Basic Questions & Answers thread

Okay this is a more complex one that is sort of an theory throughout all 3 games, but I wanna know if it's possible to turn off the animation reset when landing on the ground or on an object.

Like when you land on something it reverts to standing or running, and even on something you bounce off it just converts your animation (eg. when you bounce off a breakable rock, it doesn't continue the rolling animation, it just commands it again so it looks like the loop is continuing, turn that off as it defaults to walking animation).

I wanna know if there's something that can turn that off and let an in-air animation continue until it's finished even when you land.

 

You'd have to change how it handles setting the animation and resetting it in (Player)_Move, (Player)_Move(Direction), ResetOnFloor, and AnglePos. Just check for a flag or specific animation and skip over setting/resetting the animation in those routines, and I think you should be good to go.

 

A'ight this is a question intended for Selbi to answer - in Sonic Erazor (one of my favourite games, even if it is a romhack) the giant rings in Uberhub Place take you to different levels. I'd like to know how you did that, along with the haptic effects when you hit a monitor or Badnik.

Also, how did you add textboxes? I'd like to actually incorporate a story into my game by interacting with NPCs (i.e objects) to show textboxes.

 

@AppleSauce Selbi hasn't even been online for over a year, what makes you think that he's gonna turn up now to answer your question?

I'm gonna give you the best, last advice you'll ever get from me: TRY to learn to program, instead of asking everyone else to tell you how to implement cool ideas. Start small, follow some bugfix guides, learn the engine. Don't just follow the guides by rote, actually try to understand the changes you're making. If you don't understand a line, look it up in the instruction set. Make mistakes, learn from them, try to improve yourself.

And next time you come to ask a question, don't aim it specifically at a stranger just because you don't like the advice that you've already been offered.

 

A characters animation is reset to 0 upon landing on the floor. Take a look at X_resetonfloor (x being the character name, in most cases), perhaps you could make a check for the specific animation you want, and if it is positive, branch over the line that sets the animation to 0.

Perhaps, set a flag when Sonic is bounced off the object. Check in the resetonfloor subroutine for the flag, and if so, subtract his y_pos by a few pixels.

 

Thanks! My level is very, very newbie. I've never edited Mster system games before and have not much technical knowledge haha. Thanks for the info! Ive been replacing the text, keeping the same number of characters and changing when any word has less characters than the ones that were before into EB (blank space). But it still wont work. I'l try with a better emulator then and see what can I do. Thanks!

 

@ashthedragon Cool. I just had a crack at this myself based on the information on the wiki and I got positive results after a couple of attempts, no need to change the checksum, at least on Emulicious and Kega. I did trip up over the control codes a bit, so just be wary of those. But no matter what I did to the data, it didn't stop the ROM from loading in Emulicious or Kega, so I'm not sure what's causing your issues.

 

Can someone tell me if this code is correct?

Code (Text):

1. Chase_Object: ; a0 = MainCharacter a2 = object
2.         move.w    d0,d2            ; d0 = Maximum speed
3.         neg.w    d2                   ; reverse max speed?
4.         move.w    d1,d3            ; d1 = acceleration
5.         move.w    x_pos(a0),d4 ; move x_pos of a0 to d4
6.         cmp.w    x_pos(a2),d4   ; compare the x_pos of a2 to a0's
7.         seq        d5                   ; set if equal
8.         beq.s    loc_8545E         ; branch if equal as well
9.         bcs.s    loc_8544C         ; branch if carry set
10.         neg.w    d1                   ; reverse acceleration
11.  
12. loc_8544C:
13.         move.w    x_vel(a0),d4  ; move x_vel of a0 to d4 now
14.         add.w    d1,d4              ; add acceleration of d1 to d4
15.         cmp.w    d2,d4             ; compare reversed max speed
16.         blt.s    loc_8545E          ; if it's lower than max, branch
17.         cmp.w    d0,d4             ; compare max speed
18.         bgt.s    loc_8545E        ; if it is higher than max, branch
19.         move.w    d4,x_vel(a0) ; otherwise move max speed to x_vel
20.  
21. loc_8545E:
22.         move.w    y_pos(a0),d4     ; move y_pos of a0 to d4 now
23.         cmp.w    y_pos(a2),d4     ; compare with y_pos of a2 to a0's
24.         beq.s    loc_85480        ; if equal, branch
25.         bcs.s    loc_8546C        ; if carry clear, branch
26.         neg.w    d3                 ; otherwise, reverse max speed
27.  
28. loc_8546C:
29.         move.w    y_vel(a0),d4     ; move y_vel of a0 to d4 now
30.         add.w    d3,d4            ; add acceleration of d3 to d4
31.         cmp.w    d2,d4            ; compare with y_vel of a2
32.         blt.s    locret_8547E     ; if less than, branch
33.         cmp.w    d0,d4            ; compare max speed with acceleration
34.         bgt.s    locret_8547E     ; branch if greater than
35.         move.w    d4,y_vel(a0)     ; move acceleration of d4 to y_vel
36.  
37. locret_8547E:
38.         rts
39. ; ---------------------------------------------------------------------------
40.  
41. loc_85480:
42.         tst.b    d5                 ; test for d5
43.         beq.s    locret_8547E     ; if yes, branch
44.         clr.w    x_vel(a0)         ; clear x_vel of a0
45.         clr.w    y_vel(a0)         ; clear y_vel of a0
46.         rts
47. ; End of function Chase_Object

My thought is, player is in a0, object being chased is in a2. If conditions are met, it ends, otherwise continues.

 

You are more or less on the right track, except you have them swapped, and a few of the terminology is somewhat wrong (or vague/incomplete).

Code (Text):

1. Chase_Object:
2.     move.w  d0,d2           ; copy and create a negative version of the maximum speed
3.     neg.w   d2              ; ''
4.     move.w  d1,d3           ; store current speed in d3 (for Y later)
5.  
6.     ; --- Checking X position ---
7.  
8.     move.w  x_pos(a0),d4    ; load object's X position
9.     cmp.w   x_pos(a2),d4    ; check against character's X position (subtraction)
10.     seq d5                  ; if they are in exactly the same spot on X, set d5 as a reminder for later
11.     beq.s   CO_FinishX      ; if they are in exactly the same spot on X, branch
12.     bcs.s   CO_MoveRight    ; if carry set, then character is to the right of the object, so branch
13.     neg.w   d1              ; convert speed to negative (go left instead of right)
14.  
15. CO_MoveRight:
16.  
17.     ; --- Handling X speed ---
18.  
19.     move.w  x_vel(a0),d4    ; load object's X speed
20.     add.w   d1,d4           ; add current speed
21.     cmp.w   d2,d4           ; is the speed passed its maximum in negative (left)?
22.     blt.s   CO_FinishX      ; if so, branch (don't change the speed)
23.     cmp.w   d0,d4           ; is the speed passed its maximum in positive (right)?
24.     bgt.s   CO_FinishX      ; if so, branch (don't change the speed)
25.     move.w  d4,x_vel(a0)    ; update object's new X speed
26.  
27. CO_FinishX:
28.  
29.     ; --- Checking Y position ---
30.  
31.     move.w  y_pos(a0),d4    ; load object's Y position
32.     cmp.w   y_pos(a2),d4    ; check against character's Y position (subtraction)
33.     beq.s   CO_FinishY      ; if they are in exactly the same spot on Y, branch
34.     bcs.s   CO_MoveDown     ; if carry set, then character is below the object, so branch
35.     neg.w   d3              ; convert speed to negative (go up instead of down)
36.  
37. CO_MoveDown:
38.  
39.     ; --- Handling Y speed ---
40.  
41.     move.w  y_vel(a0),d4    ; load object's Y speed
42.     add.w   d3,d4           ; add current speed
43.     cmp.w   d2,d4           ; is the speed passed its maximum in negative (up)?
44.     blt.s   CO_Return       ; if so, branch (don't change the speed)
45.     cmp.w   d0,d4           ; is the speed passed its maximum in positive (down)?
46.     bgt.s   CO_Return       ; if so, branch (don't change the speed)
47.     move.w  d4,y_vel(a0)    ; update object's new Y speed
48.  
49. CO_Return:
50.     rts                     ; return
51.  
52.     ; --- Destination reached check ---
53.  
54. CO_FinishY:
55.     tst.b   d5              ; has the object reached the character exactly on X (and Y)?
56.     beq.s   CO_Return       ; if not, branch/return
57.     clr.w   x_vel(a0)       ; stop object from moving on X
58.     clr.w   y_vel(a0)       ; stop object from moving on Y
59.     rts                     ; return

 

Wouldn't this do the opposite of what I was looking for, in a sense? If I am reading it correctly, this is check to see if the object (a0) is reaching the player's (a2) position.
I am looking for if the player (a0) reached the object's (a2) position. Hit me up in DMs on discord maybe.

Edit: What I am looking for, is what I call persistent tracking. I want the player to continuously move towards the object's location until it is reached. It seems, what this routine does, at least in my testing, is controls the player's max speed depending on distance from the target object.

 

This subroutine is designed to move an object in a0 towards an object in a2 in a gravity like way, at the acceleration speed of d1, and a maximum speed of d0. This is likely the subroutine responsible for moving the rings towards the main character when they have an electric shield on.

It sounds to me like you're looking for something more along the lines of a homing attack?

 

Actually its current setup might be useful to me. I want to make a routine for a projectile so it homes back to the player when it's finished it's thrust forward routine. Would the above code be advisable for such behaviour? (And if so, would you be against me stealing it? :P)

 

You are more than welcome to use it how you see fit. All you have to do is reverse the registers in order to make the object come to the player.

 

Thanx. I'm not sure I need to though, because I placed it in the object's routine where the main character is already a2 (and switching them around only tries to forcibly move the main character instead).

Here's what I have so far, but it doesn't seem to do the job, the object just seems to delete when the counter is done:

Code (Text):

1.  
2.     move.w     #$740,x_vel(a0)                ; speed of laser
3.     move.w     #-$490,y_vel(a0)                ; speed of laser
4.     move.b    #$38,$30(a0)                 ; distance laser will travel
5.  
6. Obj4D_Cont:
7.     btst    #0,($FFFFB001).w
8.     beq.s +
9.     neg.w    x_vel(a0)
10.     add.w    #$40,x_pos(a0)
11.     bset    #0,$22(a0)                    ; Flip to the left
12.     bra.w    ++
13. +
14.     sub.w    #$40,x_pos(a0)
15. +
16.     move.w #$9E00,d2
17.     addq.b    #2,$24(a0) ;
18.  
19.  
20. Obj_Blob_Move:
21.     cmp.b    #0,$30(a0)
22.     bne.w    ContCounter
23.  
24. Reel_Homing:
25.         move.b  #1,anim(a0)
26. Chase_Object:
27.     lea    (MainCharacter).w,a2
28.         move.w  d0,d2           ; copy and create a negative version of the maximum speed
29.         neg.w   d2              ; ''
30.         move.w  d1,d3           ; store current speed in d3 (for Y later)
31.  
32.     ; --- Checking X position ---
33.  
34.         move.w  x_pos(a0),d4    ; load object's X position
35.         cmp.w   x_pos(a2),d4    ; check against character's X position (subtraction)
36.         seq d5                  ; if they are in exactly the same spot on X, set d5 as a reminder for later
37.         beq.s   CO_FinishX      ; if they are in exactly the same spot on X, branch
38.         bcs.s   CO_MoveRight    ; if carry set, then character is to the right of the object, so branch
39.         neg.w   d1              ; convert speed to negative (go left instead of right)
40.  
41. CO_MoveRight:
42.  
43.     ; --- Handling X speed ---
44.  
45.         move.w  x_vel(a0),d4    ; load object's X speed
46.         add.w   d1,d4           ; add current speed
47.         cmp.w   d2,d4           ; is the speed passed its maximum in negative (left)?
48.         blt.s   CO_FinishX      ; if so, branch (don't change the speed)
49.         cmp.w   d0,d4           ; is the speed passed its maximum in positive (right)?
50.         bgt.s   CO_FinishX      ; if so, branch (don't change the speed)
51.         move.w  d4,x_vel(a0)    ; update object's new X speed
52.  
53. CO_FinishX:
54.  
55.     ; --- Checking Y position ---
56.  
57.         move.w  y_pos(a0),d4    ; load object's Y position
58.         cmp.w   y_pos(a2),d4    ; check against character's Y position (subtraction)
59.         beq.s   CO_FinishY      ; if they are in exactly the same spot on Y, branch
60.         bcs.s   CO_MoveDown     ; if carry set, then character is below the object, so branch
61.         neg.w   d3              ; convert speed to negative (go up instead of down)
62.  
63. CO_MoveDown:
64.  
65.     ; --- Handling Y speed ---
66.  
67.         move.w  y_vel(a0),d4    ; load object's Y speed
68.         add.w   d3,d4           ; add current speed
69.         cmp.w   d2,d4           ; is the speed passed its maximum in negative (up)?
70.         blt.s   CO_Return       ; if so, branch (don't change the speed)
71.         cmp.w   d0,d4           ; is the speed passed its maximum in positive (down)?
72.         bgt.s   CO_Return       ; if so, branch (don't change the speed)
73.         move.w  d4,y_vel(a0)    ; update object's new Y speed
74.  
75. CO_Return:
76.         rts                     ; return
77.  
78.     ; --- Destination reached check ---
79.  
80. CO_FinishY:
81.         tst.b   d5              ; has the object reached the character exactly on X (and Y)?
82.         beq.s   CO_Return       ; if not, branch/return
83.         clr.w   x_vel(a0)       ; stop object from moving on X
84.         clr.w   y_vel(a0)       ; stop object from moving on Y
85.     bra.w    Obj_Blob_Destroy
86.     rts
87.  
88. ContCounter:
89.     sub.b     #$1,$30(a0)
90.     bsr.w    ObjectMoveAndFall
91.     move.b    $40,$20(a0)    ; lol
92.  
93.     clr.w d0
94.     move.b $1A(a0),d0
95.     asl.w #$1,d0     ; *2 for correct offset
96.     lea (ArtUnc_Lure).l,a1
97.     adda.w (a1,d0.w),a1
98.     move.w #$9E00,d2
99.  
100.     lea    (Ani_Laser).l,a1
101.     jsr    AnimateSprite
102.     bsr.w    LoadLureDynPLC
103.     jsr    (TouchResponse).l ;Touch_KillEnemy, Touch_Monitor
104.     jmp    DisplaySprite
105.  
106. Obj_Blob_Destroy:
107.     lea    (MainCharacter).w,a2
108.     btst    #1,status(a2)
109.     bne.s    Obj_Blob_Destroy_2
110.     move.w    #0,(Chain_Bonus_counter).w
111. Obj_Blob_Destroy_2:
112.     jmp DeleteObject
113.  

I'm guessing I've made a blatant error here. Any idea?


EDIT: Okay I've partially solved this by moving the animation/PLC branches up since the new routine skipped over them, however the object still doesn't move a muscle after it's run it's distance.

What did you use to program max speed into d0 by any chance. Was it x_vel?

 

I've actually worked out how to do exactly what you are looking for. Hit me up on Discord later, and I will walk you through it.

 

Hey y'all. In Sonic 1, I'm trying to create a new jump mechanic. My original plan was to have it curl midair and stay in a ball until they reach the ground, like Pantufa: Extended Edition with the player being vulnerable if they are not in a ball. I couldn't figure out how to repeat only a segment of the animation, so instead, it also curls out of the ball midair. I think I got the animation going good, but in SAnim_RollJump, I'm having trouble keeping the animation speed consistent regardless of speed, and for some reason, no matter what I do, when I go to GHZ Act 2 and jump, the character jumps reeeeaaally quickly like he's high on caffeine. Could anyone provide me with help?

I'm using the Hivebrain 2005 disassembly.

 

I can't address your other issues, but:

Are you using the FE flag?

 

Yes, at the very start of both roll anims.

Edit: I clicked on the orange text in your reply, and I didn't know I was supposed to set the FE flag to step back a few sprites. I thought it handled speed, because if I don't have the FE flag at the start of the anims, it is really slow, like a snail carrying heavy shopping. So what's up with that?