locret_13C96 move.w #$F000,d4 move.l #Art_Sonic,d6 SPLC_ReadEntry: moveq #0,d1 move.b (a2)+,d1 lsl.w #8,d1 move.b (a2)+,d1 move.w d1,d3 lsr.w #8,d3 andi.w #$F0,d3 addi.w #$10,d3 andi.w #$FFF,d1 lsl.l #5,d1 add.l d6,d1 move.w d4,d2 add.w d3,d4 add.w d3,d4 jsr (QueueDMATransfer).l dbf d5,SPLC_ReadEntry ; repeat for number of entries locret_13C96: rts
At this point, your ROM should be safe to build, so go ahead and build. Go play a level and see if Sonic appears on screen. If so, that means you did good and you deserve a cookie.
Step Two: Separating the Shield and Invincibility objects
This step is probably the most difficult step, but once it is outta the way, it'll make things easier.
First, go to Object 38, you should see this.
Obj38: moveq #0,d0 move.b $24(a0),d0 move.w Obj38_Index(pc,d0.w),d1 jmp Obj38_Index(pc,d1.w) ; =========================================================================== ; More more code.
Delete the whole object. In it's place put this in.
Obj38: ; XREF: Obj_Index move.l #UnC_Shield,d1 ; Call for Regular Shield Art move.w #$A820,d2 ; Load Art from this location (VRAM location*20) ; In this case, VRAM = $541*20 move.w #$200,d3 jsr (QueueDMATransfer).l ; --------------------------------------------------------------------------- ShieldObj_Main: moveq #0,d0 move.b $24(a0),d0 move.w Shield_Index(pc,d0.w),d1 jmp Shield_Index(pc,d1.w) ; =========================================================================== Shield_Index: dc.w Shield_Init-Shield_Index dc.w ShieldChecks-Shield_Index ; =========================================================================== Shield_Init: addq.b #2,$24(a0) move.l #Map_Obj38, $0004(A0) ; Load Shield Map into place move.b #4,1(a0) move.b #1,$18(a0) move.b #$18,$19(a0) move.w #$541,2(a0) ; Set VRAM location btst #7,($FFFFD002).w beq.s ShieldChecks bset #7,2(a0) ; --------------------------------------------------------------------------- ShieldChecks: tst.b ($FFFFFE2D).w ; Test if Sonic has a shield bne.s SonicHasShield ; If so, branch to do nothing tst.b ($FFFFFE2C).w ; Test if Sonic got invisibility beq.s jmp_DeleteObj38 ; If so, delete object temporarily ShieldProperties: move.w ($FFFFD008).w,8(a0) ; Load Main Character X-position move.w ($FFFFD00C).w,$C(a0) ; Load Main Character Y-position move.b ($FFFFD022).w,$22(a0) ; Something about Character status lea (Ani_obj38).l, a1 ; Load Animation Scripts into a1 jsr AnimateSprite jmp DisplaySprite SonicHasShield: rts jmp_DeleteObj38: ; loc_12648: jmp DeleteObject
This object is now just the shield object. Now, let's go add in the invincibility object.
Find Obj4A, you should see this.
; --------------------------------------------------------------------------- ; Object 4A - special stage entry from beta ; --------------------------------------------------------------------------- Obj4A: ; XREF: Obj_Index moveq #0,d0 move.b $24(a0),d0 move.w Obj4A_Index(pc,d0.w),d1 jmp Obj4A_Index(pc,d1.w) ; More code after this
Replace the whole object with this.
; --------------------------------------------------------------------------- ; Object 4A - New Invincibility Object ; --------------------------------------------------------------------------- Obj4A: ; XREF: Obj_Index move.l #UnC_Stars,d1 move.w #$A820,d2 move.w #$200,d3 jsr (QueueDMATransfer).l Invincibility_Main: moveq #0,d0 move.b $24(a0),d0 Invincibility_Init: addq.b #2,$24(a0) move.l #Map_obj38,4(a0) ; loads mapping move.b #4,1(a0) move.b #1,$18(a0) move.b #$10,$19(a0) move.w #$541,2(a0) ; shield specific code ; =========================================================================== Obj4A_Stars: ; XREF: Obj38_Index tst.b ($FFFFFE2D).w ; does Sonic have invincibility? beq.s Obj4A_Delete2 ; if not, branch move.w ($FFFFF7A8).w,d0 move.b $1C(a0),d1 subq.b #1,d1 bra.s Obj4A_StarTrail ; =========================================================================== lsl.b #4,d1 addq.b #4,d1 sub.b d1,d0 move.b $30(a0),d1 sub.b d1,d0 addq.b #4,d1 andi.b #$F,d1 move.b d1,$30(a0) bra.s Obj4A_StarTrail2a ; =========================================================================== Obj4A_StarTrail: ; XREF: Obj4A_Stars lsl.b #3,d1 move.b d1,d2 add.b d1,d1 add.b d2,d1 addq.b #4,d1 sub.b d1,d0 move.b $30(a0),d1 sub.b d1,d0 addq.b #4,d1 cmpi.b #$18,d1 bcs.s Obj4A_StarTrail2 moveq #0,d1 Obj4A_StarTrail2: move.b d1,$30(a0) Obj4A_StarTrail2a: lea ($FFFFCB00).w,a1 lea (a1,d0.w),a1 move.w (a1)+,8(a0) move.w (a1)+,$C(a0) move.b ($FFFFD022).w,$22(a0) lea (Ani_obj38).l,a1 jsr (AnimateSprite).l jmp (DisplaySprite).l ; =========================================================================== Obj4A_Delete2: ; XREF: Obj4A_Stars jmp (DeleteObject).l
This completes the object replacement portion of the tutorial, let's move on. If you tried to build at this point, you'll notice it won't as there is a few errors. This next step will remedy that.
Step Three: Adding and fixing the Art
This step is the second most easiest step of this tutorial. First, you need to download these two files and save them into the "artunc" folder.
Uncompressed Invicibility Stars Art
Uncompressed Shield Art
(btw, click on the names, they are hyperlinks straight to the art downloads.)
Once that has been taken care of, go to "nem_Shield". You should see this. Nem_Shield: binclude artnem/shield.bin ; shield align 2 Nem_Stars: binclude artnem/invstars.bin ; invincibility stars align 2
Now, assuming you've already placed the art into the correct folder, go ahead and replace that with this.
UnC_Shield: binclude artunc/shield.bin align 2 UnC_Stars: binclude artunc/stars.bin ; invincibility stars align 2
Now your objects will load the art. But before you go off and build, go open your "Pattern Load Cues.asm" file. You'll need to fix just one portion of the cues.
Go to "PLC_Main2", and you should see this.
PLC_Main2: dc.w 2 dc.l Nem_Monitors ; monitors dc.w $D000 dc.l Nem_Shield ; shield dc.w $A820 dc.l Nem_Stars ; invincibility stars dc.w $AB80
Replace it with this.
PLC_Main2: dc.w 0 dc.l Nem_Monitors ; monitors dc.w $D000
This should fix all the art issues. Now, for those wondering why I'm making you load uncompressed art as opposed to Nemesis compressed art, a simple explanation shall be given.
1. The DMA queue can not load Nemesis compressed art.
2. Even if it could, you still need to remove the art from the PLC. The reason is that now your art between Invincibility and Shield now shares the same VRAM location, and will simply overwrite each other when the one of the objects is in use.
Now, there is one last step to finish, and that is....
Step Four: Object loading from the Monitors
For those who have noticed, the shield and Invincibility objects are now separate objects. As such, the way that the monitor loads said objects must also be updated. Luckily for us, since only the Invincibility object is the only one that changed, this last step will be the easiest step of all.
Go to "Obj2E_ChkInvinc". Replace this.
Obj2E_ChkInvinc: cmpi.b #5,d0 ; does monitor contain invincibility? bne.s Obj2E_ChkRings tst.b ($FFFFFE19).w bne.s Obj2E_NoMusic move.b #1,($FFFFFE2D).w ; make Sonic invincible move.w #$4B0,($FFFFD032).w ; time limit for the power-up move.b #$38,($FFFFD200).w ; load stars object ($3801) move.b #1,($FFFFD21C).w move.b #$38,($FFFFD240).w ; load stars object ($3802) move.b #2,($FFFFD25C).w move.b #$38,($FFFFD280).w ; load stars object ($3803) move.b #3,($FFFFD29C).w move.b #$38,($FFFFD2C0).w ; load stars object ($3804) move.b #4,($FFFFD2DC).w tst.b ($FFFFF7AA).w ; is boss mode on? bne.s Obj2E_NoMusic ; if yes, branch move.w #$87,d0 jmp (PlaySound).l ; play invincibility music
With this
Obj2E_ChkInvinc: cmpi.b #5,d0 ; does monitor contain invincibility? bne.s Obj2E_ChkRings move.b #1,($FFFFFE2D).w ; Set Invisibility to 1 move.w #$4B0,($FFFFD032).w ; Set Invisibility timer to 4B0 move.b #$4A,($FFFFD200).w ; load stars object ($3801) move.b #1,($FFFFD21C).w move.b #$4A,($FFFFD240).w ; load stars object ($3802) move.b #2,($FFFFD25C).w move.b #$4A,($FFFFD280).w ; load stars object ($3803) move.b #3,($FFFFD29C).w move.b #$4A,($FFFFD2C0).w ; load stars object ($3804) move.b #4,($FFFFD2DC).w tst.b ($FFFFF7AA).w ; is boss mode on? bne.s DontPlayMusic ; If so, don't play music cmpi.w #$C,($FFFFFE14).w ; Check if Sonic has air left bls.s DontPlayMusic ; If so, don't play music move.w #$87,d0 ; Load Invisibility music jmp (PlaySound).l DontPlayMusic: rts
Once you have finished, save and build. If you've done everything correctly, your ROM will build.
Special Thanks to Shockwave for double checking and testing this code.
A thanks to shobiz, who already had the first part already done in a different tutorial. Nevertheless, saved me a bunch of time.
