Smooth H-scrolling platform game in AMOS, screen copy vs screen offset?

[Amiten]

Hello,

this thread is very interesting and is exactly what I'm looking, I have the same problem with the scroll in Amos, I have an image of 1024 pixels in length and reaches the end offset occurs when the image is distorted, someone has managed to repeat the scroll without distortion appears? to scroll VERTICAL

horizontal scroll offset no problem with.

would be very grateful for someone to help me.

can see my project here
[ Show youtube player ]

[Samurai_Crow]

The maximum scrolling width for AmosPro is the one supported by Kickstart 1.3: 1024 pixels. It wasn't until Kickstart 2.0 that scrolling beyond that distance was supported by the Kickstart. AmosPro, being written for a Kickstart 1.3 based system doesn't have the facilities to do that.

[Retro1234]

But VERTICAL you can open a screen of 1024 but BOBs become distorted after about 500 I dont think this is just an AMOS problem.

using one image/iff instead of tiles is unusual in games instaed of using tiles/Maps.

probably best to use Wrap around like described.

Also Pasting a Tile at the same point as a enemie/BOB I get graphics error any ideas?

But even so using one large screen would make life easyier for reasonable sized screens can anyone name some Commercial games using one large screen insted of Wrap around?

[Codetapper]

Chris Sorrell said that James Pond used a single large screen for all the levels.

[Retro1234]

Thanks
"JP1 the scrolling system is actually fairly low tech - I just allocated enough screen memory to contain the entire play area. That's why some levels are wide but shallow and others are less wide but deeper"

None of the Maps seem that big below 1024*1024

Originally Posted by Samurai_Crow

This one loads a Tome formatted tile map and displays it...without using the Tome commands because they're just too slow. BTW, I didn't check the code or try to run it so there may still be mistakes in it.

Screen Open 1, 672, 256, 32, lowres
Flash off
Curs off
Cls 0
Load "tilemap.abk",6: Rem Load the map
Load "tiles.abk",2: Rem load the tile images as an icon bank
Get Icon Palette
Rem get size of map from tilemap.abk
T=Start(6)
MAXX=Deek(T)
MAXY=Deek(T+2)

Rem Draw the initial map starting at top left
Screen Hide
For Y=0 to 256 Step 16
  ROW=Y*MAXX+4+T : Rem add 4 to skip size header
  For X=16 to 336 Step 16
    Paste Icon X,Y,Peek(ROW+X/16)
  Next X
Next Y
Screen Show

Rem Scroll right until you get to the end of the map
MAXXP=MAXX*16-320 : Rem Maximum pixel coordinate
For X=0 to MAXXP
  LX = X mod 320
  Y=X and 15 : Rem Pixel offset and tile row
  If Y=0
    Rem This code is only accessed on even multiples of 16 pixels
    X1=LX
    X2=X1+336 : Rem 336=320+16
    COL1=X/16+T+4
    COL2=COL1+21 : Rem 21=336/16
  Endif
  YT=Y*16
  ROW=Y*MAXX
  Rem If you scroll faster than 1 pixel per frame
  Rem then you have to plot that many more tiles
  Paste Icon X1, YT, Peek(COL1+ROW)
  Paste Icon X2, YT, Peek(COL2+ROW)
  Wait Vbl
  Screen Offset LX+16, 0
Next X
Screen Close 1

I tried your example but AmosPro says Syntax error and pointing to MAXX=Deek(T) for some reason.

I'm quite a newbie at Amos so I can't figure out what's wrong with that line of yours.

What could I change that into?

I've made a map of some tiles using TOME IV and I just started to try to figure out how to view it. Screen offset is the way to go so I would really like to be able to use that before anything else.

Thank you!

[Lonewolf10]

AMOS converts

MAXX=Deek(T)

into

MaxX=Deek(T)

as the variable name clashes with the Max function. The easiest way to fix this is to add an underscore to all occurences of MAXX, for example

_MAXX=Deek(T)

OK. Thank you very much! :-) I'll try that.

[Photon]

Moved this thread to the Coders.Languages.AMOS forum. Please post in the designated forums in future! Carry on

[Bastich]

From what I can remember from my AMOS days screen offset basically did a hardware scroll around a large bitmap by just altering the screen pointer/hardware position. This is effectively cost free compared to the scroll command which basically did a bitmap copy. I never managed to get an infinite scroll working with more than around 8 colours as AMOS is just not quick enough. This and AMOS being interpreted not compiled was one of many reasons why I moved onto Blitz Basic 2. The AMOS compiler that came out later was terrible compared to BB2 but at least gave a moderate speed boost.

[Amiten]

Reading this post again , the cuestion are:

¿is posible to have a bigger scroll (Tiles one) than 1024 pixel in amos pro 2.0?

if yes please tell us how to...

all the best
amiten

[alpyre]

Maybe a little too late of a reply but, take a look at this:
https://aminet.net/package/dev/amos/PlatformGameEngine

[Inner200k]

Originally Posted by alpyre

Maybe a little too late of a reply but, take a look at this:
https://aminet.net/package/dev/amos/PlatformGameEngine

Sorry to necro an old thread, but the code above is beautifully created .. do you sense a but coming? well .. but .. there seems to be massive disparity with results, if this ever ran on real hardware A500+ you can laterally draw the frames on paper faster and use them as a flip book, the only way this works smoothly is either you'd need some sort of high powered Amiga or set the emulation to fast as possible then it works.