7800 Qix

[+Pat Brady]

I’ve been sad for a while about the lack of a really good Qix port for a machine that I have. The 5200 one is pretty good. I don’t have a 5200.

Has anybody explored doing this on the 7800?

I believe the conventional wisdom is that you need a full-screen bitmap, 2 bits per pixel. I can’t think of any way around this without limiting the sorts of shapes you can draw — which would be an unacceptable limitation. So the memory requirement for 160x240 resolution is just shy of 10K. Too much for the stock 7800 but doable with extra memory, i.e. the XM. Alternatively could do a 120x120 play area which would take 3600 bytes, leaving 496 bytes for everything else.

Any thoughts or suggestions? I’m interested in doing this. I haven’t worked with the 7800 at all but am a software developer (not game related) and have dabbled in 2600 programming.

[+sramirez2008]

1 minute ago, bizarrostormy said:

The 5200 one is pretty good. I don’t have a 5200.

I love the 5200 version. It works well with the stock controller too.  I also really like the Lynx version. I'd buy a 7800 version, if one became available.

[Synthpopalooza]

Use character memory in RAM.  Write to the character memory directly.  You have to access it like the C64 access bitmaps.

[Jinks]

Geez guys... Is anyone awake!?!

 

 

Cart please

 

?

 

 

Edited April 3, 2020 by Jinks

[+Pat Brady]

7 minutes ago, Jinks said:

Cart please

 

?

 

 

LOL!

I am somewhat surprised it hasn’t been done yet.

[Jinks]

There is allot that has not been done on the 7800. Programmers are slowly starting to change that. 

The 2600 and 8-bit computers get most of the games.  

[+Pat Brady]

45 minutes ago, Jinks said:

There is allot that has not been done on the 7800. Programmers are slowly starting to change that. 

The 2600 and 8-bit computers get most of the games.  

Qix makes sense for the 7800, to me at least, because it’s not really feasible on the 2600. (Everybody feel free to take that as a challenge.)

 

My initial idea for playfield representation was not quite correct. I was thinking 2 bits per pixel because there are 4 colors. But there are actually 5 states (empty, slow-filled, fast-filled, finished edge, and active edge). On the other hand, there are some impossible combinations (like slow-filled adjacent to fast-filled, or empty adjacent to either fill). Apparently the arcade version only had 2K RAM so there must be some clever representation.

 

Too much information?

 

No promises but my mind is definitely on it.

[Bobby Nelson]

It's funny you posted this because over the past few days I've been thinking "what games would be perfect for the 7800 with its superior sprite-handling capabilities?". I'm no programmer so all I'm basing this on is "hey I guess the 7800 is really good at handling a lot of sprites"...and I recall seeing the demo with all of the balls bouncing around the screen....

 

 Qix is one of the games that came to mind. The other one was Bubble Bobble since you have the 1-2 main characters, all of the enemies, and then the bajillion bubbles on the screen at any given time.

[TrekMD]

Oh, I love Qix.  I play it on my Lynx and my 5200.  Would love to have it on my 7800.

[Synthpopalooza]

2 hours ago, Bobby Nelson said:

It's funny you posted this because over the past few days I've been thinking "what games would be perfect for the 7800 with its superior sprite-handling capabilities?". I'm no programmer so all I'm basing this on is "hey I guess the 7800 is really good at handling a lot of sprites"...and I recall seeing the demo with all of the balls bouncing around the screen....

 

 Qix is one of the games that came to mind. The other one was Bubble Bobble since you have the 1-2 main characters, all of the enemies, and then the bajillion bubbles on the screen at any given time.

I've already got the main music done too, and someone else did sprites

 

 

 

Edited April 4, 2020 by Synthpopalooza

[+Pat Brady]

I just took a shower, a good time for me to think. What I wrote above about needing 5 states is nonsense! One state for each of the four colors is enough — which suits the 7800 well.

[gambler172]

Quix is not that exciting game.....i really need.

[Shawn]

Qix on the 7800 would be an instant purchase for me

 

[+Cafeman]

It would be great. I just got done playing 2 hours of 5200 Qix.  I have never understood how the games logic is programmed. How does it know you have split a Qix?  How are the sparx paths programmed To follow the outside edge?  How do the Qix see the open areas and never bleed into the filled in areas, even when it is tight? 

 

It looks like 5200 Qix is in a bitmap mode like antic D or E.  I don't have any idea how a character map design would work! 

[+cvga]

I've been playing Qix on the XEGS. It's a great game!

[Bobby Nelson]

16 hours ago, Synthpopalooza said:

I've already got the main music done too, and someone else did sprites

 

 

 

This sounds amazing!!!!!  Just out of curiosity are the music and sprites just for fun/testing/experiments OR is there a 7800 release of Bubble Bobble in the works?

 

[Synthpopalooza]

Just testing.  No one has started a port yet.

[+Pat Brady]

3 hours ago, Cafeman said:

It would be great. I just got done playing 2 hours of 5200 Qix.  I have never understood how the games logic is programmed. How does it know you have split a Qix?  How are the sparx paths programmed To follow the outside edge?  How do the Qix see the open areas and never bleed into the filled in areas, even when it is tight? 

 

It looks like 5200 Qix is in a bitmap mode like antic D or E.  I don't have any idea how a character map design would work! 

Great questions!

I don’t know all of the answers yet but here’s what I’m thinking.

Detecting split qix is really the same as determining which side of the line a single qix is on. I’m pretty sure there’s a known algorithm to do that (though I’ll have to look it up). I’m not certain but I think it is the same algorithm as deciding which pixels to fill.

Sparx paths could be hard depending on how the polygons are represented. With what I have in mind I don’t think it will be too tough.

I’m planning for each line of qix to be an object. Each qix movement deletes the last line and adds a new front line. Detecting whether it hits a polygon is then fairly straightforward. If it does, then it just bounces off. I don’t believe it has any additional logic to seek open areas.

How you represent everything is probably very system-dependent. On the 7800 there seem to be a few options.

[+Pat Brady]

Sparx is somewhat more difficult than I thought, especially in the case where a polygon surrounds it.

[+GoldLeader]

Quick question,  Have you ever played Ultimate Qix (Sega Genesis), Volfied, or Neo Qix (All the same game, give or take which port you play)?

 

It's like playing Arkanoid instead of Breakout.  I have a hard time going back to regular old Qix now. 

 

 

Sorry to be off topic.

Just wondered...

[Jaden (JRH)]

What about Super Qix? That would be a great game to port to the 7800. But I love regular Qix too. Really, any version of Qix on the 7800 would be fantastic.

[Jinks]

Checked out the modern ones and I like the original better. Could have yamaha sound on the original one for cooler effects..

[+Pat Brady]

5 hours ago, Jinks said:

Checked out the modern ones and I like the original better. Could have yamaha sound on the original one for cooler effects..

I too am a fan of the abstract and minimalist vibe of the original.

It will be interesting to see how well TIA handles the sound for this game.

This project is in its infancy. I don’t want to constrain it, but for now I am pretty focused on the original game on stock hardware.

 

[+Cafeman]

I've played a lot of Volfied.  I still prefer the purity and simplicity of Qix!  The 5200 version is fantastic. There was an earlier Qix for the 400/800 , it featured extremely slow drawing / filling in of the boxes,  far too slow to be fun. 

[HammR25]

I like Fortix and Fortix 2 on Steam.  Got those because I was missing Qix.