[F8] Operation: Random background?

How can a random background function be made?

I mean Im trying - very hard - to make a game like the game "Tanks", currently Im stuck with programming on the background generating.

By that I mean EASY ways to generate random backgrounds which 'ent too impossible.

Now I dont want to generate the Y position for 400 movieclips (1pixel wide) and then getting the proximity and recheck, reposition. Thank you

THx for any help I could get.
<Tongxn>

heh i dont know that there is a way to randomly generate a background easily.

however you could have an array of several different backgrounds and pick one to use at random.

thx but that's blunt work.
Something else?

what do you mean blunt work?

well you need to create more than 1000 of those and make AS for them all...

what do you mean a random bg? i can make you a script for a randomly generated "hilly" bg is that what you mean?

yes please!

p.s.to.everybody. I needed it vectored though, for there could be movieclips that are running on the background.. or do I? Im nonpussed this is something I never attempted before.

here you go:

Code:

---

function createBackGround(fc:Number, bc:Number, height:Number, hillSizeRange:Number, hillsAmount:Number):MovieClip {
        var cont:MovieClip = _root.createEmptyMovieClip("cont", -10000);
        var backGround:MovieClip = cont.createEmptyMovieClip("backGround", 0);
        var foreGround:MovieClip = cont.createEmptyMovieClip("foreGround", 1);
        var ran:Number = Math.round(Math.random()*100);
        var xInc:Number = Stage.width/(hillsAmount*2);
        var points:Array = new Array();
        for (var z = 0; z<=Stage.width; z += xInc) {
                var randH:Number = Math.round(-hillSizeRange+Math.random()*(hillSizeRange*2));
                points.push({x:z, y:height+randH});
        }
        with (backGround) {
                beginFill(bc, 100);
                moveTo(0, 0);
                lineTo(Stage.width, 0);
                lineTo(Stage.width, Stage.height);
                lineTo(0, Stage.height);
                lineTo(0, 0);
                endFill();
        }
        with (foreGround) {
                beginFill(fc, 100);
                moveTo(0, height);
                for (var z = 0; z<points.length-1; z++) {
                        curveTo(points[z].x, points[z].y, (points[z].x+points[z+1].x)/2, (points[z].y+points[z+1].y)/2);
                }
                curveTo(points[points.length-1].x, points[points.length-1].y, Stage.width, height);
                lineTo(Stage.width, Stage.height);
                lineTo(0, Stage.height);
                lineTo(0, height);
                endFill();
        }
        return cont;
}
createBackGround(0x00ff00, 0x0066FF, Stage.height/2, 50, 5);

---

function parameters are as follows:
fc = foreground colour
bc = background colour
height = the "average" height of the hills
hillSizeRange = the max value the that hills' size varies
hillsAmount = the number of hills to be made

HTH,

zlatan

what you can do, as my function returns a container clip in which the background is contained, is you can draw the BG to a bitmapData, then you can incorporate the BitmapData.hitTest(); method to add the "movie clip running on the BG" functionality you speak of.

interesting.. but wont the hitTest recongnise the BG as a rectangle instead of a ..er.. what Im looking for? coz I need to randomly generate cannons that are exactly ON the background no more no less space in between, by which I meant knowing exactly where is the background and what Y position is the right position on a random X position.
Thanks that looked complicated yet it make sense, or atleast the easy bit to me.

the "ground" clip is just nested in the returned clip, so if you want to check for a conventional hitTest then just target createBackGround().foreGround;

if you are going to use bitmapData hittest then it will be fine as it works buy checking colour values, check out flash's help files.

zlatan

very interesting....
Thanks dudeqwerty!