making an eraser?

[Mesmay]

well, i have a little problem, and i assume you guys have the answer, you generally do :D

I want to make an eraser which follows the mouse automatically, which will be used to erase a layer of solid colour, not "all of it" when you rollover, just the bit you rollover.
If that makes any sense?
All help appreciated, thanks

oh and also- there will be an image underneath, so the eraser mustnt erase right through to the canvas.

[matthewt]

Good luck in finding a program that helps you make the eraser. I've seen something like this before, online. I've been a webmaster for about 6 years now and I'd have to say that it's already been built. A good approach, for you, right now, is to do a focused keyword search at Google and visit as many web pages as you can. Maybe: erasing curser. There might be some tips on making this eraser, somewhere.

[StaliN98]

How about have whatever is behind the layer to erase IN FRONT, but with a mask layer. Now, on the mask layer, have an empty movie clip. Call it "erase". Then put this on the main timeline. (This is AS2)

var lastx:Number = 0; // Last x mouse
var lasty:Number = 0; // Last y mouse
function onEnterFrame() {
if(Key.isDown(1)){ // If mouse is down
erase.lineStyle(16,0,100); // 16 so it is thick, colour doesn't matter so it is 0 (black), full alpha
erase.moveTo(lastx,lasty); // Move to last mouse position
erase.lineTo(_xmouse,_ymouse); // Draw a line to new position
}
lastx = _xmouse; // Update last x
lasty = _ymouse; // ... and y
}

[StaliN98]

Forget that, lines don't register with masks it seems :S

[Mesmay]

At 2/27/09 03:58 PM, StaliN98 wrote: Forget that, lines don't register with masks it seems :S

yeah, i tried something like that already.
thanks for trying though :)

[StaliN98]

Done, using bitmapdatas.
http://spamtheweb.com/ul/upload/270209/7 6363_erase.php
It basically makes a transparency enabled BitmapData of the image, and then you can draw rectangles with 0 alpha onto it to make it have holes.

import flash.display.*;
import flash.geom.*;
var lastx:Number = 0;
// Last x mouse
var lasty:Number = 0;
// Last y mouse

var maskBit:BitmapData = new BitmapData(640,480,true,0);
mask.attachBitmap(maskBit,0,"auto",false);

maskBit.draw(erase);

function onEnterFrame () {
	recta = new Rectangle(_xmouse - 16,_ymouse - 16,32,32);
	if (Key.isDown (1)) {
		maskBit.fillRect(recta,0);
	}
	lastx = _xmouse;
	// Update last x
	lasty = _ymouse;
	// ... and y
}

erase is the mc that holds the image you want to erase. the dimentions should be your stage size (of the bitmapdata). Mask is an mc above the one you want to be behind the erased image.