Happy to see a new video! Is it a bug in AMOS that the raster creeps up by one with each loop around when using screen offset for horizontal scrolling or just how the Amiga does it? I was, perhaps incorrectly, under the impression that this was just how the hardware works. (Because if it isn't we need a new library to fix it!) In my tile scroller I keep track of the level X position relative to the display width and do an offset to shift the tile drawing / bob positions down by one * the multiple of the display width I am on. Then you have to start doing things like using two bobs at the intersection between the screen wrap to make it seamless but it works. It is all a bit tricky and messy though. Another thing to look out for when using dual playfield is a real bug in AMOS that makes it impossible to horizontally scroll by 1 px when scrolling both playfields. (It always gets rounded to two pixels or something like that... It has been a while.) There is a patched library that fixes the problem. I experimented with using dual playfield for a while but I found the restriction of 8 colors per playfield too difficult to work with.
Thanks for the comment. 😁 As far as I know the horizontal scrolling issue is down to a bug in Amos. People have come up with workarounds but they too apparently have their limitations from what I hear. Do you know if the AMCAF library would fix some of these issues? I’ve downloaded it and will get around to installing it sometime in the near future as folks seems to speak quite highly of it.
Love the video, but I have a recommendation: Remove the ball from the inside of the bells. I think the hat is valuable as a signature, but the sound is not. Without removing the bells, if you bend one of the tabs you can get the ball out, then, bend it back into place.
I don't code in AMOS, but how Big is Integer? How Big SC_VAL can get and what happen if it reaches the max INT? Maybe a "IF SC_VAL > 200 THEN SC_VAL=1" would be the safer solution, instead of the mod 200? Just asking for a friend :D But still a great trick to make the scrolling smoother :)
a 32 bit int will hold a value of 4,294,967,295 so should run for just short of 1200 hours before either overflow or wrapping round, depends on how amos handles these things I guess. having said that you only increment after vbl (so every 20 ms @ 50fps) so could be longer
Now add some parallax to this, shove a spaceship at the bottom and some unfriendly folks at the top and we have a banger!
It’s on the (very long) list of things to do… 😅
Happy to see a new video!
Is it a bug in AMOS that the raster creeps up by one with each loop around when using screen offset for horizontal scrolling or just how the Amiga does it? I was, perhaps incorrectly, under the impression that this was just how the hardware works. (Because if it isn't we need a new library to fix it!) In my tile scroller I keep track of the level X position relative to the display width and do an offset to shift the tile drawing / bob positions down by one * the multiple of the display width I am on. Then you have to start doing things like using two bobs at the intersection between the screen wrap to make it seamless but it works. It is all a bit tricky and messy though.
Another thing to look out for when using dual playfield is a real bug in AMOS that makes it impossible to horizontally scroll by 1 px when scrolling both playfields. (It always gets rounded to two pixels or something like that... It has been a while.) There is a patched library that fixes the problem. I experimented with using dual playfield for a while but I found the restriction of 8 colors per playfield too difficult to work with.
Thanks for the comment. 😁
As far as I know the horizontal scrolling issue is down to a bug in Amos. People have come up with workarounds but they too apparently have their limitations from what I hear.
Do you know if the AMCAF library would fix some of these issues? I’ve downloaded it and will get around to installing it sometime in the near future as folks seems to speak quite highly of it.
Love the video, but I have a recommendation: Remove the ball from the inside of the bells.
I think the hat is valuable as a signature, but the sound is not.
Without removing the bells, if you bend one of the tabs you can get the ball out, then, bend it back into place.
Glad you enjoyed the video, and thanks for the comment. 🃏
I don't code in AMOS, but how Big is Integer? How Big SC_VAL can get and what happen if it reaches the max INT? Maybe a "IF SC_VAL > 200 THEN SC_VAL=1" would be the safer solution, instead of the mod 200? Just asking for a friend :D
But still a great trick to make the scrolling smoother :)
I was going to suggest the same thing. Eventually it will crash.
Yes, good point. To be fair I’ve used this in other code and left things running and it’s been okay, but it never hurts to code defensively. 👍
a 32 bit int will hold a value of 4,294,967,295 so should run for just short of 1200 hours before either overflow or wrapping round, depends on how amos handles these things I guess.
having said that you only increment after vbl (so every 20 ms @ 50fps) so could be longer
I kinda like how it bugged out too …but very interesting
Cheers. 😁
As with all coding, it’s finding cool ways to do things that aren’t documented anywhere that give me a buzz. 😅
I find it hard to concentrate on your videos because there's not enough bells. Is it possible you could add more?
Many apologies. I am in contact with a local campanologist in order to rectify this oversight for future videos. 😱🔔😉
I've used Screen Offset loads of times, but never like this. The 'mod' function should really be demonstrated in the manual this way.
Agreed. It is a bit of a game changer. 😁