Custom Movement Graphic Glitch

[icicle]

I'm working on a 2d platformer with custom platform movements, but my sprite seems to have some kind of graphical glitch when moving left or right.

I used 2 alterable values and 2 fast loops for my custom movement.
My idea was to make my first alterable value, "X-Speed," be the number of pixels my sprite moves every second. That way, I could program both very fast and very slow speeds for my sprite.

The sprite moves perfectly, but it tends to sort of "vibrate" when I change directions quickly.
Does anyone have an idea what might be causing this glitch, and how I could fix it?

This is what my events look like:
1. Repeat while right arrow is pressed
=>Add X-Speed of "active" to X-Counter of "active"
2. Repeat while left arrow is pressed
=>Subtract X-Speed of "active" to X-Counter or "active"

3. X-Counter of "active" >= 50
=>Start loop "X+" (X-Counter of "active"/50) times
4. X-Counter of "active"<= -50
=>Start loop "X-" (-1)(X-Counter of "active"/50) times

5. On loop "X+"
+"Active" is not overlapping a backdrop
=>Subtract 50 from X-Counter of "active"
=>Set X position of "active" to (X position of "active"+1)
6. On loop "X+"
+"Active" is overlapping a backdrop
=>Stop loop "X+"
=>Set X-Counter of "active" to 0
=>Set X position of "active" to (X position of "active"-1)

7. On loop "X-"
+"Active" is not overlapping a backdrop
=>Add 50 to X-Counter of "active"
=>Set X position of "active" to (X position of "active"-1)
8. On loop "X+"
+"Active" is overlapping a backdrop
=>Stop loop "X-"
=>Set X-Counter of "active" to 0
=>Set X position of "active" to (X position of "active"+1)

P.S. I've never actually posted on the forums before, but I've been experimenting with MMF and MMF2 on and off as a hobby for almost 10 years now.

[nivram]

Hi and welcome to the forums.
Are your graphic hotspots, animation frames, the same for both directions?

Marv

[icicle]

I don't think so. My sprite only has one animation frame, so I don't think the hotspot is changing.

I made a new frame separate from my main programming frame to try and isolate this glitch. There's no events other than the 8 I posted above, and the only other objects are the backdrops.

I've also noticed another part of the glitch. When the sprite is moving left, the left-most "column" of pixels in the image disappears; this doesn't happen when the sprite's moving right, though.
I think that means it's probably a problem with my events, but I don't know for sure...

[Jacob]

Sounds like a display bug. Increase the size of the sprite by two pixels an all directions, so there's a 1px padding of transparency all the way around your image. That should take care of the column disappearing.

[ProdigyX]

Also, if u have "force load on call for all objects" or "load on call" unchecking might remove this problem

[Konidias]

If you post the mfa with your 8 events then we could solve this a lot faster.

[icicle]

Ok, I think I'm attaching a copy of my "bug" testing frame (thanks for the idea, Konidias). I'm still learning how replying in this forum works...

I decided to leave the app unchanged for now, so it can be tested.

I've done some more experimenting with the graphic glitch. It seems one "column" of pixels disappears for every 50 "pixels per. second" the sprite is moving.
Also, the object "vibrates" most often when you suddenly change directions.

P.S. As a bit of advice for anyone testing this: if you want to change the sprite's speed, just adjust its first alterable value, X-Speed.
And thanks, Jacob and ProdigyX, for your suggestions. I'll try them out

[icicle]

I tested Jacob and ProdigyX's ideas. Adding a pixel "buffer zone" does seem to stop the "column of pixels" from disappearing, but the sprite is still vibrating (and somewhat violently at that).

Does anyone know what else might cause the object to "vibrate" when it's moving?

[LB]

I tested your example MFA and I don't really see any vibrating or glitching - have you tried running it in HWA?

[Skyhunter]

Yes, i dont see any problems either, it could be your screen refresh rate is less than the frame rate of the game? That would cause graphical glitches in standard mode.