Scrolling

[Newbie]

I now know how to scroll the graph screen, but if I wanted to draw a map of the world what would I save it to or how would I draw it in order to get it all onto one screen to scroll? I want to be able to do something like this application HERE

[DigiTan]

That's a tricky one. You'd definatly do it through the use of offsets (this essentially what longitutde and lattitude do for flat cartesian maps.) Since you're dealing with a world map, I'm assuming you'd also like that map to loop constantly and scrool freely in either direction. Since your map is 1 screen lenght you could "rotate scroll" left and right using combinations of the RL (HL), RR (HL), SLA (HL), and SRA (HL) commands for smooth-shifting. Verticle scrolling could be done using LDIR methods. Longitude and Latitude could be used as shift counters for saving purposes.

[X1011]

I think he means in basic, this is the basic forum after all.

[Jedd]

There arent very many games in Basic that can scroll. Take a look at Civilization Simulator if you really want to, but that game sucks. I think all you do is draw something on the graph screen, then change the window vars, then re-draw it again. It takes forever and is not worth the wait, so avoid scrolling in Basic at all costs.

[Newbie]

I really need to do this, because I'm making a risk game and with the size of the screen scrolling is nessesary. I can get the screen to scroll left and right but it takes forever to get the cursor from one side to the other and I don't know how to do it up and down.

[X1011]

How do you do it left and right?

[DigiTan]

[Newbie]

Delvar Y1
ZStandard
Clrdraw
"94"->Y1
RecallPic1
Trace

Thats how you get it to scroll left and right.

How would drawing a map in a matrix work?

[DarkerLine]

[Newbie]

How do you get it to scroll left right up down and not have it clear?

[Arcane Wizard]

Redraw everything.

ClrDraw
AxesOff
..etc
0->Xmin:94->Xmax
0->Ymin:63->Ymax
For(X,1,20,4 //create some random lines
randInt(0,94->L1(X
randInt(0,63->L1(X+1
randInt(0,94->L1(X+2
randInt(0,63->L1(X+3
End
Repeat K=45
getKey->K
Xmin-(K=24)+(K=26->Xmin
Xmax-(K=24)+(K=26->Xmax
Ymin-(K=34)+(K=25->Ymin
Ymax-(K=34)+(K=25->Xmax
If K:Then
For(X,1,20,4 //draw all the lines stored to L1
Line(L1(X),L1(X+1),L1(X+2),L1(X+3
End
End
End

[Newbie]

So after everytime you draw a line ina program you would store it to L1?

[Arcane Wizard]

No, it's just an example of how you could use a list to store lines in and have something to know where to redraw them.

There's no point in storing the same value's in L1 every game cycle.

[Newbie]

After drawing all the lines in a program how would you store every line to L1?

[Arcane Wizard]

Well, you'd need pixeltest, and you'd end up with a huge list with every pixel stored in it, since you can't really tell if something's a line or not.

You should store them while drawing, just get the coordinates from the vars, and put those in a list.

[Newbie]

So there is no way to amke the scrolling go faster?

[DigiTan]

If there is, it hasn't been documented.

[Ray Kremer]

Since it's basic, probably the best thing is to not use actual scrolling but just create enough individual views to cover the entire game board. Something like using the page down key to go through a web page instead of the down arrow.