Graphics protocol: Image cropping with x,y,w,h not working with unicode placeholders

[jonifndef]

When using the "traditional" method of rendering images, I can crop an image successfully using the x, y, w, and h flags in the control data. However, when using unicode placeholders I cannot get it to work.

What I'm trying:

Uploading and creating a placement with a=T:

let crop_w = 250;
let crop_h = 250;

let cols = crop_w / win_info.cell_width_px;
let rows = crop_h / win_info.cell_height_px;

let control = if is_first {
    format!("a=T,f=24,t=d,U=1,i={id},s={width},v={height},x=350,y=450,w={crop_w},h={crop_h},c={cols},r={rows}q=2,m={m}")
} else {
    format!("m={m},i={id},q=2")
};

m is set accordingly. Then I print the placeholders in the area enclosed by the cols and rows values above. But when I do that, the x,y offset is not used, but the width and height are correct since I am only printing those unicode characters. However, if I print them for the entire area of the original (uncropped) image, the whole image appears. It seems as if the x,y,w,h flags did nothing in the scenario, the placement included the whole image.

Am I misunderstanding something? Grateful for any pointers :)

[kovidgoyal]

The unicode placeholders define the area of the image, not the placement. This is because it is expected that tmux or vim or whatever the underlying program is will manipulate the unicode characters itself.

[jonifndef]

Thank you for your answer. So, if I understand correctly, you cannot crop part of an image then rescale the cropped square with the c and r flags? My use case is I want to implement zooming. My idea was to crop the image using x,y,w,h and then rescale it using c,r to fit the whole terminal window.

Now that I think of it, my use case might not work with the "tradiotional" render method (not unicode placeholders) either? I've not tried the rescaling part, only the cropping part.