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I'm writing a little game for the Master System.

I'm finding my way with the help of you guys, and have already learned a lot of things.

But now I am having another problem with the scroll functionality.

Whenever I move the hero in a direction that causes the screen to scroll, the actual scrolling looks jumpy.
The screen moves to where it should, but it looks like it's "shaking".

I wonder if I should only update the tile map during the v-blank or something like that.

Here's a short video that shows the problem:

Can you guys help me out - again :) - ?

Cheers

ruibjr wrote

I wonder if I should only update the tile map during the v-blank or something like that.

Yep!

ruibjr wrote

I wonder if I should only update the tile map during the v-blank or something like that.

definitely like 95% of the time anything you do with the VDP needs to be done during VBLANK.
There are extremely special cases for doing stuff during the frame draw period and usually those are done during a line interrupt.

Wow!

It works.
Thanks for the tip.

Cheers!

Author	Message
ruibjr Joined: 21 Aug 2021 Posts: 41	Why is my scroll jumpy? Posted: Tue Aug 31, 2021 4:11 pm
ruibjr Joined: 21 Aug 2021 Posts: 41	I'm writing a little game for the Master System. I'm finding my way with the help of you guys, and have already learned a lot of things. But now I am having another problem with the scroll functionality. Whenever I move the hero in a direction that causes the screen to scroll, the actual scrolling looks jumpy. The screen moves to where it should, but it looks like it's "shaking". I wonder if I should only update the tile map during the v-blank or something like that. Here's a short video that shows the problem: Can you guys help me out - again :) - ? Cheers

SavagePencil Joined: 23 Aug 2009 Posts: 213 Location: Seattle, WA	Posted: Tue Aug 31, 2021 4:42 pm
	ruibjr wrote I wonder if I should only update the tile map during the v-blank or something like that. Yep!

IllusionOfMana Joined: 08 Sep 2018 Posts: 270	Posted: Tue Aug 31, 2021 7:53 pm
IllusionOfMana Joined: 08 Sep 2018 Posts: 270	ruibjr wrote I wonder if I should only update the tile map during the v-blank or something like that. definitely like 95% of the time anything you do with the VDP needs to be done during VBLANK. There are extremely special cases for doing stuff during the frame draw period and usually those are done during a line interrupt.

ruibjr Joined: 21 Aug 2021 Posts: 41	Posted: Tue Aug 31, 2021 8:07 pm
ruibjr Joined: 21 Aug 2021 Posts: 41	Wow! It works. Thanks for the tip. Cheers!

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