Critique This Game Idea - QuadraTank

[starfighter1314]

Since I haven't received much interest in programming for the VSM, I might try my hand at hacking a game (if I can get college credit for it). Let me know if you think this idea is worthwhile/possible:

 

I want to make Combat a 4-player (but still 2 tank), paddle-controlled game. I would eliminate all of the existing airplane games and only have tank games. The tank games would be modified as follows:

 

• custom mazes (maybe have a contest)

 

one paddle would control the tank cannon while the other controlled tank movement; flip roles after each score

 

the tank movement paddle would use the fire button to move forward

 

the tank cannon paddle button would be pressed to fire or held down to activate the shield (2 hits strong)

 

the cannons for both tanks would be drawn in alternating frames (will this cause untolerable flicker?); probably use 22.5 degree increments for cannon rotation

 

even though I am typically against them, I would try to incorporate cumulative power-ups (shudder). The ball graphic object would be used. Possible power ups include (in no particular order): shield recharge, faster tank movement, faster missle speed, missle duplication, shock effect (if your shot hits a wall and the opposing tank is touching any wall, he is destoyed or his shield is lessened if activated), power shot (destroys shield in one shot). Plow into the power up-object with your shield on and you lose all power-ups, including your shield.

 

difficulty setting on = after each score, player returns to no power ups

difficulty setting off = after each score, player retains all power ups

 

Maybe someone with Combat-hacking experience can let me know if there are enough cycles for the added gameplay and offer an opinion regarding if this project is too ambitious for a first-time game hacker.

 

Thanks!

[vdub_bobby]

Will the controls work since the paddles are non-centering?

 

Other than that, sounds pretty cool; whether it is doable as a first-time hack depends on your skill as a coder.

[+batari]

Also, reading paddles requires modifying the display kernel. Just so you know

 

The only control issue I see is that the paddles only have a range of about 270 degrees lock to lock. The driving controllers have an infinite range of motion and thus would be better suited for such a thing, but you can only connect two of them

[vdub_bobby]

• one paddle would control the tank cannon while the other controlled tank movement; flip roles after each score

 

the cannons for both tanks would be drawn in alternating frames (will this cause untolerable flicker?); probably use 22.5 degree increments for cannon rotation

 

even though I am typically against them' date=' I would try to incorporate cumulative power-ups (shudder). The ball graphic object would be used. Possible power ups include (in no particular order): shield recharge, faster tank movement, faster missle speed, missle duplication, shock effect (if your shot hits a wall and the opposing tank is touching any wall, he is destoyed or his shield is lessened if activated), power shot (destroys shield in one shot). Plow into the power up-object with your shield on and you lose all power-ups, including your shield.[list']

I don't think straight 30Hz flicker would be that bad. You might be able to use a smart flicker routine and only flicker when the cannons are on overlapping scanlines.

 

And after rethinking the paddle control a little, I think it would work ok - you just want to make it easy to find the center of the paddle; having the cannon drift on you (rotate when you don't want it to) would be extremely annoying. The easiest way would be to divide the paddle's range into thirds: the left third rotates the cannon left, the middle third leaves the cannon still, the right third rotates it to the right.

Pros:

-easier to read the paddles (you wouldn't have to read them every scanline).

-pretty easy to control: crank it hard right/left to rotate, find the (wide) middle to stop rotating.

Cons:

-only can rotate cannons at one speed.

 

Here's a question for you: will the cannons be positioned independently of the tanks? For example, if the cannon is pointing east and the tank is heading north, if the tank turns west will the cannon then be pointing north? Or will it still be pointing east?

[Zach]

Having worked on the Tank AI demo and Combat Redux, I feel qualified to respond.

 

I can't comment on paddle control since I have no experience there, but in regard to everything else it seems doable. Offhand I can think of a few obstacles you would have to deal with. First of all, RAM is very limited. In the original Combat there are about 8 bytes free. In Tank AI, I was able to gain some extra RAM by having only one maze thereby freeing certain maze control variables.

 

It will take some substantial changes to the kernel to add two more tanks, because you will need to keep track of their x-coordinates. The Stella chip has registers to store the x-coordinates of two player sprites, but it gets more complicated with higher numbers. Even though I only had two tanks, I added code to Tank AI to track the x-coordinates. One problem, which I haven't solved completely, is how to restore the x-coordinates when the tanks wrap across the screen.

 

I surmise that Quadratank can be done, but it's more ambitious than you may think. My suggestion is to start hacking a two player Tank game with paddles, and if you still feel encouraged, continue onto 4 players. Good luck!

[s0c7]

I've never done a controller hack, so take this with a grain of salt. I would imagine doing any kind of hack where you are changing the controller from one type to another would require you to have access to a real 2600 and a means to play your bin on it to test with. 4 players at once would probably be very hard to test properly with an emulator. Just something to think about....

[starfighter1314]

Thanks for all the feedback! I think I will take others advice and try to convert Combat into a 2-player paddle game before going forward. I like the idea of using a three-zone paddle to find the center point easier. Hopefully the shortage of RAM won't kill the project off. Luckily I have a modded Supercharger/mp3 player combo to test out results on my heavy-sixer.

 

As for this question:

will the cannons be positioned independently of the tanks? For example, if the cannon is pointing east and the tank is heading north, if the tank turns west will the cannon then be pointing north? Or will it still be pointing east?

 

This is a good consideration. I think I do not want independent positioning even though it will probably require more programming effort (therefore the cannon would point north). I think having the cannon move according to tank direction is more lifelike and could make the game more strategic.

[Zach]

I should add that there are ways to get around the RAM shortage. For instance you take advantage of the Superchip, as used in Dig Dug etc. Although PCB's for the Superchip are hard to come by, one can still use a Cuttle Cart or Kroko Cart. Another possibility is to make it a Supercharger game whereby you'd have 6K of RAM. This is all just something to think about for the future. You should have enough RAM in a regular 4K game to do Tank with paddles.

 

Correction: you should have about 16 rather than 8 bytes of free RAM. I apologize for the error in my previous post.

[starfighter1314]

Phase I is complete. Have a look! Navigation for the two tanks works using paddle 0 and paddle 2. The fire button now functions as forward, so this is a pretty peaceful game for the time being. Fire control will be present on the other paddles.

 

Now I have to work on turret control. I think I will take the non-flicker approach and put all combinations of turrent angle/tank angle in the ROM. Otherwise, I would have to draw the turrets on every other frame. Sound reasonable?

 

If anyone knows how I can fix the attract mode craziness, please let me know.

 

Thanks!

Edited April 20, 2007 by starfighter1314

[Gateway]

Hey Nick! You still relaxin' under Hawaii's sun these days?

 

I like it!

 

I can get 1 tank(red) to move with the arrows in z26 and can shoot at the blue tank. This takes some patience since the shot moves with the rotating tank so it takes some practice to shoot at the right time.

[starfighter1314]

Thanks Weston! Actually, I have been travelling so I just got to your posting. That's funny, I forgot that the joystick fire button still works if you have one plugged in. (I have been using Stella for most of the emulation). I'll probably make most of the games be non-guided missile ones, but leave in a couple for fun.

 

I am hoping someone can run this on real hardware to see if the paddle zones are roughly even (each zone should be about a third of the paddle range). I loaded it onto my Supercharger, but my paddles are very old and the pots are somewhat defective.

 

Maybe someone viewing this thread could comment on this if they know. If I finish the firing control, could this game be sold or are there copyright issues with Atari? How much of the original needs to be modified?

 

-s1314

 

BTW Is Trotter on another world tour? I am in the Portland Oregon area for the next few weeks but will be going back to sunny Honolulu then. If Trotter is in the area and is up for another Hawaiian getaway, please let me know! Trotter Rocks!

[starfighter1314]

Beta added to Atari 2600 Hacks forum

[starfighter1314]

**file removed**

 

ThomasJ solved my playfield shifting problem! I haven't heard any interest on taking the game further, so please consider this the final release.

 

-s

Edited April 20, 2007 by starfighter1314