actionscript 3 - Breakout with Flash: I need help to improve my Brick n Ball collision -

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i've been stuck on problem long time now, i've searched around alot , tried stuff, nothing works. explanations hard me understand im pretty new programming overall , got alot learn.

i have 2 problems

1: ball wont collide bricks when speed fast.

2: ball capable of hitting 2 bricks. both problems related fact 60 fps isnt enough type of collision detection work properly.

i need explain in simple way possible need make collision detection prevent happen.

here's current collision code:

private function checkcollision(): void {   grdx = math.floor((ball.x) / 28);   grdy = math.floor((ball.y) / 14);   ngrdx = math.floor((ball.x + dx) / 28);   ngrdy = math.floor((ball.y + dy) / 14);   var flipx: boolean = false;   var flipy: boolean = false;   if ((grdy <= level.length - 1) &&        (ngrdy <= level.length - 1) &&        (grdy >= 0 && ngrdy >= 0)) {     if (testblock(grdx, ngrdy)) {       flipy = true;       paddleflag = 1;     }     if (testblock(ngrdx, grdy)) {       flipx = true;       paddleflag = 1;     }     if (testblock(ngrdx, ngrdy)) {       flipx = true;       flipy = true;       paddleflag = 1;     }     dx *= flipx ? -1 : 1;     dy *= flipy ? -1 : 1;   } } private function testblock(xpos: int, ypos: int): boolean {   if (level[ypos][xpos] > 0 && level[ypos][xpos] != 13) {     trace("hit on x,y");     level[ypos][xpos] = 0;     breakblock("block_" + ypos + "_" + xpos);     trace("block: " + totalbreaks + " / " + totalblocks);     return true;   }   return false; } private function breakblock(blockname: string): void {   if (this.getchildbyname(blockname)) {     this.removechild(this.getchildbyname(blockname));     totalbreaks++;   } }

thank , sorry bad english, not motherlanguage.

one solution move ball in smaller iterations, multiple times in given frame.

for example, , giving solution assuming moving ball based on time elapsed last frame.

suppose 30 milliseconds have elapsed since last frame update. in case update movement/collision twice in frame using 15 millisecond time elapsed.

the higher resolution of collision want, more iterations do.

here's example :

 // class declarations  var lastframe:number;  var iterationsperframe:int;  function startgame():void {      // lets specify 3 updates per frame      iterationsperframe = 3;       // save initial time      lastframe = gettimer();       // create listener      addeventlistener(event.enter_frame, update); }  function update(e:event):void {      var currentframe:number = gettimer();      var deltatime:number = (currentframe - lastframe)/1000;       var iterationdelta:number = deltatime/iterationsperframe;       (var index:int = 0;index < iterationsperframe;index++)      {           // i'm assuming dx,dy velocity of ball, in pixels per second           ball.x += dx * iterationdelta;           ball.y += dy * iterationdelta;          // check collision      }        // set lastframe currentframe time, preparing next frame      lastframe = currentframe;       // after this, frame going render }

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