New Super Mario Bros (demo)

[djnzx48]

CaFe 2019 demoparty stuff:
https://events.retroscene.org/cafe2019

such a good entries

Certainly there are many extremely high quality releases from that party. I'm surprised no-one has mentioned the new port of Super Mario Bros.

[g0blinish]

yup, hard to catch ZX prods.

[Alessandro]

CaFe 2019 demoparty stuff:
https://events.retroscene.org/cafe2019

such a good entries

Certainly there are many extremely high quality releases from that party. I'm surprised no-one has mentioned the new port of Super Mario Bros.

Is it a demo or a full release?

I am stuck here anyway, the right chimney is too distant from the left one and you cannot go back to give you enough room for a running jump.

[abelenki]

I am stuck here anyway, the right chimney is too distant from the left one and you cannot go back to give you enough room for a running jump.

you have to hold fire button (running) while jumping, for higher jump.

EDIT: i didn't read your post to the end. i see, you already tried running jump.

[Daren]

At the end of level 5-2 it takes me back to 1-3. Is this right??

[djnzx48]

That's probably intentional for now, there are only five levels on the disk and it's a demo version after all.

[abelenki]

R-Tape, can you please make separate Super Mario Bros. topic, and move all related replies to it?

[R-Tape]

Agreed abelinki, this should have its own thread.

(moving posts now)

[Ast A. Moore]

That flicker, though, is really hard on the eyes. I wish people didn’t use it for full screen effects.

Other than that, this is mighty impressive.

[stupidget]

This is fantastic work and is a joy to play.

[Alessandro]

Pretty good for a demo, although there are many features lacking (backgrounds, coins etc.), and the fact that you cannot scroll the screen backwards is very limiting - it may trap you into a no-exit situation. Let's see what will come next.

That flicker, though, is really hard on the eyes. I wish people didn’t use it for full screen effects.

You should activate Gigascreen. The image in my post above was saved while running the demo in RealSpectrum DOS emulated in DOSBox with Gigascreen enabled.

[DenisGrachev]

Was at party and have some talk with author. It's more than a game, this one is only a demo of a whole framework to make a scrolling arcades. So finger crossed and wait for release

[djnzx48]

Pretty good for a demo, although there are many features lacking (backgrounds, coins etc.), and the fact that you cannot scroll the screen backwards is very limiting - it may trap you into a no-exit situation. Let's see what will come next.

Scrolling backwards would likely require some work. The scrolling is done pixel-by-pixel, with the camera position truncated to two-pixel increments for display. Every 16 pixels new tiles get processed, but if the camera were allowed to move backwards then this would have to occur in reverse order, and things could get complicated.

It's arguably not needed for this type of game anyway - I don't think you can get stuck anywhere except in the warp zones, and moving backwards isn't necessary.

You can use these POKEs to get a constant 1 pixel scrolling rate (wait until after the interrupt occurs to apply them)
POKE 58102, 62
POKE 58105, 1

[JasonUK]

I am stuck here anyway, the right chimney is too distant from the left one and you cannot go back to give you enough room for a running jump.

Me too...

[djnzx48]

There should be enough room for a running jump if you hold fire (space).

[Daren]

Doctor Snuggles theme music at two minutes in!

https://www.youtube.com/watch?v=nRsCGpagBXk

[Ralf]

It's very good, smooth engine. Great job!

I'm usually a bit skeptical about gigascreen in games as it involves flicker and is painful to watch for a longer time. But here flicker is very gentle, I guess I could stand it for hours

Mario looks a bit strange with black, empty background but you can get used to it too.

Btw, this Youtube video doesn't do justice for the game. Looks like all the gigascreen effect was lost during video capture. So you should really try it in emulator.

[Joefish]

It's pretty smooth. Although I notice even with 'Gigascreen smoothing' (i.e. two-frame blending) turned on, the stipples appear as it scrolls. Might be better to have the stipple stay in place as the object moves. That's not a problem with two-pixel scrolling, but with one-pixel scrolling it means the stipple moves out of step with the flicker effect.

I would guess there's a lot of pre-shifting going on, and there are two versions of each pre-shifted step to do the flicker. So it would just mean adding an extra calculation step to swap between the two flicker versions when moving something by an odd number of pixels.

What's smart about the stippling technique is it stil looks pretty good even without extra screen smoothing.

[djnzx48]

I was looking through some images and remembered these old mockups of Mayhem in Monsterland:

Spoiler

Maybe it wouldn't be possible to recreate the level of detail seen in the mockups, but I wonder if some approximation of this game would be feasible using the new scrolling engine.

[4thRock]

Interesting and it plays well.

I don't understand using gigascreen with 50fps gameplay.
Gigascreen limits you to 25fps, otherwise the objects move between frames and that affects the pixel mixing.
As mentioned on a post above, you see stipples when moving.

The black background is not that nice, Mario should be happy and colourful.

But for a demo that plays so well, it's top work! Looking forward for more

[Joefish]

I was looking through some images and remembered these old mockups of Mayhem in Monsterland:

Spoiler

Maybe it wouldn't be possible to recreate the level of detail seen in the mockups, but I wonder if some approximation of this game would be feasible using the new scrolling engine.

Probably not. Too much on-screen. And doesn't MiM scroll up/down as well?

As for Gigascreen, there's no reason it can't work with 50Hz updates. PAL TVs only draw alternate lines on each 50Hz frame - it takes two frames to refresh the whole picture - but the picture still changes from one frame to the next.

Typically Gigascreen flickers alternate lines of the same picture, which on some TVs actually appear as a higher vertical resolution, but usually just blends the pairs of lines. If you were to scroll such a screen vertically by 1 pixel at 50fps, you'd also have to consider doing an extra frame-swap to keep up the regularity of the colour swapping. Just as scrolling this flickering pixel stipple needs an extra flick, whenever it moves vertically or horizontally by 1 pixel.

[Ersh]

As for Gigascreen, there's no reason it can't work with 50Hz updates. PAL TVs only draw alternate lines on each 50Hz frame - it takes two frames to refresh the whole picture - but the picture still changes from one frame to the next.

As far as I know the Spectrum doesn't interlace, it uses 240p, 50hz single fields like most computers of the era. Or am I missing something?

[Ast A. Moore]

As for Gigascreen, there's no reason it can't work with 50Hz updates. PAL TVs only draw alternate lines on each 50Hz frame - it takes two frames to refresh the whole picture - but the picture still changes from one frame to the next.

As far as I know the Spectrum doesn't interlace, it uses 240p, 50hz single fields like most computers of the era. Or am I missing something?

That’s right. And the game does exhibit flicker on real hardware and CRT TV. It’s mostly tolerable, but it’s there. Large areas of solid color (i.e. the right edges of the pipes) are the worst offenders. That, and the aforementioned stipples. Occasionally, the game doesn’t seem to keep up with the syncing, so the whole screen shimmers every second or so.

[Ersh]

That’s right. And the game does exhibit flicker on real hardware and CRT TV. It’s mostly tolerable, but it’s there. Large areas of solid color (i.e. the right edges of the pipes) are the worst offenders. That, and the aforementioned stipples. Occasionally, the game doesn’t seem to keep up with the syncing, so the whole screen shimmers every second or so.

When the two colours that are to be blended are far from each other in brightness you perceive stronger flickering, like with black and white, especially if it covers larger areas. I did a colour-interlace routine back 20 years ago on the c64, and that palette offers more options when it comes to blending with less flicker.

What Joe suggested about making a small calculation and display the 'correct' version of the checkerboard pattern during scrolling would at least eliminate the stipples.

[4thRock]

Gigascreen works by blending two frames, so the output is always 25fps (50/2)
By scrolling at 50fps the blending gets broken.

Here's the correct sprite (captured at left margin, with no scroll):


And here's the messed up version (captured while scrolling):


Of course, this on an emulator with Gigascreen mode active.