Super Minimal Bro' - Fast scrolling 48k platformer

[rothers]

Here is my frantic scrolling platformer.

Originally it was just a Mario style game, but I found it a bit boring, a coding error meant I found a much more fun and frantic game where I accidentally made it so you could not stop. 5 levels of crazy scrolling jumping ahead of you. Any key is jump, the longer you hold it the higher you jump. Tap it for a little hop.

I used the colour layer as a dual playfield, which I think looks pretty cool. I do have a version which supports 128k music, but the player randomly slowed the game down, so I decided not to use it.

Play it (and download it) here:

https://toastyfox.com/zx/

[lexi]

Oh that is so nice and smooth, and the parallax works so well! Great presentation, and a fun game

[Daveysloan]

I absolutely love this!

Had a few goes this morning, I felt like a total hero when I finally got 5 coins!!

[R-Tape]

Congrats! I'm glad you completed this. It gives a decent illusion of a fullscreen scroller. Most importantly it plays really well, and I can see you've designed the levels to be excruciatingly difficult!

I've sent you a PM btw.

[Mpk]

I got to level 2!

This is good fun. Critically, restarting is instant, and you restart on level 2, doesn't kick you back to L1.

Nice work @rothers

[rothers]

Thanks everyone!

I promise the game gets easier once you learn to react quickly, and it does keep your progress, there is no going back to level 1!

I've said I'll give a free heated hoodie to anyone who completes all 5 levels, and the prize is still available!

I've got major plans for this and want to recreate this demo: which looks absolutely amazing, the peak of spectrum scrolling I reckon.

I think it's possible, although it seems that exact demo, once logic and sprites were added, was too slow due to the multicolour.

So I'm going to do the screen write via the regs trick but without the multicolour to see how fast I can get a similar engine...

[cmal]

Excellent simple game!! Well done and Thanks! The scrolling is awesome.
After losing many many lives I made it to level 2.

[Andre Leao]

Completed. Wonderful game!!!!

Spoiler

[cmal]

Completed. Wonderful game!!!!

Spoiler

Well Done!! I just completed it too. Great game indeed

[rothers]

Completed. Wonderful game!!!!

Spoiler

Ohhh well done, PM me your address if you want the hoodie!

There is a second ending if you beat my score on each level, it has a 'par' at the end of every level once you've completed it.

Time to port it to the CPC I think, a machine which does not have many fast scrollers. I'm using it as a base for all retro machines!

[Andre Leao]

Wow! It means I will have to play it to the end again. Always a pleasure

[DVDfever]

Great fun! Made a video here

[Joefish]

I've got major plans for this and want to recreate this demo:

which looks absolutely amazing, the peak of spectrum scrolling I reckon. I think it's possible, although it seems that exact demo, once logic and sprites were added, was too slow due to the multicolour. So I'm going to do the screen write via the regs trick but without the multicolour to see how fast I can get a similar engine...

This is for 128K Speccies:

https://spectrumcomputing.co.uk/entry/3 ... um/50Hurts

It repaints the whole screen and regular attributes at 50fps, but with barely any time left for sprites. It POPs the background block graphic into AF then one type of screen block, pre-shifted, into BC, DE, HL (BC holds the front edge of the block, DE the repeating middle of a row of blocks, and HL the trailing edge of a block), then another type of block into the alternate registers, then it paints the rows of the screen with PUSH. The list of PUSHes is re-written each frame from the level scenery map. And it can do an EXX between rows to swap the block type. It paints the first pixel line of all the rows of blocks first, then the second pixel line, and so-on. That makes it hard to synch with the raster as it keeps jumping ahead, so it's done on the shadow screen, hence 128K only.

I suppose it is re-prepping the PUSH lists from the scenery map every frame, which is wasteful, as that only needs updating every 16 scrolls. So it could do just a part of it every pass into a secondary buffer, possible leaving time for a sprite. Similarly, the attributes only need repainting every 8 scrolls, so some saving to be made there too. And obviously, reducing the screen window size would speed things up.

[rothers]

I figured it was doing that on the 128k, isn't that how the Super Mario game does it?

I want to get as close as possible on the 48k.

I'll probably limit the amount of platforms which can be visible on the screen, draw as little as possible using all the tricks I know.

I'm trying a few interesting tricks, manipulating the attribute layer might be a better approach with hires sprites on top, I've seen that done in some demos. I assume

is doing just that on the Wolfenstein engine.

So a fast scrolling game at 4px per scroll might work. I'll only move the player as he builds speed then switch to 4px scrolling once he gets going to offest the speed jump. I'm already pre-shifting everything (by hand, need to write a tool to do that!).

I'm reluctant to get in to any crazy timing issues, and I want this to work on a 48k or even a 16k. Super Minimal Bro could be made to work on 16k, it did until I added the extra levels, which are not compressed at all.

I want to make a kind of Sonic game at that speed, 8 way scrolling sort of thing, and I'll target a 16k until I can't essentially

[Joefish]

That sort of effect works so much better on a 128K because you can swap screens at the attribute mid-line so it costs you hardly any CPU time to do 8x4 attributes - so long as you can time other routines around the switches. On a 48K machine it would take you two scan lines to change the row of attributes at the mid-point, plus you'd still have to copy the top halves up at some point, if you're not completely re-writing them all every frame.

You could PUSH a pixel pattern of 00000001 00000001 then 00000011 00000011 then 00000111 00000111 to give you pre-shifted pixel edges on various rows of the screen, then use INK/PAPER combinations to draw your platforms. They'd be in solid blocks of colour, but the ends would be pixel-precise and instantly scrollable to any position at any speed. You could then use cells with INK and PAPER the same as static bits of background, or fast-moving foreground.

You could use the same trick, on other non-overlapping rows of the screen, to make solid-block background scenery scroll pixel-perfect but more slowly.

[rothers]

This is my attempt at what Sonic would look like using attribute writes on the 48k

It would absolutely fly in this mode, I'm trying to do an ASM routine that writes this at the fastest speed I can, then I'll do a little scrolling demo.

Please note, I know nothing about drawing graphics, will have to find an 8bit artist

[Andre Leao]

Ohhh well done, PM me your address if you want the hoodie!

There is a second ending if you beat my score on each level, it has a 'par' at the end of every level once you've completed it.

Time to port it to the CPC I think, a machine which does not have many fast scrollers. I'm using it as a base for all retro machines!

Sent you a PM

[rothers]

I've uploaded a demo of my Sonic game, it's absurdly fast using the 4x attribute trick I wanted to try.

https://toastyfox.com/zx/sonic.html

Super Sonic Bro' coming soon...

[HEXdidnt]

Please note, I know nothing about drawing graphics, will have to find an 8bit artist

Looks like a very promising project - happy to help if I can.

[worcestersource]

I've uploaded a demo of my Sonic game, it's absurdly fast using the 4x attribute trick I wanted to try.

https://toastyfox.com/zx/sonic.html

Super Sonic Bro' coming soon...

That’s quite something! The patterns remind me of Robocod too.