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sooooo there was always a thing with sonic 1 objects that really bothered me a lot like doing this
what this does is calculate where objects are located in object ram and limits it to $7F slots (that being the amount of object ram slots available for sonic 1)
this is used to get child objects adresses in object ram and to do whatever with it
by doing this bit later in code
what this does is get the byte stored basically a slot ID in object ram stored in the main object and then multyplies that by $40 (object ssts in sonic 1) whis can be a bit of pain to deal with if you had lets say $42 ssts (if you had followed a guide for s3k object manager witch there is way better ways to import it now days)
or to have $4A ssts if you wanted to do stuff s3k's way these codes in s1 would fail because calculating for $40 in those lsr,lsl lines
other people use mulu/muls but that takes a lot of proframnce so here is my code i optimized in s1 (warning does contain sonic 3 stuffs)
what this does insted is remove those lines and then makes a table for available words in the object and whever the game loops to spawn an object or loops to calculate an object adress to do (movement and stuffs) it goes to here Ob57ChildSSt that contains the words you stored object slot adresses you stored at the start of code and then when you need to use them to do stuff you just loop a2 and a2 gets the correct stored adresses for the object slots this method uses ssts space so every sprite is an sst used to store where the child object is located at in RAM this is faster than the orignal method although sst space shouldnt be a problem if you have $4A ssts because then you can store over $16 sprites in 1 table and thats the max amount of sprites ive seen sonic 1,2,3,k do with child objects and lines that are changed usually got replcaed by
and
what the first thing does is get ssts and the objects stored inside them in a1 and the second does is store child objects adresses in object ram in the ssts in Ob57ChildSSt thanks for reading 
Code:
move.w a1,d5
subi.w #$D000,d5
lsr.w #6,d5
andi.w #$7F,d5
move.b d5,(a2)+this is used to get child objects adresses in object ram and to do whatever with it
by doing this bit later in code
Code:
moveq #0,d4
move.b (a2)+,d4
lsl.w #6,d4
addi.l #v_objspace&$FFFFFF,d4
movea.l d4,a1or to have $4A ssts if you wanted to do stuff s3k's way these codes in s1 would fail because calculating for $40 in those lsr,lsl lines
other people use mulu/muls but that takes a lot of proframnce so here is my code i optimized in s1 (warning does contain sonic 3 stuffs)
Code:
Ob57ChildSSt:
dc.w St1Child3 ;0
dc.w St1Child6 ; 1
dc.w St1Child7 ; 2
dc.w St2Child1 ; 3
dc.w St2Child2 ;4
dc.w St2Child3;5
dc.w St2Child4;6
dc.w St2Child5;7 ; extra just incase
dc.w St2Child6;8 ; extra just incase
; ===========================================================================
; ---------------------------------------------------------------------------
; Object 57 - spiked balls (SYZ, LZ)
; ---------------------------------------------------------------------------
obj57IgnoreAdding:
rts
Obj57: ; XREF: Obj_Index
moveq #0,d0
move.b obRoutine(a0),d0
move.w Obj57_Index(pc,d0.w),d1
jsr Obj57_Index(pc,d1.w)
jmp Add_SpriteToCollisionResponseList
; ===========================================================================
Obj57_Index: dc.w Obj57_Main-Obj57_Index
dc.w Obj57_Move-Obj57_Index
dc.w Obj57_Display2-Obj57_Index
; ===========================================================================
;Ob57DevideBranch:
; sub.b d1,d0
; bra.s SetObj57Normally
Obj57_Main: ; XREF: Obj57_Index
addq.b #2,obRoutine(a0)
move.l #Map_obj57,obMap(a0)
addq.b #1,$28(a0)
move.b $28(a0),d1 ; get object type
andi.b #7,d1 ; read only second numbers
move.b d1,$29(a0)
move.b #4,obRender(a0)
move.w #$200,obpriority(a0)
move.b #8,obActWid(a0)
move.w obX(a0),$3A(a0)
move.w obY(a0),$38(a0)
move.b #$98,obColType(a0) ; SYZ specific code (chain hurts Sonic)
clr.b $1A(a0)
cmpi.b #1,($FFFFFE10).w ; check if level is LZ
bne.s loc_107E8
move.b #0,obColType(a0) ; LZ specific code (chain doesn't hurt)
move.w #$310,2(a0)
move.l #Map_obj57a,obMap(a0)
move.b #2,$1A(a0)
loc_107E8:
move.b $28(a0),d1 ; get object type
andi.b #$F0,d1 ; read only the 1st digit
ext.w d1
asl.w #3,d1 ; multiply by 8
move.w d1,$3E(a0) ; set object twirl speed
move.b $22(a0),d0
ror.b #2,d0
andi.b #-$40,d0
move.b d0,$26(a0)
lea Ob57ChildSSt(pc),a2
move.b $28(a0),d1 ; get object type
andi.w #7,d1 ; read only the 2nd digit
move.w d1,d3
lsl.w #4,d3
move.w d3,$3C(a0)
move.w $3C(a0),$32(a0)
moveq #0,d1
move.b $29(a0),d1
Obj57_MakeChain:
bsr.w SingleObjLoad
bne.s Ob57FailToMakeChildSprite
move.w (a2)+,d0
move.w a1,(a0,d0.w)
move.b #4,obRoutine(a1)
move.b 0(a0),0(a1)
move.l obMap(a0),obMap(a1)
move.w 2(a0),2(a1)
move.b obRender(a0),obRender(a1)
move.w obpriority(a0),obpriority(a1)
move.b obActWid(a0),obActWid(a1)
move.b obColType(a0),obColType(a1)
subi.w #$10,d3
move.w d3,$3C(a1)
; cmpi.b #1,($FFFFFE10).w
; bne.s loc_10890
; tst.b d3 ; is it the last obj ?
; bne.s loc_10890
; move.b #2,$1A(a1) ; turn its frame to 2
loc_10890:
dbf d1,Obj57_MakeChain ; repeat for length of chain
loc_10894:
; move.w (a2)+,d0
; move.w (a0,d0.w),a1
; move.w a0,a2
; cmpi.b #1,($FFFFFE10).w ; check if level is LZ
; bne.s Obj57_Move
; movea.w a1,a0
move.b #$8B,obColType(a1) ; if yes, make last spikeball larger
cmpi.b #1,($FFFFFE10).w
bne.s ChangeChainFrames
move.b #1,$1A(a1) ; use different frame
NormallinkSetting:
move.w $32(a0),d3
subi.w #$10,d3
move.w d3,$3C(a1)
clr.w $32(a0)
Ob57FailToMakeChildSprite:
rts
ChangeChainFrames:
move.b #0,$1A(a1)
bra.s NormallinkSetting
Obj57_Move: ; XREF: Obj57_Index
bsr.w Obj57_MoveSub
bra.w Obj57_ChkDel
; ===========================================================================
Obj57_MoveSub: ; XREF: Obj57_Move
move.w $3E(a0),d0
add.w d0,$26(a0)
move.b $26(a0),d0
jsr (CalcSine).l
move.w $38(a0),d2
move.w $3A(a0),d3
lea Ob57ChildSSt(pc),a2
moveq #0,d6
move.b $29(a0),d6
Obj57_MoveLoop:
move.w (a2)+,d4
move.w (a0,d4.w),a1
moveq #0,d4
move.w $3C(a1),d4
move.l d4,d5
muls.w d0,d4
asr.l #8,d4
muls.w d1,d5
asr.l #8,d5
add.w d2,d4
add.w d3,d5
move.w d4,obY(a1)
move.w d5,8(a1)
dbf d6,Obj57_MoveLoop
rts
; ===========================================================================
Obj57_ChkDel: ; XREF: Obj57_Move
move.w $3A(a0),d0
andi.w #$FF80,d0
move.w ($FFFFF700).w,d1
subi.w #$80,d1
andi.w #$FF80,d1
sub.w d1,d0
cmpi.w #$280,d0
bls.w Obj57_Display
move.w obRespawnNo(a0),d0 ; get address in respawn table
beq.s Obj57_Delete ; if it's zero, object was placed in debug mode
movea.w d0,a2 ; load address into a2
bclr #7,(a2) ; clear respawn entry, so object can be loaded again
; ===========================================================================
Obj57_Delete: ; XREF: Obj57_ChkDel
moveq #0,d2
move.b $29(a0),d2
lea Ob57ChildSSt(pc),a2
Obj57_DelLoop:
move.w (a2)+,d0
move.w (a0,d0.w),a1
bsr.w DeleteObject2
dbf d2,Obj57_DelLoop ; delete all pieces of chain
DeleteErred:
bsr.w DeleteObject ; delete main object
rts
; ===========================================================================
Obj57_Display2:
bra.w DisplaySprite
Obj57_Display: ; XREF: Obj57_Index
bsr.w DisplaySprite
jmp Add_SpriteToCollisionResponseList
Code:
move.w (a2)+,d0
move.w (a0,d0.w),a1
Code:
move.w (a2)+,d0
move.w a1,(a0,d0.w)
Last edited:
