sprite_hide

#Sprite.Hide

##Syntax Sprite.Hide (spriteID : int)

##Description Hides a previously visible sprite. Sprite.Hide has no effect if the sprite is already invisible.

##Example The following program animates four balls on the screen. When the balls are close to each other or to a wall, they appear, otherwise they are hidden.

    var pic, sprite, x, y, dx, dy, radius : array 1 .. 6 of int
    var visible : array 1 .. 6 of boolean
    
    setscreen ("nocursor")
    
    % Create all the sprites.
    for i : 1 .. 6
        radius (i) := Rand.Int (10, 25)
        Draw.FillOval (25, 25, radius (i), radius (i), 8 + i)
        Font.Draw (intstr (i), 20, 20, 0, black)
        pic (i) := Pic.New (0, 0, 50, 50)
        Draw.FillBox (0, 0, 50, 50, 0)
        x (i) := Rand.Int (radius (i), maxx � radius (i))
        y (i) := Rand.Int (radius (i), maxy � radius (i))
        dx (i) := Rand.Int (3, 3)
        dy (i) := Rand.Int (3, 3)
        sprite (i) := Sprite.New (pic (i))
        Sprite.SetPosition (sprite (i), x (i), y (i), true)
        Sprite.SetHeight (sprite (i), i)
        visible (i) := false
    end for
    
    % Now move all the sprites around the screen.
    loop
        for i : 1 .. 6
            if x (i) + dx (i) < radius (i) or
                    x (i) + dx (i) > maxx  radius (i) then
                dx (i) := dx (i)
            end if
            x (i) := x (i) + dx (i)
            if y (i) + dy (i) < radius (i) or
                    y (i) + dx (i) > maxy  radius (i) then
                dy (i) := dy (i)
            end if
            y (i) := y (i) + dy (i)
        end for
        for i : 1 .. 6
            var near : boolean := false
            if (x (i) < 50) or (x (i) > maxx  50) or
                    (y (i) < 50) or (y (i) > maxy  50) then
                near := true
            end if
            if not near then
                for j : 1 .. 6
                    if i not= j then
                        if sqrt ( (x (i) � x (j)) ** 2 +
                            (y (i) � y (j)) ** 2) < 100 then
                            near := true
                            exit
                        end if
                    end if
                end for
            end if
            if near and not visible (i) then
                Sprite.Show (sprite (i))
                visible (i) := true
            elsif not near and visible (i) then
                Sprite.Hide (sprite (i))
                visible (i) := false
            end if
            Sprite.SetPosition (sprite (i), x (i), y (i), true)
        end for
        Time.Delay (40)
        exit when hasch
    end loop
    for i : 1 .. 6
        Sprite.Free (sprite (i))
    end for

##Status Exported qualified.

This means that you can only call the function by calling Sprite.Hide, not by calling Hide.

##See also sprite_show.html.