Scrolling

[Badsniper]

I have the movement in my program working perfectly, no I just need to do scrolling. But I don't know how I would scroll across a screen. If I could get an "outline" of how to do it, I could probably start.

Thanks!

[Raknarg]

umm... we need the context. What exactly does your game do? And if you have any code, that would be helpful.

[Badsniper]

Well, Here is the code for my movement.

code:

var screen : int screen := Window.Open ("graphics:700;800,nobuttonbar") View.Set ("title:GAME;offscreenonly") var x : int := 673 var y : int := 60 var jv : int := 15 var key : array char of boolean var back : int := Pic.FileNew ("back.bmp") var fall, jump, horizontal : boolean := false var Possible_Jump : boolean := true var grav : real := 1 var del : int var x1,y1,x2,y2 : int Pic.Draw (back, 0, 0, picMerge) View.UpdateArea (0, 0, maxx, maxy) loop         %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%      INITIALIZE      %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     del := 2     Possible_Jump := true     horizontal := false     Pic.Draw (back, 0, 0, picMerge)     Input.KeyDown (key)     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   MOVE TO THE RIGHT   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     if key ('d') and whatdotcolour (x + 5, y - 5) ~= 7 and whatdotcolour (x + 5, y) ~= 7 and jump = false and fall = false then         x += 2         horizontal := true         for a : 1 .. 8             if whatdotcolour (x, y - a - 5) = 7 then                 y -= a                 exit             end if         end for     elsif key ('d') and whatdotcolour (x + 5, y + 5) ~= 7 and jump = false and fall = false then         x += 2         horizontal := true         for decreasing a : 8 .. 1             if whatdotcolour (x, (y + a) - 5) = 7 then                 y += a                 exit             end if         end for     end if     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   MOVE TO THE LEFT   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     if key ('a') and whatdotcolour (x - 5, y - 5) ~= 7 and whatdotcolour (x - 5, y) ~= 7 and jump = false and fall = false then         x -= 2         put 1 ..         horizontal := true         for a : 1 .. 8             if whatdotcolour (x, y - a - 5) = 7 then                 y -= a                 exit             end if         end for     elsif key ('a') and whatdotcolour (x - 5, y + 5) ~= 7 and whatdotcolour (x - 5, y - 5) = 7 and jump = false and fall = false then         x -= 2         put 2 ..         horizontal := true         for decreasing a : 8 .. 1             if whatdotcolour (x, (y + a) - 5) = 7 then                 y += a                 exit             end if         end for     end if     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    POSSIBLE JUMP     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     for a : 1 .. 10         if whatdotcolour (x, y + 5 + a) = 7 then             Possible_Jump := false         end if     end for     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%         JUMP         %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     if key ('w') and whatdotcolour (x, y - 5) = 7 and jump = false and whatdotcolour (x, y + 5) ~= 7 and Possible_Jump then         if key ('d') and whatdotcolour (x + 5, y) ~= 7 and whatdotcolour (x + 6, y) ~= 7 and whatdotcolour (x + 7, y) ~= 7 and horizontal = false then             x += 3         end if         if key ('a') and whatdotcolour (x - 5, y) ~= 7 and whatdotcolour (x - 6, y) ~= 7 and whatdotcolour (x - 7, y) ~= 7 and horizontal = false then             x -= 3             put 3 ..         end if         y += jv         jump := true         del := 16         for a : y - jv .. y             if whatdotcolour (x, a + 5) = 7 then                 jump := false                 jv := 15                 y := a                 exit             end if         end for     elsif jump = true and whatdotcolour (x, y + 5) ~= 7 then         if key ('d') and whatdotcolour (x + 5, y) ~= 7 and whatdotcolour (x + 6, y) ~= 7 and whatdotcolour (x + 7, y) ~= 7 and horizontal = false then             x += 3         end if         if key ('a') and whatdotcolour (x - 5, y) ~= 7 and whatdotcolour (x - 6, y) ~= 7 and whatdotcolour (x - 7, y) ~= 7 and horizontal = false then             x -= 3             put 4 ..         end if         y += jv         for a : y - jv .. y             if whatdotcolour (x, a + 5) = 7 then                 jump := false                 jv := 15                 y := a                 exit             end if         end for         jv -= 1         del := 16         if jv < 2 then             jump := false             jv := 15         end if     end if     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%         FALL        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     if whatdotcolour (x, y - 5) ~= 7 and fall = false then         grav := 1         y -= grav div 1         if key ('d') and whatdotcolour (x + 5, y) ~= 7 and whatdotcolour (x + 6, y) ~= 7 and whatdotcolour (x + 7, y) ~= 7 and horizontal = false then             x += 3         end if         if key ('a') and whatdotcolour (x - 5, y) ~= 7 and whatdotcolour (x - 6, y) ~= 7 and whatdotcolour (x - 7, y) ~= 7 and horizontal = false then             x -= 3             put 5 ..         end if         grav += 0.5         fall := true         del := 16     elsif fall = true then         y -= grav div 1         for decreasing a : y + grav div 1 .. y             if whatdotcolour (x, a - 5) = 7 then                 fall := false                 grav := 1                 y := a                 exit             end if         end for         if grav < 12 then             grav += 0.5         else             grav := 13         end if         if key ('d') and whatdotcolour (x + 5, y) ~= 7 and whatdotcolour (x + 6, y) ~= 7 and whatdotcolour (x + 7, y) ~= 7 and horizontal = false then             x += 3         end if         if key ('a') and whatdotcolour (x - 5, y) ~= 7 and whatdotcolour (x - 6, y) ~= 7 and whatdotcolour (x - 7, y) ~= 7 and horizontal = false then             x -= 3             put 6 ..         end if         del := 16     end if     if whatdotcolour (x, y - 5) = 7 then         grav := 1         fall := false         jump := false         jv := 15     end if     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    VARIABLE TRACE    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     exit when whatdotcolour (x, y) = 145     drawfilloval (x, y, 3, 3, 3)     locate (2, 1)     put "fall : ", fall, "    ", "jump : ", jump, "    ", " X/Y  ", x, " ", y     put "jumpvalue : ", jv, "    ", "gravity : ", grav     put "Dot colour for positive slopes: ", whatdotcolour (x + 5, y - 5), " ", whatdotcolour (x + 5, y + 5)     put "Dot colour for negative slopes: ", whatdotcolour (x - 5, y - 5), " ", whatdotcolour (x - 5, y + 5)     View.UpdateArea (0, 0, maxx, maxy)     delay (del)     cls end loop

Now I need it to be able to scroll, but I don't even know how to start.[/code]

[Badsniper]

Is there anyone who can help me?

[Raknarg]

Hmm... So assuming you want the character in the middle (you forgot the picture, btw ;P), you could just move the x and y coordinates of the field. Have you ever worked with Input.Keydown or some form of charachter movement?

[Badsniper]

I am using Input.Keydown. I just need to know how scrolling normally works in 2D games, so I can adjust it to work in mine...

and you could really create any picture in paint called "back.bmp" and save it in the same file as that program.

[RandomLetters]

Scrolling does not move the screen across the field in scroller games. Instead, the sprites or background are moved across the screen. This makes it easy to loop background animations by creating them offscreen, moving them across the screen, and removing them from the picture.