The "howto solve this" thread

[emkay]

Well... it is no problem to stumble over threads that have "C64" as the topic, when viewing through different Forums on the I-Net.

So again I found a game that looks very hard to do on the A8. I am pretty shure it can be done much faster than on the C64 without looking weaker though.

 

 

http://www.c64unlimited.net/games/e/Elimin.../Eliminator.htm

[emkay]

Ähm.... The cause for this thread is that people that read this thread and have some experience on the A8 ... Just give their "idea" of "how to solve it by using the A8 HW capabilities...

 

Ergo: What is (in your opinion) the best way of coding to adapt the game onto the A8?

[Cybernoid]

Elimiator is a great game! I played and played it on my ST.

 

I would love to see it for the 8bit. I know I have not provided any help in the conversion, but just knowing that there are people out there that would _want_ to see a conversion should provide some motivation...

 

 

--Chris

[Heaven/TQA]

i havent played the game yet... just quick thoughts depending on the screenshot...

 

the carpet is done via DLIs (see rainbow walker or trailblazer, dimension X as reference). maybe not in highres but in antic 4...so the sprites could be antic 4 softsprites...

 

with PMs it would be possible to enhance the gfx esp. the 2 panels on the side...

 

but i have to see the game...

[TMR]

The ground isn't going to work as pure DLI splits because it moves, there are corners and hills (or both at the same time) and the C64 version is writing back to every other line of a bitmap to move it.

[Cybernoid]

Screenshots of the ST version:

 

http://www.atari.st/view.php?id=506

 

Note that there could be "carpet" or road on the top and the bottom.

 

The road is always simple and could be manipulated the same as in Ballblaster (I think... I haven't seen how Ballblaster was coded, but I read that it makes use of exclusive or'ing checker-board data to make it look like it is moving... I need to investigate the math there...)

 

Your ship only moves left and right, but it occasionally jumps, spins and lands on the top road. However, it still only moves left and right. The "depth" of it never really changes.

 

The enemies move in a manor that reminds me of the space harrier enemies, however they only move on the road and not through the "air" so their movement is restricted.

 

I think that the main play area and the 2 side panels could be done with Antic 4 characters. You are right, PM Graphics could be used to enhance the screen a bit as well, especially in "Priority 0 Mode". I have been looking at this mode and have been experimenting with it for a small puzzle game I am working on.

 

You can easily get 12 colors by doing the following:

set player 0 and player 2 color to 8

set player 1 and player 3 color to 2

set playfield 0 and playfield 2 to color 4

set playfield 1 and playfield 3 to color 1

 

asm(" LDA #$84");

asm(" STA $D012");

asm(" STA $d014");

 

asm(" LDA #$24");

asm(" STA $d013");

asm(" STA $d015");

 

asm(" LDA #$44");

asm(" STA $d016");

asm(" STA $d018");

 

asm(" LDA #$14");

asm(" STA $d017");

asm(" STA $d019");

 

 

If you set the PM graphics mode to create a 3rd color when they overlap, then you can receive the following colors:

 

0x8 = player 0 only

0x2 = player 1 only

0xa = player 0 and 1 overlap.

 

Since in priority 0 mode, player 0 and 1 interact with playfield 0 and 1, then if you have Antic mode 4 characters under these players that only select playfield 0 or playfield 1, you get the following colors:

 

0xc = player 0 and playfield 0

0x6 = player 1 and playfield 0

0xe = player 0 and player 1 and playfield 0

 

0x9 = player 0 and playfield 1

0x3 = player 1 and playfield 1

0xb = player 0 and player 1 and playfield 1

 

Similar for player 2/3 and playfield 2/3.

 

If you set the PM graphics to quadruple-width, and set player 0 and 1 to the same horizontal position, and set player 2 and 3 to the same (but different from 0/1) horizontal position. You have a nice section in the center of the screen (where the road would be) that could have high color.

 

For example:

Set $d000 and $d001 to $60.

Set $d002 and $d003 to $80.

Set each Size register ($d008-$d00b) to $03.

 

Anyway, I am rambling, but you can also receive 16 colors per line with this mode if you set the player/playfield 0/1 and 2/3 to different colors. However, you cannot get the same colors all over the screen, but this was already discussed in a different thread...

 

 

--Chris