Move scroll

Definition

INT Move_scroll ( <INT scrollnumber>)

The move_scroll function is a slighty more advanced function. It allow the scroll's internal coordinates x0, y0, x1 and y1 of the scroll structure to be updated in a forcefull way. This gives great flexibility when multiple scroll windows are used.

For instance, in a situation where multiple scroll windows are active on screen, and one scroll is controlled by the main player, the other scrolls can be updated manually. However, the function can also be usefull when there's only one scroll active. In that case you can have any process take control over the scroll.

Also called scroll_move().

Parameters

INT scrollnumber

- The ID for the scroll window to be moved

Returns

INT : true

Example

IMPORT "mod_video";
IMPORT "mod_map";
IMPORT "mod_scroll";
IMPORT "mod_screen";
IMPORT "mod_key";
IMPORT "mod_proc";

GLOBAL

int graphics;
int counter;

PRIVATE



PROCESS main();


BEGIN
    set_fps(100, 0);
    graphics=load_fpg("help.fpg");
    start_scroll(0, graphics, 103, 102, 0, 15);

    scroll.camera=id; // assign the "main" process instance (this one) to the scroll's camera.
    priority=100;

    FROM counter=-2000 TO 2000 step 100;
        movable_process(counter);
    END

    say("Use the right and left cursors to move");

    graph=101;
    ctype=c_scroll;


    LOOP
        if (key(_right))
            x+=2;
            flags=0;
        END
        if (key(_left))
            x-=2;
            flags=1;
        END

        move_scroll(0); // Updates the scroll structure[], in this case affect scroll 0.

        FRAME;
    END
END

PROCESS movable_process(x_scroll);

PRIVATE

BEGIN
    ctype=c_scroll;
    z=100;
    graph=104;
    LOOP
        x=x_scroll-scroll.x0; 
        FRAME;
    END
END

Using Scrolling

For each process that you want to be part of a scroll window, you must set the local variable ctype to value C_SCROLL. It should also be noted that the local variable c_number is used for selecting in which scroll a process should be displayed. Additionally, you must set the camera property of the scroll structure to the processID of the process you wish to be followed.