Adjust rendered DisplayObjects' dimensions with filters

[NexIsDumb]

This is has been an old bug;
For example if you put one or more filters on a Flixel's FlxCamera (that for rendering Shaders, and so Filters, uses an OpenFL's Sprite) on certain screens you can easily notice that the camera gains +1 pixel on the right and bottom side (and so it's oblivious that this doesn't happen on FlxCameras only but on every OpenFL's Rendered DisplayObjects).
Me and @NeeEoo found an easy way to fix this on certain resolutions which comprehends a lot of screen sizes actually (still testing on FlxCameras), but we feel like there could be a more dynamic fix so this is going to stay a draft until we find out a better fix.
Here's an example of two overlapped cameras with the bottom one using filters (filters on that camera'a OpenFL Sprite) and the top one not using them but having a black sprite that uses the camera's dimensions (better visible on larger screens or zooming):

As you can see the bottom camera with filters has one more pixel on bottom and right side than the one without filters.
This disappears with this Pull Request's fix.

[joshtynjala]

Here's an example of two overlapped cameras with the bottom one using filters

Please post the code for this example. Thanks!

[NexIsDumb]

Here's an example of two overlapped cameras with the bottom one using filters

Please post the code for this example. Thanks!

Sure thing, here's WITHOUT the fix (the original code was tested on CodenameEngine, so sorry for the delay I had to rewrite it so you would be able to use it) (Also one last reminder: I'm using FlxCamera since for filters it uses an OpenFL normal Sprite):

package;

import flixel.FlxCamera;
import flixel.FlxG;
import flixel.FlxGame;
import flixel.FlxState;
import flixel.system.FlxAssets.FlxShader;
import openfl.display.Sprite;
import openfl.filters.ShaderFilter;

class Main extends Sprite
{
    public function new()
    {
        super();
        addChild(new FlxGame(1280, 720, PlayState));
    }
}

class PlayState extends FlxState
{
    override public function create()
    {
        super.create();

        FlxG.camera.bgColor = 0xFF0000FF;
        FlxG.camera.filters = [new ShaderFilter(new FlxShader())];

        var cam2:FlxCamera = new FlxCamera();
        cam2.bgColor = 0xFFFF0000;
        FlxG.cameras.add(cam2, false);
    }
}

And this is what I noticed when resizing to big window mode:

If instead I include this Pull Request's fix that +1 pixel is gone.

[NexIsDumb]

Oops, had to edit, attached the wrong image

[joshtynjala]

Thanks!

[NexIsDumb]

With this the problem shouldn't be happening again because it's going to round for defect