ASCII Shader doesn't respect image scaling

[zolrath]

I don't know shader programming or I'd attempt a PR but when using the legacy shader ascii it seems it converts the image using its original dimensions, ignoring any scaling of the image texture performed by the user in OBS.

Image scaled to fill screen:

With the filter active the displayed image only fills the original image size:

[exeldro]

I am not sure what I am doing different, but it seems to be working fine for me