Allow gravity to be relative about imgproxy

[DarthSim]

Hey @dunklesToast!

I believe, the fp gravity type is what you are looking for

[dunklesToast]

Hey @DarthSim

Thanks for the prompt reply - I actually fiddled around with fp but seems that i cannot use it due to this

that define the coordinates of the center of the resulting image

Just to give some more context what I am trying to do:

We're using react-image-crop in our frontend to get a cropping area of images. This package outputs the selected crop in either pixels or percentages and uses the top left (northwest) as origin.
The output of the cropper can look something like this:

{
    "unit": "%",
    "x": 33,
    "y": 0,
    "width": 66,
    "height": 50
}

The according selection would be this

With the "normal" gravity options supporting relative values, I could easily do something like crop:0.66:0.5/g:nowe:0.33:0.
I've validated this approach by using absolute values as I know the proportions of this example image: Using crop:0.66:0.50/g:nowe:66:0 (66px as the image is 200px wide and 33% of that is 66) results in the correctly cropped image

Since fp uses the center of the already cropped image, I'd need to do some calculations based on the images width and the cropped center point to the calculate the correct fp values where I am not currently sure how to it - I'll play around with that a bit, but if you have any ideas or suggestions let me know. IMO having gravity support relative values as well would be the easiest as it allows to define the origin but I'll try using. fp.

[DarthSim]

If all the coordinates returned by react-image-crop are relative to the image dimensions, then the fp coordinates will be (x + width/2) / 100 and (y + height/2) / 100

[dunklesToast]

oh yea that works. thanks a lot!