Quick question 'bout bitmapData and tile-based

[Baukereg]

Just a quick question, I have decided to learn myself to create a tile-based engine not based on gotoAndStop tiles but based on tiles being attached as bitmapData. Everything is working well so far, this is the png with the tiles:



Just 3 tiles, dirt grass and water. The testmap is only 6 by 4 so far, and you can use the arrow keys to scroll around:

http://www.planetbauke.com/test/engine.html

There's a map_bmd (bmd = bitmapData) that contains the entire map, and there's a view_bmd that copy's the 80x80 canvas that is the visible area of the map. It's attached then to view_mc. That should make sense doesnt it?

But as you can see, once you cross the border of the map, you get this magic mushroom kind of effect, and although I like mushrooms I'd rather have just a black background being visible. This is the function activated when you press a key:

code:

---

function updateView() {

	var rect = new Rectangle(viewX, viewY, viewWidth, viewHeight);

	var point = new Point(0,0);

	view_bmd.copyPixels(map_bmd, rect, point);

}

---

As you can see, I copy the visible canvas of the map_bmd once again to view_bmd without clearing view_bmd first. How can I clear view_bmd? Or is this not the best way to handle and update the view?


Btw, here's a as file with all the actionscript from the first frame of the fla. Anyone interested and/or willing to give feedback, check it out:
http://www.planetbauke.com/test/firstframe.as

[mr_malee]

function updateView() {

var rect = new Rectangle(viewX, viewY, viewWidth, viewHeight);

var point = new Point(0,0);

view_bmd.fillRect(rect, 0x000000)

view_bmd.copyPixels(map_bmd, rect, point);

}

[ImprisonedPride]

Heh, that looks like a familiar function...

[Baukereg]

It that so, haha, seems I'm on the right way then. This topic of yours was a big help:

http://board.flashkit.com/board/hist.../733499-1.html

Edit:

Little correction, it needs to be:

view_bmd.fillRect(new Rectangle(0, 0, viewWidth, viewHeight), 0x000000);

[ImprisonedPride]

Good, I'm always glad to see that my thread can help others.